Thermal stress reduction of quasi-Z source inverter drive by model predictive control

The quasi-Z source inverter (qZSI) is one of the most promising power electronics converter topologies suitable for traction applications. The thermal stress in power modules is one of the most important causes of their failure, which is not considered during the control of qZSI drive. Thus, this paper proposes a thermal stress reduction scheme for qZSI drive, which utilizes finite control set model predictive control. The cost function is designed by including terms of switching counts, number of cycles to failure and inverter constraints in addition to the currents and capacitor voltage. This allows one to achieve the minimum thermal stress for the best possible overall performance of qZSI drive. The approach is proved using simulation and experimental results.