Research on static VAR generator with direct current control strategy

The operating principle of three-phase static VAR generator (SVG) with voltage source inverter (VSI) structure is analyzed in detail. Adopting a novel direct current control strategy under abc coordinate system, this paper realizes the rapid detection of system reactive current by applying instantaneous reactive power theory. On the basis of double closed-loop controlling method with voltage and current, the hybrid control approach based on the feed-forword control of grid voltage and DC voltage is proposed, which can eliminate the disturbance of grid voltage fluctuation and flicker and suppress the fluctuation of capacitor voltage at DC side effectively. The excellent static and dynamic performances of the system could be obtained. Finally, system simulation and experimental studies are performed respectively, and the results further verify the feasibility and effectiveness of the proposed control strategy.