Comparative evaluation of multi-loop control schemes for a high-bandwidth AC power source with a two-stage LC output filter

This paper presents a comparative evaluation of four different multi-loop control schemes for a high-bandwidth AC power source. The power source considered in this work is based on a three-level T-type inverter with a two-stage LC output filter. The control schemes evaluated in this paper have an output voltage controller in the outer loop. For the inner control loop the following options are evaluated: capacitor current feedbacks, proportional-integral and proportional inverter output current control in combination with reference voltage and load current feedforward, and first LC stage capacitor voltage and inverter output current feedback.