An Improved DSTATCOM Topology with Reduced VSI Rating, DC Link Voltage and Filter Size

This paper proposes an improved hybrid distribution static compensator (DSTATCOM) topology to compensate reactive and non linear loads with reduced VSI rating, DC link voltage and filter size. An LCL filter with small value of inductor compared to traditional L filter has been used at the front end of a voltage source inverter (VSI), which provides the elimination of switching harmonics. Voltage of the DSTATCOM can be reduced with capacitor to be connected in series with an LCL filter. Consequently the power rating of the voltage source inverter has been decreased. With reduced dc-link voltage, the voltage across the shunt capacitor of the LCL filter will be also less. It will reduce the power losses in the damping resistor as compared with the traditional LCL filter with passive damping. Therefore, the proposed DSTATCOM topology will have reduced weight, cost, rating, and size with improved efficiency and current compensation capability compared with the traditional topology. A systematic procedure to design the components of the passive filter has been presented. The effectiveness of the proposed DSTATCOM topology over traditional topologies is validated through simulation.