The necessity of reactive compensation aiming directly at the harm of reacitve power is illustrated, and the importance of reactive compensation focusing on energy sources is emphasized. The paper also states the hiatory and the present situation of reactive compensation according to the facts home and abroad. It is pointed out that dynamic reactive compensation is the development tendency of reactive compensation and ASVC is the development tendency of dynamic reactive compensation. In addition, the paper prospects the optimisation methods of the dynamitic reactive compensation ASVC.