Model predictive control with secondary objective functions for power module loss reduction

This paper presents a finite control set model predictive control (FCS-MPC) method to reduce the power module loss while meeting the converter performance requirements. Many modulation-level and system-level loss reduction strategies are proposed by either changing the switching frequency or adjusting the reactive power. However, increased control loops and complicated modulation schemes restrict the system performance and implementation. With the features of model predictive control, FCS-MPC has the capability to achieve several control targets by simultaneously optimizing multiple objective functions. In the proposed FCS-MPC, a secondary objective function is defined to reduce the power loss of semiconductor devices and relieve the thermal stress for power modules. This control mechanism provides the system with not only the straightforward effectiveness, but also maintaining the converter performance requirements. The proposed FCS-MPC is validated in the simulations and experiments. A 2.5-kW PWM rectifier prototype is developed to demonstrate the proposed control method.