1. Generator Management Relay
SR489
4/15/2017
Generator Management Relay
Protection, metering, and monitoring functions for generators.
Presented by:
John Levine, P.E.
Levine Lectronics and Lectric, Inc.

2. SR489
4/15/2017
Outline
Overview
Theory
Wiring
Security

3. What a Generator looks like
Generator Protection

4. Generator Protection

5. SR489
4/15/2017
Overview

6. Why Upgrade? Generator and Transformer
Existing generator and transformer protection (more than 5 years or non-digital) may:
Cause protection security issues
Tripping on through-faults, external faults, swings, load encroachment and energizing
May lack comprehensive monitoring and communications capabilities
Not provide valuable forensic info that can lead to rapid restoration
Not be up to ANSI/IEEE Standards!
Insurance, Asset Reliability and Personal Liability Issues
C37-102: Guide for the Protection of Synchronous Generators
C37.91: Guide for Transformer Protection

7. Generator Management Relay
SR489
4/15/2017
Generator Management Relay
Product Overview
Ideal Protection for Induction and Synchronous Generators at 25, 50 and 60Hz
Complete Generator Protection including:
Generator Stator Differential
2 or 3 Zone Distance Backup
100% Stator Ground
High speed sampling, 12 samples per cycle
Drawout Case Installation
Powerful Fault Recording: Waveform, Sequence of Events
Ethernet and Serial Communications
Metering of all important parameters

8. SR489
4/15/2017
Theory

9. SR489
4/15/2017
Show Generator Theory General Overview and Typical System from Training CD

10. Internal and External Short Circuits
SR489
4/15/2017
Generator Protection
Internal and External Short Circuits

11. Generator Protection Review
SR489
4/15/2017
Generator Protection Review
Abnormal Operating Conditions
Loss of Synchronism
Abnormal Frequency
Overexcitation
Field Loss
Inadvertent Energizing
Breaker Failure
Loss of Prime Mover Power
Blown VT Fuses
Open Circuits

12. Abnormal Operating Conditions
SR489
4/15/2017
Generator Protection
Abnormal Operating Conditions

13. PSRC = Power System Relay Committee
IEEE PSRC Survey
Conducted in early ’90s, showed many areas of protection lacking
Unwillingness to upgrade:
Lack of expertise
To recognize deficiency
To perform the work
“Generators don’t trip” (wrong)
Operating procedures will save the day
PSRC = Power System Relay Committee

14. ANSI/IEEE Standards Latest developments reflected in:
Std. 242: Buff Book
C37.102: IEEE Guide for Generator Protection
C37.101: IEEE Guide for AC Generator Ground Protection
C37.106: IEEE Guide for Abnormal Frequency Protection for Power Generating Plants
These are created/maintained by the IEEE PSRC & IAS
They are updated every 5 years

15. Small Machine Protection IEEE Buff Book
SR489
4/15/2017
Small Machine Protection IEEE Buff Book
32 Reverse Power
40 Loss of Excitation
51V voltage restraint
51G Ground overcurrent
87 Differential
Small – up to 1 MW to 600V, 500 kVA if >600V

16. Small Machine Protection IEEE Buff Book
SR489
4/15/2017
Small Machine Protection IEEE Buff Book
32 Reverse Power
40 Loss of Excitation
46 Negative Sequence
51V voltage restraint
51G Ground overcurrent
87 Differential
Medium – up to 12.5 MW

17. Small Machine Protection IEEE Buff Book
SR489
4/15/2017
Small Machine Protection IEEE Buff Book
32 Reverse Power
40 Loss of Excitation
46 Negative Sequence
49 Thermal Overload
51V voltage restraint
51G Ground overcurrent
64 Ground Relay
87 Differential
Large – up to 50 MW

18. Large Machine Protection IEEE C37.102
SR489
4/15/2017
Large Machine Protection IEEE C37.102
Unit Connected,
High Z Grounded
32 Reverse Power
40 Loss of Excitation
46 Negative Sequence
49 Thermal Overload
51V voltage restraint
51G Ground overcurrent
64 Ground Relay
87 Differential

19. SR489
4/15/2017
HYBRID SYSTEM

20. Protection Functions Protection Functions Include:
SR489
4/15/2017
Protection Functions
Protection Functions Include:
Generator Stator Differential
Backup Distance Protection
100% Stator Ground
Generator Unbalance
Loss of Excitation
Accidental Energization
Breaker Fail
Phase Overcurrent – Voltage Restraint
Neutral Inst. / Timed Overcurrent
Neg. Sequence Overcurrent
Under / Over Voltage
Under / Over Frequency
Generator Thermal Model
RTD Temperature
Overexcitation – Volts/Hertz

