Presentation on theme: "1 INTERMOUNTAIN POWER PROJECT STABILITY ENHANCEMENT (IPPSE) SYSTEM Presentation to WECC Remedial Action Scheme Reliability Subcommittee April 30, 2010."— Presentation transcript:
1 INTERMOUNTAIN POWER PROJECT STABILITY ENHANCEMENT (IPPSE) SYSTEM Presentation to WECC Remedial Action Scheme Reliability Subcommittee April 30, 2010 Ontario Hilton Ontario, CA
2 INTERMOUNTAIN POWER PROJECT STABILITY ENHANCEMENT (IPPSE) SYSTEM Presented by: Ken Silver-Electrical Service Manager (Manager of Energy Control and Extra High Voltage Stations ) Travis Smith-Assistant Manager (Manager of Intermountain Converter Station) Brian Cast–Electrical Engineer (Grid Operation and Energy Prescheduling Supervisor ) Ken Lindquist – System Protection Engineer Attendees: Ken Silver, Mukhlesur Bhuiyan, Travis Smith, Tom Snyder, Brian Cast, Saif Mogri, Ken Lindquist, Carlos Garay and John Hu Chuck Wu (On Phone)
3 Agenda 1.System Overview – Ken Silver 2.Performance and Operational History – Travis Smith 3.System Studies – Ken Lindquist 4.System Design – Travis Smith 5.Arming Function – Brian Cast 6.Operation and Monitoring – Brian Cast 7.Operating Procedures for Abnormal Conditions - Ken Silver 8.Commissioning, Maintenance, and Testing – Travis Smith 9.Conclusions – Travis Smith
4 1. System Overview
5 The Purpose of Intermountain Power Project Stability Enhancement (IPPSE) is to ensure WECC system stability after outages to the Intermountain Power Project DC system (IPPDC). This is achieved by arming predetermined remedial actions prior to the occurrence of a disturbance associated with the IPPDC. Due to IPPDC system upgrade from 1920MW to 2400MW, the IPPSE is submitted for review.
6 1. System Overview Remedial Actions Required: The Intermountain Power Project (IPP) Contingency Arming System (CAS) has been implemented to mitigate IPPDC disturbances by tripping one or two IPP generating units. The IPP CAS has been in operation since The design and operations of this RAS has been reported to WECC on April 1986 with a report entitled Intermountain Power Project Contingency Arming System: One Unit Operation and on August 1992, with a report entitled Intermountain Power Project Contingency Arming System: Non-Credibility of Remedial Action Scheme Failure. Formal Operating Procedure: The IPP CAS consists of arming-charts where real-time power output of the IPP generating units and the IPPDC line flows are used to select the no-unit, one-unit or two-unit arming of remedial actions. The IPP CAS and associated operating procedures are included with the LADWPs Energy Control Center Energy Management System (ECC-EMS) computers.
7 1. System Overview IPP DC Upgrade Project
8 1. System Overview Intermountain Power Project System
9 1. System Overview System Map
10 1. System Overview Intermountain One-line Diagram One Line Diagram: Adelanto
11 2. Performance and Operational History
12 2. Performance and Operational History The existing IPPSE was installed May 10, 1986 A design criteria of one operational failure in 3 years was used. How have we done ?
13 2. Performance and Operational History In 24 years there have been 28 actions. Seventeen of which occurred prior to August There have been 6 failures 5 of which occurred prior to August The system did not achieve its goal from 1986 to However from 1992 to the present, the system has achieved its goals.
14 2. Performance and Operational History What Changed in 1992? A problem with the Monopolar Out signal was discovered and corrected. A design change was initiated to allow for 1 restart in Monopolar Operation.
15 2. Performance and Operational History Success After the modifications, the system operated correctly.
16 3. System Study
17 3. Study Process Summary Co-ordinate with Impacted System Operators (PacifiCorp) in preparing study plan and study conditions. Determine Impact on the WECC System. Determine Maximum IPP Net Import Capability. Determine Generation Tripping delay times. Determine IPP Contingency Arming Scheme (CAS) Operational Nomograms.
