Zero Sequence Voltage Control of Open-End Winding Induction Motor by a Model-Free Predictive Control

Abstract

Supplying the open-end winding induction motor (OEWIM) with two typical voltage source inverters is an efficient mechanism to achieve a multi-level voltage on the stator. The asymmetric switching states of these two inverters generate a zero-sequence voltage (ZSV). The ZSV must be controlled in a way to prevent the production of zero-sequence current (ZSC) in the motor windings. This paper presents a finite-set model-free predictive control (FS-MFPC) to eliminate the ZSC. The proposed FS-MFPC utilizes an ultra-local model, which is independent of the system parameters. So, the robustness of the control scheme is improved against the uncertainties of the OEWIM. The ultra-local model of the proposed FS-MFPC is constructed by an extended state observer (ESO), which estimates the unknown function of the system. To avoid the complexity of applying ZSV in the modulation techniques, the proposed scheme is implemented in the finite-set predictive voltage control approach. The simulation results confirm that the proposed ZSV control has a good steady-state and dynamic performance.