Performance comparison of PI and P compensation in average-current-controlled three-phase six-switch boost PFC rectifier

In this paper, it is shown that in the three-phase six-switch boost PFC rectifier with average-current control and unbalanced input-voltage and/or input-current sensing gains, the current controller with proportional (P) compensation exhibits lower total harmonic distortion (THD) and higher power factor (PF) compared with that of proportional and integral (PI) compensation. It is also shown that the P compensation with input-voltage feedforward is effective in improving output-voltage transient response with respect to input-voltage changes only if duty-cycle feedforward is also implemented. Finally, it is shown that zero-sequence-signal (ZSS) injection, in addition to enabling the output-voltage regulation in a wider input-voltage range, also improves the THD of the input currents.