単相SCを用いた電圧不平衡抑制装置の導入による配電系統へのPV導入量拡大効果

抄録

In recent years, it is concerned that rapid introduction of residential photovoltaic generation system (PVs) may cause voltage unbalance in high voltage distribution system. Load Ratio control Transformer (LRT) at substation and Step Voltage Regulator (SVR) are used for voltage regulation, however, unbalanced voltage make SVR and LRT difficult to regulate the line voltage. The authors have studied on voltage unbalance suppression system using single phase static capacitors (named SC system), and presented the control method for regulating the line voltage in proper range suppressing the unbalanced voltage. However, the input pattern of SCs is restricted due to the voltage rise caused by PVs. In order to solve this problem, cooperative control in SVR is required to expand the working range of SC system for suppressing voltage unbalance. In this paper, the authors propose the method of determination of a target voltage of SVR for cooperative control with SC system in distribution line connected large amount of PVs. The proposed method is verified by simulation study on distribution system model and the impact on amount of PV is discussed by suppressing unbalanced voltage using SC system.