Cascade control applied to asymmetric multilevel converter based-STATCOM

This paper shows how a single phase STATCOM model can be seen as a two block series connection. In this way, it is suitable to use a cascade control in order to regulate both DC links voltages and reactive power needed by AC main. This last is achieved through control strategy consisting in two parts: one of them is a cascade multi-loop control which delivers only one average control signal and the other part consists of adjustment mechanism which calculates the deviations from average control signal allowing generating the control signals for each cell. Tuning of cascade control is treated. In this case STATCOM is based on an asymmetrical multilevel converter. In order to verify the control strategy simulation and experimental results are presented.