Research On Immunity Of Wireless Sensor Unit In Substation Under Partial Discharge Electromagnetic Disturbance

The installation of wireless networks in substations has become an inevitable trend in the development of smart grids.Wireless sensor units used for signal acquisition and transmission have become an important part of the Internet of T hings.However,the electromagnetic environment of substations is complex.Partial discharges generated in or on the surface of high-voltage equipment,power switching operations,and space electromagnetic fields generated by other devices and equipment may cause electromagnetic interference to wireless sensing units.In order to better deploy the new LoRa wireless network in the substation,this thesis studies and analyzes the immunity of the wireless sensor unit under partial discharge electromagnetic disturbance.Aiming at the propagation and leakage characteristics of partial discharge electromagnetic disturbance,taking GIS substation as an example,a GIS strai ght cavity model is built.Strategies for the spatial orientation of units.Aiming at the coupling characteristics of the wireless sensor unit in the substation to the partial discharge electromagnetic disturbance,firstly,the simulation model of the wireless sensor unit is built;then,the back door coupling of the wireless sensor unit is combined with the noise tolerance,the characteristics of the 230 MHz helical antenna and the receiving sensitivity.The interference mechanism and the front door coupling interference mechanism are simulated and analyzed.Finally,the electromagnetic disturbance immunity test of the wireless sensor unit is carried out.According to the back door coupling,the front door coupling simulation analysis and the immunity test of the wireless sensor unit,the coupling characteristics of the wireless sensor unit to the partial discharge electromagnetic disturbance are comprehensively evaluated.The research results show that the partial discharge electromagnetic disturbance signal is easier to be received by the receiver through the antenna system,which leads to the communication error and packet loss of the wireless sensor unit.Aiming at the interference of partial discharge impulse noise in substations to LoRa wireless communication,firstly,the principle of LoRa modulation and demodulation is analyzed,and a feasible LoRa simulation model is established on this basis;Modeling,and the accuracy of the measured partial discharge signal represented by the Middleton Class A impulse noise with specific parameters is verified by mathematical statistics methods;finally,the LoRa in the Gaussian noise environment and the Middleton Class A impulse noise with specific parameters are evaluated through the bit error rate curve Communication performance differences in environments.The research results show that the partial discharge impulse noise will cause the loss of the signal-to-noise ratio of the LoRa system,resulting in the degradation of the system communication performance.The results of this paper can provide theoretical reference and practical basis for deploying LoRa wireless sensor units in substations.