Multi-channel monitoring method for tower current under lightning strike and its characteristics analysis

A parallel circuit of multiple Rogowski coils is used to monitor the lightning current flowing through the tower. Based on the working principle of a typical Rogowski coil, a model of a multi-Rogowski coil parallel outer integral circuit was established. The theoretical analysis of the dynamic characteristics (time domain and frequency domain) of the circuit model was carried out, and according to the outer integral conditions, the theoretical formula of the circuit model was obtained. According to the lightning current measurement requirements, the circuit model was simulated and analyzed, and the parameters of the sensor have been obtained based on the simulation parameters, which have been verified by the impact current experiment. The simulation and experimental results show that the designed multiple Rogowski coils parallel outer integral sensor can correctly restore the lightning current waveform flowing through the tower, the error is less than 2%, and the dynamic characteristics meet the actual measurement requirements. Accuracy of the theoretical results is verified, which provides a theoretical basis for the parallel application of multiple Rogowski coils. The current sensor has been applied in the actual lightning monitoring system. © 2021, Harbin University of Science and Technology Publication. All right reserved.