A fast current control method for voltage type PWM AC-DC converter system

This paper proposes a new fast current control method for a voltage type PWM AC/DC power converter with an LC filter on its AC side. In this control method, the state variables of the filter capacitor and filter reactors are fed back to the PWM pattern generator to compensate an inherent DC offset of the source current as well as oscillations of the DC output current and voltage during transients. Computer simulation of the power converter system is used to determine an optimum set of feedback gains of the control system. Simulation results show that the transient responses of source current and DC output current and voltage are improved greatly. The experimental results of the proposed system have confirmed the simulated results and showed that the transient current and voltage responses can be significantly improved and can be made very fast. The proposed control strategy can be applied successfully to both rectifying and inverting modes of operation