Model Predictive Control for Neutral-Point Voltage Balance Based on Improved T-type Three Level Inverter

In this paper, the improved T-type three-level topology can significantly reduce the conduction loss in zero state compared with the traditional T-type three-level topology. And it is applied to model predictive control utilizing the characteristics of its switchless redundancy state. In the dq rotating coordinate system, a model predictive control method based on neutral-point voltage balance is proposed. This method reduces the computational burden by reducing the number of rolling optimization under the condition of ensuring the neutral point voltage balance. Compared with the traditional multilevel model predictive control, the method eliminates the need of predicting the neutral-point voltage as well as the cost function computation, and the control method is more direct and effective. Simulation and experimental results show that the proposed model predictive direct power control (MPDPC) method based on the improved T-topology can improve system robustness, fast dynamic response, wide operating range and stability.