A Dual Five-Phase Space-Vector Modulation Algorithm Based on the Decomposition Method

Open-end winding variable speed drives with dual-inverter supply have been extensively investigated for various applications, including series hybrid power-trains and propulsion motors. The topology is simple to realize while offering a higher number of switching states without the need for capacitor voltage balancing algorithms, when compared to standard multilevel converters. The overwhelming majority of work is, however, restricted to the three-phase electric machinery. One of the reasons for this is that inclusion of a multiphase machine leads to exponential increase in the number of possible switching states, and so the design of a suitable space vector modulator (SVM) represents a considerable challenge. This paper considers a relatively simple SVM algorithm based on the decomposition of the three-level space vector decagon into a number of two-level decagons. The proposed modulation technique has the advantage of being relatively simple to implement. The drive produces multilevel load phase voltages with negligible low-order harmonic content. Despite the simplicity of the method, the quality of the output voltages is improved, compared to the previously proposed methods. The developed scheme is verified via detailed simulations and experiments using a five-phase induction machine under open-loop V/f control.