Transient and steady-state analysis of three-phase PWM buck rectifier

This study presents a qualitative and quantitative analysis of the output current response of a three-phase buck rectifier. The DC-side of the three-phase pulse-width modulation (PWM) buck rectifier is loaded by a typical series equivalent circuit comprising a resistor, an inductor and a constant voltage. An analytical solution of transient and steady-state processes is obtained using the difference equation method in the continuous conduction mode. The proposed analytical solution exhibits two repetition intervals, which accurately predict the ripple components of the output current. Hence, the solution of the process envelopes is obtained. The derivation of the plant transfer function from the analytical solution of the output current is also presented. System simulations and experimental studies are carried out to validate the analytical approach with various output loads.