Performance of independent two induction motor drives fed by a four-leg inverter with vector control method

This paper presents the experimental results of the independent drives of two induction motors (IMs) fed by a four-leg inverter with vector control method. The inverter consists of four legs and two capacitors connected in a series. Recently the four-leg inverter and four switch inverter have been studied, but there are known to have several disadvantages. First, the balanced three-phase current cannot be obtained. Second, the drift phenomenon is happened by the two capacitor voltages fluctuation. This paper analyzes the cause of the unbalanced three-phase current and resolves about it by vector control method. Next, the independent drive of two IMs fed by the four-leg inverter with the vector control method is demonstrated by the experimental results. Moreover, the load characteristics of four-leg inverter are also investigated.