59th Annual Conference for Protective Relay Engineers, 2006.
... PMU Now that the a clearer vision of the use of synchrophasor data for wide area monitoring, ... more ... PMU Now that the a clearer vision of the use of synchrophasor data for wide area monitoring, protection and ... Connections to the PMU are also a consideration. ... The basic functions of the PMU are to sample and process the analog data, compute the positive sequence phasor ...
Page 159. 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. ... more Page 159. 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITAL FAULT RECORD The application of the fault recording function to the pro-tective relay has considerably ...
This paper introduces the logical "next step" in the evolution of P&C implement... more This paper introduces the logical "next step" in the evolution of P&C implementation a bridge between today's conventional substation and tomorrow's IEC 61850 substation. It will introduce the concept of application building using a library of discrete software protection, control, communication, and logic function blocks that are based upon the IEC 61850 logical node. Using a graphical user interface tool
The reliable performance of faulted phase selectors to identify the faulted phase or phases and a... more The reliable performance of faulted phase selectors to identify the faulted phase or phases and appropriately block or permit tripping is critical to the application of distance protection. The most difficult fault type to identify correctly is a two-phase-to-ground fault. Incorrect detection methods of this fault type has lead to undesired overreaching and/or tripping for remote two-phase-to-ground faults beyond the underreaching zone reach setting. It is also important to provide accurate fault location and record correct faulted phase information after the fault has cleared to correctly access the fault type characteristics. This paper analyzes the issues related to two-phase-to-ground faults and discusses several methods used for faulted phase identification and the advantages and disadvantages of each. It also shows how different phase selection methods may be used to complement each other to provide more reliable faulted phase identification.
Line distance protection technology has evolved from sound operating principles using phase compa... more Line distance protection technology has evolved from sound operating principles using phase comparators used in electromechanical relays to the present day relays using microprocessor technology. Initial microprocessor relays used full cycle Discrete Fourier Transformation to extract the fundamental phasors from sampled analog data and apply them in comparator equations to determine impedance reach. This technique is still being used in most the modern microprocessor relays today. In order to address the effects of dc offset and CCVT transients a compromise is however required between operating speed, reach and security. Also, their performance is relatively independent of Source Impedance Ratio (SIR) once the transients have subsided, usually in two to three cycles. A totally different approach was introduced in 1997 using a time domain algorithm that mimics the operation of the electromechanical phase comparator. This algorithm proved to be one of the fastest and most secure for protection of medium and long lines typical for distance protection applications. The only compromise with this algorithm is the higher operating time for very short lines with high Source Impedance Ratios. This paper discusses the relative performances of each of the above approaches individually and about the advantages of combining the two algorithms to run in parallel.
2010 63rd Annual Conference for Protective Relay Engineers, 2010
This paper introduces the logical "next step" in the evolution of P&C implement... more This paper introduces the logical "next step" in the evolution of P&C implementation a bridge between today's conventional substation and tomorrow's IEC 61850 substation. It will introduce the concept of application building using a library of discrete software protection, control, communication, and logic function blocks that are based upon the IEC 61850 logical node. Using a graphical user interface tool
The present invention is directed to a method and apparatus for improving operational reliability... more The present invention is directed to a method and apparatus for improving operational reliability during a loss of a phase voltage (LOV) in a multi-phase power system, wherein a voltage representative of the LOV phase is calculated. The representative voltage is used for computing a reference polarizing voltage suitable for a protection unit.
2008 61st Annual Conference for Protective Relay Engineers, 2008
Line distance protection technology has evolved from sound operating principles using phase compa... more Line distance protection technology has evolved from sound operating principles using phase comparators used in electromechanical relays to the present day relays using microprocessor technology. Initial microprocessor relays used full cycle Discrete Fourier Transformation to extract the fundamental phasors from sampled analog data and apply them in comparator equations to determine impedance reach. This technique is still being used in most the modern microprocessor relays today. In order to address the effects of dc offset and CCVT transients a compromise is however required between operating speed, reach and security. Also, their performance is relatively independent of Source Impedance Ratio (SIR) once the transients have subsided, usually in two to three cycles. A totally different approach was introduced in 1997 using a time domain algorithm that mimics the operation of the electromechanical phase comparator. This algorithm proved to be one of the fastest and most secure for protection of medium and long lines typical for distance protection applications. The only compromise with this algorithm is the higher operating time for very short lines with high Source Impedance Ratios. This paper discusses the relative performances of each of the above approaches individually and about the advantages of combining the two algorithms to run in parallel.
