Comparison of LCL-Filter-Based PWM Rectifier with Different Current Sensor Positions

For LCL-based PWM rectifier, there are two options of sensing currents. Either grid side currents or converter side currents can be selected as the feedback signals for the current control loop. The selection of sensor position makes the design of the control system different. In this paper, the control stability and dynamic performance of LCL filter-based PWM rectifier with converter side current control or with grid side current control are compared. System stability and dynamic performance are compared with taking into account the effect of all possible variants. Further more, the comparison results provide a very useful design guideline for LCL filter-based PWM rectifiers. Finally experimental results prove the theoretical analysis.