Control of Cascaded H-Bridge Converter based DSTATCOM for High Power Applications

This paper presents the simulation studies on a cascaded H-bridge converter based distribution static synchronous compensator (DSTATCOM) for improving the power quality of a distribution system. Voltage source converter based DSTATCOM has been established as the most preferred solution for management of reactive power in distribution utilities and for improving voltage regulation, power factor and power quality in industries. For high power applications, cascaded H-Bridge converter is the most ideal choice compared to two-level inverter with series connected power devices. In the present work DSTATCOM controller is designed using DQO modelling for reactive power management and thereby improving the power factor in distribution systems. The dc link voltage and the three phase load currents are used as feed back signals for the controller and it is designed in such a way that DSTATCOM is able to supply the reactive current demanded by the load both during steady state and transient conditions using sinusoidal pulse width modulation control.