2008 61st Annual Conference for Protective Relay Engineers, 2008
The reliable performance of faulted phase selectors to identify the faulted phase or phases and a... more The reliable performance of faulted phase selectors to identify the faulted phase or phases and appropriately block or permit tripping is critical to the application of distance protection. The most difficult fault type to identify correctly is a two-phase-to-ground fault. Incorrect detection methods of this fault type has lead to undesired overreaching and/or tripping for remote two-phase-to-ground faults beyond the underreaching zone reach setting. It is also important to provide accurate fault location and record correct faulted phase information after the fault has cleared to correctly access the fault type characteristics. This paper analyzes the issues related to two-phase-to-ground faults and discusses several methods used for faulted phase identification and the advantages and disadvantages of each. It also shows how different phase selection methods may be used to complement each other to provide more reliable faulted phase identification.
2012 65th Annual Conference for Protective Relay Engineers, 2012
TVA applies shunt capacitor banks to their 161 kV system to regulate the local substation bus vol... more TVA applies shunt capacitor banks to their 161 kV system to regulate the local substation bus voltage over a range of light to heavy load and load switching conditions. The substation capacitor bank configuration may consist of up to 6 separately switched capacitor stacks. The entire substation bank is switched with a circuit breaker. The voltage level is monitored and
2009 62nd Annual Conference for Protective Relay Engineers, 2009
Transmission lines that are terminated into transformers are applications where the line and tran... more Transmission lines that are terminated into transformers are applications where the line and transformer cannot be separated by a circuit breaker and are therefore in the same zone of protection. These applications may be addressed with either current differential or line distance protection. In either case the implementation of separate transformer differential protection isolating the protection zone is recommended. The
2014 67th Annual Conference for Protective Relay Engineers, 2014
Ferroresonance is a widely studied phenomenon but it is still not well understood because of its ... more Ferroresonance is a widely studied phenomenon but it is still not well understood because of its complex behavior. It is “fuzzy-resonance.” A simple graphical approach using fundamental frequency phasors has been presented to elevate the readers understanding. Its occurrence and how it appears is extremely sensitive to the transformer characteristics, system parameters, transient voltages and initial conditions. More efficient transformer core material has lead to its increased occurrence and it has considerable effects on system apparatus and protection. Power system engineers should strive to recognize potential ferroresonant configurations and design solutions to prevent its occurrence.
10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITA... more 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITAL FAULT RECORD The application of the fault recording function to the pro-tective relay has considerably increased the availability of data for system disturbance analysis ...
The paper discusses phase comparators, magnitude comparators and their applications in the design... more The paper discusses phase comparators, magnitude comparators and their applications in the design of a new high-speed microprocessor distance relay. Regarding ground distance units and phase-to-phase distance units, the torque created by a phase comparator or a magnitude comparator is described in terms of fault impedance and source impedance ratios. Both phasor- and time-domain approaches for computing torque are described.
1999 IEEE Transmission and Distribution Conference (Cat. No. 99CH36333), 1999
The paper discusses phase comparators, magnitude comparators, and their applications in the desig... more The paper discusses phase comparators, magnitude comparators, and their applications in the design of a high-speed microprocessor distance relay. Regarding ground distance units and phase-to-phase distance units, torque created by phase comparators and magnitude comparators is described in terms of fault impedance and source impedance ratios. Both long- and short-data window approaches for computing torque are described. Post-filters which process torque are utilized to ensure speed and security of the high-speed distance relay. Finally, typical test results of the high-speed distance relay tested on a model power system and digital fault record data from the relay are presented.
59th Annual Conference for Protective Relay Engineers, 2006.
