A DTC Algorithm of Induction Motors Fed by Three-level Inverter With Neutral-point Balancing Control

The paper mainly focuses on the direct torque control (DTC) system of induction motors fed by three-level inverter.Based on the fixed synthesizing vectors,an induction motors DTC method fed by three-level inverters is proposed. And then,the neutral-point balancing Bang-Bang control method,which is based on the detection of each phase leg current's and neutral-point voltage ripple's direction,is employed to make neutral-point potential balance.With the proposed DTC strategy,the neutral-point voltage unbalance,the dv/dt of output voltage and the switching loss is restrained. Furthermore,it does not deteriorate the performance of DTC schemes.The experimental results verify the correctness and feasibility of the proposed control scheme.