An Online Insulation Monitoring System Based On Partial Discharge For Mine High Voltage Cable

The transmission tower is the foundation of the power system,and it undertakes the role of supporting the transmission line to transmit electric energy.However,when selecting the tower foundation for construction,due to the overall arrangement of the comprehensive line and the lack of strict terrain inspection,it is easy to be affected by the geographical location for a long time after the completion of the transmission pole tower erection.The tower above the empty area,because the underground coal mine has been excavated,the ground will slowly subside under the action of time,which will affect the transmission tower on the ground.my country has a vast territory and a wide distribution area of ??towers.Most of them are in remote mountainous areas.Some areas are accompanied by natural disasters such as lightning strikes,rain and snow,desert winds,mountain torrents,and debris flows.Severe natural disasters increase the possibility of displacement and inclination of transmission towers.At the same time,it brings inconvenience to the work of the inspectors.At present,the tilt monitoring of towers in some areas mainly relies on methods such as manual inspection and video surveillance.The manual inspection efficiency is low and the measurement error is large.Video surveillance often cannot grasp the tower inclination parameters in time,and is also greatly affected by the outside world.The measurement methods such as optical fiber sensor and stress sensor are compared,so the measurement method using MEMS sensor is proposed for the monitoring of transmission towers.Mainly because of its low power consumption,low cost and easy implementation.Aiming at the problem of low precision of MEMS-IMU,this paper analyzes two main random errors that cause low precision of IMU,namely,zero bias instability and angular random walk.The random drift error of MEMS gyroscope is modeled by Allan method.Based on the model,Kalman filter is used to compensate the error.In order to overcome the shortcomings of traditional Kalman filtering,Sage-Husa adaptive filtering algorithm is adopted to improve the accuracy of filtering results,forgetting factor is adopted to weaken the influence of "old data" on "new data",and adaptive nearest neighbor factor is adopted to make the established model more suitable for IMU.Under static or dynamic conditions,the improved IMU is simulated experimentally to obtain the best estimation,and the gyroscope is self-compensated without other sensor information.The results show that compared with the traditional Kalman filter,the improved Sage-Husa adaptive robust Kalman filter not only improves the filtering accuracy,but also has the ability of anti-anomaly,ensuring the stability of the filter,thus improving the performance of IMU.With the rapid rise of low-power,long-distance,anti-interference low-power wide area network(LPWAN),combined with the working environment requirements of the device,the data transmission technology combining Lo Ra module and NB-Io T module is selected to achieve long-term sleep.Combined with short-time work,it is more convenient to realize the requirements of low power consumption in the field and low cost of communication.While ensuring the completion of system transmission tasks,the purpose of long-term operation with low power consumption is achieved.After the design of the background monitoring platform of the system is completed,finally,this paper verifies the designed online monitoring system.In the laboratory,the turntable experiment and the communication scheme experiment are mainly carried out.In the turntable experiment,the data of MEMS-IMU are collected and processed by noise reduction.The simulation results show that the noise reduction effect is good and online processing can be realized.In the communication experiment,the stability of data transmission is mainly tested.The data transmission system is placed in different places of the school.The amount of data obtained in the background proves that the data transmission system is stable and the packet loss rate is small.After the laboratory test is completed,the device is installed on several towers in the goaf under the jurisdiction of Pingdingshan Coal Group.After several months of experimental data collection,it is proved that our system can transmit the tilt angle normally and in real time without external interference,and the design goal is well achieved with high reliability and accuracy.There are 50 drawings,8 tables and 74 references.