Automatic fault location system
First Claim
1. A fault location system for locating a fault associated with one or more conductors of an electric power transmission or distribution system, comprising:
- a first transducer set for measuring a first voltage (VA) and a first current (IA), at a first prescribed location on at least one conductor;
a second transducer set for measuring a second voltage (VB) and a second current (IB) at a second prescribed location on said at least one conductor;
(c) a first relay, coupled to said first transducer set, for generating data (VAf, IAf), indicative of an amplitude and phase of said first voltage and current;
(d) second relay, coupled to said second transducer set, for generating data VBf, IBf) indicative of an amplitude and phase of said second voltage and current; and
(e) a fault location estimation processor, coupled to said first and second relays, for generating a fault location parameter m indicative of the location of the fault;
wherein m is obtained from one of the following equations;
##EQU8## wherein δ
represents a phase difference between said first and second voltages, A is a real number having a value which is a first predetermined function of IAf and a resistance and reactance of said at least one conductor, B is a real number having a value which is a second predetermined function of IAf and said resistance and reactance of said at least one conductor, C is a real number having a value which is a first predetermined function of IBf and said resistance and reactance of said at least one conductor; and
D is a real number having a value which is a fourth predetermined function of IBf and said resistance and reactance of said at least one conductor.
1 Assignment
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Accused Products
Abstract
A fault location system comprises voltage/current transducers 10A, 10B located at terminals A and B, respectively; digital relays 12A and 12B respectively coupled to transducer blocks 10A and 10B; and a fault location estimation processor 14, which may comprise a substation controller at substation SA or substation SB, a relay at A or B, a stand alone computer at A or B, or a computer at a central location. The digital relays receive analog voltage and current signals (VA, IA, VB, IB) from the respective transducers and output digital phasor or oscillographic data to the fault location estimation block. The fault location estimation block is programmed to provide the fault location parameter m. The fault location estimation provided by the inventive technique is unaffected by the fault resistance, load current, mutual coupling effects from a parallel line, uncertainties in zero sequence values, shunt elements, and X/R characteristic of the system. The fault location can be estimated accurately even in cases of substantial resistance and load flow. In addition, the invention does not require synchronization of the data received from the respective A and B terminals, nor does it require pre-fault data or fault type selection.
92 Citations
6 Claims
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1. A fault location system for locating a fault associated with one or more conductors of an electric power transmission or distribution system, comprising:
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a first transducer set for measuring a first voltage (VA) and a first current (IA), at a first prescribed location on at least one conductor; a second transducer set for measuring a second voltage (VB) and a second current (IB) at a second prescribed location on said at least one conductor; (c) a first relay, coupled to said first transducer set, for generating data (VAf, IAf), indicative of an amplitude and phase of said first voltage and current; (d) second relay, coupled to said second transducer set, for generating data VBf, IBf) indicative of an amplitude and phase of said second voltage and current; and (e) a fault location estimation processor, coupled to said first and second relays, for generating a fault location parameter m indicative of the location of the fault;
wherein m is obtained from one of the following equations;
##EQU8## wherein δ
represents a phase difference between said first and second voltages, A is a real number having a value which is a first predetermined function of IAf and a resistance and reactance of said at least one conductor, B is a real number having a value which is a second predetermined function of IAf and said resistance and reactance of said at least one conductor, C is a real number having a value which is a first predetermined function of IBf and said resistance and reactance of said at least one conductor; and
D is a real number having a value which is a fourth predetermined function of IBf and said resistance and reactance of said at least one conductor. - View Dependent Claims (2, 3, 5)
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4. A fault location system for locating a fault associated with one or more conductors of an electric power transmission or distribution system, comprising:
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(a) a first transducer set for measuring a first voltage (VA) and a first current (IA) at a first prescribed location on at least one conductor; (b) a second transducer set for measuring a second voltage (VB) and a second current (IB) at a second prescribed location on said at least one conductor; (c) a first relay, coupled to said first transducer set, for generating data (VAf, IAf) indicative of an amplitude and phase of said first voltage and current; (d) a second relay, coupled to said second transducer set, for generating data (VBf, IBf) indicative of an amplitude and phase of said second voltage and current; (e) a fault location estimation processor, coupled to said first and second relays, for generating a fault location parameter m indicative of the location of the fault and for determining whether compensation is required of parameter m to compensate for long conductors in the electric transmission or distribution system;
wherein m is obtained from one of the following equations;
##EQU10## wherein δ
represents a phase difference between said first and second voltages, A is a real number having a value which is a first predetermined function of IAf and a resistance and reactance of said at least one conductor, B is a real number having a value which is a second predetermined function of IAf and said resistance and reactance of said at least one conductor, C is a real number having a value which is a first predetermined function of IBf and said resistance and reactance of said at least one conductor, and D is a real number having a value which is a fourth predetermined function of IBf and said resistance and reactance of said at least one conductor.
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6. A fault location system for locating a fault associated with one or more conductors of an electric power transmission or distribution system, comprising:
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(a) a first transducer set for measuring a first voltage (VA) and a first current (IA) at a first prescribed location on at least one conductor; (b) a second transducer set for measuring a second voltage (VB) and a second current (IB) at a second prescribed location on said at least one conductor; (c) a first relay, coupled to said first transducer set, for generating data (VAf, IAf) indicative of an amplitude and phase of said first voltage and current; (d) a second relay, coupled to said second transducer set, for generating data (VBf, IBf) indicative of an amplitude and phase of said second voltage and current; (e) a fault location estimation processor, coupled to said first and second relays, for generating a fault location parameter m indicative of the location of the fault; and for determining whether compensation is required of parameter m to compensate for shunt elements in the electric transmission or distribution system;
wherein m is obtained from one of the following equations;
##EQU11## wherein δ
represents a phase difference between said first and second voltages, A is a real number having a value which is a tint predetermined function of IAf and a resistance and reactance of said at least one conductor, B is a real number having a value which is a second predetermined function of IAf and said resistance and reactance of said at least one conductor, C is a real number having a value which is a first predetermined function of IBf and said resistance and reactance of said at least one conductor, and D is a real number having a value which is a fourth predetermined function of IBf and said resistance and reactance of said at least one conductor.
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Specification