Research And Implementation Of Single-Phase High Power Factor Charging And Discharging Device For Battery

In recent years, battery is widely applied in single-phase system, but conventional charged and discharged device appears many problems, such as harmonic pollution, lower power factor, separation of charged and discharged device, which demands a charged and discharged device developed for single-phase system. Currently, researches on charged and discharged device mainly focused on its application in three-phase system and direct current (DC) system, and there are few studies on its application in single-phase system. Therefore, this paper studied single-phase two-stage energy conversion device constructed by single-phase(Voltage Source PWM Rectifer -VSR)and bi-directional Buck/Boost converter, and its main content is as follows:(1) Select single-phase VSR as pre-stage of a charged and discharged device to make the device run under unit factor and provide stable DC voltage for the post-stage. Double closed loop control of simplified current loop based on rotating coordinate system was adopted for the shortage of unavailable d-q theory in single-phase system, and could reach the requirements of the device. Engineering design method was used to complete the design of control parameters of the inner electric current ring and outer voltage ring, and to finish the design of main circuit inductance and capacitance parameter. Charge and discharge of single-phase VSR in the device were simulated, analyzed and verified by experiment on MATLAB/Simulink software platform.(2) Select bi-directional Buck/Boost converter as post-stage of a charged and discharged device. According to battery charged and discharged characteristics, current closed control was conducted to fulfill constant current charge-discharge and current-voltage double-loop was adopted to reach constant voltage charge. Also, relevant control parameters, inductance and capacitance parameters were designed by frequency domain. Constant current charge, constant voltage charge and constant current discharge of Buck/Boost bi-directional converter in the device were simulated and verified by experiment on MATLAB/Simulink software platform.(3) Establish experimental platform for single-phase battery charged and discharged device with high power factor by selecting TMS320F2808 as main control chip, designing main control circuit, IGBT driving circuit, current-voltage sampling circuit, main routine, interrupt routine and control routine.