Optimization And Research Of The Xinyelian Distribution Network Relay Protection Configuration At PZH Steel

With the development of the enterprise,the Xinyelian distribution network continually develops and the installed capacity increases.Many distributed generations are involved(e.g.Blast Furnace Top Gas Recovery Turbine Unit and Waste Energy Gas Generator)in this network,which causes the short-circuit capacity increasing,and the short-circuit current along with the change of operation mode enlarging,the relay protection configuration becomes complicated and the calculation becomes difficult.In recent years,with the development of the 220 kV network frame and the change of the 110 kV network frame in Panzhihua,as well as PZH Steel Power Plant's 3×100MW to be let down in the grid,the Xinyelian distribution network short-circuit current should be changed.Therefore,it's of great theoretical and engineering practical importance to study the short-circuit characteristics of the Xinyelian distribution network and the impact on the relay protection.Firstly,the structure and the existing equipments and the relay protection configuration of the Xinyelian distribution network are analyzed,and the relay protection configuration problems and countermeasures are put forward in this paper.Then,the fault characteristic is analysed and the existing protection configuration of the Xinyelian distribution network is studied.Combining with the relay protection configuration of the distributed generation grid research at home and abroad,the short-circuit current characteristics of the distributed generation is studied.By building the simplified model of the distribution network,the influence of the distributed generation on the protection are analyzed and the corresponding solution is put forward.A equivalent simulation model of the Xinyelian distribution network is built,the affect of different fault location,distributed power supply,power distribution network structure under the condition of the impact on the relay protection are simulated.The short-circuit capacity,voltage and current value of each node for protection calculation are obtained.According to the simulation results,a new calculating method of relay protection setting calculation are distributed computing by the short-circuit current and voltage.In the last,the relay protection configuration of the buses,transformers and feeders are calculated at the Xinyelian distribution network,and the relay protection configuration optimization scheme and measures are obtained.The main transformer and generator protection configuration are adjusted,the whole network protection action time is optimized and the restriction condition of the protection to the operation mode is proposed.The research provides safety and stability running for the Xinyelian distribution network.