wesm
DESCRIPTION
WESMTRANSCRIPT
Trading Operations in the Philippine WESM
Philippine Electricity Market Corporation
Objectives Familiarize the participant with the WESM operations. Describe the responsibilities of the different entities involved,
specifically the Trading Participants, the Market Operator, and the System Operator.
Provide an overview of the scheduling and dispatch in WESM Establish the WESM Timetable Show an illustration of the dispatch implementation
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Introduction A clear definition and delineation of responsibilities are necessary to
ensure the reliable operation of the grid, especially with the Market Operator (MO) and the System Operator (SO) being two separate entities – Dispatch Protocol Issue 6.0
As a result, the WESM Manual on the Dispatch Protocol was formulated after rigorous discussions between MO and SO
The Dispatch Protocol Clearly establishes the WESM Timetable for the execution of
specific processes (WESM Rules 3.4.2 and 10.4.8.1) Establish scheduling and dispatch procedures to be followed in Normal Conditions Emergency Conditions that should be consistent with the WESM Timetable and features of the MMS
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Scheduling and Dispatch Procedures Prior to WESM Operations
Scheduling and dispatch of generating facilities were the sole responsibility of SO
SO was also responsible in demand forecasting Generating facilities were required to submit daily nominations of
capacities they want to be scheduled for dispatch on the following day
Regardless of contractual commitments of generating units, the SO shall prepare a day-ahead generating schedule using the nominations considering system conditions and requirements such as (1) load forecasts, (2) weather forecasts, (3) reliability and security standards, and (4) scheduled outages
Week-ahead nominations were also required by SO
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Scheduling and Dispatch Procedures Prior to WESM Operations
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System Operator
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Nomination of available capacities
Forecast of demand Scheduling - forecast (load and weather) - security and reliability - scheduled outages
Day –Ahead Schedules
The Day-Ahead schedules shall be implemented by SO subject to changes at real-time (forecast error, tripping, etc.)
Energy and Reserve
Scheduling and Dispatch upon Establishment of WESM Operations
WESM was established as the trading platform of energy transactions in grids with WESM operations (Luzon and Visayas)
WESM was also established as the central platform for the scheduling and dispatch of generating facilities with WESM operations
SO is still responsible in the dispatch of generating units at real-time
MO has the responsibility of forecasting demand, and prepares a Security Constrained Economic Dispatch (SCED) schedule of generators and loads based on the hourly demand bids and generation offers. MO also maintains a Market Network Model (MNM) which shall
be used by the Market Dispatch Optimization Model (MDOM), which shall be able to consider transmission constraints and losses
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Responsibilities in WESM’s Scheduling and Dispatch
The Market Operator (MO), System Operator (SO), and Trading Participants (TPs) are the three entities involved in the scheduling and dispatch of generating facilities in WESM
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MO Responsibilities in Scheduling and Dispatch
Maintenance of the Market Network Model (MNM) in coordination with the SO
Generation of dispatch schedules using the MDOM Transmittal of dispatch schedules to the SO for implementation
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SO Responsibilities in Scheduling and Dispatch
Submission of overriding constraints to ensure the reliable operation of the grid Outage Schedule - List of Equipment (e.g. generators, lines,
transformers, breakers, etc.) that will be out of service for a certain defined period.
Contingency List - List of Equipment enlisted for contingency analysis (As Per Grid Code: N-1 Contingency Requirement).
Security Limits - List of Generators and Branch Groups that will have its limits overridden for security purposes (e.g. MRU/testing/commissioning).
Transmission Limits - list of transmission capacities of lines and transformers to be consider in the scheduling process
Implementation of the dispatch schedules provided by MO Issuance of deviation report to MO (actual vs. schedule)
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TP Responsibilities in Scheduling and Dispatch
Submission of bids and offers to WESM consistent with the WESM Timetable
Comply to the dispatch instructions of SO
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Scheduling and Dispatch upon Establishment of WESM Operations
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WESM Timetable Trading activities in WESM operate at different time frames Week Ahead Projection (WAP) Day Ahead Projection (DAP) Hour-Ahead or Real-Time Dispatch (RTD) Real-Time Ex-post (RTX)
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WESM Timetable: WAP The Week-Ahead Projection (WAP) gives indicative hourly dispatch
schedules and spot prices for the next seven days Its results serve as a guide to the following entities Participants when bidding transactions in the market for the next
seven days SO in the determination of the cost impact of planned outages
It considers the following information, which shall be used by the Market Management System (MMS) to generate schedules Demand bids and energy offers from Trading Participants Demand forecasts Outage Schedules Security Limits Latest available system snapshot
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WESM Timetable: WAP WAP is executed every day to produce results for the next seven
days
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D-1 D D+1 D+2 D+3 D+4 D+5 D+6 D+7 D+8 D+9
TRADING DAYS
Execution of WAP at Day D
Study Period of WAP at Day D (From D+1 to D+7)
WESM Timetable: WAP WAP is executed at 0900H of each trading day
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TRADING HOURS
… 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 …
WAP Results and Analysis Coordination with SO
WAP Execution
Prior to 0900H, the following activities are made for D+1 to D+7 Gathering of weather
forecasts Preparation of
