This paper introduces application of high-voltage conversion in 700MW units condensate pump. Compared energy consumption with before

it shows that high voltage converter has notable saving electric energy effect which basically eliminating the throttle loss of valve and ensuring that the system maintain the optimum operating conditions at any time.The problems during the process of frequency conversion transformation were discussed. The bad heat elimination often leads to equipment failure. The paper provided some measures to prevent similar problems from recurring response which can be reference of the same kind problem in other power plants.