RELIABLE 3-PHASE PWM BOOST RECTIFIERS EMPLOYING A STACKED DUAL BOOST CONVERTER SUBTOPOLOGY

This paper describes circuit topologies for 3-phase pulse-width modula tion (PWM) boost rectifiers that operate dth a unity fundamental power factor and a low-distortion ac line current. Overlap delays between t he switching of the upper and lower devices in a PWM I rectifier leg a re not critical and diodes eliminate the possibility of the de-link ca pacitor discharging into short circuits and shoot-through fault condit ions, The rectifiers are controlled using a ''stacked dual boost conve rter cell'' subtopology model that can be used in two current control modes, The dual current-control mode shapes two line currents and ran achieve current distortion levels below 5 % The single current-control mode shapes one line current and can achieve current distortion level s close to 5% with the rectifier output de voltage at the standard lev el associated with a rectified mains voltage, The per-unit current rat ings for the switches in the 3-phase PWM switch networks are around 15 -20 % of the input rms line current as compared to 71 % for a standard 3-phase PWM rectifier, Circuit simulations and experimental results a re used to demonstrate the performance and feasibility of the rectifie rs described.