SF₆ Circuit Breaker Online Monitoring System Based On Image Processing And Wireless Transmission Technology

With the progress of science and technology and the improvement of economic level,people's demand for the reliability,safety,and energy saving of the power system's regulation and operation has been continuously improved.The large centralized control management model has become the dominant mode of the substation management model.The traditional way of regular maintenance requires preventive testing and regular outages.This will affect the production,result in wastage of manpower and material resources,and overhaul and failure to monitor equipment anomalies in real time,etc.The on-line inspection mode based on the acquisition terminal and advanced sensors can solve the above problems well.It will surely become a maintenance mode that the contemporary power system attaches great importance to and promotes.SF₆ gas has the excellent characteristics of insulation and arc extinguishing,making the SF₆ circuit breaker used in power systems as an important electrical equipment widely.SF₆ gas leakage is one of the common defects in the use of equipment,and its monitoring work is extremely important.At present,the domestic SF₆ gas leakage on-line monitoring system is used to monitor the pressure and temperature of SF₆ gas,and then converts it to gas density,thereby reflecting the leakage of SF₆ gas.This method can cause gas leaks that are not reflected in time and can easily cause safety accidents.The method of positioning the leak source by the handheld SF₆ gas detector in the station staff has a large workload and is time consuming,and the measurement must also consider the constraint of the line length.This article focuses on the online monitoring technology of SF₆ gas leakage optical imaging.The CO₂ laser camera is used for high-speed continuous shooting of SF₆ gas equipment.The image acquisition uses image target detection techniques such as image graying,three-frame difference method,threshold segmentation,image morphology,and so on.Using Kalman filtering and Blob geometric area extraction,the positioning of SF₆ gas leakage source,the real-time tracking of leakage trajectory and the quantification of gas leakage are realized.The image processing results are sent to the upper computer of the monitoring room through the WiFi wireless communication technology and presented in the LabVIEW software so that the on-site staff can visually observe the gas-tight state of the gas-insulated equipment,accurately find the source of the gas leakage fault,and timely follow-up maintenance and defect reporting.The image acquisition terminal includes a monitoring terminal module,a wireless transceiver module,and a human-computer interaction interface.The image acquisition terminal hardware includes a camera COMS OV7740 module,an OV780 module for image processing,an MSP430 module for controlling the displacement and angle,a memory module,and a power module for supplying power to each chip.The software of the image acquisition terminal adopted the modular design concept,controlled the image sensor through the SCCB bus protocol,and uses the WiFi wireless transmission module to implement data transmission and reception.Each module is an independent subroutine that can be configured according to customer needs to implement the functionality of each module.The system's human-computer interaction interface adopts the LabVIEW software development platform,which can real-time display SF₆ gas leakage status,data text records,and historical data curves,and vividly show the gas leakage images of SF₆ circuit breakers.Finally,the data receiving performance of WiFi wireless transmission technology is tested.The two performance indexes of the receiving sensitivity and the receiving maximum input level verify the feasibility and effectiveness of the real-time monitoring system of SF₆ circuit breaker based on image processing and wireless transmission technology.