Simulation of reactor turn to turn short circuit detection based on finite element analysis

Dry-type air-core reactors are widely used in transmission lines, generally working outdoors, and the working environment is relatively harsh, so there are many fires caused by inter-turn short circuit faults. Therefore, it is necessary to take the necessary monitoring means to detect the abnormal operation of the reactor in time and maintenance it. Firstly, the structure of dry-type air-core reactor and the circuit model of inter-turn short circuit are analyzed, and a scheme for collecting the magnetic field signal of reactor is proposed; then the calculation principle of the magnetic induction intensity of the electrified coil is further analyzed. On this basis, a new type of reactor inter-turn short circuit detection device based on finite element analysis is designed, in which the finite element simulation analysis is the key step to realize the device. Through the establishment of ANSYS finite element simulation model, the changes of winding current of fault layer and overall magnetic field of reactor during normal operation and interturn short circuit of reactor are simulated. The simulation results show that when the inter-turn short circuit occurs in the reactor, a closed loop will be formed in the winding of the fault layer, and a large induction current will be generated in an instant which is shown as a peaked mutation current at the output port of the reactor. At the same time, due to the distortion of the magnetic field at the fault location, the distribution of the spatial magnetic field is uneven, which affects the stable operation of the reactor. Taking the simulation data as the early warning value of the monitoring device, the requirements of on-line monitoring of inter-turn short circuit fault of the reactor are realized.