HomeMy WebLinkAboutCity of Saint Paul Generator Switchgear Equipment & Function Final Design Report - Mar 2013 - REF Grant 7030002Engineering Information Transmittal
1 01 Mar 2013
St. Paul Wind-Diesel Integration Project
Generator Switchgear Equipment & Function
Final Design
01 March 2013
Engineering Information Transmittal
2 01 Mar 2013
Table of Contents
PART 1 Genset Control Equipment and Integration...................................................... 4
1.1 Control Architecture Selection............................................................................. 4
1.2 Proposed Genset Control Upgrade....................................................................... 6
1.2.1 Master Control Section................................................................................. 6
1.2.2 Genset Control Section (typical of 3) ........................................................... 9
1.3 Proposed Integration With Existing Equipment................................................. 10
1.3.1 Exhaust Manifold Valve Control................................................................ 10
1.3.2 Genset 1 – CAT 3512, 1200RPM, 855 kW, 4160V................................... 12
1.3.3 Genset 2 – ................................................................................................... 18
1.3.4 Genset 3 – CAT 3406, 1800RPM, 210KW, 480V ..................................... 20
1.3.5 Genset 4– CAT 3412, 1200RPM, 300KW, 480V ...................................... 21
1.3.6 Genset 5 – CAT 3512, 1200RPM, 650KW, 480V ..................................... 22
1.3.7 Genset 6 – CAT 3512, 1200RPM, 855KW, 480V ..................................... 24
1.3.8 Station Service Panel .................................................................................. 26
PART 2 Basic Operation .............................................................................................. 27
2.1 Basic Operation – How To:................................................................................ 27
2.1.1 Start and Stop Diesel Gensets..................................................................... 27
2.1.2 Recover from an Outage............................................................................. 27
2.1.3 Enable/Disable Genset for Maintenance..................................................... 28
2.1.4 Genset Error Acknowledgement................................................................. 28
2.1.5 Wind Import Control................................................................................... 29
2.1.6 Recorded Energy Generation and Usage.................................................... 30
PART 3 Diesel Genset Controls and Dispatch............................................................. 31
3.1 Major Components and Function....................................................................... 31
3.1.1 Genset Control Description......................................................................... 31
3.1.2 Genset Operating Mode Switch.................................................................. 32
3.2 Manual Operation/Override of Automatic Controls .......................................... 39
3.3 Automatic Operation.......................................................................................... 40
3.3.1 Details of RUN Signal Logic in AUTO Mode ........................................... 40
3.3.2 Increasing Genset Capacity......................................................................... 43
3.3.3 Reducing Genset Capacity.......................................................................... 44
PART 4 Load Regulation ............................................................................................. 46
4.1 Genset Minimum Load Regulation.................................................................... 46
4.1.1 Determination of Load Command.............................................................. 46
4.1.2 Maximum Wind Import Load Command During Genset Transitions........ 47
PART 5 Electric Boiler................................................................................................. 52
5.1 General Description............................................................................................ 52
5.2 Excess Energy Metering Strategy...................................................................... 52
PART 6 Operator Interface Computer.......................................................................... 56
6.1 Human-Machine Interface (HMI) Program ....................................................... 56
6.1.1 General Information.................................................................................... 56
6.1.2 System Overview........................................................................................ 57
Engineering Information Transmittal
3 01 Mar 2013
6.1.3 Setpoints...................................................................................................... 57
6.1.4 Trends Screen.............................................................................................. 58
6.1.5 Energy Screen............................................................................................. 59
6.1.6 Alarm Screen .............................................................................................. 59
6.1.7 Diesel Dispatch Screen............................................................................... 61
6.2 SCADA.............................................................................................................. 61
6.2.1 Reporting – Monthly Report Template....................................................... 62
6.3 Other Software................................................................................................... 62
6.4 Local Communications ...................................................................................... 62
6.5 Plant Communications....................................................................................... 63
Engineering Information Transmittal
4 01 Mar 2013
PART 1 GENSET CONTROL EQUIPMENTAND INTEGRATION
1.1 CONTROL ARCHITECTURE SELECTION
This 95% design submission reflects several iterations of switchgear and genset operator
interface design between the City and TDX. This submission reflects the City’s
prescription for control, protection, and operator interface design. TDX has committed to
implementing these requirements to the extent possible within the budgetary constraints
of the project, as described below.
The proposed switchgear lineup, to be delivered and commissioned under the project, is
envisioned to have a total of four switchgear cubicles (sections), plus additional control
hardware to be retrofitted into the existing switchgear. Generator sets 3 & 4 will not be
automated, although they will be capable of running in parallel with the other units.
Load Sharing:
Existing engine governors on units 1, 5 and 6 will be replaced with Woodward 2301D
speed governors, to take advantage of their increased capability for dual dynamics and
other advanced tuning features. (Although Woodward has indicated a 2301E will soon
be available, the project is proceeding with the 2301D).
Proposed is to use the Woodward 2301 controllers for load sharing. In terms of affecting
the 2301 speed bias, the EasYgen controllers will be used as auto synchronizers only, i.e
will control the bias input to the 2301D during synchronization, then shut off bias signal
once online. Unloading will take place by EasYgen initiating rampdown by toggling the
2301D “LOAD/UNLOAD” input, then waiting until [time delay] or waiting until Power
< [threshold] etc. On genset 2, which has an LSM module, the EasYgen will open the
2301D “DROOP/ISOC” input to initiate ramp-down before taking the unit offline.
(We had considered that load sharing could be performed in both the 2301D and the
EasYgen, and the control could be switched from one system to the other in some
fashion. While this is possible, there seemed to be little or no benefit in terms of
reliability or availability.)
VAR Sharing:
VAR sharing is presently accomplished by balancing the droop setting on the voltage
regulators. It is assumed that since power factor is most always close to unity, that
voltage fluctuation is minimal.
Engineering Information Transmittal
5 01 Mar 2013
With wind turbines online, the VAR loading on the city will potentially vary more than it
does presently. The EasYgen provides both reactive power sharing and voltage trim
functionality, which will be enabled to help maintain constant genset bus voltage.
ECU Functions:
For the purposes of the project, “ECU” (or engine control unit) is defined as the hardware
and programming/setup which turns on/off engine fuel supply and exhaust valves, and
performs starter crank initiation and disconnect, and monitors and shuts down for engine
conditions such as low oil pressure, high jacket water temperature, overspeed, etc.
The EasYgen control modules have capabilities to provide for the ECU functions defined
above. The existing gensets all have existing ECU functions (of sorts), either provided
by Caterpillar or a 3rd party. The new Gen 2 is expected to be supplied with on-board
speed regulator and AVR, but without complete factory integrated ECU functionality.
It should be noted that Gen 5 is not equipped with existing starter management, and as
such, is incapable of being started automatically by contact closure from a new EasYgen
controller. Gen 5 will require more scope in terms of automating engine startup.
It is beyond the scope of this project to rework ECU functionality for units 1, 2, and 6,
nor does ECU functionality impact integration of wind power. Proposed is that the new
control initiates an engine start on the existing engine controllers by closing a single dry
contact. When the existing ECU is switched into the “Auto” position, the new dispatch
controller will close a “run” contact which will cause the existing ECU to start the unit
and keep it running “at rated speed” indefinitely (after a brief idle warm-up time, if
required)
The alarm/fault contact from the existing ECU (if equipped) will be retained, and also
added as a control input to the EasYgen module to trip the generator breaker, and for
indication and recording purposes.
Please note that from the operator’s standpoint, bringing gensets on and offline, whether
manually or automatically, will be common for all units (except units 3 and 4):
o Existing ECU control switches will always be left in “AUTO” (except when
clearing ECU faults or taking the unit out of service)
o Manual or Auto mode selection is made using the new operating switch on the
new switchboard section.
o Manually starting a unit will be done using the new operating switch on the
unit’s new switchboard sections (Common for all units)
o “Manually” closing a unit’s breaker is only done when in “FALLBACK” mode.
Breaker close control is handled by the EasYgen via pushbutton interface on
units 2 and 5. Unit 1 has an existing breaker control switch that will be retained,
Engineering Information Transmittal
6 01 Mar 2013
and Unit 6 will have a new breaker control switch installed on the engine-
mounted control panel.
1.2 PROPOSED GENSET CONTROL UPGRADE
Refer to specification 26 2413 for a listing of drawings and other documents with specific
information regarding the physical layout and interconnections.
1.2.1 Master Control Section
The Master cubicle contains the 2500A breaker connecting the 480V generator bus to the
City 12470V:480V step up transformer.
The Master section also contains the feed breaker or fused disconnect that feeds power to
the 480V Electric Boiler.
Engineering Information Transmittal
7 01 Mar 2013
MASTER SECTION ZOOM IN
Dispatch/Wind
System warning
light (red)
Enable/Disable
Wind Import
Control Switch
Human Machine
Interface Touch
Screen
Bus Meter
480 Bus main
tie breaker
(manually
operated)
Boiler Meter
Breaker Closed
Light (red)
Breaker Open
Light (green)
Dispatch/Wind
System warning
light (amber)
Engineering Information Transmittal
8 01 Mar 2013
The control compartment contains a GE PAC RX3i (PLC) that collects power data from
the generator controllers and from the POSS Camp interconnection and is used to set
wind import limits and to automatically dispatch generators.
This compartment contains a data collection computer and touch screen graphical Human
Machine Interface (HMI). A screen/mouse splitting device will be used to connect the
HMI computer to an operator control station (desktop monitor, keyboard, and mouse)
located in the power plant office. Refer to PART 6 of this document for details of the
HMI computer.
There is one manual control switch installed on this compartment face, a “WIND
IMPORT” switch with left position as maintained “OFF” and right position maintained
“ON”. When switched ON, the TDX wind farm may connect and run wind turbine(s),
subject to wind import limits required for system stability. Refer to PART 4 of this
document for details of wind import control.
