Design Of Power Quality Monitoring Device For Traction Power Supply System

In recent years,with the rapid development of China's high-speed railway,the traction load of electrified railway is also increasing sharply,and the impact on the power system is constantly strengthened.As a result,the traction load power quality problems have become increasingly prominent.The electric locomotive is a single-phase rectifier load,featuring in nonlinearity,asymmetry,characteristics of randomness,volatility and so on,will produce such as harmonics,three-phase unbalance,voltage fluctuation and other a series of power quality problems,which would have many negative effects on the other electrical equipment of the higher grid level,even cause misoperation of relay protection and serious hidden dangers for the stable operation of the traction power supply system even grid power system.With the expansion of Chinese railway scale and promotion of electric locomotive speed,it is necessary to develop an electric power quality monitoring device for the traction power supply system quality characteristics,monitoring the power quality indicators of traction power supply system accurately in real time,providing the basis for the development of positive and effective preventive measures and management measures.This paper first introduces the characteristics of the traction power supply system,analyzes the main problems of three-phase unbalance,harmonic,voltage fluctuation and flicker,voltage deviation in power supply system,and corresponding methods of monitoring are adopted according to the characteristics and problems.Power quality monitoring device hardware platform is constructed using POWERPC P1010 CPU,and FPGA control AD chip sampling.The application of C++ language procedures monitoring program for the power quality parameters and the external program,and all program has passed debugging and commissioning.After a series of tests,The device satisfy the requirement of the traction power supply system.