... PMU Now that the a clearer vision of the use of synchrophasor data for wide area monitoring, ... more ... PMU Now that the a clearer vision of the use of synchrophasor data for wide area monitoring, protection and ... Connections to the PMU are also a consideration. ... The basic functions of the PMU are to sample and process the analog data, compute the positive sequence phasor ...
Page 159. 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. ... more Page 159. 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITAL FAULT RECORD The application of the fault recording function to the pro-tective relay has considerably ...
This paper introduces the logical "next step" in the evolution of P&C implement... more This paper introduces the logical "next step" in the evolution of P&C implementation a bridge between today's conventional substation and tomorrow's IEC 61850 substation. It will introduce the concept of application building using a library of discrete software protection, control, communication, and logic function blocks that are based upon the IEC 61850 logical node. Using a graphical user interface tool
The reliable performance of faulted phase selectors to identify the faulted phase or phases and a... more The reliable performance of faulted phase selectors to identify the faulted phase or phases and appropriately block or permit tripping is critical to the application of distance protection. The most difficult fault type to identify correctly is a two-phase-to-ground fault. Incorrect detection methods of this fault type has lead to undesired overreaching and/or tripping for remote two-phase-to-ground faults beyond the underreaching zone reach setting. It is also important to provide accurate fault location and record correct faulted phase information after the fault has cleared to correctly access the fault type characteristics. This paper analyzes the issues related to two-phase-to-ground faults and discusses several methods used for faulted phase identification and the advantages and disadvantages of each. It also shows how different phase selection methods may be used to complement each other to provide more reliable faulted phase identification.
Line distance protection technology has evolved from sound operating principles using phase compa... more Line distance protection technology has evolved from sound operating principles using phase comparators used in electromechanical relays to the present day relays using microprocessor technology. Initial microprocessor relays used full cycle Discrete Fourier Transformation to extract the fundamental phasors from sampled analog data and apply them in comparator equations to determine impedance reach. This technique is still being used in most the modern microprocessor relays today. In order to address the effects of dc offset and CCVT transients a compromise is however required between operating speed, reach and security. Also, their performance is relatively independent of Source Impedance Ratio (SIR) once the transients have subsided, usually in two to three cycles. A totally different approach was introduced in 1997 using a time domain algorithm that mimics the operation of the electromechanical phase comparator. This algorithm proved to be one of the fastest and most secure for protection of medium and long lines typical for distance protection applications. The only compromise with this algorithm is the higher operating time for very short lines with high Source Impedance Ratios. This paper discusses the relative performances of each of the above approaches individually and about the advantages of combining the two algorithms to run in parallel.
2010 63rd Annual Conference for Protective Relay Engineers, 2010
This paper introduces the logical "next step" in the evolution of P&C implement... more This paper introduces the logical "next step" in the evolution of P&C implementation a bridge between today's conventional substation and tomorrow's IEC 61850 substation. It will introduce the concept of application building using a library of discrete software protection, control, communication, and logic function blocks that are based upon the IEC 61850 logical node. Using a graphical user interface tool
The present invention is directed to a method and apparatus for improving operational reliability... more The present invention is directed to a method and apparatus for improving operational reliability during a loss of a phase voltage (LOV) in a multi-phase power system, wherein a voltage representative of the LOV phase is calculated. The representative voltage is used for computing a reference polarizing voltage suitable for a protection unit.
2008 61st Annual Conference for Protective Relay Engineers, 2008
Line distance protection technology has evolved from sound operating principles using phase compa... more Line distance protection technology has evolved from sound operating principles using phase comparators used in electromechanical relays to the present day relays using microprocessor technology. Initial microprocessor relays used full cycle Discrete Fourier Transformation to extract the fundamental phasors from sampled analog data and apply them in comparator equations to determine impedance reach. This technique is still being used in most the modern microprocessor relays today. In order to address the effects of dc offset and CCVT transients a compromise is however required between operating speed, reach and security. Also, their performance is relatively independent of Source Impedance Ratio (SIR) once the transients have subsided, usually in two to three cycles. A totally different approach was introduced in 1997 using a time domain algorithm that mimics the operation of the electromechanical phase comparator. This algorithm proved to be one of the fastest and most secure for protection of medium and long lines typical for distance protection applications. The only compromise with this algorithm is the higher operating time for very short lines with high Source Impedance Ratios. This paper discusses the relative performances of each of the above approaches individually and about the advantages of combining the two algorithms to run in parallel.
