Fault diagnosis method for distribution network based on synchronous phasor measurement and random matrix theory

Abstract

The disclosure discloses a fault diagnosis method for a distribution network based on synchronous phasor measurement and random matrix theory. The power system operation is monitored in real time, theamplitude and phase information of three-phase voltage, current, and zero-sequence current are uploaded regularly, and the amplitude and phase information of negative sequence components are obtainedby calculation; using the amplitude and phase of three-phase voltage and current as input features to form a global monitoring matrix, when the average spectral radius of the global monitoring matrixis lower than its threshold value, a fault is considered to occur and the time of the fault is determined; using the amplitude and phase of the zero-sequence current as input to form a preliminary classification matrix, the fault type is judged preliminarily; selecting the average spectral radius of the global monitoring matrix as the dynamic reference value, and the change of the average spectral radius of the phase selection matrix relative to the dynamic reference value as a diagnostic standard, the fault phase selection is performed; the entire node network is divided into several partitions, the input matrix is formed by the PMU measurement data corresponding to the fault phase selection results in the partition, and the fault location is carried out by combining the fault type.

Description

technical field [0001] The disclosure relates to the technical field of distribution network fault diagnosis, in particular to a distribution network fault diagnosis method based on synchronized phasor measurement and random matrix theory. Background technique [0002] According to statistics, about 90% of my country's annual power outage losses come from distribution network faults. The problem of distribution network fault diagnosis and location has always been a research hotspot in power systems. The single-phase ground fault and intermittent faults in the distribution network have a high probability of occurrence. At this time, the ground current is very weak, and even the compensation current of the arc suppression coil may make the zero-sequence current smaller than the non-fault line current. On the other hand, the distribution network There are many high-resistance faults in the faults, which makes it difficult to detect the short-circuit current. The faults may exis...

AI Technical Summary

Problems solved by technology

Relying on line distributed capacitive coupling and distributed power supply grounding points, the system forms a variety of current loops, coupled with dynamic changes in network topology, the distribution network operation mode is more complicated, resulting in frequent changes in fault current characteristics, and current protection criteria are no longer fixed

However, traditional protection and fault diagnosis schemes using local information need to be adjusted offline in advance. In practical applications, the scope of action is limited, susceptible to interference, and the judgment results are relatively one-sided. There is a possibility of misoperation and cannot cover all scenarios.

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