Influence Analysis And Improvement Of Grid Connected Photovoltaic Power Generation On Distribution Network Protection

In recent years, new energy industry the rapid rise, the solar energy in one fell swoop won the first prize, become a leader in the new energy, various countries also to more and more attention. However after the photovoltaic power generation system of grid connected PV system changed original distribution network network structure and power distribution, the fault current magnitude, direction and duration change, has a direct influence on the protective properties of the relay device, fit between the failure protection and security automatic equipment. The research of this topic is of great significance to ensure the safe and stable operation of distribution network, and to promote the application of photovoltaic power generation technology.This paper discusses the development status, key technologies and domestic and foreign research situation of photovoltaic power generation. On the basis of this, the research on the influence of the photovoltaic power generation access to the distribution network protection and the countermeasures are carried out.PV system connected to relay protection of distribution network of influence is studied in this paper. First, we analyze the when fault occurs, the different protection configuration scheme is applied in the distribution network, the PV grid connected system of relay protection and automatic safety device effect. Then by PSCAD/EMTDC simulation, in building a distribution network model, for PV systems from different locations of access, different network capacity and failure in different positions under the premise, through comparison of distribution network fault current changes. To sum up PV grid connected system of distribution network fault current is generated.Finally, by combining the simulation conclusion, discusses the protection scheme for wide area measurement system based on improved, on the original protection configuration, protection of the scheme of distribution network is improved, in order to determine the fault accurate location, through the wide area measurement system the multiple protections, and enable the maloperation of protection to prevent. In the permanent fault, using short time to stop power supply method to form the islanding operation. Only in this way can get good application of the positive effect of photovoltaic power, also makes the safety and reliability of power supply is improved.