1 / 15

Donald Davies Chief Senior Engineer

Donald Davies Chief Senior Engineer. White Paper: Recognition of Power Plant Control, Protection, and Operation in Transmission System Simulation Studies October 24, 2013 Operations Committee Meeting, Anaheim. White Paper Overview. Categories of events and conditions related to tripping

jemima
Download Presentation

Donald Davies Chief Senior Engineer

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Donald DaviesChief Senior Engineer White Paper: Recognition of Power Plant Control, Protection, and Operation in Transmission System Simulation Studies October 24, 2013 Operations Committee Meeting, Anaheim

  2. White Paper Overview • Categories of events and conditions related to tripping • Generator trips versus turbine trips • Issues related to plant representation in studies • Control issues for each major technology type

  3. Background • NERC/FERC report on September 8 outage Finding and Recommendation 21 identifies trips related to turbine control as an issue • The WECC Response O&P19 indicated that CWG and WECC would develop a white paper to identify issues involved. • Develop joint understanding between plant and transmission communities of capabilities and limitations.

  4. Event/Condition Categories • Mandatory Immediate trip – regardless of transmission system conditions • Plant is unable to provide desired response due to inherent physical characteristics, • Plant could respond but only with significant cumulative equipment damage or by compromising plant stability • Plant can respond but only at high immediate monetary and/or environmental cost

  5. Overriding Priorities • Safety of Personnel • Avoid immediate equipment damage • Minimize cumulative equipment damage • Safety issues/immediate damage prevented through automatic protections in the primary plant controls • Margin/cost/environmental situations mitigated by standing orders and operator action

  6. Electrical vs Other • Electrical generator trips initiated outside of the plant • Event may disturb conditions in the plant so non-electrical actions must act to protect key plant elements.

  7. Grid Studies • Many important plant functions not modeled in grid studies, other functions depend upon control room operators. • Plant issues affect plant operation • Maintenance • Recent history (e.g. recent start) • Problems in the plant (i.e. leaking valve) • Judgment, sensitivity studies needed

  8. Large Steam Plant • Large amounts of stored energy • Over-speed protection needed – potential catastrophic consequences • Cannot rely on breaker status • Signals directly available to turbine protection system • Rapid valve closure essential, triggers include: • Turbine acceleration exceeds a threshold • Turbine power minus electrical power exceeds a threshold (approx 40% of rated turbine power)

  9. Large Gas Turbine • Electrical load changes: • Less issue with overspeed • Combustion stability issues • Temperature control issues – operated near limits • Turbine must act first to ensure internal stability and controllability, may result in: • Large change in turbine power • Emissions, efficiency compromises

  10. Large Gas Turbine • Frequency response • Low frequency results in reduced air flow, increased temperature. • Reduce fuel flow proportional to frequency squared • Resulting decreased power output when an increase is desired

  11. Hydro Plants • Less concern about over-speed than steam plants • Governor limits over-speed • Hydro plant operational constraints: • Water levels in underground galleries • Flow change restrictions • Cavitation, rough running • Draft tube pulsation • Limitations on use of jet deflectors, bypass valves

  12. Second-Level Auxiliaries • Many motors • Cooling fans to hydraulic pressuring pumps • Fractional horsepower to many kilowatt • A routine disturbance immediately after another event or condition can result in auxiliary motors running slow or tripping, can result in a generator trip

  13. Converter Connected Generation • Less Experience with electronically connected generators than with direct connected (synchronous) generators. • Similar issues related to: • Over-speed • Auxiliaries • Expect higher sensitivity to high voltage, lower sensitivity to low voltage and frequency

  14. Conclusions • Could include individual protections such as over-speed protection • Impractical to describe individual details for each power plant • Power plants must protect themselves, may require generator tripping – proper operation is the responsibility of plant owners • Non-electrical protections cover diverse physical situations, often cannot coordinate with transmission protection

  15. Donald Davies donald@wecc.biz Questions?

More Related