18 3. System Condition Studied IPP DC Upgrade
19 3. Utah South Conditions Stressed TOT2 to Path Rating TOT2C TOT2B
20 3. Net IPP Import Sensitivity (Post-Transient Power Flow) * IPP DC Will Operate with Maximum Net IPP Import of 600MW – Limited by Line Overload
21 3. Determine Delay Generation Tripping Accommodate possible DC restart sequence after a DC fault; To lessen the stress by possibly using a less stressful turbine or boiler trip. DC Fault Restart1st2nd3rd Deionization Time (ms) Deionization Time (cycles) Cumulative (cycles) Simulate CAS time (cycles) (trip unit) Generator Tripping Methods Time to 0 Output Comments Electrical Trip< 10 Cycles Most Stressful on boilers and turbines Boiler Trip~ 42 Seconds 15 second Delay 20 seconds to 100MW, 6 second to breaker Open Turbine Trip~ 23 Seconds 15 second delay, 2 seconds to 100MW, 6 seconds to breaker Open
22 3. Stability Plot for Loss of Bipole with Restart (for DC Fault Only) (Worst Stressed Condition) Trip 1 Unit after First Restart Failed and Second Unit after the Second Restart Failed Trip Both Units after First Restart Failed * CAS Will Trip Units after 1 Restart Attempt Failed
23 3. Stability Plot for Loss of Bipole with Delayed CAS Generation Tripping for Lower IPP DC Schedule IPP DC Schedule 1500MWIPP DC Schedule 1400MW * CAS Will Delay Generation Tripping for IPP DC Schedule 1400MW or Less
24 3. Delayed CAS Generation Tripping for Loss of 1 Pole Short Term Overload Capability of IPP DC
25 3. Delayed CAS Generation Tripping for Loss of 1 Pole (IPP AC Fault Trip 1 Unit + MWC Generations) Delayed Tripping * CAS Will Delay Generation Tripping for Loss of 1 Pole Fast TrippingNo RAS
26 3. IPP CAS Generation Tripping Level Operating Nomogram for Bipole Operation for the Loss of Bipole
27 3. IPP CAS Generation Tripping Level Operating Nomogram for Bipole Operation for the Loss of 1 Pole
28 3. IPP CAS Generation Tripping Level Operating Nomogram for Mono-pole Operation for the Loss of 1 Pole
29 3. Study Summary IPP DC limited to net AC Import capability of 600MW under maximum Utah South export conditions CAS will Trip Units after 1 Restart Attempt Failed CAS will Delay Generation Tripping for IPP DC Schedule 1400MW or Less CAS will Delay Generation Tripping for Loss of 1 Pole - Limited by Voltage Deviations
30 4. System Design
31 4. System Design Design Philosophy 1. Meet the System Studies Guidelines 2. Insure Redundancy 3. Reduce the Hardware 4. Centralize the Logic
32 4. System Design Following the guidelines established by the system studies were the driving force in the design of the IPPSE. All parameters of the studies have been met which also allowed for a simpler more efficient design. Only 1 operational failure in 3 years is allowed.
33 4. System Design
34 4. System Design The Bipole Controls are a completely redundant Mach 2 Control System designed by ABB. All protection actions are routed through this control system. The IPPSE Logic is fully contained in this system thus reducing the system hardware requirements. All remedial outputs are generated from this control system.
35 4. System Design The remedials from the IPPSE Logic have been simplified into two outputs. Monopolar Out Bipolar Out Based on these two signals and the Nomograms, all IPPSE actions are appropriately taken.
37 4. System Design IPP Digital Microwave System Original analog system installed 1985 System was replaced with Harris Stratex (now Aviat Networks) digital microwave radios in 2004 LADWP operated and maintained
38 4. System Design IPP Microwave Power Redundancy Propane Back up Generators 24 VDC Power Plants
39 4. System Design IPP Microwave One Line
40 5. Arming Function
41 5. Arming Function Overview: Arming is automated by an application running in LADWPs energy management system. Nomograms, called charts, specify the arming level. Each chart has a series of curves that provide arming levels as a function of IPP net generation (including Milford generation) and the DC line flow. The application selects charts based on monitored power system conditions and the specific trigger being armed.
