Research on the Algorithm and Test of Transmission Line Voltage Measurement Based on Electric Field Integral Method

The non-contact voltage measurement of the transmission line is of importance to the operation and intellectualization of the electrical power system. Presently, the non-contact measurement of the transmission line voltage based on the field sensor has been widely studied. The methods of obtaining the voltage by solving the electric field inverse problem have difficulties in solution and calibration. This problem can be effectively solved by adopting the numerical integral algorithm of electric field. In this paper, the voltage measurement by using the Chebyshev piecewise integral algorithm, Gauss-Legendre integral algorithm and Gauss-Legendre improved algorithm was analyzed and the integral intervals of the algorithms were optimized. The multi-index comprehensive evaluation model was established for evaluating the measurement effect, adopting improved subjective weighting method. The finite element simulation model of the 10-kV transmission line was built with the Maxwell software platform to carry out the simulation test. The measurement effects of different voltage measurement methods were compared and it was proposed to apply the Chebyshev piecewise integral algorithm to the voltage measurement system of the transmission line. Finally, the transmission line voltage measurement test platform based on D-dot sensor was built and the measurement safety and accuracy of the Chebyshev piecewise integral algorithm was verified.