The　static　var　generator(SVG)　with　cascaded　H-bridge　structure　can　dynamically　track　the　change　of　the　reactive　load　and　improve　the　power　quality　of　the　grid.　For　SVG　with　H-bridge　cascaded　structure,　the　DC　voltage　control　has　been　a　hot　topic.　Compared　to　the　carrier　based　modulation　method,　the　space　vector　modulation　method　has　more　applications　on　the　DC　voltage　and　can　be　more　convenient　for　digital　implementation.　Therefore,　this　paper　proposes　a　three　layers　control　system.　The　first　layer　is　for　total　active　power　control.　The　second　layer　is　for　interlayer　voltage　balance　control　which　use　the　phase-shifted　space　vector　pulse　width　modulation(SVPWM)　method.　The　third　layer　uses　the　space　vector　modulation　method,　through　selecting　the　appropriate　redundant　states,　the　DC　voltage　balance　control　and　reduce　of　DC　voltage　fluctuation　can　be　achieved.　Lastly　the　experiments　results　verify　the　correctness　and　validity　of　the　method.　©,　2015,　Chinese　Machine　Press.　All　right　reserved.