The Research On A Battery Charging And Discharging Device Based On Three-phase Pwm Rectifier

With more and more widely use of the storage battery in several fields of nation, such as agriculture, forestry, railways, post and telecommunications, mine, port, power systems, computer UPS system, converters and special power systems. Forestry operations in the transport and machinery also often used in batteries, how can the rapid, safe and efficient manner to the battery charge and discharge becomes very importanthow to charge the battery quickly,safely and efficiently becomes more and more important,Direct rectifying or rectifying using thyristors is adopted by most traditional charging-discharging device of battery. Though it is used completely technique and low price,it also has many disadvantages. For example,there are low input power factor,low working frequency,and only one-way ransformation of energy. With the development of power electronic devices and power control technique,The rectifier based on PWM technique which has the advantages of bidirectional power flow,low AC harmonic and unit power factor is appeared. A new way of the design of PWM storage battery charging and discharging system is shown. So in this paper the needs of practical use is centered on. A high-efficiency,high-power and energy-saving PWM storage battery charging and discharging system is presented in this paper.The main studying object in this paper is Three-phase PWM rectifier. Firstly, the demands of charge-discharge devices are analysed. The total scheme is designed according to the performances of charge-discharge device. Three-phase converter is selected as main circuits, and its mathematical model is studied. Then this paper also introduces the fundamental structure of the system which is mainly composed of a DC/DC converter and three-phase PWM rectifier. The parameters of the devices are analyzed.This paper introduces the design of the control system which is based on DSP-TMS320F2812.After analysing several control methods, the arithmetic of SVPWM is selected to implement PWM wave, and its detail process is introduced. Secondly, the control scheme is designed based on control targets. The MATLAB simulation model and the experimental results of the system are given in this paper.Those results indicate that good trace performance of input current is realized, the input power factor is close to 1, the output voltage of the converter is stable and high quality battery charge-recharge current which has small ripple is achieved. The system designed satisfies the expect demands.