A Space-Vector Modulation Scheme for Multilevel Open-End Winding Five-Phase Drives

Abstract

Open-end winding three-phase variable speed drives with dual-inverter supply have been extensively investigated for various applications, including series hybrid powertrains 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 the standard multilevel converters. This paper extends the open-end winding concept to a five-phase drive. A relatively simple space-vector modulation (SVM) algorithm, based on the already well-understood five-phase two-level drive SVM method, is developed. The proposed modulation technique has the advantage of being straightforward to implement and, like its two-level counterpart, is able to generate output voltages with minimum low-order harmonic content. The method generates up to 17-level output phase voltage and, therefore, offers superior harmonic performance when compared to the two-level five-phase modulation. The developed scheme is verified via detailed simulations and experiments, using a five-phase induction machine operating under open-loop V/f control.

Ac Five-Phase Drive Systems Based on Cascade Converters and Open-End Winding Five Phase Machine

“…Another possible multilevel configuration in AC drive is the open windings configurations, first reported in [25] and widely explored since then [26][27][28][29][30][31]. The so called open-end winding configurations allow for multilevel voltages at the machine windings, higher power levels with smaller rated power converters, and reduced losses [32].…”

“…Hence, several research effort has been dedicated to such configurations [33], [34]. For instance, in [29] is shown a space vector PWM for the dual-inverter five-phase open-end winding topology.…”

A Space Vector PWM With Common-Mode Voltage Elimination for Open-End Winding Five-Phase Drives With a Single DC Supply

“…An asymmetrical six-phase machine was also the subject of [4], where four isolated dc supplies were utilized in order to reduce the system PWM control to the well-known 'nearest three vector' method, customarily used in three-level threephase neutral point clamped (NPC) voltage source inverters (VSIs). Multiphase open-end winding topology with dual inverter supply has been further considered in [5][6][7], where space-vector and carrier-based PWM techniques have been developed for five-phase systems.…”

“…The common feature of [3][4][5][6][7] is that isolated dc sources are used to supply VSIs at two sides of the multiphase machine's winding. A drawback of the requirement for isolated dc sources is that one or more isolation transformers are required in all applications where separate dc sources do not exist naturally (the requirement for isolated dc sources can be easily met in autonomous power systems that exist in, for example, ships, aircraft, and electric vehicles).…”

“…In contrast to the existing body of work [3][4][5][6][7], this paper considers a dual two-level inverter supplied five-phase motor drive where a single dc bus is used to supply both inverters. Such a possibility has only ever been considered in conjunction with the three-phase configuration.…”