Sinopak indoor water cooled Statcom adopts high degree of protection(IP55), power valve tower are placed in a sealed space, heat is took away through water cooling system, there is no interaction with outer environment.Power module in water cooled SVG has good heat dissipation conditions,workign shell temperature and junction temperature more less compared with air cooled SVG，which increased IGBT reliability and life. The maintenance costs of water cooled STATCOM will be less than the air-cooled SVG in future.