Switching scheme for static synchronous compensators using cascaded H-bridge converters

摘要

A static synchronous compensator includes at least one converter pole for producing a first phase of an AC voltage waveform having a fundamental cycle. The first phase of the AC voltage waveform includes alternating converter pole charging and discharging regions in each fundamental cycle. The at least one converter pole includes a plurality of cascaded H-bridge cells, each having a DC voltage source and a plurality of switches. The switches are capable of being switched to produce a plurality of switching states. There is a controller configured to control the switching states of the plurality of switches of each of the cascaded H-bridge cells based on the voltages of DC voltage sources of the H-bridge cells and on whether the AC waveform is in the converter pole charging region or the converter pole discharging region.