skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Characteristics of Vector Surge Relays for Distributed Synchronous Generator Protection

Abstract

This work presented a detailed investigation on the performance characteristics if vector surge relays to detect islanding of distributed synchronous generators. A detection time versus active power imbalance curve is proposed to evaluate the relay performance. Computer simulations are used to obtain the performance curves. The concept of critical active power imbalance is introduced based on these curves. Main factors affecting the performance of the relays are analyzed. The factors investigated are voltage-dependent loads, load power factor, inertia constant of the generator, generator excitation system control mode, feeder length and R/X ratio as well as multi-distributed generators. The results are a useful guideline to evaluate the effectiveness of anti-islanding schemes based on vector surge relays for distributed generation applications.

Authors:
; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
944774
Report Number(s):
PNNL-SA-48743
TD5008010
DOE Contract Number:
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Electric Power Systems Research, 77(2):170-180
Country of Publication:
United States
Language:
English
Subject:
Distributed Generation; Islanding Detection; Synchronous Generators; Vector Surge Relays; Vector Shift Relays

Citation Formats

Freitas, Walmir, Xu, Wilsun, Huang, Zhenyu, and Vieira, Jose C. Characteristics of Vector Surge Relays for Distributed Synchronous Generator Protection. United States: N. p., 2007. Web. doi:10.1016/j.epsr.2006.02.011.
Freitas, Walmir, Xu, Wilsun, Huang, Zhenyu, & Vieira, Jose C. Characteristics of Vector Surge Relays for Distributed Synchronous Generator Protection. United States. doi:10.1016/j.epsr.2006.02.011.
Freitas, Walmir, Xu, Wilsun, Huang, Zhenyu, and Vieira, Jose C. Wed . "Characteristics of Vector Surge Relays for Distributed Synchronous Generator Protection". United States. doi:10.1016/j.epsr.2006.02.011.
@article{osti_944774,
title = {Characteristics of Vector Surge Relays for Distributed Synchronous Generator Protection},
author = {Freitas, Walmir and Xu, Wilsun and Huang, Zhenyu and Vieira, Jose C.},
abstractNote = {This work presented a detailed investigation on the performance characteristics if vector surge relays to detect islanding of distributed synchronous generators. A detection time versus active power imbalance curve is proposed to evaluate the relay performance. Computer simulations are used to obtain the performance curves. The concept of critical active power imbalance is introduced based on these curves. Main factors affecting the performance of the relays are analyzed. The factors investigated are voltage-dependent loads, load power factor, inertia constant of the generator, generator excitation system control mode, feeder length and R/X ratio as well as multi-distributed generators. The results are a useful guideline to evaluate the effectiveness of anti-islanding schemes based on vector surge relays for distributed generation applications.},
doi = {10.1016/j.epsr.2006.02.011},
journal = {Electric Power Systems Research, 77(2):170-180},
number = ,
volume = ,
place = {United States},
year = {Wed Feb 28 00:00:00 EST 2007},
month = {Wed Feb 28 00:00:00 EST 2007}
}
  • This paper presents simple and reliable method for predicting the islanding detection performance of vector surge relays. The relay performance is characterized by a tripping-time versus power-imbalance curve. With the curve, one can determine the time taken by a vector surge relay to detect islanding for any generation-load mismatch level. The main contribution of this paper is the development of analytical formulas for directly determining the behavior of vector surge relays. As a result, efforts needed to asses the relay performance for a given distributed generation scheme can be simplified significantly. The accuracy of the formulas has been verified bymore » extensive simulation study results.« less
  • This paper presents a comprehensive comparative analysis between rate of change of frequency (ROCOF) and vector surge (VS) relays for distributed generation islanding detection. The analysis is based on the concepts of detection-time versus active power-imbalance curves and critical active power imbalance. Such curves are obtained through dynamic simulations. The performance of these devices considering different scenarios is determined and compared. Factors such as voltage-dependent loads, generator inertia constant and multi-distributed generator system are analyzed. False operation of these relays due to faults in adjacent feeders is also addressed. Results show that ROCOF relays are more reliable to detect islandingmore » than vector surge relays when the active power imbalance in the islanded system is small. However, ROCOF relays are more susceptible to false operation than vector surge relays.« less
  • This paper describes the protective relaying schemes employed by Georgia Power Company to protect synchronous generators from single-phase-to-ground faults. Three types of relays are connected in the secondary of a distribution grounding transformer. These include a conventional electromechanical overcurrent relay with time overcurrent unit and instantaneous overcurrent unit, a solid-state overvoltage relay (with timing module) tuned to reject frequencies near 180 hertz, and a solid-state undervoltage relay (with timer) tuned to reject frequencies near 60 hertz present at the generator neutral. The proper method of selecting the generator grounding components and protective relays is described, and detailed setting instructions formore » all relays are also included.« less
  • Generator withstand voltages, overvoltages from the power system and arrester capabilities are critically reviewed. The specified withstand is compared with tested breakdowns for some 248 coils in five large machines using dc, power frequency and impulses. System stresses normally prescribed to lightning are supplemented to include HV line faults, circuit breaker closing, reignitions and restrikes, fault clearing, arcing faults on the isolated phase bus, harmonic line resonance, ferroresonance, transformer HV to LV faults, the effects of stuck breaker poles and other contingencies. Internal winding stresses may be amplified due to resonance and slot reflection effects. The vulnerability of arresters tomore » temporary overvoltages is considered. The paper provides practical guidelines for the design of generator surge protection.« less
  • The use of microcomputers in synchronous generator protective systems along with other positive factors make it possible to achieve more sophisticated, and hence, more complicated algorithms to broaden the functions of protective equipment. The system described is the first digital protection system for a synchronous generator based on a general-purpose, mass-produced microcomputer. The design of the digital protection system is discussed.