Originated in Germany, VEP-12 indoor medium-voltage enclosed vacuum circuit breaker is the first complete series of medium-voltage enclosed vacuum breaker around the globe jointly developed by R&D team under the leadership of senior vacuum breaker experts of China and Germany. To meet the demand of grid and industrial mine enterprise users for automatic operation and condition overhaul of the breaker, Xiamen Huadian has separately developed VEP motor-operated breaker and VEP intelligent breaker based on VEP medium-voltage vacuum breaker, which have been put into domestic and overseas market; they improve automatic level of the breaker and realize condition overhaul, thus largely reducing breaker maintenance work for users and saving maintenance cost.