Research On The Influence Of Distributed Photovoltaic Generation On The Relay Protection Of Lvliang Power Grid

Fossil energy has provided a huge thrust for modern economic prosperity and social progress,but at the same time it has also caused serious environmental pollution and ecological problems.In this context,photovoltaics,as a representative of clean and efficient green energy,are favored by countries all over the world.Lvliang City has also earnestly implemented various decisions and deployments of the Central and Provincial Party Committee,and continued to promote the photovoltaic poverty alleviation project in Lvliang City.However,after a large number of distributed photovoltaic power generation has been integrated into the Lvliang power grid,it has caused various impacts on the existing power grid structure of Lvliang.Since the distributed photovoltaic power generation in Lvliang City is usually connected to the 10 k V low-voltage distribution network,the low-voltage distribution network has changed from the original single-radiation power supply network to a dual or multiple power supply network.Some relay protection devices also have an impact.In view of the distributed photovoltaic connection in Lvliang City,this paper analyzes the influence of distributed photovoltaic power on the relay protection after being connected to the Lvliang power grid,and proposes a relay protection improvement plan to solve the adverse effects.This article takes the Jiaocheng 110 k V Qianhuoshan under the jurisdiction of the State Grid Shanxi Province Lvliang Power Supply Company as an example to explain the operation status of the Qianhuoshan,the wiring method of primary equipment and the main protection configuration.Then,taking the Wangcun line of 10 k V line as an example,the influence of distributed photovoltaic power generation on line relay protection after the connection of distributed photovoltaic power generation is analyzed from the theory of different fault locations and different connection capacities.The theoretical analysis was simulated using PSCAD simulation software,and the simulation results showed that distributed photovoltaic power generation would cause the three-stage current protection of the line to malfunction.In order to reduce the adverse effects of distributed photovoltaic power generation,an improved adaptive quick-break current protection scheme is proposed.This scheme can make the line protection automatically calculate the fixed value,and can reliably remove the upstream,downstream,and adjacent feeder faults of the distributed photovoltaic power generation.The program has verified the feasibility through simulation and improved the power supply reliability of the Lvliang power grid.