A Control Strategy for SiC-Based High-Frequency High-Power Train Auxiliary Inverter

In this paper, a harmonic suppression control strategy for inverters based on an improved composite repetitive controller applied at high switching frequencies is proposed. Dual closed-loop control based on conventional repetitive controllers suffers from the disadvantages of poor dynamic performance, small gain in the low-frequency band, and narrow control bandwidth. In this paper, a new dual-loop control strategy based on an improved repetitive controller is proposed, in which the repetitive controller adopts a higher-order damping-based trapped filter to improve the control bandwidth and system harmonic rejection capability while ensuring the stability, and a fundamental resonance controller is added to the outer loop to improve the dynamic performance of the controller and the low-frequency band gain, and a differential control is added to the inner loop to calibrate the control object. After that Nyquist Stability Criterion is used to ensure the stability of the controller and the proposed control strategy is simulated and analyzed in Simulink. Finally the simulation results show that the proposed novel control strategy has better harmonic suppression capability and dynamic performance compared to the conventional control.