Railway power telecontrol system Power telecontrol system in an increasingly important role in the management of power system, safe, high quality and economical operation of power supply to the railway provided an important technical tool. This article describes the development of railway electric power telecontrol system in China, analyzed the composition of railway electric power telecontrol system, exploring the main features of power telecontrol systems.（1）Overview of railway power telecontrol system in ChinaRemote technology is widely used in China for long, but developed very rapidly, generally experience three stages in the development process: the contact point on the phase-phase, which is based on relays as the main component, supported by step selector switch, vacuum tubes and other components of the remote device. Remote device has a large number of such contact, maintenance, reliability, short life, an early remote products. Railway power supply without going through this phase. Second stage-routing logic stage, this stage through the transistor, integrated circuit process. Remote device is non-contact type of routing logic device, design according to requirements and constitute parts of the device logic circuits at a fixed time, to complete the intended function. These devices are hardware devices, not at liberty and expansion of functions. In the 70 's, the bulk power system in China has been using such devices, and there have been used on the electrified railway. Third-phase software phase, remote system of SCADA system in electrified railway in China on technology breakthroughs had been made, there are rapid application development. Because of electrified railway power systems have different characteristics, SCADA systems and power systems on the development of the road is not exactly the same. Due to the stable and reliable power systems are critical to the operation of the railway, in order to give full play to railway continuous power lines, closed lines (now General dutong called "through the wire"), ensure the safety of railway continuous power lines and reliable power supply, improve the management level of railway continuous power lines and control, reducing the impact on railway transport production, remote control technology in the 90 's were introduced in railway power systems in China.（2）composition of railway electric power telecontrol system2.1 remote control master stationMain stations generally use the computer network structure of remote control, distributed control systems, computer equipment for the core, to network nodes to be configured. System hardware configuration of the main front, back-end processing, maintenance operator network nodes such as node a workstation, analog screen man-machine interface device and corresponding device, set up real time data printing, document management report printers, peripherals such as monitors and satellite clock synchronization in real time. Application software is the soul of telecontrol system as a whole, together with various remote Terminal application software data communication tasks; various data acquisition hardware system application software such as voltage, current, power, calculated and displayed for operator reference in a reasonable manner; operators also have to apply software toperform. Application software is good or bad, directly affects the level of application of telecontrol system performance and stability.2.2 remote control TerminalRemote terminal equipment into the power distribution Terminal (RTU), Rod switch terminal (FTU) and signal power supply terminal unit (STU). Substation integrated automation installed centralized RTU, according to the distribution function of the entire system requirements, RTU implementation for telemetry and remote control, remote signaling by the distribution, the distribution of the base unit on all protected information by remote systems to send the main station to meet far away, remote control, telemetry, remote signaling, remote online monitoring and remote diagnosis and maintenance requirements. Distribution by installed RTU collection into line voltage, and bus voltage: power into line current, and active power, and no Gong power, and power factor; feeder current, and active power; through feeder voltage, and current, and active power, and no Gong power; capacitor compensation device current, and no Gong power; collection all circuit breaker device location away letter and the protection action away letter; records power low voltage, and had flow, and speed broken Shi circuit breaker device action triggered points before and after 10 a cycle data, and save 10 a fault recorded wave data for system accident analysis. Switch monitor on Terminal (FTU) to remote control of power distribution terminal for the core unit, with a stainless steel control cabinet, operator, smart charging devices, maintenance-free batteries, and other peripheral devices. FTU is mainly installed in electric power transfixion line segments on/off switch, to detect and control the running status of the switch, measuring circuit of voltage, current, active power, reactive power, electric, acquisition of remote loading of high voltage switching, high voltage line passing flow and short circuit grounding remote remote remote, high-voltage lines, saving 10 fault recording data for system analysis. Signal power supply terminal unit (STU) located along the station signal equipment room, enabling the power of signal building telemetering, remote letter, remote control functions. Signal power supply terminal unit (STU) with remote control platform as the core of power distribution unit, and switch monitor on Terminal (remote control terminal of FTU, make up the station monitor nodes, remote control of the data and forward them to the main station, complete