There is no automatic genset dispatch control switch on the Master control panel.
Automatic genset dispatch control is enabled by use of the 4-position switch at each
individual genset, rather than a ‘system-wide’ switch. Refer to section PART 3 of this
document for details of genset dispatch control.
The PLC automatic dispatch control cannot trip genset breakers, and as such, there is no
red fault light associated the auto dispatch functionality. If generators fail to start when
called upon to dispatch, then the individual genset controller for that unit will latch a fault
and light its red fault indicator light. The fault will also be picked up by the EasYgen,
communicated to the PLC, and displayed on the operator HMI screen, located in the
master section.
Likewise, malfunctions with the wind import function do not cause any genset trips, and
as such there is no red fault light associated the wind import functionality.
A single amber warning/alarm light is provided on the Master control panel to indicate a
problem or condition with the auto dispatch or wind import functionality warranting
attention. The light will flash until acknowledged on the HMI screen, and will then
remain on steady if the alarm condition persists, or go dark if the alarm condition is no
longer present.
The majority of these components will be powered from a separate battery-backed 24Vdc
supply, fed from a control power transformer tapped from the bus.
Two power meters (ION 6200 transducer with 24Vdc supply, RS-485 MODBUS comm
port, enhanced measurement package #2, and remote display) are installed in the Master
section, for metering the total bus output and the Electric Boiler load.
Engineering Information Transmittal
9 01 Mar 2013
1.2.2 Genset Control Section (typical of 3)
Shown below is a general representation of proposed breaker and control sections for
units 2, 5, and 6. Refer to drawing E4.2 for detailed elevations of each cabinet. Details
of the genset controls can be found in section PART 3 of this document.
GENSET SECTION ZOOM IN
Gen
Warning/Pre-
Alarm Light
(AMBER)
Gen
Fault/Lockout
Light (RED)
“AUTO” Light
(gen is enabled
for auto dispatch)
(BLUE)
Genset Mode
Switch
Unit E-Stop
EasYgen 3200
P1
Multi-function
Relay
MFR-13
FALLBACK
Mode Operator
Controls
Engineering Information Transmittal
10 01 Mar 2013
1.3 PROPOSED INTEGRATION WITH EXISTING EQUIPMENT
1.3.1 Exhaust Manifold Valve Control
The gensets share a common exhaust manifold. Each genset has a control valve in the
lead-in exhaust pipe upstream of the connection to the common manifold that opens
(allows exhaust flow) when the engine is running, and closes when the engine is stopped.
The existing control scheme is to open the valve at the same time as the engine is
cranked. The valves are controlled with a +24V signal from the control panels, usually
tied to the engine start relay or other similar signal. Since all gensets are started manually
by operators, the operator confirms the exhaust valve is opened before proceeding to put
the genset online.
When the new switchgear and controls is installed, the gensets will be able to be started
and stopped automatically based on the measured load level and other factors. Since the
operator need not be present during a startup, a position status signal from the exhaust
valve actuator must be wired back to the new control panels to prevent engine operation
when the valve is closed.
The City has proposed a scheme for each genset whereby the valve is first commanded to
open, and then the engine is allowed to crank/start/run once the valve position status
indicates the valve is open. If the valve closes during normal operation, the controls must
stop the engine, open the breaker, and indicate to the EasYgen.
Proposed then is to use an interposing relay in each of the new controls sections with the
relay’s coil powered by the valve position status (dry) contact, in order to provide
sufficient control contacts for these various purposes. The valve position dry contact
shall close when the valve is open. Normally open (NO) relay contacts will be hard-
wired into the engine RUN contact circuit and EasYgen discrete input, and normally
closed (NC) contact wired in series with breaker UVR trip/open command circuits.
1.3.1.1 Informational background research from site
The Fuel Control Panel at the front (engine, radiator side) of Genset 1 against the back
wall contains the wiring interface for the exhaust valves. A set of interposing relays is
used to interface the +24V “VALVE OPEN” commands from the genset control panels to
a 120Vac switched contact to actuate the valve. The valve position feedbacks (both
OPEN and CLOSED are available) are landed in a terminal strip above the PLC in the
Fuel Control Panel, and then wired into PLC input cards. According to the City, this
PLC is not programmed to use these position signals, therefore they can be disconnected
from the PLC. Since these signals are commoned and wetted with +24V from the Fuel
Control Panel, interposing relays will be installed in the Fuel Control Panel in order to
provide dry contacts that will be wired back to the genset control panels for use as safety
status signals as described above. These interposing relays can be installed on the empty
Engineering Information Transmittal
11 01 Mar 2013
section of din-rail at the top right corner of the panel. TDX preference is to only install
relays and wire the signals associated with the “VALVE OPEN” status signal.
There is an existing 2” PVC conduit shown on the drawings that is routed between the
Fuel Control Panel area and the trench. From the site visit, it appears this conduit has
room for additional conductors, however it may be necessary to add another short conduit
between the pullbox where the 2” conduit ends, and the Fuel Control Panel just above the
pullbox. The proposed wiring interface for the valve position feedback signals would be
one dry pair for each of six gensets, with the pairs for Gensets 3 and 4 routed to the
existing cabinets and either terminated (for future use), or taped off. Depending on the
exact placement of the new genset control panels, some of the valve control wires may
need to be re-pulled as well, or spliced.
Fuel Control Panel internal photo – the valve control relays are to the right of the lower
PLC rack, and the terminals for valve position feedback are above the upper PLC rack.
Valve position feedback signals
Valve control relays
Engineering Information Transmittal
12 01 Mar 2013
1.3.2 Genset 1 – CAT 3512, 1200RPM, 855 kW, 4160V
Unit #1 has a reasonably up to date (1995) and high quality, custom designed genset
control and switchgear assembly. The intent is to retain as much of the equipment as
possible, however to make the operation and setup of this unit as identical to the other
units as possible.
Proposed plan for integration with new switchgear on control on units #1:
1. Existing 24Vdc supply to be used for powering EasYgen, 2301D governor, and
breaker trip relay.
2. The Woodward SPM synchronizer will be removed in favor of an EasYgen
control module for auto synchronizing.
3. The Woodward 2301A governor/load controller will be replaced with a
Woodward 2301D governor.
4. The existing PT and CT wiring will be connected to the new EasYgen control
module, and to the 2301D governor.
Engineering Information Transmittal
13 01 Mar 2013
5. The new 2301D governor control speed bias input will be driven from the
EasYgen (for synchronizing only).
6. The governor load share lines will be retained
7. The existing voltage regulator (Basler SR4A) will be replaced with Basler SSR63-
12 which will be connected to the voltage bias output signal from the EasYgen
module.
8. The existing Basler sync check relay will be retained, and wired as a permissive
for the manual breaker close switch. (It is presumed the relay is set up to allow
deadbus closure).
9. The existing protective relays will be retained
10. The existing panel-mounted E-stop button and functionality will be retained. An
auxiliary contact will be added to the existing e-stop switch and wired to the
new EasYgen module for indication and recording.
11. The existing lockout device functionality will be left in place.
12. The existing generator control switch will be retained, with functionality the
same as that on the existing ECUs on the 480V units (OFF/RESET –STOP-AUTO-
MANUAL). Intended operation will be to leave the engine existing ECU switch in
“AUTO”, except when it is needed to reset an engine fault that is triggered by
the existing ECU.
13. An EasYgen and switch/light interface identical to the ones on units 2, 5 and 6
will be fitted into a new plate on the front of the existing gear, bus PT section
(upper left).
14. The “RUN INITIATE CONTACT” dry contact interface at terminals 207,208 (ref
Line No 59 of CAT drawing 6183) will be used as the genset start/stop control
interface to the EasYgen. The EasYgen will not be configured for engine start
sequencing since that functionality already exists (ECU-57 and associated
relays/circuits).
15. The tie breaker closure appears to proceed automatically (via existing circuits)
once synchronization has occurred; the EasYgen will bias the 2301D to control
the genset phase/frequency and will close an output contact (R 06) as a
permissive for the breaker close coil circuit. The output contact (R 06) will be
connected to the Breaker Close Relay (BCR) circuit in the place of the “25A”
contact of the SPM (to be removed) (ref wires 299, 300, at line no. 171)
16. The “RUN INITIATE CONTACT” dry contact interface at terminals 207,208 (ref
Line No 59 of CAT drawing 6183) is also used as the breaker open command.
The EasYgen will open this contact to open the breaker (once closed). (Closing
this contact only enables breaker closure). The timing of the opening of this
contact will require custom logic within the EasYgen (doesn’t fit the usual
behavior of the native “GCB open” output). Control of the engine cooldown is
handled by existing relays/controls, and not by the EasYgen.
17. Spare breaker aux contacts are available for feedback to EasYgen (ref line no.
290)
18. Genset 1 “ALARM” signal is available from the spare Horn Relay (HR) contacts
(ref line no. 212), the NO (or NC) contact will be wired to the EasYgen to initiate
immediate genset shutdown.
Engineering Information Transmittal
14 01 Mar 2013
19. The City requires that all existing functionality for “fallback” mode operation be
kept intact and operational. There are some issues with certain features:
a. The speed raise potentiometer is incompatible with 2301D, must be
replaced with a speed raise/lower switch (rotary 3 position, spring
return to middle).
Please refer to the drawing E4.2 for detailed elevation; the following photos are a
generalized representation of the proposed operator interface rework detail.
