Line phase-to-phase fault single-end distance measuring method based on distributed parameter measurement impedance amplitude value characteristics

Abstract

The invention discloses a line phase-to-phase fault single-end distance measuring method based on distributed parameter measurement impedance amplitude value characteristics. According to the line phase-to-phase fault single-end distance measuring method based on the distributed parameter measurement impedance amplitude value characteristics, a distributed parameter model is used as a physical model, a fault distance initial value is selected to be 1x, and the 1x is gradually increased by step length delta1, distributed parameter measurement impedance amplitude values z (1x) from each point on a power transmission line to a phase-to-phase fault point are calculated in sequence until the whole length of the power transmission line, the distance, corresponding to the distributed parameter measurement impedance amplitude value z (1x) in a minimum mode, at the point-distance power transmission line protection installing position is selected as the fault distance. According to the line phase-to-phase fault single-end distance measuring method based on the distributed parameter measurement impedance amplitude value characteristics, the distributed parameter model is used as the physical model; the line phase-to-phase fault single-end distance measuring method based on the distributed parameter measurement impedance amplitude value characteristics has a natural capacity for resisting distributed capacitance and current influence, and is suitable for ultra-high / extra-high voltage power transmission line.

Description

technical field [0001] The invention relates to the technical field of electric power system relay protection, in particular to a method for single-end distance measurement of faults between phases of lines based on distributed parameter measurement of impedance amplitude characteristics. Background technique [0002] Divided from the electrical quantities used in fault location, fault location methods can be divided into two categories: double-ended fault location and single-ended fault location. The double-ended fault location method is a method to determine the fault location of the transmission line by using the electrical quantity at both ends of the transmission line. It needs to obtain the electrical quantity of the opposite end through the communication channel, so it is highly dependent on the communication channel, and it is also vulnerable to double-ended fault location in actual use. Influence of sampled value synchronicity. The single-ended fault location metho...

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Problems solved by technology

In the case of medium and low-resistance short-circuit faults, due to the obvious drop in voltage along the line, the error in estimating the voltage phase angle of the fault point by using the negative-sequence current phase angle at the observation point has little effect on the ranging results; but in the case of high-resistance short-circuit faults, Because the voltage difference of each point along the line is very small, the error in estimating the voltage phase angle of the fault point by using the negative sequence current phase angle at the observation point plus the influence of the transient process, the distance measurement error of this method is relatively large

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