Fault Evolution and Life Prediction Model for Inter-turn Short Circuit of Dry Air Core Reactor Based on Multiple Time Scales

For studying the development process of inter-turn short-circuit fault in dry-type air-core reactors，in this paper the modles of inter-turn short circuit faulr evolution and life prediction of reactors based on multi-time scale is proposed. Firstly，the inter-turn short-circuit process is divided into such three stages as normal operation state，interturn arc short - circuit and inter - turn metal fusion short - circuit in accordance with the time characteristics，and the simulation model of fault evolution is set up respectively based on long-time scale，short-time scale and very-short - time scale. The event-driven model trigger mechanism is adopted to handle the evolution relationship of different simulation models and the simultion algorithms of inter-turn short circuit faulr of reactor is set up on the basis of event-driven. Finally，the preddition model of residual operation life of the reactor based on long-term and short-term memory networks is set up using the extracted electromagnetic and temperature characteristic parameters and fault samples. The study results show that the multi-time scale evolution model set up in this paper considers the time charac- teristics of inter-turn short-circuit process and is capable of effectively distinguishing different stages of the fault developemnt process. Furthermore，the remaining life prediction model can be used to accurately predict the process of inter-turn short-circuit，provide timely warning in the early stages of inter-turn arc short-circuit and reduce the damage and losses caused by fires of the reactor.