Research On LCL-Filter-Based Three-Phase Voltage Source PWM Rectifier

The high frequency PWM rectifier can provide nearly sinusoidal and low harmonic distortion current of the utility, controllable power factor and bi-directional power flow. Because of these features, they become more and more popular in practical application. To reduce the current harmonics around the switching frequency a high value of input inductance should be used. However, for applications in high power, it becomes quite expensive to realize higher value filter. Moreover, the system dynamic response may become poorer. This problem could be solved by adopting a LCL-filter configuration, which allows to use reduced values of the inductances and to reduced the switching frequency pollution emitted in the grid.This paper analyzes the high frequency PWM rectifier principle, then presents a three-phase abc coordinates and dq coordinate system on the mathematical model of L-filter and LCL-filter configuration. This paper adopt the parameters of the PI-based controller that is already used for the L-filter-based active rectifier. On the basis of model in the dq coordinate system, the paper proposes a mult-closed-loop control strategy. Decoupling feed forward control is used in the inner loop current. Typicalâ… type system design is used in current controller design, in order to improve the follow-up ability of current. Typicalâ…¡type system design is used in voltage controller design, in order to improve the anti-jamming ability.This paper describes the resonance problem of LCL-filter, and proposes damping method. A step-by-step procedure for designing the LCL filter of the high frequency PWM rectifier is proposed. The simulation model of PWM rectifier is established in the MATLAB/SIMULINK environment. According to the article's theory imitation of the real system design with good dynamic and static performance.