Research On Data Transmission Stability Of High-Speed Rail Catenary Wireless Sensor Network

Catenary is an essential part of the traction power supply system,its work state has direct influence on the safety of high-speed railway traction power supply system.The catenary ground monitoring equipment is installed at the key nodes of the catenary system to monitor the status of catenary equipment in real-time and realize the fault diagnosis and early warning of catenary.Owing to the complex and changeable natural environment and electromagnetic environment,caternary faces great challenges in stable data transmission in wireless sensor network for high-speed railway catenary condition monitoring.Therefore,this paper studies it from the following three aspects:(1)This paper analyzes the basic requirements of wireless sensor network data transmission of high-speed railway catenary state ground monitoring system,and studies antenna,MAC protocol and network topology.It also designs communication mechanisms and user protocol packet format in accordance with GB/T 24339,and avoids data frame loss,data frame insertion,data frame disorder and data frame error through equipment ID,serial number,confirmation frame and cyclical redundancy check(CRC).(2)To ensure stable communication of sensor nodes in the wireless sensor network of high-speed railway catenaries and low-power consumption,this paper studies and analyzes the relationship between RSSI,packet loss rate and distance,designs the adaptive power control algorithm,adopts Kalman-mean processing approach,improves the accuracy of link quality assessment,and realizes the adjustment of node transmission power according to the mean value RSSI.The testing indicates that the algorithm enhances the efficiency of power regulation and reduces power consumption when the packet loss rate is less than 1%.(3)To achieve reliable data transmission of key sensor nodes,this paper conducts the optimization research on service quality of wireless sensor networks for highspeed railway catenary,proposes a CSMA/CA communication mechanism for the wireless sensor network of high-speed railway catenaries,and studies the relationship between the two parameters,backoff index and backoff times,and failure rate,average delay as well as handling capacity.the paper deduces the Markov mathematical model,analyzes the probability of the access channel of different priority nodes,the probability of CCA detection channel occupation,and the probability of successful transmission,and verifies its feasibility.The testing result indicates that,through multiple experiments on this mechanism,the mechanism realizes service differentiation,improves the communication quality of key sensor nodes,enhances the handling capacity of the whole network,and shortens the overall network delay,providing a favorable basis for improving the performance of wireless sensor network of high-speed railway catenary.The last part of this paper summarizes and looks forward to wireless sensor networks of high-speed railway catenary monitoring systems.The research outcomes of this paper were tested in the laboratory and communication performance in the actual natural environment.Some of them were tested on a great sea crossing bridge in the Wenzhou-Fuzhou section of Hangzhou Shenzhen High-speed Railway,achieving stable communication for six months.