21. Generator Protection

22. Generator Protection with GSU Wrap PTs on Low Side

23. Generator Protection with GSU Wrap PTs on High Side

24. Generator Protection PTs on Low Side

25. Desirable Attributes - Generator
SR489
4/15/2017
Desirable Attributes - Generator
Reverse Power (32)
Should be sensitive to 0.05 pu to properly detect motoring in large steam turbines
Existing E/M and Static relays not sensitive enough
May cause shutdown difficulties
Negative Sequence (46)
Should be sensitive to low values to detect open poles/conductors on system after GSU
Long time low level events may cause excessive rotor heating, thermal tripping and damage rotor
100% Stator Ground (59N / 59D)
Protects all of the stator winding
Existing schemes typically only see 90%
Stop low level fault near neutral from degrading into a high level fault and causing large amounts of damage
Very secure

26. Desirable Attributes - Generator
SR489
4/15/2017
Desirable Attributes - Generator
Inadvertent Energizing (50/27)
High speed tripping of unit after breaker accidentally closed on dead machine, also pole flashover prior to syncing
Most existing schemes do not incorporate
Many schemes fail due to complexity (reliance on breaker auxiliary switches, yard distance relays, etc.
If breaker is not tripped rapidly, mechanical and electric damage can occur to machine in fractions of a second!
Pole flashovers must be cleared by high speed breaker failure, as the breaker is open!

27. Line – Ground faults – Delta Connected Generator
SR489
4/15/2017
Line – Ground faults – Delta Connected Generator

28. Line – Ground faults – Wye Connected Generator
SR489
4/15/2017
Line – Ground faults – Wye Connected Generator

29. Protection Functions Generator Stator Differential
SR489
4/15/2017
Protection Functions
Generator Stator Differential
Stator Phase Differential
Dual Slope Percent Restraint Operating Characteristic
Directional Supervision under saturation conditions
Distance Backup Protection
2 or 3 Zone Mho Distance Protection
Backup for primary line protection
Configurable Reach and Angle Distance Characteristic
Dual Slope Phase Differential
100% Stator Ground Protection
95% Fundamental OverVoltage
15% Third Harmonic UnderVoltage
Two Zone Distance Backup

30. Protection Functions Voltage Protection Current Protection
SR489
4/15/2017
Protection Functions
Voltage Protection
Phase Overvoltage
Phase Undervoltage
Neutral Overvoltage (fundamental)
Neutral Undervoltage (3rd Harmonic)
Voltage Phase Reversal
Current Protection
Phase, Ground and Negative Sequence Overcurrent Tripping
IEC, ANSI , IAC and Customizable Overcurrent Curves
Voltage Restraint increasing sensitivity under low voltage conditions
Voltage Restraint Overcurrent
Frequency Protection
Overfrequency
Underfrequency
Undervoltage Trip Curves 13

31. Protection Functions Thermal Protection Inadvertent Energization
SR489
4/15/2017
Protection Functions
Thermal Protection
Generator Thermal Model
RTD Alarming and Tripping
RTD Biased Thermal Model
Inadvertent Energization
Prevents Accidentally Closing a Stopped Generator onto a Live Line
Armed when Generator is Offline and Voltage is below a pre-set level
Thermal Model – Voltage Dependant Overload Curves
Loss of Excitation (show Training CD)
Uses Impedance Circle for loss of excitation detection
2 Zones for fault detection and control
Volt/Hertz (Overexcitation)
Detects changes in the Volts/Hertz ratio of the generator or associated transformer
Loss of Excitation 13

32. SR489
4/15/2017
Wiring

33. SR489
4/15/2017

34. SR489
4/15/2017

35. SR489
4/15/2017

36. SR489
4/15/2017

37. SR489
4/15/2017
Example

38. Security strategy – conforms to industry and regulated guidelines
SR489
4/15/2017
Enhanced Security
Prevents Unauthorized Access and Provide Traceability
Security Audit Trail
Date and time of hardware, firmware or setting changes to your relays
Logging of the MAC address of computers and users making settings changes
Track method of how settings changes were made (i.e. keypad, serial port, ethernet)
Date/time security report was generated
Description of the GE Multilin Relay
Summary of the last time the configuration was changed
History of last 10 occurrences the configuration was changed
Security strategy – conforms to industry and regulated guidelines

39. Questions?
SR489
4/15/2017