42 5. Arming Function Charts: One curve per remedial action. Arming is a function of net gen vs. DC flow. Top-most curve provides DC flow limit. Added remedial actions will require an increase in the number of curves per chart.
43 5. Arming Function Chart Sets: There may be up to five triggers for remedial actions. Each trigger has its own arming for remedial action. Therefore, there is one chart per trigger. The set of charts for the triggers is a chart set.
44 5. Arming Function Chart Set Selection: There are multiple chart sets to accommodate varying system conditions. Chart sets are functionally organized into rows and columns. Columns are selected based on monitored line flows. Rows are selected based on line outages and IPP operating modes.
45 5. Arming Function Chart Set Selection (contd): Original design provided for 24 columns. Although they no longer affect arming, three power flows are still monitored: Pacific AC Intertie, Arizona– California, and Utah South. The system study indicates nomogram sensitivity to Utah South power flow, so use of multiple columns may become necessary.
46 5. Arming Function Imports: Chart shows a 600-MW import limit. IPP AC lines have 1317-MW import capability. Chart is worst- case scenario. Other cases allow more imports.
47 5. Arming Function Import Example: A 72-MW on Sigurd–Three Peak may allow a 400-MW in imports. This can be implemented via multiple columns or via dynamic shifting of affected curves.
48 5. Arming Function Summary of Arming Function Changes: Increase in the number of curves per chart due to increase in number of remedial actions. Decrease in the number of charts per chart set due to decrease in the number of triggers. Increase in the number of chart set columns and/or addition of dynamic curve adjustments due to varying AC import limits depending on Utah South flow.
49 6. Monitoring and Operation
50 6. Monitoring and Operation Overview: LADWPs Energy Control Center (ECC) and IPP both have monitoring capability. The arming application runs at the ECC, but either site can arm manually. Except for automatic arming, the RAS operation occurs entirely at IPP, but is monitored by both sites. The slides that follow show monitoring and operation as seen at the ECC.
51 6. Monitoring and Operation The interface at the ECC includes the following displays: Curves & DC Limits Columns & Charts Panel Status (i.e. RAS Status) Annunciators These displays are summarized and shown in the slides that follow.
52 6. Monitoring and Operation Curves & DC Limits: Shows summary data in upper-right corner. Provides for viewing and update of curves and charts. Shows remedial action selected for each active chart. Shows DC limits from charts and other nomograms.
53 6. Monitoring and Operation Curves & DC Limits Display
54 6. Monitoring and Operation Changes to Curves & DC Limits: System studies do not show a need for separate nomograms for DC limits from Utah North, Utah South, or Northeast/Southeast flows. DC limit for power flows flow will be inherent in the contingency arming limit from the selected charts. Dynamic offsets to curve data, when implemented, will be shown on this display.
55 6. Monitoring and Operation Columns & Charts: Shows power flows for chart set column selection. Shows line status. Shows plant operating mode. Shows column and chart set selection in the summary data in the upper-right corner.
56 6. Monitoring and Operation Columns & Charts Display
57 6. Monitoring and Operation Changes to Columns & DC Charts: Column selection is no longer influenced by Pacific AC Intertie and Arizona–California flows. Additional columns may be needed to model the effects of Utah South flow on AC import capability.
58 6. Monitoring and Operation Panel Status: The RAS is currently implemented at IPP via redundant hardware systems called panels. Each arming control point is wired to operate both panels from a single control operation. Each panel independently reports its status. Arming controls can be issued via the arming application or manually via SCADA control actions.
59 6. Monitoring and Operation Panel Status (contd): Provides a control and pair of state indications for each combination of trigger and remedial action that may be armed. Provides for manual entry of an arming pattern when in MANUAL mode and shows the application-determined arming pattern when in AUTOMATIC mode. Shows panel status values. Shows triggers actuated. When a trigger is actuated, the RAS will execute any remedial actions armed for that trigger.
