Robust Model Predictive Control for AFE-Inverter Drives With Common Mode Voltage Elimination

Abstract

This paper proposes a novel and robust version of Model Predictive Control scheme for AC drives based on Voltage Source Inverter (VSI) with Active Front End (AFE). The main feature of the proposed MPC is elimination of Common Mode Voltage (CMV) without imposing a penalty on the corresponding term in the cost function, but rather by a smart utilisation of the restricted set of switching states in a computationally efficient algorithm. Furthermore, the paper proposes to split the conventional MPC scheme into separate Control and Modulation stages, and to enhance the Control stage by integral action, and the Modulation stage - by a Feedback Quantizer. The resulting AC drive scheme provides high tracking accuracy over the full speed range, robustness to disturbances and parameters error, coupled with practically zero CMV and consequently - very low levels of conducted and radiated electromagnetic interference (EMI). This makes the proposed scheme a competitive alternative to the existing AC drive solutions in the most challenging industrial applications. The benefits of the proposed scheme are validated by simulation and experiment.