Similarity single-phase earth fault line selection method based on active full compensation arc suppression control

Abstract

The present invention discloses a similarity single-phase earth fault line selection method based on active full compensation arc suppression control. In a small current grounding system, an active full compensation arc suppression control device replaces an arc suppression coil compensation device; when a single-phase earth fault occurs, circuit zero-sequence current at a compensation stage is notably characterized in that neither the size nor the direction of non-fault circuit zero-sequence current is changed while both the amplitude and the phase position of a fault line are changed; at the compensation stage, similarity analysis is carried out in pairs on zero-sequence current waveforms of all circuits to obtain a similarity coefficient matrix, every row of the coefficient matrix is added to obtain a series of comprehensive similarity coefficient values, and thus the circuit corresponding to the minimum comprehensive similarity coefficient is the fault circuit. With adoption of the method provided by the present invention, compensation and arc suppression aims are achieved when single-phase earth faults occur in a system, the rapidity is also ensured, rapidity and accuracy in fault line selection are realized during compensation, and interferences of other signals on the system are also avoided.

Description

technical field [0001] The invention belongs to the technical field of power grid ground fault line selection, and relates to a single-phase ground fault line selection method, in particular to a similarity single-phase ground fault line selection method based on active full compensation arc suppression control. Background technique [0002] The safe, stable and reliable operation of the distribution network is the basis for ensuring the development of the national economy and plays an important role in social life. At present, most of the domestic distribution networks adopt the operation mode of small current grounding (neutral point is not grounded or grounded through the arc suppression coil). Single-phase ground faults often occur during system operation. When the system is running, the fault current generated by the single-phase ground fault is very small, and the harm to human body, power equipment and communication is relatively small. The overvoltage will enda...

AI Technical Summary

Problems solved by technology

There are few features available for arc suppressing coil ground fault line selection, and each fault feature is not very reliable, and some additional injection signal line selection methods will cause certain disturbances to the compensated and stable system, affect the ground current and even cause re- arcing

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