60 6. Monitoring and Operation Panel Status Display
61 6. Monitoring and Operation Changes to Panel Status: The application currently implements the arming matrix by using an obscure feature to control multiple arming state points with a single control operation. (This is much quicker than using time-consuming discrete control actions for each arming state point.) This set of arming state points to specify remedial actions for each trigger will be replaced with a single analog point for each trigger that specifies the remedial actions to execute. The RAS implementation will be part of the DC control system.
62 6. Monitoring and Operation Annunciator Displays: The RAS trigger inputs are actually aggregations of multiple triggering inputs from relay and DC control systems. For this reason, the RAS trigger inputs are in some places called super triggers. The annunciator displays show each trigger input and identify the super triggers that it activates.
63 6. Monitoring and Operation Annunciator Display 1
64 6. Monitoring and Operation Annunciator Display 2
65 6. Monitoring and Operation Annunciator Changes: According to system studies, many of the triggering inputs will no longer require remedial actions. Only triggering inputs for monopole and bipole blocks will continue to be relevant. The number of super triggers needed will reduce from five to two. The triggering inputs no longer requiring remedial action may be retained on the annunciator displays for reference.
66 6. Monitoring and Operation Summary of Monitoring and Operation Changes: The RAS function will be located in the DC control system. Arming will be specified via analog arming levels rather than discrete digital states. Arming may use real-time power flow to bias affected nomogram curves. Additional remedial actions are being added. The inputs that affect remedial action arming and execution are being updated according to study results.
67 7. Operating Procedure for Abnormal System Conditions
68 7. Operating Procedures for Abnormal System Conditions The RAS operates incorrectly (failure to operate or false operation) As soon as the IPPSE has failed or operated improperly, generation and DC flows will be curtailed to a point where remedial action is not required. The condition will be maintained until repairs can be made or the RAS is proven to be stable.
69 7. Operating Procedures for Abnormal System Conditions One part of a redundant RAS system is unavailable so that complete redundancy is no longer assured Personnel will be dispatched immediately to work on the unavailable system to restore it to operational status as soon as possible. Curtailment is not required in this condition.
70 7. Operating Procedures for Abnormal System Conditions When unscheduled, or unplanned and not coordinated, unavailability of the subject RAS (complete loss of RAS) impacts operation Generation and DC flows will be curtailed to a point where RAS is not required or until such time as the RAS becomes available again.
71 7. Operating Procedures for Abnormal System Conditions When a partial or total loss of input data required for arming decisions All input data required for arming originates from Intermountain Converter Station (ICS) and Intermountain Generating Station (IGS). The ICS operator will manually set the proper arming as directed by the Energy Control Center (ECC). The ICS operator has the ability to determine and set proper arming independent of ECC.
72 8. Commissioning, Maintenance and Testing
73 8. Commissioning, Maintenance, and Testing Commissioning Testing of the IPPSE Logic will begin during the Factory Acceptance Tests in Sweden. This will begin in May Commissioning of the new system will begin in October of 2010 when the first Mach 2 control comes on line. The IPPSE system will be fully operational by Mid December 2010.
74 8. Commissioning, Maintenance, and Testing Maintenance All critical components such as communication links, test switches and computers are monitored by the new Alarm Reporting and Monitoring System (ARMS) Emergency maintenance can be done on line without degrading the system. Only redundancy will be lost. Scheduled Maintenance is every 2 years.
75 8. Commissioning, Maintenance, and Testing Testing Testing will be End to End, from ECC to the Generator and Milford Intermountain Line 1 Blocking Switches. Each arming level in the Nomograms will be tested to assure that the proper remedial is sent to the blocking switch. All intermediate signals, remedial outputs and trip signals will be recorded for analysis.
76 9. Conclusions
77 9. Conclusions System Studies Guidelines System studies were extensive and the results were incorporated into the system design. All system hardware and software is monitored for correct operation.
78 9. Conclusions Redundancy All Protections, Control Systems, Communication Systems and Monitoring Systems are completely redundant.
79 9. Conclusions Reduce and Simplify the Hardware The input triggers have been reduced from 19 to 2. The Nomograms have been reduced from 38 to 3.
80 9. Conclusions Centralize the Logic All IPPSE Logic is now contained in the HVDC Mach 2 control system.