Temperature Balancing Method Based on FCSM2 PC for Three-level Inverters

The three-level neutral point clamped (3LNPC) inverter has the problem of unbalanced power loss and temperature. This paper proposes a temperature balance method based on finite control set modulation model predictive control (FCS-M
²
PC). Firstly, the periodic current of the current switch is measured and the delay compensation is made to predict the current and power loss of the next switching cycle. Then, the evaluation function value is calculated to find the optimal switch state sequence and the switching time. The output is the control signal that instructs the switch to move in sequence at the corresponding time. After the current switch sequence is complete, the prediction of the next switch cycle begins. This method can be used in low and medium switching frequency systems, and it does not need to make prediction in every sampling period, which saves computation. The simulation results show the effectiveness of the proposed method.