Explicit Consideration of Inverter Losses in the Cost Function for Finite Control Set Model Predictive Control of Induction Machine, Experimental Results

A Finite Control Set Model Predictive Controller (FCS-MPC) is developed and implemented in real time on a FPGA platform. The classical trajectory tracking cost function of this controller is extended to include the inverter switching and conduction losses explicitly. Depending on phase current magnitude and its direction, different combinations of switching losses (IGBT turn on, IGBT turn off, diode reverse recovery) and conduction losses (IGBT or diode) have been considered in the implementation. This approach aims to reduce the inverter switching and conduction losses while keeping the dynamic performance of inverter-fed Induction Machine (IM) intact.Simulation and experiment provide very similar results indicating correctness of inverter losses calculation. The experimental results show a considerable reduction of the drive system losses as well as the inverter losses while the dynamic performance of the IM remains the same. This comes with a moderate increase in current THD, yet the RMS error between the estimated torque and reference torque remains almost intact.