Cascaded Predictive Control of a Single Power Supply-Driven Four-Level Open-End Winding Induction Motor Drive Without Weighting Factors

Abstract

A dual-inverter can synthesize four-level space vector using a single dc power supply and a floating capacitor by utilizing an open-end winding induction motor (OEWIM). In this article, a cascaded predictive current control (CPCC) method is proposed for this drive that completely avoids weighting factors. Sequential control of multiobjectives by identifying the order of evaluation of individual objectives is introduced. In this article, motor torque and flux are controlled first followed by voltage balancing of floating capacitor to determine the optimal switching combination of the dual-inverter. To improve computational efficiency of the proposed CPCC, a reference voltage vector is used in this article, in place of current prediction for identifying the candidate switching combination. Ruggedness of the envisaged CPCC is demonstrated through simulations and experimental studies covering speeds below and above motor base speeds of operation. Performance of the proposed CPCC is also compared with the existing model predictive control (MPC) methods to showcase torque ripple reduction, improved current total harmonic distortion (THD), reduced inverter switching frequency, improved inverter efficiency, etc. Above all, due to the simplicity of the proposed CPCC, a drastic reduction in the execution times is achieved when compared to the existing MPC methods.