Equivalent temperature estimation‐based FCS‐MPC for thermal stress balance of 3L‐NPC traction inverter

Abstract This paper proposes an equivalent temperature estimation‐based finite control set model predictive control (ETE‐FCS‐MPC) method to balance the thermal stress among transistors in three level neutral point clamp (3L‐NPC) traction inverters, which can be used to prolong the whole service life and improve the reliability of the traction inverter. Compared with other methods, the proposed ETE‐FCS‐MPC method requires lesser calculation without additional sensor. Firstly, an energy loss‐based equivalent temperature estimation method is proposed to avoid the complexity of junction temperature prediction. Secondly, an energy variance‐based thermal stress balance control objective is introduced. Then, a normalized evaluation function is established to select the optimal switching state. Finally, the effectiveness of this method is verified on hardware‐in‐the‐loop tests.