Cooperation voltage control method of LRT and SVR in distribution system with PV systems corresponding to bank fault restoration

Voltages in distribution system are maintained within a proper voltage range by adjusting a tap position of Load Ratio control Transformer (LRT) and Step Voltage Regulator (SVR). In Japan, many voltage control methods have been researched. However, these conventional methods do not presuppose the bank fault restoration. Since the main purpose of voltage control of the conventional restoration approach is to reduce the amount of voltage violation in distribution system, the number of customers with voltage violation cannot be reduced to zero during a bank fault restoration. In this paper, the authors propose a cooperation voltage control method of LRT and SVR to minimize the number of customers with voltage violation corresponding to the bank fault restoration in distribution systems with PV systems. In the proposed method, the tap position of SVR is controlled after the control of LRT to avoid frequent tap changes and each tap position of voltage control devices is controlled to minimize the number of customers with voltage violation. In order to check the effectiveness of the proposed method, the simulation using distribution system model with PV systems is performed under various conditions.