Shea, John J., Sundareswaran, K., Poljak, D., Cvetkovic, M., Islam, M. M., He, J., Birke, K. P., Vertigan, G., Brieda, L., and Wypych, G.
Power electronic drives consist of semiconductor switches arranged in a way such that the circuit can be controlled with certain gate pulse patterns to produce the desired output power waveforms. These circuits can be used to convert DC-DC, AC-DC, DC-AC, or AC-AC. Typical applications include variable speed drives for motors, both AC and DC motors (VSD), uninterruptible power supplies (UPS), Flexible AC transmission systems (FACTS), voltage compensators, and photovoltaic inverters. Topologies for these converters can be separated into two distinct categories: voltage source inverters and current source inverters. Voltage source inverters (VSIs) are named so because the independently controlled output is a voltage waveform. Similarly, current source inverters (CSIs) are distinct in that the controlled AC output is a current waveform. [ABSTRACT FROM AUTHOR]