Simplified model for control design of STATCOM using three-level inverter

A simplified closed-loop model is proposed for a static compensator (STATCOM). Although PI and PD controllers for the proposed model have been investigated, the latter controller is found to offer better performance. This model makes it possible to extract instantaneous active fundamental component of the load current. The STATCOM is configured using a three level voltage source inverter. For high power applications the multilevel inverter is preferred over the commonly used two level voltage source inverter from the standpoint of harmonic components, DC link voltage and inverter switching frequency. The STATCOM is capable of providing reactive power compensation for fundamental and harmonics; power factor correction under balanced and unbalanced loading conditions. The performance of the STATCOM together with the proposed model is validated by extensive simulation results.