Research On The Adaptive Protection Of Distribution Network With Microgrid

It is researched that distributed generation has characteristics of randomness and clearance, which will have a significant impact on power system. In order to make more rational and effective use of distributed generation, microgrid has been put forward.Firstly, the definition, structure, control method and characteristics of microgrid are introduced and then the structure of microgrid which the Consortium for Electric Reliability Technology Solutions (CERTS) proposed was selected for study in this paper. The microgrid is composed of load, micro-power and energy storage device. There are grid-connected mode and the islanded mode in microgrid. In most cases, microgrid runs in the grid-connected mode, and the load of microgrid can be supplied from microgrid or main power grid. When fault occurred in the main power grid, microgrid will quickly disconnect the main power grid and smoothly switch to islanded mode, to ensure that critical loads are not affected. According to the above study, a simulation model of the microgrid is built using.Meanwhile, impacts of microgrid on protection of distribution networks are researched. It is researched that the location, size and type of microgrid would have different effects on the protection of the traditional distribution network. The simulation model of distribution network with microgrid was built using PSCAD. Then this paper did setting calculation for protection of original grid by simulation and studied the impacts of short-circuit current provided by microgrid on the protection.Finally, this paper further studied the adaptive protection of the distribution network with microgrid based on the analysis of the impacts of microgrid on protection of distribution network and the characteristics of microgrid. In addition, the feasibility of the adaptive protection of distribution network with microgrid is verified using the method of combining the MATLAB programming and PSCAD simulation.