This paper presents a twenty seven level Asymmetrical cascaded multilevel inverter based STATCOM. The STATCOM is characterized by series connection of low voltage converter, middle level voltage converter and high voltage converter. Asymmetrical switching configuration can be adopted with trinary dc sources. This configuration results in reduced number of switches for higher voltage levels. Artificial neural network controller is used for obtaining switching angles. The performance of twenty seven level inverter based STATCOM is analyzed by MATLAB simulation. The results confirm that harmonic performance is improved and unbalanced load compensation can be achieved effectively.

Keywords: Cascaded H-bridge (CHB), Total harmonic distortion (THD), Artificial neural network controller (ANNC)