Research on grounding fault analysis and wire selection technology of coal mine power grid

Single-phase ground fault, as the most frequent type of fault in coal mine power grid, not only damages the power grid equipment, but also easily causes fire and other accidents, which seriously affects the reliability of power supply. Aiming at the above problems, we analyze and study the coal mine power grid grounding fault and routing technology, and propose a single-phase grounding fault routing scheme based on information fusion. Firstly, the amplitude-phase method and zero-sequence conductivity method are compared to carry out experimental analysis of single-phase grounding routing, and the error influencing factors of the two methods are derived as the basis for improvement and optimization. Subsequently, the zero-sequence admittance method is optimized by the method of harmonic admittance accumulation, so that the admittance angles of non-faulty lines and faulty lines are further away from the positive imaginary axis, thus improving the differentiation margin between faulty and non-faulty line admittance angles, and achieving the purpose of decreasing the error area of zero-sequence admittance multiplane, making the direction of the fault clearer, and decreasing the misjudgement rate. After experimental testing, the average speed of the improved scheme is ≤60ms, and the fault line identification is accurate and reliable, which can effectively improve the speed, accuracy and reliability of fault line selection in coal mine power grid, and ensure the safe and stable operation of coal mine power grid.