Multilevel Power Electronic Systems Adjusted by Algorithms of Multi-Zone Space-Vector Modulation: A Survey

This publication provides a brief overview of the results of dissemination of the method of multi-zone space-vector pulse-width modulation (PWM) for the adjustment of inverter-based installations (with low switching frequency of inverters) characterized by multilevel output voltage: a) of split-phase variable speed drives; b) of transport-oriented ac drives with two windings of the stator of electrical machine; c) of three-inverter-based power systems with modular configuration; d) of photovoltaic (PV) systems with twin inverters; e) of five-phase installations with asynchronous machine with open-end winding; f) of six-phase structures with quad inverters, and g) of photovoltaic installations based on triple inverters and transformer of multi-winding configuration. It has been shown that the developed schemes, techniques, and algorithms of multi-zone synchronous PWM (MZS PWM) applied for control of the mentioned above inverter-based systems (with specialized phase-shift between signals of separate inverters) assure synchronization and symmetry of the basic voltage waveforms of installations over the entire control range. It provides minimization of unwanted sub-harmonics (of the operating frequency) in spectral composition of the basic voltages of these installations, leading to reducing of losses in systems and to increasing of its efficiency.