Research on Rapid Self-healing Technology of Smart Distribution Network with DG

Since China's urban distribution network did not consider the smart grid at the beginning of construction, it is difficult to conFigure the communication channel at present, and the distributed power supply access distribution network makes the traditional three-stage overcurrent protection difficult to adapt to the topology change and loses the criterion.. In order to solve this problem, the paper firstly analyzes the equivalent mathematical model of the inverter-type distributed power supply under the positive sequence component control strategy, and then analyzes the influence of the distributed power source on the fault current by using the symmetrical component method as an example. Finally, a non-channel protection rapid self-healing scheme suitable for distribution lines with distributed power supply is proposed. The circuit breakers are divided according to the area, and the fault line is quickly cut off by combining the eddy current repulsive vacuum high-speed switch. The solution does not rely on the communication channel, which saves the cost of constructing and maintaining the communication channel. The distribution line can achieve self-healing within 0.3s, which meets the requirements of the relay protection setting principle of the medium voltage distribution network. The correctness of the proposed method is verified by PSCAD/EMTDC fault simulation.