A Novel Composite Control Strategy of Three-Phase Intermediate Frequency Multiple Inverter Power Supply

For the 400Hz intermediate frequency inverter power supply, the fundamental frequency is high, and the carrier wave ratio in large-capacity intermediate frequency inverter power supply is relatively small. The traditional control method is difficult to suppress harmonics and it is difficult to realize tracking without steady-state error. In this paper, a composite control method with repetitive control and proportional resonant control is proposed, and the feasibility of the scheme is verified by theoretical analysis and simulation. Finally, an experiment on a 90kW principle prototype shows that the control scheme not only can suppress the voltage waveform distortion of the intermediate frequency inverter power supply, so that the three-phase output voltage achieve THD < 1.5% when the inverter power supply at 90KW , also can guarantee good steady-state and dynamic performance.