Sequence Data, Power Flow & Transient Stability (PF & TS)

1. Sequence Data, Power Flow & Transient Stability (PF & TS) MSRATF - July 10, 2013 Joe Seabrook

2. NERC MOD-B Development (May 9, 2013) • http://www.nerc.com/pa/Stand/Pages/MODBInformalDevelopmentProjectRF.aspx

3. MOD-B Proposed Approach (May 9, 2013) Proposed single modeling standard to combine and replace MOD-010 through MOD-015 • Requirement R1: provide steady-state, dynamics, and short circuit data to Planning Coordinator(s) and Transmission Planner(s) according to the data requirements specified in Attachment 1 and other criteria. • Attachment 1: Specifies a three column detailed matrix of data requirements for steady-state, dynamics, and short-circuit data

4. MOD-B Proposed Approach (May 9, 2013) Proposed single standard (R2): • Requirement R2: Provides a requirement for entities that submit data to provide correct data • Covers data sufficiency, usability, consistency, and accuracy • Tool for PC or TP in collecting data • Does not obligate a process to check/confirm data • Uses format similar to MOD-26-1 requirements (see, e.g., MOD-26-1, Requirement R3)

5. MOD-B Proposed Approach (May 9, 2013) Proposed single standard (R3): • Requirement R3: To facilitate creation of interconnection-specific models, a requirement for Planning Coordinator to submit data collected under Requirement R1 according to a (proposed) NERC list of modeling organizations (which are the organizations that currently exist) • Intended to create clear expectation that each Planning Coordinator will provide the data they collect under Requirement R1 according to an interconnection-specific process • Recognizes the differences among interconnections in model building process, but creates obligation for PC to provide the data in a manner that accounts for those differences. • Replaces MOD-014 and MOD-015

6. MOD-B Attachment 1 (June 17, 2013 conference)

7. MOD-B Attachment 1 (June 17, 2013 conference) • Positive Sequence Data – provide for all applicable elements in column “steady-state” • Negative Sequence Data – provide for all applicable elements in column “steady-state” • Zero Sequence Data – provide for all applicable elements in column “steady-state” Bus, Generator, Transmission line, Transformer (include connection type) • Mutual Line Impedance data Resistance, Reactance, Mutual Coupling Locations

8. Sequence Data in Transient Stability • WECC TSS/MSRATF - Represent the response of simulation programs to fault conditions through Relay and RAS models • TS fault simulation historically has been through pre-determined fault impedances and expected relay response. • Relay and RAS models will require fault detection and appropriate clearing • Will include all NERC standard faults (3Φ and 1Φ)

9. Sequence Data in Transient Stability • Negative and Zero sequence data is network data; R, X, B, connections • Machine models are + Sequence • Include features to approximate – and 0 sequence, like gen braking, or 1Φ motors • Simulation programs use sequence data to calculate fault currents in PF • Fault currents needed in TS

10. Sequence Data in Transient Stability • In TS, the + sequence network is solved each time step. • For Unbalanced Faults require • Negative and zero sequence currents at each time step • TS models of relays that trip breakers on negative and zero sequence currents • Common example: Directional zero sequence inverse time over-current relay – used for 1Φ faults

11. Sequence Data in Transient Stability • Simulation Programs would solve negative and zero sequence networks at each time step • Would provide access to sequence currents and voltages for relay actions • Would provide decaying fault currents from TS generator models and inverse time over-current relay responses