An Active Dumping Current Controller Design for Current Source Converter in PMSM Drive System

Current source inverter is considered as an excellent candidate for permanent magnet synchronous motor drive systems due to its superior output waveform and inherent short-circuit protection capability. However, due to its requirement for the DC bus to exhibit current-source characteristics, it often needs to be connected in series with a front-end. Considering the power quality on the grid side, a current source converter with bidirectional energy flow capability can be chosen as the front-end for current source inverter. In current source converter systems, there is a resonant issue in the grid-side filtering section, which includes parallel inductance and capacitance. Due to efficiency limitation, this study investigates active damping current controller as replacement for traditional passive damping method. For the proposed active damping current controller, the paper models it in the Laplace domain and considers dynamic performance, resonance suppression capability, and stability margin for designing the active damping loop. Additionally, decoupling term design in the synchronous rotating coordinate system is conducted, taking into account the impact of the active damping loop. Finally, simulations are carried out to validate the proposed control and solution, considering the efficiency of the system.