The distribution network is located in a complex environment, and the installation height of the line and the time-varying parameters of the surrounding medium all cause changes in the capacitance to the ground, which is the main reason for affecting the accuracy of non-contact voltage measurement. In this paper, a non-contact voltage measurement method based on displacement current of dual coupling mechanism is proposed to eliminate the influence on the variation of ground capacitance. Firstly, construct a coaxial cylindrical dual copper pole coupling mechanism; Next, a system of equations containing line voltage and ground capacitance is established through two adjacent coupling mechanisms, and the inversion formula for line voltage is solved; Then, design the voltage measurement devices based on dual coupling mechanism displacement current method; Finally, this article takes 10kV single-phase lines with a height of 80-160cm to ground as the test object, and the voltage measurement error at different heights is less than 5%, proving that the proposed method has adaptability to ground capacitance. At the same time, the experimental conditions have a greater rate of change in ground capacitance compared to the actual conditions, so the proposed method has practical promotion significance.

Noncontact voltage measurement; Coupler; Displacement current; Parameter sensitivity; I-V converter.