Voltage-drop phenomenon and countermeasures in distribution grids with large amount of photovoltaic power generation

Abstract

In Japan, rapid voltage drop and reduction in interconnection capacity due to degradation of system stability have occurred in long-distance distribution lines with large amounts of photovoltaic power generation (PV). Distributed energy resources such as PV are regarded as the main energy sources in microgrids. To develop microgrid facilities, we need to understand both the system condition of the voltagedrop phenomenon and the limited interconnection capacity based on system stability. In this paper, we describe the distribution system conditions based on the voltage-drop situation. We propose a method to calculate the limited interconnection capacity of grids without using power flow calculation. The validity of the proposed method was verified by comparison with the power flow calculation. Therefore, good results were obtained.