The Research Of Wireless Intelligence Technology For Switch Station

The special line railway of large-scale mining enterprises and defense projects is the foundation of national economy and national defense construction.The power supply of the contact network is safe and reliable,which directly affects the locomotive running.The "intelligent switch station" is set up on the connection of the dedicated line and the main line railway,it can rapid diagnosis and removal of the dedicated line contact network fault.The intelligent switch station is of great significance to ensure the normal operation of the main railway line.Because the existing fault diagnosis of power supply lines is not perfect,the research not only lacks relevant theoretical research but also has no relevant engineering pratical experience,such as:transient and permanent fault can not be able to identify;the existing technology can't achieve the efficacy of"intelligent switch".Therefore,we based on the theory and experimental engineering experience to design such "intelligent switch".The research results can provide reference for newly-built railway and existing railway reconstruction project design,construction and safety operation.First of all,this article based on intelligent electrical definitions and the actual needs of dedicated railway power supply to put forward the technical requirement of intelligent switch station.The article elaborates the design contents of the switch station,including the main wiring of the switch station,the structure of the cabinet,the circuit breaker,the automatic measurement and control system,the working power,electromagnetic compatibility and grounding,etc.The traction power station in order to ensure the requirement of uninterrupted power supply on dedicated railway during the maintenance of the switch station,we has developed a new kind of three isolation switch.To achieve for catenary fault intelligent diagnosis,we has analysised the fault tripping process of substation and switching station.According to the physical mechanism of the fault voltage and current,we has established the equivalent circuit and researched new algorithm for identification of fault properties.It is found that the transient fault identification is the gordian technique.The transient residual voltage is attenuated by exponential law,and the attenuation curve has two time constants which means the attenuation curve has an inflection point.Based on the above results,we extrated the intelligent identification criterion of the fault.In order to test the theoretical identification criterion the experiment was carried out on the catenary of dedicated railway.The experimental scheme used grounding wire which series fuse to simulate the transient fault.By comparing between the measured value and the calculated value the results indicated the relative error of the two values was only 1.5%at the inflection point of the transient residual pressure.The experimental results show that the theory is correct and the new algorithm has engineering application value.We put forward a new automatic control strategy to response the problem of power overload on dedicated railway.When the temporary overload occurred,the control system give the tripping warning signal,the catenary rely on automatic reclosing technology to restore power supply.When continuous overload occurred,the control system is subject to punitive power outages.Then we were established load current model and derived the formula of the load current.The error of control signal and sample signal was controlled under 5%by using the neural network BP algorithm.It was verifed the feasibility of the new strategy in the practical engineering.In order to guarantee the safe operation of the vacuum circuit breaker in the switch station,we based on the existing sensor technology to design and implemented the on-line monitoring of the mechanical and electrical characteristics of the vacuum circuit breakers.This dissertation has analyzed the physical process of the closing and breaking switch,the analysis result has determined the beginning time and transposition point time of the swich closing and breaking,then we puts forward the Newton interpolation difference algorithm for closing and breaking speed.We tested the type ZN-27.5 handcart vacuum circuit breaker with 27.5 kV high voltages in the laboratory in practice.The experiment results show that the time point extraction way can do on-line monitoring of mechanical and electrical parameters of vacuum circuit breaker.The intelligent early warning strategy of vacuum circuit breaker is put forward according to the requirements of technical regulations,the factory test data and historical operation data.This dissertation analyzes the demand of wireless communication technology of switch station and puts forward six technical requirements of wireless communication for intelligent switch station.In order to guarantee the security of GSM network communication,the encryption algorithm of wavelet decomposition and reconstruction is proposed.The research derived the formula and procedure of wavelet decomposition and reconstruction.According to the problem of electromagnetic noise affecting the wireless communication during the operation of power locomotive or the high-speed train,amounts of analysis shows that non-offline state between the pantograph sliding and block-contact wire is the normal running state.By using engineering electromagnetic field theory,and based on the characteristic of contact points in the pantograph-catenary neighborhood space to establish the discharge plasma electromagnetic radiation antenna array model.The non-offline electromagnetic radiation field intensity formula of pantograph-catenary was deduced.According to the actual parameters electromagnetic radiation was simulated.In order to verify the correctness of the algorithm,the electromagnetic noise radiation generated by the electric locomotive and the high-speed train under the non-offline state is measured by the field intensity measuring instrument.The measured results are in good agreement with the calculated values in the area of 5m?6m from the center line of the railway.This dissertation applies the theory of the above research to the development of intelligent switch station.Through several years' operation of the switch station,the actual operation effect shows that intelligent switch station can good solved the actual on-site problem the results achieved the target of study.