LCL output filter design and the influence to the D-STATCOM compensation characteristic

As an important dynamic compensation device, the D-STATCOM is widely used in the power system, but its output current contains a lot of high-frequency harmonic composition. The LCL filter, a typical output filter, has good filter characteristics, but the compensation characteristic of D-STATCOM has strong sensitivity to the filter parameters. The paper firstly analysis the influence caused by the components of the output filter. Considering the compensation capacity of the D STATCOM, the compensation current switching ripple, the grid THD, the resistance loss and the other factors, a method of designing LCL filter was presented, and then analysis the compensation characteristic of the D-STATCOM with the LCL filter, the results proved that the output filter designed in this method has very good inhibitory effect on high-frequency switching ripple, and greatly improved the compensation performance of the D-STATCOM.