Abstract: Aiming at the problem of low voltage in rural distribution grid, based on the theoretical basis of the π-type equivalent circuit of the line,the paper analyzes the topological structure and wiring form of the medium and low-voltage distribution grid, and applies the voltage calculation of the π-type equivalent circuit to the middle and low voltage distribution grid. In low voltage lines, a theoretical model of voltage point-by-point calculation is formed. According to the theoretical model of voltage point-by-point calculation, a scientific, practical and easy-to-use low-voltage comprehensive management software system is compiled using the VC programming language, which is convenient for basic level technicians to judge whether there will be a low voltage problem in the power supply area in time, so as to make preparations for construction and transformation in advance. The system also provides a direct basis for the compilation of the construction and transformation plan of the distribution grid to more accurately solve the low voltage problem of the rural distribution grid.

Key words: distribution grid, low voltage, software system development