A variable amplitude multilevel voltage source inverter used for transient power dip compensation

Multilevel voltage source inverters have been considered as being suitable for high voltage, high power applications. Typical applications can be found in static VAr generation, power line conditioning, and voltage balancing. Multilevel voltage source inverters consist of many single-phase inverters. Charged capacitors may be used as DC input voltage sources. In most cases, the single-phase inverters are treated as identical. This paper presents the design and implementation of a variable amplitude multilevel voltage source inverter. In this inverter, capacitors used as input DC voltage sources are charged at different voltage levels according to pre-designed values. Several approaches in searching the optimal levels are investigated. A near optimal scheme is studied. It is found that the near optimal pattern has almost the same level of harmonics distortion as the optimal one. The near optimal scheme is implemented using a TMS 320C50 DSP card. Some experimental results are compared with simulated data. The two results are in agreement