GEN 1 EXISTING SWITCHGEAR
Engineering Information Transmittal
15 01 Mar 2013
GEN 1 EXISTING SWITCHGEAR WITH NEW CONTROLS ADDED
Automatic Controls
Upgrade for Gen 1
Engineering Information Transmittal
16 01 Mar 2013
GEN 1 NEW CONTROLS ZOOM IN
Gen
Warning/Pre-
Alarm Light
(AMBER)
Gen
Fault/Lockout
Light (RED)
“AUTO” Light
(gen is enabled
for auto dispatch)
(BLUE)
Genset Mode
Switch
EasYgen 3200
P1
Engineering Information Transmittal
17 01 Mar 2013
GEN 1 OPERATOR INTERFACE ZOOM IN
Replace with
RAISE/LOWER switch
Engineering Information Transmittal
18 01 Mar 2013
1.3.3 Genset 2 –
A new unit #2 is coming online in early 2013. The City is installing the new genset and
any new cabling required, and commissioning the new unit with the existing switchgear
and controls. TDX plans to reuse the existing power cables for Gen 2. A new breaker
and control section will be provided for this position, but the new section cannot be fully
defined until the genset equipment and wiring is fully defined. TDX assumes that the
new genset will not be fitted with an on-board Engine Control Unit (ECU), but will be
fitted with on-board speed regulator/governor, and voltage regulator.
The on-board AVR interface is assumed to have voltage bias input, which will be
connected to the EasYgen for VAR sharing.
The City’s plans for near-term integration with the existing Gen 2 switchgear and
controls is that the on-board speed regulator will take a speed bias input signal from a
Woodward load share module (LSM) (Woodward p/n 9907-252), which will be
interfaced with the other 2301A,D devices in the plant.
???
Engineering Information Transmittal
19 01 Mar 2013
A new, equivalent model LSM will be installed in the place of the 2301D in the new
switchgear section. The LSM’s load share terminals will be connected to the load share
lines commonly connected to all 2301A,D units in the system.
The LSM accepts a speed trim potentiometer as input (as opposed to 2301D which
accepts raise/lower switch contact inputs). The requirement for installing this speed trim
pot for fallback mode operations is dependent on whether the genset ECU has a similar
pot or raise/lower switch, and whether operator preference would be to have all fallback
mode controls located at the switchgear panel.
The LSM accepts a synchronization bias input from the EasYgen.
It is expected that all fallback mode controls will be populated and wired in the new
switchgear section for Gen 2. This is based on the expected interim operation of the new
Gen 2 with the existing control cabinet which already has the fallback mode controls,
therefore the design direction for the engine-mounted controls will be to not mount to the
engine, instead wire out to the control interface at the panel.
The existing Electro Industries meter will be retained in the existing Gen 2 cabinet. The
existing CTs for this Gen 2 meter will be relocated as needed to encircle the genset
cabling as terminated in the new Gen 2 switchgear cabinet, and CT wiring will be
replaced to accommodate the expected longer run between CTs and meter.
Since details of the new genset’s on-board controls are not available, some questions
remain regarding implementation of the desired fallback mode controls:
-Providing a DROOP/ISOC selector switch which is connected only to the LSM may not
result in the desired operation, depending on the details of the on-board ECU’s speed
regulator – does the on-board control interface have droop/isoc selection?
-Speed IDLE/RATED selector switch is not an input to the LSM, how should such a switch
be interfaced with the on-board ECU?
-Since generator reactances and other parameters are not available, typical values have
been assumed for determining available short circuit current for specifying the Isc rating
of the new switchgear.
Engineering Information Transmittal
20 01 Mar 2013
1.3.4 Genset 3 – CAT 3406, 1800RPM, 210KW, 480V
Genset 3 controls and switchgear will be left intact and operational. The following
modifications are planned:
A new digital power meter (ION 6200 transducer with 120Vac supply, RS-485
MODBUS comm port, enhanced measurement package #2) will be installed inside the
rear top compartment, and wired to the existing PT and CT signals (the existing Electro
Industries meter will be left intact and operational). The Master Controller will
communicate with the meter and pick up the breaker aux status from the Gen 3 control
panel for positive indication of online status.
Engineering Information Transmittal
21 01 Mar 2013
1.3.5 Genset 4– CAT 3412, 1200RPM, 300KW, 480V
Genset 4 controls and switchgear will be left intact and operational. Same control panel
modifications as for Gen 3.
Engineering Information Transmittal
22 01 Mar 2013
1.3.6 Genset 5 – CAT 3512, 1200RPM, 650KW, 480V
Unit 5 appears to have a custom made generator ECU. There appears to be no central,
integrated controller that provides crank control, overspeed or oil or jacket water shut
down.
The control interface between the engine and the switchgear/control panel at the trench is
relatively simple, suggesting that the bulk of the engine start sequencing occurs on-board
the engine skid.
The control panel delivers +24V to wet the Engine Low oil pressure and low oil level
switch contacts, which are then wired back to the control panel.
The startup of unit 5 currently involves manually pressing and holding buttons at the
engine. The EasYgen relay outputs will be specially configured to simulate the pressing
of these buttons in order to automate the startup of unit 5. The unit’s MPU, or a speed
Engineering Information Transmittal
23 01 Mar 2013
switch, will be wired into the EasYgen to confirm successful engine start (enable the oil
pressure alarm etc).
Unit 5 is PMG equipped, therefore a CPT circuit for the AVR is not required installed in
the new section.
The on-board AVR is a CAT VR6 and can be either left in place, or abandoned in place
in favor of a new AVR. The panel datasheet for this AVR suggests that there is a bias
input available for use with various other devices including EL-200 excitation limiter,
VAR/PFC controller SCP-250, DSLC, and/or BE3-25A. The datasheet for the Basler
SCP-250 indicates the output signal is +/-3V range (or optional higher range +/-9V),
which suggests compatibility with the EasYgen analog output signal configured for VAR
sharing.
The current plan is to use the existing Cat VR6. The panel layout of the new Unit 5
section will have a space provision to allow installation of a new Basler SSR 63-12 AVR
and terminal interface for the AVR interface.
Engineering Information Transmittal
24 01 Mar 2013
1.3.7 Genset 6 – CAT 3512, 1200RPM, 855KW, 480V
UNIT 6 ECU AND OPERATOR INTERFACE
Gen 6 has a complete ECU and genset control panel mounted above the generator end,
this control package is dubbed the engine-mounted control panel. The ECU and
associated engine-side sensors, indicators, protective relays (and equipment will be left in
place, and disable (optionally remove) the 2301A.
The new Gen 6 control panel will be fitted with all new switchgear, CTs, PTs, 2301D,
Basler SSR 63-12 AVR, EasYgen, and MFR-13 relay. The “fallback mode” operator
controls panel dial meters and sync lights will remain in place on the doghouse. A new
circuit breaker close control switch will be added to the doghouse, enabling Gen 6 to be
brought online manually (at the engine-mounted control panel) even if the EasYgen unit
is completely failed.
Inside the engine-mounted control panel, the 2301A will be replaced with one or more
terminal strips in order to facilitate connection to the mag pickup and fuel actuator
circuits which must be wired back to the 2301D in the control panel.
Engineering Information Transmittal
25 01 Mar 2013
The existing ECU has a clean remote control interface: a “REMOTE START” dry
contact input is available for start/stop control from the EasYgen, and the wetted terminal
is connected to (fed from) the engine control switch (for AUTO position feedback). An
interposing relay coil will be connected to the wetted terminal to derive “AUTO position
status” contacts for EasYgen input (DI 09). The EasYgen engine run output (R 04) will
energize an interposing relay, the NO contact of which will connect to the “REMOTE
START” terminal pair. The use of these interposing relays is necessary because the
Engine side circuitry is powered from the Engine Battery. Both pre-alarm and alarm
output contacts (form C) are available for fault signal annunciation to the EasYgen.
The circuit breaker interface is also well-defined. The ECU requires a 52a (aux contact)
input. The ECU has a logical output terminal that is designed to energize the breaker
shunt trip coil. This output can be wired in parallel with other ST control branches
located in the control panel.
AVR – The existing AVR is a Basler SSR 63-12X. According to Basler, the “X” means
it’s a 400Hz power input, usually used with a 400Hz PMG. Gen 6 does not have a PMG
anymore. Excitation power is now provided by a 2kVA VRPT, located in the Units 5&6
Tie Cabinet of the old 480V switchgear. 480V is tapped from phases A&C on the
generator side of the generator breaker, run through a pair of ATDR3 fuses to the VRPT.
The 120VAC output of the VRPT is fused 2 each FNM-10, enroute to the AVR.
The new Basler SSR 63-12 AVR will be installed in the control panel and be powered
from the gen side of the bus tie breaker using a similar line-side supply circuit as
recommended by Basler.
A new AVR droop CT will be installed into the new switchgear cabinet.
Note that if the new AVR is used in the final installation, install a 2 ohm resistor in series
with the field (preferably in the exciter enclosure).
Sync check and reverse power flow protective relays located in the ECU will remain
enabled as primary protection devices. The MFR-13 relay to be mounted in the panel
will handle all other protective relay functions.
Engineering Information Transmittal
26 01 Mar 2013
1.3.8 Station Service Panel
The station service panel, including station service feed breaker and fuses, metering, Zig-
Zag ground fault detector, and other misc equipment located in the existing 480V
switchgear lineup will be left intact and operational. The following modifications are
planned:
A new digital power meter (ION 6200 transducer only with 120Vac supply, RS-485
MODBUS comm port, enhanced measurement package #2) will be installed inside the
rear top compartment of the station service section, and wired to the existing PT and CT
signals (connected in tandem with the existing Electro Industries meter). The Master
Controller will communicate with the meter.
The existing Zig-Zag circuit fused disconnect switch will be retained, but relocated to the
front corner of the Gen 5,6 tie cabinet, and rotated (90 deg) to face front.
Engineering Information Transmittal
27 01 Mar 2013
PART 2 BASIC OPERATION
2.1 BASIC OPERATION –HOW TO:
2.1.1 Start and Stop Diesel Gensets
The genset operating mode is selected using the rotary handle operator switch on the
front of the cubicle.
Basic Genset Operation Summary:
1 – FALLBACK: allows full manual
operation of the genset
2 – OFF: takes genset offline, and stops
engine (after a cool-down period)
3 – AUTO: gives genset start/stop control
to the Master PLC dispatch controller
4 – MANUAL RUN/LOAD: starts engine
to rated speed, and puts genset online
2.1.2 Recover from an Outage
There is no automated blackstart recovery provided. Generators will not automatically
connect to a dead bus under any circumstance.
