Design Of Battery Management System For EMUs

With the rapid development of high-speed railway technology in China,the safety of high-speed railway trains has become the focus of attention.For operation safety of EMU,we need for real-time monitoring of the EMU auxiliary power unit,power supply system of EMU once malfunction,also need timely in auxiliary power as an emergency standby power.Bullet in the Auxiliary Power Unit(Auxiliary Power Unit,APU)mainly provide power for lighting,lift bow,communication signals,door control and drive,brake and other special important load.Power supply reliability of the APU directly affects the safe operation of the emu.The back-up power supply of APU generally uses battery pack.When it is running normally,the APU is charged by the charging generator.When the voltage loss of the catenary or the converter fault occurs,the battery group is used as an emergency standby power supply for the above important loadFirst of all,this paper introduces the working principle and characteristics of nickel-cadmium accumulator.Nickel cadmium battery has many advantages,such as small volume,light weight,high safety,fast charge and discharge rate,and no memory effect,and a discharge experiment algorithm is used to complete the estimation of state of charge(SOC)and the internal resistance method is used to assess the state of health(SOH).Then,according to the structure of the EMU battery management system(BMS)device,the paper introduces that the EMU battery management system hardware and software and other functional modules.Only the coordination of software and hardware can fully reflect the structural advantages and functional characteristics of the device.In addition,this article has carried on the thorough research to the EMU battery management system of the battery cell voltage,current and temperature monitoring and reasonable control scheme for each battery.This paper uses the battery monitoring chip LTC6803 of the Linear,and uses a design scheme for a high-performance battery management system based on a 32-bit microcontroller STM32.This article through the experimental environment in the laboratory debugging and installation in the 350 km per hour Chinese standard EMU for the current vehicle experiment.The battery management system designed in this paper can carry out on-line monitoring of the battery.According to the continuous monitoring and write down the battery management system monomer battery voltage,working current and temperature of the battery and other related information,accurate real-time data collection and analysis,and then to estimate the battery SOC and SOH value,if the battery management system is in a state of abnormal,will be in a timely manner acousto-optic alarm,can prolong the service life of battery an,thereby improve the emu train operation safety.