Railway Communication Power Design

In the era of industry,information processing technology has become extremely important,and the communication power supply plays an important role in information processing technology system.The stable and reliable communication power supply is the key to ensure the safe and reliable operation of the communication system.Because the communication power supply is directly connected to the power grid,its performance have an important impact on the power grid.Railway communication power supply refers to the high-frequency switch communication power supply,mainly used in communication systems such as railway communication sections and railway intermediate station communication machinery rooms.Because of the importance of the railway system,stability and safety are the premise of railway communication power supply design.In addition,according to the difference of communication network grade and location,the centralized monitoring and management of railway communication system is realized,the maintenance of few people and even no one on duty are realized,and the intelligent monitoring system is finally realized.In this dissertation,various aspects in the design of railway communication power module are studied.Through the optimization and design of the power module structure,the performance of the power supply is improved.The control circuit is set to provide state information for the railway centralized monitoring system,so that the railway communication system is more intelligent.Setting up soft switch of power supply unit can reduce switch stress of power supply module,protect circuit device and improve efficiency of power supply.In this dissertation,various topology of railway communication power supply are studied and compared.The main parts of the power supply are preliminary determined:input filter circuit,power factor correction circuit,DC/DC conversion circuit,control circuit,sampling circuit,and driving circuit and so on.Firstly,the research on the power factor circuit is carried out.Because of a large number of harmonics after rectification,the phase of input voltage and current is different.Active Power Factor Correction(APFC)is selected to correct the voltage after rectification,and its modeling and simulation are carried out.For the phenomenon that the high-frequency turn-on and turn-off of the main switch tube of the APFC circuit causes energy loss,a new passive lossless network is proposed in the design scheme,so that the circuit switch tube realizes zero voltage zero current switch.The model construction of the buffer network,the detailed analysis of the circuit state of the buffer network in each stage of the circuit operation process;then,according to the characteristics of the designed power supply level,the phase shift is full.The design method of the bridge current rectifier circuit is DC/DC conversion,the principle of the designed circuit is analyzed in detail.Finally,the selection of the control circuit is completed,so that the control system can not only realize the control function of the power circuit.Also,the status information of each power module is provided for the centralized monitoring system at any time.To ensure the intelligent monitoring of the centralized monitoring system,other circuits in the circuit such as the driving circuit,the sampling circuit and the input filter circuit are designed in this process.On the basis of completing the topology selection of railway communication circuit,this dissertation separately calculates the electrical parameters of the above model,and selects the main components in the circuit to lay the foundation for the subsequent circuit construction.In order to verify the correctness of the circuit structure,the design of each circuit module is simulated and verified on the MATLAB SIMULINK simulation platform,and the results are analyzed.Since the simulation waveform of MATLAB SIMULINK platform is too ideal,in this dissertation,in order to simulate the actual working switch.The waveform of the switch process was changed,and the simulation model of the soft switch part was built in SABER,which verified the feasibility of the designed circuit.