Research on the Energy Efficiency Measurement for Electric Multiple Unit Traction System

In order to accurately measure and analyze energy efficiency of traction systems, especially in the current absence of relevant standard references, this article presents an energy efficiency measurement system developed based on the requirements of IEC 62888-2:2018 for electric energy testing and GB/T 25117.1-2010 for torque and speed measuring instruments, taking the traction system of electric multiple units (EMUs) as the research object. To improve measurement accuracy, a purpose-made high-voltage acquisition board with isolation is designed to directly collect the output voltage signal of the 27.5 kV transformer and a pulse-type output torque-speed sensor to measure the mechanical parameters of the traction motor, enabling synchronous collection of both electrical and mechanical parameters. Through experiments conducted with standard signal sources, it is verified that the measurement accuracy of system energy consumption surpasses the standard requirement by 1.5%. Furthermore, regarding measurement of mechanical parameters, the torque accuracy exceeds the standard requirement by 0.5%, while the speed accuracy surpasses it by 0.1%. Meanwhile, in order to verify the system accuracy in dynamic energy consumption measurement, a high-precision power analyzer and this measurement system were used to simultaneously measure the energy consumption of the traction system with the same track data, revealing a relative error of less than 1%