Abstract
Medium-Voltage Variable Speed Drives (VSDs) are the backbone of several critical industries. Providing the proper dc-link voltage to support the VSD's converter is crucial. Conventionally, dc-link voltage is supplied either by a two-level rectifier with series-connected Insulated Gate Bipolar Transistors (IGBTs) and front-end isolation transformer or by a 12-pulse uncontrolled rectifier with a complex phase shifting transformer. This work proposes a new approach using series-connected multi Half-Bridge (HB) modules to generate the required dc-link voltage. The proposed topology is able to perform the AC-DC power conversion by employing lower voltage rating switching devices. Moreover, the proposed control strategy yields well-regulated dc-link voltage and a negligible Total Harmonic Distortion (THD) of the input ac source current. A simulation for the proposed system is investigated using MAT LAB/Simulink platform.