Single-pole ground fault locating system for pseudo bipolar DC transmission and distribution line

Abstract

The invention discloses a single-pole ground fault locating system for a pseudo bipolar DC transmission and distribution line, and can meet the DC line voltage measurement of at least kilovolts undernormal working condition of the pseudo bipolar DC transmission and distribution system. The method of time-sharing sampling can be used to achieve the effect of stable output, high accuracy, good reliability and automatic calibration of DC high voltage measurement, and ensure long-term accuracy stability of the measurement system. At the same time, the single-pole ground fault locating system provided by the invention can automatically switch the range when a single-pole ground fault occurs on the DC line, so that the residual voltage of the ground fault point to the measurement point of up to100 volts can be accurately measured, whether there is a shunt branch between the measurement points is further determined according to the measurement result, and the ground fault point position islocated in the corresponding situation.

Description

technical field [0001] The invention belongs to the field of electrical engineering, instrument science and technology, in particular to a single-pole grounding fault location system for pseudo-bipolar direct current transmission and distribution lines. Background technique [0002] In the DC transmission and distribution system, it mainly includes three parts: the AC system, the converter station and the DC transmission line. According to the fact that the converter station is the most important part of the DC power transmission and distribution system, the current common electrical main wiring schemes of the DC converter station mainly include bipolar symmetrical wiring schemes and unipolar symmetrical wiring schemes. Bipolar symmetrical wiring is also called true bipolar. Due to its high cost, large grounding area and the fact that the converter transformer needs to withstand a DC bias that is half the voltage of the DC pole line, so in the existing DC transmission and di...

AI Technical Summary

Problems solved by technology

However, the rapid increase of the non-grounded pole DC voltage and the voltage of the AC outlet side of the converter station at this time will cause insulation damage and serious inter-electrode short circuit after long-term operation; and, in the case of a single-point ground fault, if If there is a second or more grounding points, no matter whether it is in the fault pole or not, it may cause DC system protection, switch malfunction or refusal to operate, and in severe cases may cause DC system collapse

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