Transformerless Cascaded AC-DC-AC Converter for Multiphase Propulsion Drive Application

Abstract

-A transformerless converter suitable for multiphase drive application is presented in this paper. The topology employs a cascaded H-bridge rectifier as the interface between the grid and multi inverters which drive the multiphase motor. Compared with the conventional structure, the new topology eliminates the input transformer and also has the advantages such as four quadrant operation, simple configuration, low cost, high efficiency, and so on. The control strategies for the grid-side cascade H-bridge rectifier and the motorside inverter are studied accordingly. Based on the multi-rotational reference frame, modular control scheme is developed to regulate the multiphase drive system. Simulation results show the proper operation of the proposed topology and the corresponding control strategy.

A Transformerless Medium Voltage Multiphase Motor Drive System

“…With the goal of eliminating this heavy and costly phase-shifting transformer, some significant work has been done [12][13][14][15][16][17][18][19]. Reference [12] presents a hybrid cascaded H-bridge multilevel motor drive control scheme for electric/hybrid electric vehicles.…”

“…In [18], a transformerless hybrid active filter is integrated into a conventional MV motor drive system to mitigate harmonic currents. A theoretical transformerless cascaded AC-DC-AC converter for multiphase propulsion drive is proposed in [19]. However, less attention was paid to the areas of the high efficiency and high performances of MV multiphase motor drives.…”