An Active Damping Method Using Inductor-Current Feedback Control for High-Power PWM Current-Source Rectifier

Due to the inductor-capacitor filter, a pulse width modulation current-source rectifier (CSR) may experience LC resonance. A smaller ratio between the switching frequency and the resonant frequency of the CSR presents a challenge in designing active resonance damping methods in high-power applications. In this paper, different feedback states of filter inductor current and capacitor voltage are investigated to damp out the LC resonances. Besides proportional capacitor-voltage feedback (CVF), the derivative inductor-current feedback (ICF) provides an alternative approach for active damping and is comprehensively analyzed. Compared with the virtual-resistance (VR)-based active damping strategy, controller design is simpler in this method. Furthermore, the active damping method is able to damp the resonance under short-circuited dc-link conditions. The ICF-based active damping strategy works well for CSRs with low switching frequencies. Simulation and experimental results verify the feasibility and validity of the method.