After isolating from the failed grid, parallel any desired number of generators by first
clearing any fault/lockouts as necessary, then starting and closing in unit(s) using the
“MANUAL RUN/LOAD” switch(es) on the gen control panel(s).
If these controls are disabled, then use the “FALLBACK” position to start using full
manual controls.
After restoring power, units can be taken offline manually as desired using their operating
switch, or they can be placed in “AUTO” and automatic dispatch will scale back capacity
based on current load conditions and preset generator preference.
Engineering Information Transmittal
28 01 Mar 2013
2.1.3 Enable/Disable Genset for Maintenance
When a genset must be taken out of service, as for routine maintenance, the following
procedures apply:
1. If the genset is currently online, either in AUTO or MANUAL mode, the operator
obviously must be aware of capacity before switching off generators, and must
ensure sufficient generating capacity is online before taking the genset offline.
a. If taking the genset out of service will lead to insufficient generating
capacity, bring one or more gensets online by switching them to
MANUAL mode.
2. If the genset is currently online, either in AUTO or MANUAL mode, AND there
is sufficient capacity online besides that genset, then switch the genset to OFF
mode.
3. If the genset is currently offline, and in AUTO mode, then switch the genset to
OFF mode.
4. Once the genset is set to OFF mode, wait until the genset is offline AND the
engine is stopped (usually takes several minutes of cooldown after switching to
OFF mode).
5. Once the genset is offline and the engine is stopped, implement LOTO procedure
as warranted for the service required. Proper isolation should include a lock and
tag on the padlock provision of the circuit breaker (applicable to units 2 though 6)
When it is time to put a genset back into service, following completion of routine
maintenance, the following procedures apply:
1. Remove LOTO.
2. To test the engine without putting the genset online, switch from OFF to
FALLBACK mode. (In FALLBACK mode the unit can be run without load)
3. When the genset is ready to put back into normal operation, switch to AUTO
mode. The genset dispatch controller will put the genset online when needed.
4. Once the online genset configuration is set as desired by the operator, switch all
online units to AUTO mode first, then switch offline units to AUTO mode.
(follow this order to avoid the possibility of an unnecessary gen start)
2.1.4 Genset Error Acknowledgement
Any genset alarm or fault will be messaged on the front screen of the EasYgen associated
with that genset, combined with illumination of its associated red fault light, indicating
the unit is tripped and locked out, or by its amber warning light, indicating a pre-alarm
condition or other non-trip condition.
Use the EasYgen display to view the current (most recent) fault message.
Engineering Information Transmittal
29 01 Mar 2013
Acknowledge the fault or alarm by using the EasYgen display and determine if
reset/restart is warranted.
Reset the fault or alarm by using the EasYgen display. If the fault condition is still
present, the fault will not reset or will reoccur.
2.1.4.1 Special Procedures for Caterpillar ECU faults
Some of the St Paul gensets may have on-board controls including alarm and fault
display for engine specific faults. If the EasYgen displays “CAT FAULT”, then look at
the Caterpillar unit display for the offending fault code(s)/light.
In this case, the ECU fault must be cleared before the EasYgen “CAT FAULT” can be
cleared.
2.1.5 Wind Import Control
2.1.5.1 Wind Import Selector
The wind import operating mode is selected using the rotary handle ON/OFF switch on
the front of the Master cubicle.
When set ON, the TDX wind farm is enabled to connect and run one or more wind
turbines, subject to the maximum import limit set by the City.
When set to OFF, those wind turbines will be shut down and taken offline.
IMPORTANT: In some situations, taking the wind turbines offline may cause a capacity
shortfall in the plant. While the Master PLC will respond by starting up one or more
additional gensets (if set to AUTO mode), it is the responsibility of the plant operators to
ensure sufficient generating capacity is available during any operator-selected mode
transition.
2.1.5.2 Maximum Wind Power Import
When the selector is set ON, the Master PLC generates a maximum wind power import
setting based on keeping the City gensets at or above their minimum load setpoint, as
determined by the City.
The import limit command is continuously communicated to the POSS PLC
There are essentially 2 malfunctions that can occur while wind import is enabled:
1) Some or all genset power data is lost
2) Communication with POSS camp is lost
Engineering Information Transmittal
30 01 Mar 2013
In the first case, the PLC would detect a diesel plant power mismatch (calculation based
on bus meter, sum of all genset meters, electric boiler meter, and station service meter)
and illuminate the Master control warning light. The control would not disable the wind
resource, because there would be no guarantee that the wind capacity is not needed. The
operator would make the choice to turn off the wind import (after verifying or increasing
diesel capacity) or leave it enabled at its present import limit.
In the second case, the City PLC would detect the coms error and illuminate the Master
control warning light.
The POSS PLC would also detect the loss of coms, and trigger an alarm to alert wind
farm operations. The POSS PLC would either ramp down and stop turbines, or remain
generating at last minimum import level, or continue to run at a reduced export, based on
selection by City Operators using the City HMI.
There is no risk of an overpower/overfrequency outage resulting from a communication
loss during this condition, because the POSS wind turbines will shut down (coordinated
81O with plant controls) if there is enough generation to raise grid frequency.
It should be noted that enabling wind import (by selecting wind import “ON” using the
ON/OFF switch) does not guarantee that the wind turbine(s) will be operational.
The amount of wind power imported from POSS will be prominently displayed on the
Master control HMI. Individual wind turbine status will also be available (for
informational purposes) on lower level HMI screens.
2.1.6 Recorded Energy Generation and Usage
The HMI screen “Energy and Trends” displays a summary of the energy (kWh) produced
by the six gensets as well as imported wind energy. It will also display energy consumed
by the electric boiler, broken down by total consumed and amount consumed as excess
wind.
All energy generation and usage data, as described above, will be available to the
operators at the City and POSS via the HMI and operator work stations.
Engineering Information Transmittal
31 01 Mar 2013
PART 3 DIESEL GENSET CONTROLS AND DISPATCH
3.1 MAJOR COMPONENTS AND FUNCTION
The on/off control of the diesel gensets is called genset dispatch. When that control is
actuated from an automatic control program, we have automatic genset dispatch.
In the case of the City power plant, the “automatic dispatch controller” is the PLC control
program that actuates this on/off control of the genset controllers. The automatic
dispatch controller is a set of algorithms that are executed by the master controller PLC
Note that these code algorithms are a sub-set of the overall PLC program, thus the
reference to “automatic dispatch controller”, not “PLC”.
There are several reasons why running the plant in automatic mode is advantageous to the
operators:
- The automatic dispatch controller can help prevent outages, especially during
times when the operator is not in the plant.
o The automatic dispatch controller can start a genset in response to changes
in the City load or wind contribution
o The automatic dispatch controller can start a genset in response to a genset
pre-alarm or other warning condition
- The automatic dispatch controller can help optimize plant efficiency (gallons of
fuel consumed per kWh delivered to the City customers)
o The automatic dispatch controller can dispatch more efficient genset(s)
when City load and wind contribution allow
IMPORTANT: The automatic dispatch controller does not restore power to the City
following an outage (commonly called “black start”, refer to section PART 2 for
information about outage recovery using FALLBACK mode controls).
NOTE: Gensets 3 and 4 will not be integrated into the automatic genset dispatch system,
this section does not apply to those units.
3.1.1 Genset Control Description
The controls for all gensets configured for automatic dispatch will be very nearly
identical in configuration and equipment.
The individual genset controls are based around the EasYgen engine/genset controller
manufactured by Woodward Governor Co, of Fort Collins, CO.
Engineering Information Transmittal
32 01 Mar 2013
For each of the gensets, the EasYgen is configured for automatic start/sync/stop
operation. The EasYgen initiates ECU engine start commands, performs
synchronization, has primary control of the gen breaker, and sends voltage bias output
signals to the AVR of each genset (if required) to perform reactive load sharing between
paralleled gensets. The EasYgen speed bias output is also used to bias the governor, for
active synchronization during start-up.
Each unit will be designed for a 2301D Load Share Controller (Woodward Governor).
The 2301D units are configured and wired for speed regulation (governor) and load
share.
Each unit will be designed for a Basler SSR 63-12 voltage regulator.
The 24Vdc power supply for each section of the genset controls is derived as a diode-or
arrangement between the station 24Vdc battery and the engine start battery associated
with the particular genset.
Each unit will be designed with a safety chain circuit, a series-connected circuit of safety
device contacts that enables the unit to be started and put online when all contacts are
closed, and immediately disconnects the unit and stops the engine if any of the contacts
are open. The safety devices in the safety chain for each unit include panel-mounted E-
STOP button (or ESR relay contact), fire system shutdown, exhaust valve position
feedback, and overspeed switch or device. When closed, the safety chain circuit will
supply holding power to the unit’s breaker UVR, supply power to the 2301D, and supply
power to the breaker close coil circuit. When open, power will be removed from the
UVR, 2301D, and breaker close coil circuit.
3.1.2 Genset Operating Mode Switch
The operating mode is selected on the front of each cubicle using a rotary handle operator
switch. The four available modes are abbreviated in this document as follows:
Engineering Information Transmittal
33 01 Mar 2013
Basic Genset Operation Summary:
1 – FALLBACK: allows full manual
operation of the genset
2 – OFF: takes genset offline, and stops
engine (after a cool-down period)
3 – AUTO: gives genset start/stop control
to the Master PLC dispatch controller
4 – MANUAL RUN/LOAD: starts engine
to rated speed, and puts genset online
The detailed operation of the corresponding genset in the various modes is described
below.
