Permanent-magnet synchronous machine and induction machine independently controlled by standard three-leg inverter

The objective of this paper is to propose three parallel connected motor drive systems, employing a three-phase permanent-magnet machine and a single-phase induction machine. The configurations have been designed for applications where it is necessary to control two motors independently, by using a standard three-leg inverter. All proposed solutions employ standard three-leg converters, which represents the most common commercial converter manufactured. Such topologies can be applied, for instance, with motors for traction and compression in automotive applications. The paper presents: i) relevant characteristics of the converter, such as voltage capability, shared-leg and capacitor currents; ii) pulse-width modulation techniques based on scalar approaches; iii) control strategies for providing current control; and iv) simulated and experimental results.