demand forecasts Submission or
revision of bids and offers
The latest information provided by SO prior to 0900H shall be used System Snapshot Outage Schedule Security Limit Transmission Limit Contingency List
Publish WAP Results in WEB
WESM Timetable: DAP The Day-Ahead Projection (DAP) gives indicative hourly dispatch
schedules and spot prices covering the succeeding hours of the day up to the end of the following day
It allows the SO to prepare a more accurate contingency plan for the relevant intervals
It considers the following information, which shall be used by the Market Management System (MMS) to generate schedules Demand bids and energy offers from Trading Participants Revisions of bids and offers for consideration in the DAP run can
be done until a cut-off time (four hours prior to the trading hour) Demand forecasts Outage Schedules Security Limits Latest available system snapshot
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WESM Timetable: DAP DAP is executed every four hours to produce results for the
succeeding hours until the end of the following day
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TRADING HOURS
… 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 …
0400H DAP 0800H DAP 1200H DAP 1600H DAP
The latest information provided by SO prior to each DAP run shall be used The latest bids and offers shall be used. Submission or revision of bids and offers
relevant to the succeeding hours can be made prior to the execution of the DAP run. Demand forecasts for each of the succeeding hours evaluated by the DAP run should be
provided prior to its execution. Revisions may still be implemented prior to the DAP run
DAP Results Analysis Coordination with SO
DAP Results Analysis Coordination with SO is done up until 1 hour after the DAP execution
WESM Timetable: DAP DAP Study Period
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DAP Run at Current Day “D”
Study Horizon From To
0400H 0500H of D 2400H of D 0800H 0900H of D 2400H of D 1200H 1300H of D 2400H of D+1 1600H 1700H of D 2400H of D+1 2000H 2100H of D 2400H of D+1 2400H 0100H of D+1 2400H of D+1
WESM Timetable: RTD The Hour-Ahead or Real-Time Dispatch publishes schedules that
shall be implemented by SO, and spot prices that shall be used in the settlement of market transactions
The RTD schedules are subject to the final screening of SO before a dispatch instruction is issued to a Trading Participant
The dispatch schedule is the target MW loading of all Trading Participants at the end of a trading interval
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WESM Timetable: RTD RTD is executed every 55th minute of the hour
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40 50 00 10 20 30 40 50 0 0 10 20 30 40 50 00 10 20 30 40
HH-2 HH-1 HH HH+1
RTD Execution for Trading Hour HH
The latest information provided by SO prior to each DAP run shall be used
Gate Closure for bids and offers
Target Interval HH
Trading Interval HH
Transmit RTD Schedules and MOT to SO
Publish results in WEB Dispatch Implementation
for HH to meet Target Schedule
WESM Timetable: RTX The Real-Time Ex-Post (RTX) represents the duration of the trading
interval It is not used by the SO in the dispatch implementation since it is
merely used for “price discovery”, in which its results represent the actual events that transpired for the duration of the trading interval
Its results are used to settle imbalances in the market (schedule vs. actual)
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WESM Timetable: RTX RTX is executed every 1st minute of the hour
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40 50 00 10 20 30 40 50 0 0 10 20 30 40 50 00 10 20 30 40
HH-2 HH-1 HH HH+1
RTX Execution for Trading Hour HH
The latest information provided by SO prior to each DAP run shall be used
Trading Interval HH
During Normal Conditions Majority of the day-to-day activities in the market fall under the
category of normal conditions
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WESM Tasks during Normal System Condition
Activities Procedure in the Dispatch Protocol
Responsible Group
MO SO
Bids and Offers Appendix A.1 X
Demand Forecasting Appendix A.2 X
Outage Scheduling Appendix A.3 X
Contingency Planning Appendix A.4 X
Pre-Dispatch Market Projections Appendix A.5 X
Real-Time Dispatch Schedule Appendix A.6 X
Dispatch Implementation Appendix A.7 X
System Status Report Appendix A.8 X
Post Dispatch Report Appendix A.9 X
Market Information Publication Appendix A.10 X
Daily Operational Report Appendix A.11 X X
During Emergency Conditions WESM Rules 6.3.1.1 states that an emergency condition is a
situation which has an adverse effect on electricity supply or which poses a significant threat to system security
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Classification of Emergency Events
Market Operations System Operations
Market Failure MMS Failure System Failure EMS Failure
Medium-term supply deficiency
Communication network Breakdown
Total system Collapse
Communication network Breakdown
Effects of force majeure events
Computer systems failure
Grid Islanding or Isolation
Computer systems failure
Site-related Emergencies
Multiple forced Outages
Site-related Emergencies
Threat to system Security
During Emergency Conditions WESM Rules 6.3.1.1 states that an emergency condition is a
situation which has an adverse effect on electricity supply or which poses a significant threat to system security
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WESM Tasks during Normal System Condition
Activities Procedure in the Dispatch Protocol
Responsible Group MO SO
System Emergency and Restoration -- X X Market Suspension and Intervention Appendix B.2 X EMS Disaster Recovery Procedures -- X MMS Disaster Recovery Procedures -- X Report and Documentation of Events -- X X
Sample Normal Dispatch Process
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FOR THE 0900H TARGET TRADING INTERVAL (08:01 AM UNTIL 09:00 AM)
SUBMISSION OF ENERGY OFFERS
7:00 AM 8:00 AM 9:00 AM
SUBMISSION OF SO OVERRIDING CONSTRAINTS
RTD WORKFLOW RUN FOR 0900H
Sample Normal Dispatch Process
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FOR THE 0900H TARGET TRADING INTERVAL (08:01 AM UNTIL 09:00 AM)
RTD SCHEDULES
MERIT ORDER TABLE
SYSTEM OPERATOR
TRADING PARTICIPANTS
A
B
C
D
FOR INFORMATION
FOR IMPLEMENTATION
FINAL DISPATCH INSTRUCTIONS WILL COME FROM SO
DEVIATIONS ARE REPORTED TO MO IN CONSIDERATION OF
NON-COMPLIANCE AND MUST-RUN UNITS
End of Presentation