Model Predictive Vector Control for Four-Switch Mono-Inverter Dual IM System

Abstract

A novel dual motor synchronous control system supplied by four-switch mono-inverter is proposed, where one phase of both motors is connected to the mid-point of dc bus capacitors, and other phases are connected to inverter leg. Since only four power switches are required, the installation space, weight, and cost can be further reduced than conventional mono-inverter. However, it presents control challenges due to the limited control freedom degree. An advanced vector control method is proposed for this problem. Based on predictive model, two motors' reference voltage vectors are calculated independently, and a self-adapting composite vector is selected as the output vector of inverter. The duty cycles of switching signals are obtained based on space vector modulation of the selected vector. The use of unified-model or master–slave strategies in conventional mono-inverter control methods is avoided. The control is simplified and computation is reduced, while a good performance is ensured. Experiment results verify the effectiveness of proposed method.