3.1.2.1 FALLBACK Mode
The FALLBACK mode defaults the system to full manual “classic” controls. The
EasYgen is put into “manual” mode which allows operator control of start/stop and
breaker close/open control subject to sync check enable. FALLBACK mode is used to
check out an engine including speed governor and excitation systems without connecting
the genset to the bus. The FALLBACK mode is also useful to perform tuning or
diagnostic testing of the EasYgen synchronizer function. The operator commands the tie
breaker to close while in FALLBACK mode. All of the genset behavior is controlled by
the operator in FALLBACK mode. The PLC will hold the AUTO RUN output low
anytime the FALLBACK mode is engaged.
The EasYgen’s CAN bus and RS-485 data lines will be disconnected (via interposing
relays or additional mode switch contact decks) when in FALLBACK mode, to protect
against a single EasYgen malfunction affecting the operation of other units. As a result,
the Master PLC will not receive any data from a unit in FALLBACK mode.
IMPORTANT: upon detecting a communication link failure with an EasYgen, the Master
PLC will be programmed to declare the unit is offline (zero kW) for purposes of
automatic dispatch control of other units.
The only sequences that will cause the engine to shut down in FALLBACK mode is
operator intervention (hitting the E-STOP button), intervention by turning off the existing
ECU control switch, or due to abnormal conditions (errors, alarms, faults, outages) which
cause the EasYgen or other protective devices to shut the engine off and trip its breaker.
Engineering Information Transmittal
34 01 Mar 2013
When switched from OFF to FALLBACK:
- If the genset is online (for example if the load ramp-down hasn’t finished from a
very recent transition to OFF), the genset stays online and continues to run
indefinitely
- If the genset is offline:
o If the engine is running (for example if the cool-down period hasn’t
expired from a recent transition to OFF), the engine continues to run
indefinitely;
o If the engine is not running, the engine stays off until EasYgen interface is
used to manually start the engine
When switched from AUTO to FALLBACK:
- If the genset is online, the genset stays online and continues to run indefinitely
- If the genset is offline:
o If the engine is running (for example if the cool-down period hasn’t
expired from a recent transition to OFF), the engine continues to run
indefinitely
o If the engine is not running, the engine stays off
When switched from MANUAL to FALLBACK:
- If the genset is online, the genset stays online and continues to run indefinitely
- If the genset is offline:
o If the engine is starting or running (for example if the genset was recently
started by switching to MANUAL, but switched to FALLBACK before
synchronization with the bus), the synchronization sequence is ended, the
engine continues to run indefinitely
o If the engine is shut down (for example if the genset has errors or alarms
active that need to be cleared), then the engine may not start up. Check
the EasYgen screen for any alarms that may need to be cleared first.
3.1.2.2 FALLBACK Mode Switch Controls
Engineering Information Transmittal
35 01 Mar 2013
1. VOLTAGE ADJUST RAISE Æ - 10-turn potentiometer for Basler and Cat AVR trim input,
and voltage RAISE/LOWER switch for Gen 2.
2. GOVERNOR MODE IDLE/RATED – 2-position toggle switch, opens/closes the 2301D
IDLE/RATED input to affect engine speed, and shuts off / powers on the unit’s AVR.
3. PARALLELING MODE DROOP/ISOCH – Closes/opens the 2301D DROOP/ISOCH input, to
affect load share behavior
4. SPEED CONTROL RAISE Æ - 10-turn potentiometer for LSM (Gen 2), three-position
spring return to center NC-NO-NC switch labeled RAISE/LOWER for 2301D (Gens 1, 5, 6)
3.1.2.3 OFF Mode
The OFF mode is selected to take a genset offline and shut off the engine, or to remove
that genset from the available genset configurations for automatic dispatch control. The
behavior of the genset in OFF is controlled by the EasYgen, usually initiating a shutdown
sequence if the genset was running prior to entering the OFF mode.
There are no sequences that will cause the engine to start up or the genset to (re)connect
online in OFF mode. The genset will only start up if the operator changes the mode from
OFF to another mode.
When switched from FALLBACK to OFF:
- If the genset is online, the load is ramped down to zero and the breaker is opened.
- If the engine is starting or running and the genset is offline, the engine is shut off
after a cool-down period.
- If the engine is not running, the engine stays off.
When switched from AUTO to OFF, or MANUAL to OFF:
- The RUN signal is turned off (refer to section 3.3.1 for details of the RUN signal).
- If the genset is online in parallel with another genset in isochronous load share
mode, the genset load is ramped to zero, the genset breaker is opened, and the
engine is shut off after a cool-down period. The timing of these events is settable
within the EasYgen for each unit.
- If the genset is the only unit online in isochronous load share (either no other
gensets are online, or other online gensets are ramping up, ramping down), then
the genset breaker is opened immediately (no ramp-down is possible), and the
engine is shut off after a cool-down period.
- If the genset is offline:
o If the engine is starting or running, the engine is shut off after a cool-down
period.
o If the engine is not running, the engine stays off.
Engineering Information Transmittal
36 01 Mar 2013
3.1.2.4 AUTO Mode
AUTO mode is the only mode where genset behavior and state is not controlled
exclusively by the EasYgen. The purpose of using the AUTO mode is to allow the wind-
diesel master controller (PLC) and the automatic dispatch controller (embedded code in
the PLC) to dispatch gensets automatically (without operator intervention) in response to
changes in both City load level, wind contribution level, and genset alarm or pre-alarm
state.
In AUTO mode, the automatic dispatch controller has control of the RUN signal which is
used for high-level start / stop control of the genset. The RUN signal is issued over the
RS-485 communication lines between the PLC and the EasYgen units.
From the perspective of the EasYgen, the RUN signal being off when in AUTO mode is
identical to selecting OFF mode on the panel switch, and the RUN signal being on when
in AUTO mode is identical to selecting MANUAL RUN/LOAD mode. When the RUN
signal is on, the EasYgen puts (or keeps) the genset online. When the RUN signal is off,
the EasYgen takes (or maintains) the genset offline.
The terminology “put the genset online” and “take the genset offline” are synonymous
with the actions of turning on the RUN signal, or turning off the RUN signal, when in the
AUTO mode. Also note that turning off the RUN signal is effectively the same as
sending a “stop” signal to the genset.
When a genset is switched to AUTO mode, the automatic dispatch controller takes over
but does not initially change the state of the genset (bumpless mode change). After a
“mode adjustment delay” expires – initially 5 seconds – the genset may be put online or
taken offline as dictated by the automatic dispatch controller.
When switched from FALLBACK to AUTO:
- The RUN signal is kept off, at least for 5 seconds, before the automatic dispatch
controller may put it online as part of a configuration change sequence.
When switched from OFF to AUTO:
- The RUN signal is kept off, at least for 5 seconds, before the automatic dispatch
controller may put it online as part of a configuration change sequence.
When switched from MANUAL to AUTO:
- The RUN signal is maintained on:
o The genset continues to run online, at least for a minimum time of 60
seconds, before the automatic dispatch controller may take it offline as
Engineering Information Transmittal
37 01 Mar 2013
part of a configuration change sequence. The actual time is determined by
the maximum of either 60 seconds, or the transition delay time settable on
the HMI screen.
- If the genset is offline due to a fault, the RUN signal is kept off:
3.1.2.5 MANUAL RUN/LOAD Mode
The MANUAL mode is used to put a genset online without delay, and keep the genset
online indefinitely. All of the genset behavior is controlled by the EasYgen in MANUAL
mode. The automatic dispatch control will not affect the genset operating state while in
MANUAL mode.
The only sequences that will cause a genset that is online in MANUAL to be taken
offline is operator intervention (hitting the E-STOP button or manually tripping the
breaker – neither is recommended unless there is an emergency situation), or due to
abnormal conditions (errors, alarms, faults, outages) which cause the EasYgen or other
protective devices to disconnect the genset from the bus.
When switched from FALLBACK to MANUAL
- If the genset is online (for example genset load is ramping down after a very
recent transition from AUTO or MANUAL), the genset is maintained online,
ramping load back up to proper load-share levels as necessary.
- If the genset is offline:
o If the engine is starting or running, the genset is synchronized and
connected to the bus, and genset load ramps to proper load-share level.
o If the engine is not running, the engine is started, the genset is
synchronized and connected to the bus, and genset load ramps to proper
load-share level.
When switched from OFF to MANUAL
- If the genset is online (for example genset load is ramping down after a very
recent transition to OFF), the genset is maintained online, ramping load back up
to proper load-share levels as necessary.
- If the genset is offline:
o If the engine is running (for example if the cool-down period hasn’t
expired after a recent transition to OFF), the engine continues to run, the
genset is synchronized and connected to the bus, and genset load ramps to
proper load-share level.
o If the engine is not running, the engine is started, the genset is
synchronized and connected to the bus, and genset load ramps to proper
load-share level.
Engineering Information Transmittal
38 01 Mar 2013
When switched from AUTO to MANUAL
- The automatic dispatch controller will turn the RUN signal on
- If the genset is online, then the genset stays online.
o The genset load will ramp back up to proper load-share levels in the case
the RUN signal was recently turned off
- If the genset is offline:
o If the genset is started or running (for example if the RUN signal was
recently turned on), the engine continues to start and/or run, the genset is
synchronized and connected to the bus, and genset load ramps to proper
load-share level.
o If the engine is not running (for example if the RUN signal was off), the
engine is started, the genset is synchronized and connected to the bus, and
genset load ramps to proper load-share level.
Engineering Information Transmittal
39 01 Mar 2013
3.2 MANUAL OPERATION/OVERRIDE OF AUTOMATIC CONTROLS
Override of automatic controls occurs whenever the genset mode control switch is not set
to the AUTO position. If the operator wishes to take or keep a genset offline with
purpose, then switch the mode to OFF. If the operator wishes to put or keep a genset
online with purpose, then switch the mode to MANUAL.
IMPORTANT: the decision to change the mode from AUTO to OFF requires full
awareness of the operating state of the plant. When a genset is switched to OFF, the
controls will respond immediately to ramp that genset down to zero and take it offline.
