Overhead power transmission line short circuit impedance measurement device based on synchronization vector

Abstract

The invention relates to an electric system measurement device which is mainly used for measuring various kinds of short circuit impedance of an overhead power transmission line in an electric system.The measurement device comprises a triphase impedance relay device and an interphase impedance relay device that are electrically connected with current transformers and voltage transformers; the current transformers and the voltage transformers are electrically connected with a synchronization vector measurement device; the triphase impedance relay device and the interphase impedance relay device are connected with a first treatment device; the measurement of various short circuit voltages and currents of the overhead power transmission line is achieved; whether an impedance relay operates is decided by analysis processing of synchronously measured current and voltage vectors; and the device facilitates impedance calculation, fault type analysis and judgment and fault positioning.

Description

technical field [0001] The invention relates to a power system measuring device, which is mainly used for measuring various short-circuit impedances of overhead transmission lines in the power system. Background technique [0002] With the continuous development of the smart grid, the operating scale of the distribution network is increasing, the operating structure is becoming more and more complex, and the frequency of short-circuit faults in the transmission lines of the system is increasing. The short circuit of the transmission line can be divided into the following types: single phase to ground short circuit, two phase to ground short circuit, phase to phase short circuit and three phase short circuit. The system (low-voltage network) whose neutral point is not grounded can operate with a fault for 1-2 hours when a single-phase short circuit occurs, and when other short circuit faults occur, the circuit breaker should be required to act correctly and quickly to ensure ...

AI Technical Summary

Problems solved by technology

The short-circuit fault detection and location technology of traditional distribution network is only suitable for radial distribution network, not suitable for network distribution network

At the same time, for the current differential protection of the busbar, the problem of synchronous measurement of the current at both ends of the busbar is particularly important. Accidents that cause the differential current of the busbar current to be too large due to the non-synchronous measurement often cause the operation of the busbar current differential protection.

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