A Improved Three Phase PWM Rectifier Active Damping Control Strategy With State Observer For Battery Charging And Discharging System

Abstract

Eelectric Vehicles (EVs) and photovoltaic system have developed fastly supported by governments to promote the popularization and application of new energy in recent years. As a important part in grid-connected converter, LCL output filter can filter out harmonics effectively compared to L filter. Reaearch on LCL filter is significant to achieve higher operating performance of grid-connected converter. Additional senssors sampling LCL component variables is introduced to realize the active damping in majority of application occasions. This paper introduce the analysis and design of the state observer of three phase PWM rectifier which is used in the charging and discharging system in electric vehicles firstly. Then, the principles of some conventional active damping control methods is introduced. On the basis of a power battery charging and discharging system prototype, a novel method based on state observer is proposed to realize the LCL filter control. This method can both avoid the aditional senssors and provide benefits for control of other circuit variables and over current protection. Besides, the simulation in IV used to verify the the correctness of theory analysis and active damping method design.