An Introduction to Completing a NERC PRC Study

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1 An Introduction to Completing a NERC PRC Study For Synchronous and Distributed Generation Sources PRESENTED BY: MATTHEW MANLEY TEXAS A&M PROTECTIVE RELAYING CONFERENCE MARCH 26-29, 2018

2 Presentation Goals Describe the PRC reliability standard Overview a typical synchronous generation PRC-019 study Explain the impact of applying PRC-019 to include asynchronous generation facilities Show an interpretation of how to demonstrate compliance for asynchronous generation facilities Challenges and lessons learned 2

3 NERC Reliability Standards Developed in response to the 2003 Northeast United States Blackout Goal to improve the performance and reliability of the bulk electric power system (BES) Compliance requirements are typically clearly defined Protection and Control (PRC) 3

4 NERC PRC PRC-019-2: Coordination of Generating Unit or Plant Capabilities, Voltage Regulating, Controls, and Protection Rev. 2 adopted by NERC board of trustees Nov. 15 Purpose- verify coordination of generating unit facility or synchronous condenser voltage regulating controls, limit functions, equipment capabilities and protection system settings. 4

5 R1 R1 R The in-service limiters are set to operate before the Protection System of the applicable Facility in order to avoid disconnecting the generator unnecessarily The applicable inservice Protection System devices are set to operate to isolate or de-energize / equipment in order to limit the extent of damage when operating conditions exceed equipment capabilities or stability limits. Resubmit PRC documentation within 90 calendar days of applicable equipment or setting change PRC Requirements 5

6 P-Q Diagram R-X Diagram Inverse Time Diagram / Equivalent tables Examples of Coordination Evidence 6

7 Field overexcitation Inverter overcurrent Field underexcitation Generator reactive capabilities Volts per hertz limiter and protection functions Stator over-voltage protection / Generator volts per hertz capability Transformer volts per hertz capability Time vs. field current Time vs. stator current Examples of Equipment Capabilities, Limiters, and Protection Functions 7

8 Facility Data Collection Data Review Plot Data / Mitigate Non- Compliant Settings Write Report Describing Compliance Synchronous Generator Study Process 8

9 Generator capability Limiter settings Protection settings GSU & generator Volts/Hertz capabilities Voltage regulation system manual One and three line diagrams / Facility Data Required 9

10 Compliant P-Q Plot 10

11 Non-Compliant P-Q Plot 11

12 Suggested Settings P-Q Plot 12

13 Final Report All conclusions from study in single, cohesive report Progress from high-level summary to detailed discussion Report should assist in generating audit worksheet Report will have a range of audiences Document as-found and suggested settings if mitigation was necessary What about Asynchronous Generators? 13

14 Distributed or Asynchronous Generation Facilities Revision of the bulk electric power system (BES) definition Includes dispersed generating facilities as applicable facilities NERC PRC-019 Revision 2 Addition of identifies dispersed power producing resources, even where voltage regulating control is performed solely at the individual generating unit is included as applicable facilities. What are typical Asynchronous Generators? Solar PV Wind Turbines (Type I, II, III, IV) Synchronous vs. Asynchronous Generators 14

15 Asynchronous Facility Analysis Plant level controls Individual WTG Combined Generators 15

16 WTG diagram WTG characteristics Rotor power output limit Converter power output limit Short and long time total power output limits Main Breaker Protection Settings GSU protection settings / Individual WTG Data 16

17 Type I WTG TCC 17

18 Type III WTG TCC 18

19 Combined Generator Analysis Combined Generators 19

20 One and three line diagrams Feeder protection settings Collector/GSU protection settings VAR support protection settings Capacitor bank ratings / Combined WTG Data 20

21 Collector & GSU TCC 21

22 Plant Level Control Analysis Plant level controls 22

23 VAR Control Schemes Line Relays Trip GSU Offline WTG Trip Offline High Voltage Control (Trip Caps While In Band) 125% p.u. 120% p.u. 110% p.u. Feeder & GSU Short Time Overvoltage Trip Cap Bank, Feeder, & GSU Long Time Overvoltage Trip Fast Voltage Control Region 1.25 p.u. 1.2 p.u p.u. 1.1 p.u. WTG Inst Time Overvoltage Trip WTG Short Time Overvoltage Trip WTG Medium Time Overvoltage Trip WTG Long Time Overvoltage Trip Capacitors Online If Power Flow Is > 30 MW p.u. First Bank Switched In When VAR Control Region Real Power Flow > 45 MW) (If MW Output > 4.0) Second Bank Switched In When Power Flow > 70MW Slow Voltage Control Region Deadband Slow Voltage Control Region 1.01 p.u p.u p.u. 70.3% p.u. Fast Voltage Control Region 0.9 p.u. Capacitors Tripped Offline 0.8 p.u. Feeder Undervoltage Trip 0.5 p.u. Capacitor Undervoltage Trip 0% p.u. Power Flow Control Voltage Control 23

24 Voltage Coordination Plot 24

25 Challenges & Lessons Learned Regulatory Interpretation Justify your interpretation to compliance auditor Documentation requirements can vary by regulatory district Focus on walking compliance auditor through study process to arrive at the same conclusions 25

26 Challenges & Lessons Learned Data Availability Data lost, poor readability, or never delivered Atypical data forms Data required from manufactures considered proprietary Generation Owner/Operator Engineer Performing Study Generator Manufacturer 26

27 Challenges & Lessons Learned Additional Questions Coordination of volts/hertz protection of the GSU transformer GSU Volts/Hertz equipment capability Capacitor bank equipment capability Tolerance of VAR support system (demonstrate the active voltage band for control) Coordination graphs showing VAR/Voltage control scheme, relay settings, and relevant equipment capabilities. 27

28 Conclusions Plan Ahead Keep it Simple Take it Slow Combine Studies 28

29 Questions? 29