Line-to-ground capacitance parameter measurement system and measurement method

Abstract

The present invention discloses a line ground capacitance parameter measurement system. The system comprises an injection transformer and a calculation module; the primary side of the injection transformer is provided with a primary-side voltage measurement unit; the secondary side of the injection transformer is provided with an input line, a current source which is mounted on the input line, a secondary-side current measuring unit which is used for measuring the secondary-side current of the injection transformer, and a secondary-side voltage measuring unit which is used for measuring the secondary-side voltage of the injection transformer, wherein the current source is used for outputting amplitude-adjustable current signals within a certain frequency range; and the primary-side voltage measuring unit, the secondary-side current measuring unit and the secondary-side voltage measuring unit are all electrically connected with the calculation module. The invention also discloses a line ground capacitance parameter measurement method. With the method adopted, the precision of line ground capacitance parameter measurement can be effectively improved. The method has the advantages of high measurement precision, strong electromagnetic interference-resisting capacity and the like, and can balance the safety of an operator and the practicality of field application.

Description

technical field [0001] The invention belongs to the technical field of inductance or capacitance measurement, in particular to a line-to-ground capacitance parameter measurement system and a measurement method. Background technique [0002] The real-time and accurate measurement of the ground capacitance parameters of power system lines has strong practical value for ground fault overvoltage suppression, reactive power compensation and fault location. Traditional line-to-ground capacitance parameter measurement methods can be divided into direct measurement method and indirect measurement method. The direct measurement method needs to operate the electrical primary circuit, which is poor in safety, complicated and time-consuming. The indirect measurement methods mainly include bias capacitance method, tuning method and signal injection method. Among them, the bias capacitance method faces problems such as poor safety and real-time performance, and the tuning method has the...

AI Technical Summary

Problems solved by technology

Among them, the bias capacitance method faces problems such as poor safety and real-time performance, and the tuning method has the danger of inducing zero-sequence circuit resonance. As the most widely used signal injection method, because the excitation injected into the transformer is ignored in the traditional measurement process The impedance is nonlinear and it is treated as an open circuit, so there is a systematic error, and the relative error of the measurement result gradually increases as the frequency of the injected signal is far away from the operating frequency of the injected transformer.

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