remote control of the function. STU main detection of railway continuous power lines through the output transformer of electric parameters of the signal power, collecting signal power supply voltage and current, active power, power factor, such as positive sequence, negative sequence simulation and remote circuit breakers of low voltage overcurrent, short circuit remote volume such as remote. Record two-way signal power low voltage remote control circuit breaker over-current occurs, when the instantaneous tripping, points of failure before and after 5 cycles of voltage and current waveform curves, hold 10 fault recording data for system analysis. In addition, records limited, out of bounds before and after the 5s failure curve of the voltage and current values. Remote terminal data collection to analysis of normal load changes in the trends and failure, for rational allocation of resources, and provide a basis for scientific analysis to determine fault. Remote Terminal consists of data input and output modules, data communications,power supply segments in three parts:[1] data input/output (I/0) module. Far dynamic terminal of core part, main has three a function: a is to site instrument entered of signals transformation into digital information, and to these digital information transfer to far dynamic control main station of computer in the; II is to far dynamic control main station computer sent to of control information transformation into corresponding of signals, transportation to implementation institutions, to completed control process: three is data communications function, completed and upper machine or other device of data communications. Used for data input and output in a remote terminal (I/0) module has two main devices: data acquisition module based on single-chip microcomputer and programmable controller PLC (Programmable logicController, programmable logic controllers).[2] data communication section. Data input/output (/0) data transmission channel of the module and the monitoring center.[3] the power supply section. For data input/output module, radio, modem, instruments, such as DC power supply. Common DC power +5V,+12V,+15V,+24V. Power supply section on remote terminal has an impact on the stability of the work, so cannot be ignored. Power must be configured according to the specific situation of each RTU, but the power supply power has enough load capacity, strong anti-jamming ability, small corrugated, overcurrent and overvoltage protection function.2.3 Communication channelCommunication channel is part of the telecontrol system is very important. With the help of communication channels, remote terminals and remote control of all the main stations to exchange information with each other and share information, improve the reliability of power system operation, reducing the number of connecting cables and equipment, realizing Terminal distance monitoring and control. Remote control remote control master station of Terminal through the communication channel to transmit real-time information including: numerical size, voltage, current, power circuit breakers location status, event log, and so received remote control master station of breaker control command and control commands to queries and other operations. Telecontrol channels generally use the physical structure consists of optical cable ring structures, dynamic standby operation modes: remote control master station through tele-control channel query message query remote data terminal, remote terminal such as remote control of data is sent on the main station, such as the no data answer the normal response message. Due to the railway system of power telecontrol system itself has no communication lines, remote control master station communication system provided by rail prepared by special master/optical digital channels to communicate with the control Terminal, remote monitoring and control, optical digital channel using ring-type structure. Dual Ethernet master station configuration, together, communicate with the accused in logic form point to point communication.3 main features of power telecontrol systemPower remote system's main tasks are: characterization of power system operation State and the relevantreal-time information acquisition of power plant and substation to the remote control home station; main station remote control command sent to the remote terminal, control and regulation devices. Remote control of remote terminal to the main station of the information measure and the amount of State, active power, reactive power, measurement of voltage, current, frequency, the water level of the reservoir. Location of circuit breakers, disconnectors, automatic equipment, relay protection action state, generator, telecontrol equipment operation status. Main function has: remote control, and away letter, and telemetry; print; has on line fault for detection of ability; has on real-time data for collection, and transmission, and analysis, and processing of function has on far dynamic terminal for online since check and corresponding displayed of function; on user picture and user database implementation online modified, and edit and will on the of function; all computer has since started, and since recovery function; redundant configuration of double host system, has can automatically switch and manual switch of function; Simulation training for operators and presentation features.reference documents;[1] Qian Qingquan the. remote monitoring technology in electrified railway, China railway Publishing House, 2000.[2] the King Tiger. electromagnetic compatibility technology for electric power system automation equipment, Guangxi Water Conservancy and hydropower, 2006.[3] Tang Tao. technology development and prospect of power station automation, automation of power systems, 2004.。