Abstract:Currently, distributed photovoltaic power generation in Guizhou is experiencing an explosive growth. Distributed photovoltaic power generation has randomness, fluctuation, regional characteristics, etc. When it is connected to the distribution grid, it will cause the fluctuation of the power supply rate, etc., and consequently affect the power loss of the distribution grid. However, the existing grid line loss calculation and analysis do not consider the impact of large-scale new energy access on line loss. If the existing method is used for calculation and access work, it will cause a large error. Firstly, this paper introduces the development and grid connection of distributed photovoltaic power generation in Guizhou in recent years; secondly, it introduces the current grid connection scheme of distributed photovoltaic power generation; then, it introduces the characteristics of distributed photovoltaic power generation and the electricity consumption characteristics of substation areas from various perspectives, and conducts theoretical calculation and simulation analysis of the impact of photovoltaic access on substation line loss; subsequently, it takes a substation area with actual photovoltaic access to the grid as an example, and verifies it from the perspectives of access location and capacity through historical data and on-site application conditions. Finally, it analyzes and summarizes the impact of distributed photovoltaic access on sub-line and substation line loss.