Line protection method of warship DC zonal distribution network

Because of the poor adaptability of traditional warship protection method in the new warship DC zonal distribution network and the lack of recognition of the transient characteristics of fault in this type of network, the characteristics of this network were analyzed and a line protection method was proposed. Relationship between the short-circuit current under the current limiting control of the transformer and the protection setting of the lower line in the regional distribution was deduced. The characteristic signal of the short-circuit fault current of the lower branch of the transformer was resolved by the recursive wavelet to avoid the refusal of protection. Then, the overlap of the switch protection range was analyzed. Combined with the network topology, the breadth first search(BFS) algorithm was improved to determine the switch action priority, and the protection misoperation was solved. Finally a protection method based on the 3-dimensional comprehensive control coverage area was formed by combining with the traditional line protection method. The protection method was verified in software. The 3-dimensions used in this method are independent of each other, which can determine the coverage range of protection action and meet the needs of relay protection in warship DC zonal distribution network. © 2021, Harbin University of Science and Technology Publication. All right reserved.