Although other gensets which are set to AUTO may respond by starting up and
connecting online in response to a genset switched to OFF, the startup sequence can take
up to a minute or more. It is up to the operator to ensure that there is sufficient
generating capacity online in order to prevent overload of the other genset(s).
Engineering Information Transmittal
40 01 Mar 2013
3.3 AUTOMATIC OPERATION
There is only one control output to each genset that is used by the automatic dispatch
controller:
- RUN signal, used to start and stop the genset in AUTO.
o The genset starts at idle speed to warm up, then ramps to rated speed,
synchronizes, connects, and ramps to proper load share level when the
RUN signal is turned on. The duration of the idle speed warm up will be
pre-set to a default value for normal startups, but can be altered on-the-fly
by the PLC to force a fast startup if required by system conditions (for
example, increasing capacity in response to a pre-alarm on another unit)
o The genset ramps down load, disconnects, and stops the engine (after a
cool-down period has expired) when the RUN signal is turned off. The
RUN signal initiates the start/stop process only, the ramp rates and timing
of events is controlled by the EasYgen.
3.3.1 Details of RUN Signal Logic in AUTO Mode
The RUN signal is turned on if:
- There is not a dead bus condition (at least one genset is online), AND
- The genset mode switch is not set to OFF, AND
- The genset is not faulted (EasYgen is not tripped), AND (any of the following)
o The genset mode switch is set to MANUAL, OR
o The genset is online, and is the only genset online, OR
o The genset mode switch is set to AUTO, and the genset is being put online
by the automatic dispatch controller.
3.3.1.1 Genset Perferred Unit Selector
Each Genset has a different rating and efficiency. For maintenance reasons, there may be
other consideration for choosing a lead unit or for selecting a unit as a last resort. The
dispatch controller will require the operator to enter ratings, and preference based on
efficiency or maintenance reasons. These setting will determine the order in which
gensets are taken on and offline to achieve best match for capacity and efficiency.
If a preferred unit is unavailable (switched to OFF, has a fault or pre-alarm), the next in
order of preferred units will be used instead.
3.3.1.2 Genset Maximum Load
Each genset has a maximum load setpoint, which is settable in units of kW on the HMI.
Engineering Information Transmittal
41 01 Mar 2013
It is recommended these parameters be set according to how much load is appropriate for
the genset to supply on a continuous basis.
The individual maximum load setpoints for all gensets that are online (except gensets
which have pre-alarms active or are switched to the OFF mode) are added together to
derive a total genset maximum load level.
This total maximum load level is used by the automatic dispatch controller to decide
whether more or less genset capacity is needed.
3.3.1.3 Load Margin
The expected amount of variation in City load level is parameterized as a setpoint called
Load Margin (LM), settable in units of kW on the HMI. This setpoint is used to specify
margin or cushion to the automatic dispatch controller when deciding whether to increase
genset capacity.
The LM setpoint should be set based on the largest increase in City load that is likely to
occur within the time it takes to put a genset online (approximately one minute). Higher
settings are more conservative from a reliability standpoint, whereas lower settings tend
to produce greater fuel savings. Note also that the genset capacity (Pmax) setpoints,
when set more or less conservatively, have the same effect as lower or higher values of
LM. A lower value of LM is also allowable if the gensets have a standby rating that
allows for higher-than-rated genset loading for a time greater than the time it takes to put
a genset online.
3.3.1.4 Downward Transition Hysteresis (HYST)
The amount of hysteresis around the City load level to use when evaluating configuration
changes is termed Downward Transition Hysteresis (HYST). When deciding whether to
switch to a smaller genset configuration, the Pmax (capacity) of the target (smaller)
genset configuration is compared with City load plus LM plus HYST. If HYST is set to
zero (or too small), then frequent cycling between two genset configurations could occur
when City load hovers near the transition boundary between those two configurations.
3.3.1.5 Downward Load Transition Delay
When deciding whether to switch to a smaller genset configuration, the transition criteria
(expressed as a comparison of target generating capacity versus City load plus LM plus
HYST) must be satisfied continuously for the Downward Load Transition Delay to
ensure a stable situation following the transition. This delay is initially set to five
minutes.
Engineering Information Transmittal
42 01 Mar 2013
3.3.1.6 Reliable Wind Contribution Factor
Among the many challenges to operating a power system with medium-to-high wind
contribution is knowing how much wind power can be relied on as part of the generating
mix. The most conservative approach is to say “the wind is variable and uncertain,
therefore we cannot count on the wind output to supply any electricity – we must assume
the wind could go away at any time”. However, experienced operators of wind diesel
power systems know that the wind power contribution can at times be quite steady and
can therefore be depended upon as a reliable generation source for the system.
When wind contribution is dependable and consistent, then it becomes possible for the
automatic dispatch controller to utilize more of the wind output by running smaller
capacity gensets (or genset configurations) and thereby reduce fuel consumption.
However, too much dependence on the wind power contribution can lead to reduced
reliability of the system (more outages). Therefore, the human operators of the system
need to have some input into this decision of “how much wind” to count on.
The Reliable Wind Contribution RWC (units of kW) is a prediction of how much total
wind output (kW) can be counted on (the expected minimum value in the near future),
based on the wind conditions over the past ten minutes.
RWC is calculated using a statistical method based on the average wind output
(PWT_avg), and the standard deviation of the wind output (PWT_stdev), in order to
capture information about how strong the wind is, and also how gusty it is. Both the
average and the standard deviation quantities are calculated once per second, using the
measured data from the previous ten minutes.
The statistical method can be summarized as
RWC_raw = PWT_avg – NSD*PWT_stdev
where “RWC_raw” represents the unclamped result, and the Number of Standard
Deviations, or “NSD”, is a settable HMI parameter usually set to a value of 4.0 in order
to deliver a result that is approximately one standard deviation below the minimum value
(since three standard deviations nominally encompasses 99% of all the sampled
datapoints of a normally distributed variable).
The raw result of the statistical method calculation “RWC_raw” is then clamped to be no
less than zero, and no greater than the actual measured wind output “PWT,” and this
result is called RWC (kW).
RWC = maximum(RWC_raw, 0), or minimum(RWC_raw, PWT)
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Additionally, RWC is set to zero whenever the one-minute average wind speed exceeds a
critical threshold (currently hard-coded to 20 m/s, or 45 mph), in order to anticipate an
impending high wind shutdown of the wind turbine(s) which is an automatic safety
function of the Vestas controller. This high wind override of RWC remains in effect until
the one-minute average wind speed drops below the critical threshold by least 5 m/s
(RWC override is reset at 34 mph).
3.3.1.7 Wind Utilization Factor
Wind Utilization Factor, (WUF), settable on the HMI in percentage of genset online
capacity (from 0 to 100%) is used to effect the policy of the City operating department to
set how much spinning diesel reserve is required during wind diesel operation.
This setpoint allows the operator to decide how much to rely on the predictive algorithm
for minimum wind power, in terms of how much (if any) would the online genset(s) be
overloaded in the worst case of immediate loss of wind generation. Setting WUF to a
value of 20%, for example, means that the wind output (as predicted by RWC) will be
trusted, but only up to an amount equal to 20% of the online genset capacity. This also
means that, in the worst case of the wind output suddenly dropping to zero (as if for
example the wind turbines were paused or tripped offline), the gensets would be subject
to a load level no greater than 20% above their max load setting minus Load Margin
(LM). If LM is set greater than zero, then the load level that the gensets could be subject
to will be less than 20%.
Keep in mind the RWC will account for situations such as an impending high wind
shutdown, or extreme variability, and prevent the diesel dispatch from overextending in
these cases. The WUF represents a confidence factor in the wind generating equipment,
that is, how likely is a single turbine or – in the future – a two turbine equipment failure
and what are the ramifications of such a failure.
The limited (by WUF) versions of RWC, used for dispatch decisions is therefore defined
as
RWC_lim = maximum(RWC, Gtot_Pmax*(WUF/100))
RWC_lim_target = maximum(RWC, Gtot_Pmax_target*(WUF/100))
3.3.2 Increasing Genset Capacity
A threshold test with multiple settable threshold parameters is used to determine when
additional genset capacity should be added to the system. This usually occurs at times of
high City load and/or low wind contribution, but also may occur in response to genset
pre-alarm or trip events.
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The automatic dispatch controller will compare the measured City load P_City (kW) plus
settable load margin LM (kW) against the total online genset capacity Gtot_Pmax (kW)
plus the limited Reliable Wind Contribution value RWC_lim (kW), according to the
following logical comparison:
Gtot_Pmax + RWC_lim < P_City + LM
If this comparison is true (genset load level is too high), then initiate change of genset
configuration to increase total genset capacity. The automatic dispatch controller will
identify the next largest available configuration and proceed to change the RUN signal
for the corresponding gensets. There is no delay associated with the decision to add
capacity.
In some cases, this change may be a continuous sequence of genset run / stop commands
to arrive at a new configuration that satisfies the increased capacity requirement (for
example G2 Æ G2,G6 Æ G6). The settings and time delay(s) should be tuned to enable
the system to successfully carry through the transition, even if (say) City load is
increasing throughout the execution of the sequence.
3.3.3 Reducing Genset Capacity
A threshold test with settable threshold and time delay parameters is used to determine
when genset capacity may be reduced. Typically, genset capacity can be reduced at times
of low City load and/or high wind contribution.
The automatic dispatch controller will compare the measured City load P_City (kW) plus
settable load margin LM (kW), plus settable transition hysteresis HYST (kW), against the
total target genset capacity Gtot_Pmax_target (kW) plus the limited Reliable Wind
Contribution value RWC_lim_target (kW), according to the following logical
comparison:
Gtot_Pmax_target + RWC_lim_target > P_City + LM + HYST
Where
Gtot_Pmax_target
is the maximum load setpoint of the proposed (target) configuration, which is assumed to
be the next smallest available configuration.
