Real-Time Models for Real-Time Analysis. Motivation

Transcription

1 Real-Time Models for Real-Time nalysis Jamie Weber, Ph.D. Director of Operations, PowerWorld Corp. powerworld.com (217) , ext 13 1 Motivation Power flow studies are done using a different model than is used in real-time modeling On-line power flow study tools do not match planning study tools EMS Systems can spit-out a planning-like model, but mapping data to this model is manual Topology is constantly changing so keeping up with real-time is not reasonable lso, PowerWorld Simulator has features that online tools do not have Conditional Contingency ctions (for RS) Much easier to use and interpret results (especially when you have a limited time to make decisions) 2 1

2 Problem with Spit-out of Planning Model from an EMS System Due to breaker status, a substation may end up with one 115 kv bus, or maybe 8 different 115 kv buses Results in different bus numbers, names, etc every time Trying to match a planning contingency description to this ever-changing model is futile 3 Conceptual Problem You re trying to convert the data to what is needed by another piece of software This inevitably leads to an ongoing maintenance task EMS data is already a heavy maintenance task that has to be done to operate the system we can t change this Don t change your data, change your software 4 2

3 PowerWorld s Solution: Don t change your data, Change your software Build a model in PowerWorld that models everything that the EMS models. Every breaker is modeled as a zero-impedance branch Model will be huge, but for modern computers this isn t a problem lso, PowerWorld s filtering, and graphical interface make dealing with a large model much more manageable. 5 dvantages of PowerWorld s Solution Building an identical EMS model can be done programmatically No human intervention of matching names, numbers, etc.. No decisions about what to keep keep EVERYTHING Write software that queries your EMS system and builds an exact replica of the model Generate a PowerWorld uxiliary file including Interfaces Injection Groups Contingencies (including conditional RS) Model Conditions, Model Filters, etc More Don t change your data, Change your software 6 3

4 Problem Encountered Initial we experimented with solving the full topology model bout 75% of branches are zero-impedance branches Makes for a very large case Problem encountered: Solution Speed Solution was successful However, the speed was not very good Solution: Topology Processing Don t change your data, Change your software 7 Solution to Problem: Topology Processing Bring the topology processing inside of PowerWorld (PowerWorld handles two power system models simultaneously) Full Topology Model Consolidated Model Presently the user must perform the Topology Process via a dialog Eventually we will handle this automatically with little user-intervention Don t change your data, Change your software 8 4

5 mps mps mps MV MV mps MV mps mps MV mps mps mps mps Example Substation: Scobie Full Topology SCOBIE SCOBIE_345_7 SCOBIE_345_18 SCOBIE_345_19 SCOBIE_345_4 SCOBIE_345_21 SCOBIE_345_9999 SCOBIE_345_3 SCOBIE_345_6 SCOBIE_345_5 SCOBIE_345_23 SCOBIE_345_22 SCOBIE_345_2 SCOBIE_345_37 SCOBIE_345_8 SCOBIE_1_32 SCOBIE_115_38 41 nodes 36 energized, 5 disconnected SCOBIE_13.8_29 SCOBIE_13.8_36 SCOBIE_13.8_35 SCOBIE_115_25 SCOBIE_13.8_30 SCOBIE_13.8_31 SCOBIE_115_ Mvar 0.0 Mvar SCOBIE_115_46 SCOBIE_115_41 SCOBIE_115_14 SCOBIE_115_9 SCOBIE_115_11 SCOBIE_115_42 SCOBIE_115_26 SCOBIE_115_40 SCOBIE_115_45 SCOBIE_115_27 SCOBIE_115_33 SCOBIE_115_43 SCOBIE_115_9997 SCOBIE_115_15 SCOBIE_115_44 SCOBIE_115_12 SCOBIE_115_34 SCOBIE_115_16 8 MW 0 Mvar Don t change your data, Change your software 9 Close-up of 115 kv nodes Could be up to 7 energized 115 kv buses Only 2 in this example, but all depends on breaker status IE_1_32 SCOBIE_115_38 MV SCOBIE_115_46 SCOBIE_115_41 SCOBIE_115_14 SCOBIE_115_9 SCOBIE_115_11 SCOBIE_115_42 SCOBIE_115_25 SCOBIE_115_26 SCOBIE_115_9997 SCOBIE_115_27 SCOBIE_115_40 SCOBIE_115_45 SCOBIE_115_33 SCOBIE_115_43 SCOBIE_115_15 SCOBIE_115_12 SCOBIE_115_44 SCOBIE_115_13 SCOBIE_115_34 SCOBIE_115_16 Don t change your data, Change your software10 5

6 Example Substation: Scobie In Consolidated Case 10 buses 5 energized 5 disconnected Don t change your data, Change your software11 Example Case Statistics Full-Topology Model has 10,437 nodes 9,653 energized (786 disconnected) fter Consolidation, case has 2,366 1,647 energized (719 disconnected) Total is 4.4 times fewer Energized Total is 5.8 times fewer Don t change your data, Change your software12 6

7 Topology Processing Dialog Must specify which branches to maintain and which to throw out Maintain interfaces branches Maintain contingency branches Throw out low impedance branches that represent ties Don t change your data, Change your software13 Continuing Work Keeping all the breakers that are involved in a contingency can result in a large amount of extra nodes We are looking into performing Incremental Topology Processing Throw out breakers involved in contingency Then dynamically add them back in only for the contingency that needs them Each contingency may add back in several nodes that are needed Don t change your data, Change your software14 7