Model Predictive Current Control of Nine-Switch Inverter-Fed Six-Phase Induction Motor Drives Under Healthy and Fault Scenarios

Abstract

Recently, finite-control-set model predictive control (FCS-MPC) has become ubiquitous in multiphase drives (MPDs), whose decomposed subspaces should be regulated through the control actions of a zero <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$xy$ </tex-math></inline-formula>-voltage projection to alleviate disruptive <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$xy$ </tex-math></inline-formula> currents. Among multiphase traction inverters, the lower switch count of nine-switch inverters (NSIs) has made them a popular choice for six-phase induction motor (6PIM) drives. However, when the structure of the inverter changes, such as in the case of an NSI, it becomes necessary to redevelop finite control actions in order to attain the same objectives. Hence, this article introduces a predictive current control (PCC) for NSI-fed 6PIM drives with a new control set selected to nullify <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$xy$ </tex-math></inline-formula> voltage and maximize <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\alpha \beta $ </tex-math></inline-formula> voltage as much as possible for six-phase winding configurations. Furthermore, the postfault operation of NSI-fed 6PIM drives is also introduced under a complete open converter leg (OCL), where two phases, sharing the same faulty leg, are disconnected. The concept of phase transposition under OCL is found effective to achieve the same torque operating range of the conventional voltage source inverter (VSI)-fed 6PIM drive at the expense of additional hardware for winding reconfiguration. Experiments on 6PIMs with different winding arrangements showcase the significance of the proposal.