Distributed capacitance measurement device and measurement method for high-voltage line

Abstract

The invention discloses a distributed capacitance measurement device and a distributed capacitance measurement method for a high-voltage line. The measurement device comprises a phase voltage measurement circuit for measuring the phase voltage of a tested phase line and a biased capacitor Cf-based ground capacitance current measurement circuit, wherein the phase voltage measurement circuit is connected with the tested phase line; the ground capacitance current measurement circuit comprises a biased capacitor Cf and a current detection unit for detecting current flowing through the biased capacitor Cf; one end of the biased capacitor Cf is connected to the tested phase line, and the other end of the biased capacitor Cf is grounded. The measurement method comprises the following steps of 1, measuring the phase voltage of the line before the biased capacitor is connected; 2, measuring the phase voltage of the line after the biased capacitor is connected; 3, measuring ground capacitance current, namely measuring the current flowing through the biased capacitor Cf; 4, calculating distributed capacitance. The measurement device is reasonable in design and convenient to connect, the measurement method is simple, measurement results are accurate, the distributed capacitance of the high-voltage line can be measured in a charged state, and a measurement process is safe and reliable.

Description

technical field [0001] The invention belongs to the technical field of distributed capacitance measurement of high-voltage lines, and in particular relates to a high-voltage line distributed capacitance measurement device and a measurement method thereof. Background technique [0002] At present, in my country's 6kV ~ 10kV power distribution system, the neutral point is not grounded or grounded through the arc suppression coil. Among them, the significant advantage of the neutral point ungrounded method is that the system can continue to operate for a short time when single-phase ground faults frequently occur (accounting for more than 60%). However, due to the existence of the ground capacitance of the power distribution system, it may cause intermittent arc grounding, ferromagnetic resonance and other neutral point displacement overvoltages, and even accidents, which will lead to breakdown of the weak insulation links of the entire power distribution system and equipment f...

AI Technical Summary

Problems solved by technology

Nowadays, many capacitive current measurement methods are used, and the additional capacitance method and the metal grounding method are usually used for measurement. However, in actual use, the former measurement method is complicated and difficult to operate; the latter is dangerous and has a low safety factor.

In summary, there is a lack of a high-voltage line distributed capacitance measuring device and its measurement method with simple structure, reasonable design, simple measurement method, and accurate measurement results, which can measure the distributed capacitance of high-voltage lines in a charged state, and the measurement process is safe and reliable.

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