If this comparison is true for the Downward Load Transition delay (continuously), then
initiate change of genset configuration to decrease total genset capacity. The automatic
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dispatch controller will identify the next smallest available configuration and proceed to
change the RUN signal for the corresponding gensets.
In some cases, this change may be a continuous sequence of genset run / stop commands
to arrive at a new configuration that satisfies the decreased capacity requirement (for
example G6 Æ G6,G5 Æ G5).
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PART 4 LOAD REGULATION
The primary requirement for the loadbank in the POSS Camp wind farm is to maintain
the genset loading within acceptable limits, as determined by City power plant operations
personnel.
The ability to remove excess dump load in a timely manner is also an important design
consideration.
4.1 GENSET MINIMUM LOAD REGULATION
4.1.1 Determination of Load Command
Each genset has a minimum load setpoint “MIN LOAD”, settable on the City HMI,
which defines the minimum (time-average) load level that the genset should be allowed
to operate at. The total minimum load setpoint “Pmin” is effectively the sum of the
individual setpoints of those gensets that are online. Exceptions to this include cases
where genset transitions are occurring, which can be either gensets coming online or
going offline. Refer to subsection 4.1.2 for more details about the total minimum load
setpoint.
The load (kW) of each genset is measured by the EasYgen, and reported to the PLC by a
serial communications signal to the City PLC. The City PLC adds up the individual
genset load measurements to determine the total genset load.
The City PLC also reads wind power export KW (short time averaged) from the POSS
Camp controller, and adds that to total genset KW to determine City load which is used
in the automatic dispatch logic.
The total genset load is then compared with the total minimum load setpoint to determine
whether the maximum wind import command should be increased or decreased. This
comparison and correction happens on a relatively slow timescale (several to 10’s of
seconds), because City load generally varies at a similar timescale. Other safeguards are
in place to guard against sudden loss of distribution feeders, etc.
Unless overridden by the Operator, the PLC program will run a PID block to handle the
control of the maximum wind import command.
Err = Pmin – Pmeas
PNmax = PID(Err)
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Clamp the maximum value of PID output PNmax at lower of the maximum allowed wind
contribution and the HMI setting based on the City Operator’s discretion.
Clamp the minimum value of PNmax at zero. Note the wind turbines need not go offline
for low values of PNmax. To initiate a full wind farm shutdown, use the panel switch
located on the Master switchgear section.
4.1.2 Maximum Wind Import Load Command During Genset
Transitions
The minimum load level for the combination of online gensets is generally set equal to
the sum of the individual minimum load level setpoints for each genset that is online.
However, special care must be taken during genset transitions to prevent inadvertent
overload of the genset that remains online while the outgoing unit is ramping down.
Also, there is no specific need to increase the minimum load command rapidly; the
purpose of minimum load control is to prevent cold engine issues which are typically not
a concern for short periods of light load.
4.1.2.1 Transition Example #1
The most basic example is that of switching between one and two gensets online. This
transition sequence would usually occur when the initially online genset is in MANUAL
mode and the genset being put online / taken offline is in AUTO mode.
NOTE: It is acknowledged St Paul G3 may not be automatically dispatched, please
treat the unit numbers as examples where G2 is larger than G3.
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When putting a genset online, the maximum wind import level (command) is limited to
that based on the previous minimum load value, for a set time delay, then ramps to the
new level at a set rate labeled “MIN LOAD POS RAMP RATE” which is in units of
kW/EXECUTION RATE. Note that the “new level” is determined by the true online
configuration.
When taking a genset offline, the minimum load level (command) ramps to the new level
at a set rate labeled “MIN LOAD NEG RAMP RATE” which is in units of
kW/EXECUTION RATE, starting at the same time as the RUN signal is turned off (no
delay). Note that the “new level” is determined by the target genset configuration since
the ramp action occurs before the genset is offline.
4.1.2.2 Transition Example #2
Expanding on the first example, the next level of performance is gained by having both
gensets in AUTO mode, allowing for a third possible configuration.
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Starting with G3 only, G2 is put online, then G3 is taken offline. A continuous sequence
of steps is used to execute this transition.
During the transition, the minimum load level is held constant for a set time delay, then
ramps to the new level at a set rate. The minimum load settling delay time is set greater
than the time required to execute the complete transition. The “overlap delay” which is
the (generally brief) time that the gensets operate in parallel is set much less than the
minimum load settling delay time.
4.1.2.3 Transition Example #3
On the opposite transition where genset capacity is reduced, G3 is put online with G2
before G2 is taken offline.
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During this transition, the minimum load level (command) is held constant when G3 is
put online (effectively counting down the minimum load settling delay as if increasing
capacity), then ramps to the new level at a set rate, starting at the same time as the RUN
signal is turned off for the outgoing genset (no delay). Note that the “new level” is
determined by the target configuration since the ramp action occurs before the genset is
offline. Also note that the “new level” based on the target configuration overrides the
level being held for the minimum load settling delay.
4.1.2.4 Transition Example #4
Expanding on the first example, the situation of a genset in AUTO or MANUAL mode
that experiences a sudden error or fault and trips offline suddenly will cause the minimum
load level command to drop as fast as possible to the new level. Since the genset that
remains online will have to take a large load step, quickly relieving any excess load is the
“best-effort” way to minimize impact and potentially prevent an outage. There is no
benefit to having a delay or ramped response, as smoothness in a transition is not required
following a sudden disruption.
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PART 5 ELECTRIC BOILER
5.1 GENERAL DESCRIPTION
The design features a 3-phase 240kW electric boiler located in the City’s power plant,
near Genset #6. The boiler will be piped into an injection loop with thermostatic control,
based on the building heat loop temperature. The manufacturer’s onboard proportional
controller will be utilized to energize the injection pump and energize individual elements
to maintain the desired building heat loop supply temperature. Boiler step size is 40kW.
The boiler will be fitted by the manufacturer with various protection devices that act to
shut off the boiler elements in case there is a problem, including low water and redundant
over-temperature detection. A single “boiler error” status contact indicating the
occurrence of one or more of these protection functions will be wired back to the master
PLC for display on the operator HMI screen.
An under-frequency protective relay function will be used to externally shut off the boiler
elements, to protect the City grid against outage due to genset overload. The proposed
relay will feature either manual reset, or automatic reset after adjustable time delay.
The City will limit the import of wind power such that their diesel generator(s) carry a
minimum load level. With the installation of an electric boiler in the City power plant,
any portion of electric boiler energy used to keep diesels from dropping below minimum
load is Excess Electrical Energy, in accordance with the terms of the PPA. Any portion
of electric boiler energy consumed when diesels are above minimum load is not excess.
At times, the boiler will use both excess and non-excess wind power.
A calculation made in the City wind diesel control system accounts for this mixture of
excess and non-excess wind power being utilized by the boiler. The City rejected this
calculation method under the premise that it would be cheaper to provide heat from the
diesels by turning down the Maximum Wind Import setpoint.
The following electric energy metering strategy is proposed in order to account for this
mixture of excess and non-excess wind power being utilized by the boiler.
5.2 EXCESS ENERGY METERING STRATEGY
TDX Power will install revenue metering on the boiler feed circuit, and implement a
software algorithm to calculate the portion of energy consumed that is “excess.” The
load of the injection pump will be captured by the revenue meter.
This Excess Electrical Energy will be subtracted from total wind power delivered to the
delivery point, and billed at the excess energy rate.
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In the control method proposed at 35% design, The City Power Plant wind/diesel master
controller will calculate City load, and send a maximum wind power import limit to the
POSS Camp load bank controller, such that the genset load (on average) does not fall
below a chosen setpoint (40% for example).
If the generator is running above its minimum load setpoint, and the boiler is running,
then some or all of that boiler energy is not “excess wind”. Conversely, it is assumed that
if the generator is running at (or below) its minimum load setpoint, and the boiler is
running, then all of that boiler energy is “excess wind” (provided there is wind power
being generated).
There will be regimes of system operation where electric boiler load exceeds that which
is required to maintain minimum genset load. In those cases, taking the electric boiler
KW and subtracting the amount of KW over which genset power exceeds its minimum
power setpoint will determine the portion of excess wind power consumed.
The City power plant wind/diesel master controller (PLC) will calculate both total
electric boiler KWH and Excess Wind Energy electric boiler KWH. At the end of every
billing period, these two totals for the period will be divided to provide a ratio. This ratio
will be multiplied by the electric boiler revenue meter reading to determine the amount of
boiler energy to be discounted as Excess Wind Energy. The remainder will be considered
normal “station service” power.
The code execution would be as follows, using time averaged values and calculating
KWH values every minute:
1. Compute (previous) 1-minute block averages of genset load (PDG), genset min
load command (PDGm), and boiler load (PEB) (each of these signals sampled on
approx 1 second timeframe)
2. Compute boiler load that is Excess Wind (PEBx) using the following logical
flowchart:
IF: PDG – PDGm > 0
THEN IF: PDG – PDGm < PEB
THEN: PEBx = PEB – (PDG – PDGm)
ELSE: PEBx = 0
ELSE: PEBx = PEB
3. To account for the possibility that the electric boiler could be on when diesel
generators are running below their minimum load setpoint at a time where there is
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no wind output, the 2nd logic step would be included (executed in sequence at the
same 1 minute time interval):
IF: PEBx > Total Imported Wind Power
THEN: PEBx = Total Imported Wind Power
ELSE: PEBx = PEBx
4. Also, Excess Wind Energy must not be negative, so the following step would be
included (executed in sequence at the same 1 minute time interval):
IF: PEBx < 0
THEN: PEBx = 0
ELSE: PEBx = PEBx
5. Calculate 1-minute kWh from PEB and PEBx, and add to accumulators EEB and
EEBx
6. Then, on a billing interval (monthly), multiply the ratio (EEBx/EEB) by the actual
energy kWh reading from the boiler’s revenue meter to determine Excess
Electrical Energy. This amount of KWH will be subtracted from the total wind
power KWH delivered to the delivery point – as recorded by the revenue meter at
POSS Camp – and billed at the lower Excess Wind Energy rate.
