Improving PV Hosting Capacity of Distribution Grids Considering Dynamic Voltage Characteristic

Since the penetration of renewable energy sources is rapidly increasing in distribution grids, the hosting capacity (HC) of distribution systems becomes the main concern. According to EN 50160, in LV grids, the mean value of voltage cannot exceed 1.1 pu (static characteristic) and voltage rapid changes should be kept less than 0.05 pu (dynamic characteristic). Existing researches evaluated the HC of distribution grids just based on the static characteristic. However, wind speed variations and rapid moving cloud, casting shadow on solar panels, can cause rapid voltage changes in LV grids. This paper studies the rapid voltage change by modeling the moving cloud shadow and compares the HC from perspective of both dynamic and static characteristic, which is not done before. Since voltage dynamic characteristic could be more restrictive than the static characteristic, as shown in a German distribution grid, a static synchronous compensator (STATCOM) is proposed and controlled to regulate dynamic voltage profile and to improve the HC.