The measurement method of tower grounding resistance with shorter measuring wire based on green's theorem

Abstract

Abstract The Tower grounding grids are important power facilities for transmission line grounding protection. The accurate measurement of grounding resistance provides data support for the safe operation of the grounding grids. The existing measurement methods for grounding resistance are mainly based on the 0.618 method, which has two disadvantages: (1) The distance between the voltage electrode and the measuring point should not be less than 2.5× the length of the scattered grounding electrode; (2) the long measuring wires ensure the measurement accuracy of the 0.618 method, but the long‐distance between the electrodes and measuring point makes it difficult to carry out in the complex environment. To accurately solve the problems, this paper proposes a novel measurement method of grounding resistance with shorter measuring wire based on Green's theorem. Combined with the physical model of the actual tower grounding grid, this paper establishes the potential equations in local space around the grounding grid and analyses the distribution of the equipotential surface. The results show that the proposed novel method of measuring tower grounding resistance can conveniently measure the grounding resistance, which greatly shortens the length of the measuring wire and has better adaptability for towers in a complex environment.

Keywords

• Numerical analysis
• Other topics in statistics
• Impedance and admittance measurement
• Power system protection
• Protection apparatus