The Relay Protection Method Research And Simulation For The Distribution Network With Distributed Generation

The problems of environment and energy have become increasingly prominent and the rapid development of the distributed power generation has been promoted. Comparing against centralized power supply, distributed generation has incomparable advantages, but the distributed generation inserted in the mature big power grid brings a lot of problems. The impact of distributed generation on distribution network protection is one of the important problems. This paper builds the analysis model of relay protection for distribution network with distributed generation by PSCAD/EMTDC electro-magnetic transient simulation software, then simulates and analyzes several existing protection schemes.The paper, firstly, expounds the characteristics, advantages and disadvantages of distributed generation, then does the classification. At the same time, classifies and sums up the existing distributed power protection solutions for the distributed network with distributed generation. Next the paper briefly introduces PSCAD/EMTDC electro-magnetic transient simulation software, and bulids the model of the researching distribution grid system by this software.The influence of the distributed network with distributed generation on the three-zone current protection has been analyzed thoroughly in this paper.By changing the accessing location of distributed generation, on condition that it doesn’t affect the protections, the paper simulates the biggest capacity of distributed generation which allowing insert to the distributed network, and analyzes its characteristics.According to the distance protection has characteristics of direction and no influence with different system operating modes, this paper analyzes the influence factors of distance protection on the distributed network with distributed generation. Impacts of the Ⅰ,Ⅱ section of distance protection have been simulated and analyzed with disparate location and capacity of the distributed resource.In the network with distributed resource, the current protection and the distance protection limited capacities of the distributed resource. So the paper researches the adaptive current protection which is not limited the capacity of the distributed power, and focus on expounding its characteristics and setting method after inverting the type of distributed power connected to the distribution network. According to disparate the faulted location and capacity, this paper builds the analysis model by PSCAD/EMTDC electro-magnetic transient simulation software, the simulation results show that the improved adaptive protection can satisfy distributed power with different capacity’s accessing into the distribution network, and has very good protection effect.