A novel multi-loop control strategy for PWM converter based on LCL filter

A three-phase voltage source PWM rectifier(VSR) has some shortcomings that can lead to resonance, resulting in system instability problems. A novel multi-loop control strategy and a design of the control structure in synchronous coordinate system for LCL-VSR is proposed in this paper to solve the problem. The strategy belongs to active damping control, which introduces the filter capacitor current-loop feedback control on the basis of the traditional double-loop control system. The strategy increases the system equivalent damp which effectively inhibited the LCL filter resonance, thus ensure the stability of the system. The proposed strategy system was simulated by using the toolbox of Matlab/Simulink. Finally, the feasibility and effectiveness of the proposed method was verified by simulation results.