2008 61st Annual Conference for Protective Relay Engineers, 2008
The reliable performance of faulted phase selectors to identify the faulted phase or phases and a... more The reliable performance of faulted phase selectors to identify the faulted phase or phases and appropriately block or permit tripping is critical to the application of distance protection. The most difficult fault type to identify correctly is a two-phase-to-ground fault. Incorrect detection methods of this fault type has lead to undesired overreaching and/or tripping for remote two-phase-to-ground faults beyond the underreaching zone reach setting. It is also important to provide accurate fault location and record correct faulted phase information after the fault has cleared to correctly access the fault type characteristics. This paper analyzes the issues related to two-phase-to-ground faults and discusses several methods used for faulted phase identification and the advantages and disadvantages of each. It also shows how different phase selection methods may be used to complement each other to provide more reliable faulted phase identification.
2012 65th Annual Conference for Protective Relay Engineers, 2012
TVA applies shunt capacitor banks to their 161 kV system to regulate the local substation bus vol... more TVA applies shunt capacitor banks to their 161 kV system to regulate the local substation bus voltage over a range of light to heavy load and load switching conditions. The substation capacitor bank configuration may consist of up to 6 separately switched capacitor stacks. The entire substation bank is switched with a circuit breaker. The voltage level is monitored and
2009 62nd Annual Conference for Protective Relay Engineers, 2009
Transmission lines that are terminated into transformers are applications where the line and tran... more Transmission lines that are terminated into transformers are applications where the line and transformer cannot be separated by a circuit breaker and are therefore in the same zone of protection. These applications may be addressed with either current differential or line distance protection. In either case the implementation of separate transformer differential protection isolating the protection zone is recommended. The
2014 67th Annual Conference for Protective Relay Engineers, 2014
Ferroresonance is a widely studied phenomenon but it is still not well understood because of its ... more Ferroresonance is a widely studied phenomenon but it is still not well understood because of its complex behavior. It is “fuzzy-resonance.” A simple graphical approach using fundamental frequency phasors has been presented to elevate the readers understanding. Its occurrence and how it appears is extremely sensitive to the transformer characteristics, system parameters, transient voltages and initial conditions. More efficient transformer core material has lead to its increased occurrence and it has considerable effects on system apparatus and protection. Power system engineers should strive to recognize potential ferroresonant configurations and design solutions to prevent its occurrence.
10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITA... more 10 Protective Relay Digital Fault Recording and Analysis ELMO PRICE 1. INTRODUCTION 2. THE DIGITAL FAULT RECORD The application of the fault recording function to the pro-tective relay has considerably increased the availability of data for system disturbance analysis ...
The paper discusses phase comparators, magnitude comparators and their applications in the design... more The paper discusses phase comparators, magnitude comparators and their applications in the design of a new high-speed microprocessor distance relay. Regarding ground distance units and phase-to-phase distance units, the torque created by a phase comparator or a magnitude comparator is described in terms of fault impedance and source impedance ratios. Both phasor- and time-domain approaches for computing torque are described.
1999 IEEE Transmission and Distribution Conference (Cat. No. 99CH36333), 1999
The paper discusses phase comparators, magnitude comparators, and their applications in the desig... more The paper discusses phase comparators, magnitude comparators, and their applications in the design of a high-speed microprocessor distance relay. Regarding ground distance units and phase-to-phase distance units, torque created by phase comparators and magnitude comparators is described in terms of fault impedance and source impedance ratios. Both long- and short-data window approaches for computing torque are described. Post-filters which process torque are utilized to ensure speed and security of the high-speed distance relay. Finally, typical test results of the high-speed distance relay tested on a model power system and digital fault record data from the relay are presented.
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