Control strategies for a novel inverter which can independently control two permanent magnet synchronous motors

Electric vehicle (EV) is expected as a solution for protecting the global environment. In EV, safety and design-flexibility can be improved by configuring two or more-wheel drive which uses in-wheel motors. As in-wheel motor, permanent magnet synchronous motor (PMSM) is suitable at the viewpoints of the power density and the efficiency. However, a PMSM requires a three-phase inverter; thus, two-wheel drive vehicle using two PMSMs requires two three-phase inverters in conventional. As a solution for this problem, several inverters which consist of less semiconductor power devices compared to conventional three-phase inverter and can independently control two PMSMs are proposed. One of them is the proposed inverter, which consists of only six switching devices. This paper described control strategies for the proposed inverter. One is sinusoidal PWM control and the other is current control based on instantaneous value. The characteristics of the control schemes are compared through simulations and experiments. In addition, the advantages and disadvantages of the proposed inverter are described. The proposed inverter can be constructed by only six switching devices as same number as a conventional three-leg inverter, though output voltage is about one-third of the conventional.