Hardware experiment evaluation of STATCOMs using conventional and direct-current vector control strategies

A STATCOM is a term derived for Static Compensators that compensate reactive power and provide voltage support to an ac system. A traditional STATCOM consists of an energy storage device and ac power system both connected on either side of a voltage source converter (VSC), and a control system based on the conventional standard d-q vector control technology. This paper presents an extensive hardware experiment studies to compare the conventional and a direct-current vector control schemes for a VSC-based STATCOM. A limitation of the conventional control mechanism is analyzed and compared to a newly developed direct current vector control method. The hardware experiment evaluation demonstrates that a STATCOM system works well using the proposed direct-current vector control mechanism both within and beyond the converter linear modulation limit while the conventional control technique could result in over voltage and system oscillations in the challenging, variable, and distorted hardware experiment conditions.