A proposed monthly bill would contain the following information:
Total KWH delivered from the City to the POSS Camp wind farm (credited to the
City at the commercial customer rate)*
Total KWH delivered from the POSS Camp wind farm to the City (for
informational purposes)
Total “non-Excess” KWH (delivered from the POSS Camp wind farm to the City
and billed at wholesale rate.
Excess Wind Energy (billed at Excess Wind Energy rate)
Total City power plant Electric Boiler KWH (for informational purposes)
*Note: Power consumption by the POSS Camp wind farm is comprised of parasitic losses
associated with the wind turbines’ auxiliary equipment. There is no projection of any
significant demand, with possible exception of POSS Camp load bank testing (which
should require prior notification to the City and be included in the Operating Agreement)
As such, it is proposed that there is no demand component associated with POSS Camp
energy purchased from the City.
If the calculated multiplier data were not available for some reason, then it is proposed
billing would be calculated such that electric boiler KWH, for the time period in which
the multiplier was not available, would be multiplied by the average multiplier from the
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previous 3 billing cycles. In the absence of such data, all electric boiler kWH for the time
period in which the multiplier is not available will be billed as Excess Electrical Energy.
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PART 6 OPERATOR INTERFACE COMPUTER
The City operator interface computer (more commonly called the “HMI computer”
Human Machine Interface) will be located in the Master cubicle in the power house. It is
a Windows based PC that accesses the plant data over Ethernet, and is provided with a
separate door-mounted touchscreen installed on the front door for operator control.
A second screen will be connected to the HMI computer using a pair of KVM (Keyboard,
Video, Mouse) boxes. The second screen will display and control the same data as the
diesel engine room touch screen but will be located inside the plant office.
The HMI computer is connected to the internet using a separate Ethernet port by a
modem installed on a DSL circuit maintained by the city (separate from leased line
controller communication between POSS and the City). The city owns all hardware
within the power plant and will be the account owner for the internet account.
6.1 HUMAN-MACHINE INTERFACE (HMI) PROGRAM
The Human-Machine Interface, or HMI, program is a custom designed software program
that acts as the operator’s control and monitoring interface with the power plant
equipment, including gensets and boiler circuit breaker and alarm status as well as
displaying some Poss camp wind data and status as sent over comms from the Poss Camp
station.
The Brand name of the HMI program is “InteractX”. A run-time application license for
InteractX is installed on the HMI computer. The InteractX run-time program is
configured to start automatically when the HMI computer is powered on (or restarted).
The HMI program will be composed of a number of screens to provide readouts of
equipment status and operating conditions, as well as adjustable settings to affect the
behavior of the system. This section provides an overview of each HMI screen.
6.1.1 General Information
The right hand column of all HMI screens contains navigation pushbuttons to access the
other HMI screens.
The bottom strip of all HMI screens shows the top two rows of the Alarms screen, as a
quick indicator of any recent problems with system equipment
The HMI program screens take up the entire screen area; the taskbar, quick launch
buttons, and START menu button normally found at the bottom edge of a Windows
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computer screen are covered up by the HMI screens. To access the bottom edge features
without exiting the HMI program, press the “Windows” key on the keyboard, usually
located in the bottom row to the left and/or right of the space bar. This is useful for
“shrinking” the HMI program while running other software programs or doing other tasks
while leaving the HMI program (and SCADA programs) running in the background.
To return to the HMI program screens, click the taskbar button “InteractX Runtime” at
the bottom of the screen; the HMI program screen will re-appear and consume the entire
screen again.
6.1.2 System Overview
The System Overview screen is the default screen, meaning it is displayed when the HMI
program is first started. InteractX is set up to auto-start anytime the HMI computer is
rebooted or power is restored.
The System Overview will give the plant operator a complete survey of the status of
major equipment within the plant. The screen layout is representative of the plant
electrical one-line; circuit branches shown in RED indicate circuit branches that are live
or hot, whereas circuit branches shown in GREEN indicate circuit branches that are dead
or off.
The data displays for all Gensets will show electrical information that is read out
from the EasYgen units as well as operational status i.e. Run, Off, and Genset control
switch position status -Fallback, Auto, Off, Manual.
6.1.3 Setpoints
There are two types of setpoints: User and Factory. The User Setpoints are all the settable
parameters that are at the discretion of the plant operators.
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The procedure of changing a setpoint value will be to press or click on the value to
change. A dialog box will appear with a keypad to allow numerical entry of the new
value. Type the new number, and press “Enter”. After pressing “Enter”, a window will
appear to confirm the change – press “Ack” to accept the change. The value shown on the
Setpoints screen will now be changed.
The adjustability of user setpoints can be password protected per City request.
The Factory Setpoints will be password protected and will include all the settable
parameters that are for detailed tuning and other special uses only.
6.1.4 Trends Screen
The Trends screen will display the Historical and Real Time data as supplied by the data
logging engine. The trend screen will include kW data for each genset, the boiler and the
wind turbine connected to the City. Data traces that are plotted can be selected (or turned
off) by clicking on the “data pen” buttons along the left edge. The time horizon for the
plot can be selected using the buttons along the upper right edge. The upper left edge has
advanced features for zooming the trend window, selecting a custom time range to plot,
and saving data to file.
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6.1.5 Energy Screen
The Energy screen will display all KW-HR data from the various power producers. This
data will include: Gensets, Boiler (consumed), Wind Turbine (produced and consumed),
Station Service load, and total 480V bus output.
6.1.6 Alarm Screen
The Alarms screen will show a list of alarms (also sometimes called variously
“warnings”, “errors”, “faults”,“trips”) that indicate information about a problem or
unusual situation that has occurred in the plant. The color of the alarm text will indicate
the severity of the condition; RED text usually indicates a serious problem or failure,
whereas YELLOW text will indicate abnormal conditions or supporting information that
may help indicate the cause of the more serious problem or failure. An operator
acknowledged alarm will lose its highlight to insure a new alarm will clearly stand out.
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To clear an alarm message from the list, the underlying cause of the alarm must first be
addressed before an operator can use the “acknowledge” (if not already acknowledged)
and then “clear” pushbuttons to remove the alarm from the list.
On the Alarms screen, an additional navigation button labeled “Alarm History” will
allow the operator to access a Historical Alarm screen which has access to alarms that
occurred in the past. Typically, the HMI program saves an alarm log file once per day.
The number of alarm log files that are stored is limited to approximately thirty files, or
roughly one month.
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6.1.7 Diesel Dispatch Screen
The Dispatch Status screen shows all information relating to the automatic dispatch
controller, including:
City Load
Reliable Wind Contribution
Online Capacity
Genset Contribution
Etc.
6.2 SCADA
A data collection and database program or “SCADA” will run in the background
of the HMI computer. The Windows based software, OPC.NET, will poll both the local
PLC as well as collect a limited amount of data from the remote system. Logged data will be
within the 1-2sec update range and will be stored as CSV files. The data logger works in
conjunction with the HMI software for trending purposes.
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The SCADA system will be programmed to create two types of data files. The “Fast
SCADA” files are time-stamped data files of analog variables and other information
collected from the PLC on a 1-2 second sample rate. Data will be stored in .csv files.
Once per hour (at the start of the next hour), the Fast SCADA program creates a new data
file, and the filename is automatically generated to clearly indicate the date and time
(hour) of the data within the file. Typical example of data includes per genset: HZ, Volts,
Amps, kW, kVAR, Status Alarms.
The “Daily SCADA” files are date-stamped data files of information collected from the
PLC on a once-per-day sample rate. The data will be stored in a .csv file. Once per year
(at the start of the next year), the Daily SCADA program creates a new data file, and the
filename is automatically generated to clearly indicate the year of the data within the file.
Data contained in the Daily SCADA file includes KW-HR data.
6.2.1 Reporting – Monthly Report Template
A monthly report template will be developed to aid the City in quickly viewing and
analyzing incoming information from the wind-diesel system. The report template
collates data from the daily SCADA file and presents it in a series of graphs designed to
give a high level overview of system operation and the contribution of each generation
source, including the wind turbine and all diesel generator sets.
6.3 OTHER SOFTWARE
Besides the HMI program and the SCADA programs, the HMI computer will run
other software programs added by TDX Power in order to facilitate system upgrades,
programming code updates, debugging, and other engineering-centric tasks. For
example, configuration tools for the EasYgen and 2301D will be available on the HMI
computer to facilitate setup or adjustments in configuration parameters for these devices.
6.4 LOCAL COMMUNICATIONS
At the City Plant, there will be an Ethernet switch for much of the data exchange. The Red
lion, the GE FANUC PLC and the HMI will all have connectivity to this switch. The
EasYgen Controllers and Boiler ION Meter will be connected to the Red Lion using the
RS485 serial port and will be polled using Modbus RTU protocol.
The HMI/SCADA software products will have access to the data, over Ethernet, for display
and data collection functionality. The HMI Computer will also have a second Ethernet card
for connection to another switch or router, which will give the computer internet
accessibility. The two Ethernet based networks will be separate to insure there are no security
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risks with respect to critical data exchange.
6.5 PLANT COMMUNICATIONS
Between the City power station and POSS Camp there will be a designated leased line pair of
copper wires supplied by Alaska Telecomm. These lines will have no provisioning and will
be equivalent to copper wires. A pair of leased line modems, MuLogic LLM-336DEth,will
be installed, one at POSS Camp and one at City Plant. Each modem will be connected to the
local Ethernet switch and be ported using the local Red Lion DSPLE000 protocol converter
with data exchanged between Red Lions appearing as an Ethernet bridge. Once the data is
mapped to both of the Red Lions, the City PLC (and Poss PLC) will have access to the data
from both plants.
The assumed data speed rate will be 9600 Baud but may be higher or lower depending on
noise.