Modeling and Stability Analysis of Three-Phase PWM Rectifier

According to the instantaneous active power balance, the small-signal mathematical model from active current to dc-side bus voltage is proposed. When the rectifier operates in the rectification mode, it has a right-half-plane (RHP) zero and exhibits a non-minimum phase feature which causes a phase lag and affects system stability. The stable regions and how system stability is affected by variation of converter parameters under the modeling methods proposed in this paper is analyzed in detail. The results show the proportional gain of voltage outer-loop, AC-side filter inductor, DC-side capacitor, load resistor have an influence on system instability. At last experimental results illustrate the validity of theoretical analysis.