Based on the VQC harmony control in different substations

county harmony control by VQC for substations in regional power system is presented.The host station can get the information of load and states of switches through communication subsystems

then establish the model and forecast the load for the next day by using Kalman filter method

optimize the reactive power in the whole power grid utilizing the discrete reactive power optimization model and expanded interior-point algorithm

get the optimal curves of reactive power and voltage under the constraints of the adjusting times of transformer taps and the switching times of capacitor bank

and fix the harmony values of regional VQC.As the experiment shown

this algorithm has proved to be proper and reliable

and be capable to solve the regional discrete reactive power optimization.