A new strategy for area voltage/VAR control based on operation-state-diagnosing method

A method for improving substation voltage/VAR control based on operation-state-diagnosing of control devices is proposed to limit operating times of transformer and capacitor in this paper.This method determines whether a device can operate or not through a diagnosing function which is constituted by an inertia factor and an accelerating factor,and combined with"13 zone"theory to develop a modified strategy for substation voltage/VAR control.The strategy directly employs real time data of voltage and loads to control without load forecasting.A new model has also been built to harmonize voltage/VAR control in an area.It takes the operation effects to different voltage levels into account.Cases prove that the proposed model effectively limits operating times of devices and guarantees the high voltage/VAR quality at the same time.