Control and topologies for three-phase three-level active power filters

Most previously reported three-phase active power filters are based on two-level converters, which are suitable for low voltage systems. In this paper, three-phase three-level active power filters are presented based on several new vector strategies and one-cycle control to serve the high voltage systems. Studies at UCI Power Electronics Laboratory have shown that each vector strategy has its eminent characteristics that can be tailored to a variety of needs. By combining these strategies with one-cycle control, all resulted active power filters can automatically balance their output capacitor voltages. The theoretical findings are verified by a 1 kVA experimental prototype.