Study Of The Effects Of Distributed Generation On Distribution System Safety Operation

The development of Distributed generation (DG) is a new tendency in the new century in prospect of power sources technique. The installation of distributed generation has great influence on the traditional power system and brings about notable advancement in electrical technology. In order to make use of disperse energy sources and improve the reliability of power supply, all kinds of distributed generations have been applied in power system widely. But along with the raise of the DG penetration level, there will be some operation conflicts: protection setting and breakers operation difficulty from the raising short circuit level; the miscoordination between auto-reclosing and DG.Most distribution systems especially rural systems are operated in a radial configuration. The main reason for this structure is the simplicity of operation and economy of the overcurrent protection system. The voltage regulation and protection of distribution systems are based on radial configuration. When distributed generation installed in the system, meshed distribution networks are in place of radial systems. Most conflicts over operation with DG arise from this structure, which bring new challenges to protection and reclosing equipments.The author classifies the distributed generation and discusses four popular distributed generation techniques. Distribution systems model and DG model are built in MATLAB. The theory and setting principle of distance protection are introduced in detail. According to the type, size and location of DG, the influence of DG on selectivity and sensitivity of protection is analyzed and the conclusion is achieved too. The problem may happen in the opration is also discussed. When DG connects to the system, it may influence the auto-reclosing. According to the random synchronizing reclosing and penecontemporaneous reclosing, the distributed generation system is simulated in MATLAB.