As the most widely used device in the var compensation field

static var compensator（SVC） plays an important role in enhancing the grid reliability

improving the transmission limit and damping power oscillation

etc.The capacity of SVC installed in the key substations grows with the expansion of the power grid.This has put forward the heat increase of the valve.Based on the design of valve cooling-system of high-voltage & large capacity

this paper briefly summoned the basic demands and constitution of cooling-system

analyzed the heat-dissipation in detail

and proposed a new design scheme to adopt dual parallel branch waterway for each level cooling-circuit of valve.