A centralized distribution protection system

The access of distribution generation(DG) presented new challenges to the operation and protection of power system with the development of the smart power distribution network. The Wiring structure changes from a single power supply into a double-Power or more power. As a result, it brings impact to distributed protection. The result shows the size of DG affects protection and makes it lose selectivity probably, DG upstream protection makes it amplify protection range, DG downstream protection makes it reduce protection range. In response to the problem, this paper proposes a new scheme, which is based on the centralized processing module on the distributed protection. Firstly, a smart unit is installed in the switch, which is only responsible for merging unit and smart terminal unit function, and then SV information and GOOSE information are sent to a centralized processing unit through the fiber-optic communications. And then the centralized processing unit complete protection monitoring and control functions. Through utilizing the site-wide information collected on the distribution network to achieve network-wide protection, monitoring and control functions, it improves the reliability of the distributed protection operation. Compared with the conventional system, this scheme has more flexibility and more reliability on the coordination and the whole property. It is closer to the develop direction Of the distributed networks. Easier to transform into the intelligent distributed networks.