外文文献变电站自动化分析

Integrated Substation Automation System AnalysisAbstract Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of powers transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life.Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the countrys economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Power plants and substations are connected user link in the middle, transformation and distribution of electric energy to play the role.Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability, sensitivity and other indicators.Substations have been equipped with various protection devices, these devices are based on lower short-circuit load to a maximum load conditions, such as configuration settings and, therefore, in the event of the failure was similar to the specific circumstances under to judge by the system should automatically trip protection, and now the protection of the whole trip has been a very short time, the lifting of the fault, the system will automatically reclosing devices and the gateway to restore power quickly. This is to protect the lower the load is very favorable. This will not only protect the safety of the load equipment is in favor of extending the service life and reduce equipment investment, and improved reliability of electricity supply, which is to improve the efficiency of industrial and agricultural production is very effective.Substations have been equipped with various protection devices, these devices are based on lower short-circuit load to a maximum load conditions, such as configuration settings and, therefore, in the event of the failure was similar to the specific circumstances under to judge by the system should automatically trip protection, and now the protection of the whole trip has been a very short time, the lifting of the fault, the system will automatically reclosing devices and the gateway to restore power quickly. This is to protect the lower the load is very favorable. This will not only protect the safety of the load equipment is in favor of extending the service life and reduce equipment investment, and improved reliability of electricity supply, which is to improve the efficiency of industrial and agricultural production is very effective.Increase in the efficiency of industrial products means lower product costs, increase market competitiveness, which will enable enterprises to increase for the national economy and make a greater contribution to development. Electricity supply reliability and other fields, can improve peoples quality of life, improve their living conditions.In recent years, as computers and digital communication technology, secondary substation equipment is basically a computer-based. Computer protection, computer monitoring device in the substation have been widely used, which greatly raised the level of automation in power system reliability and operation, has achieved a lot of unmanned substations. However, due to differences in professional standards, different manufacturers used in the design of substation automation programs are not the same, thus leaving the majority of users at a loss.Substation relay protection, fault recorder, local and remote monitoring not only of different functions, and the realization of the principles and techniques are also different. Thus, the long-standing expertise in different technologies and the corresponding management departments. With the microprocessor-based protection, computer control and remote computer devices, such as widely used, it was noted that despite the different functions of these devices, the hardware configuration is the same, the collection and to control many of the same object. Thus, it appears from the overall situation to consider the idea of substation automation. However, in substation automation technologies, the implementation process of the relay, measure, control, remote features, as well as the relationship between them, are still some problems worthy of our study.Keywords: substation automationThe following currently used for many domestic substation automation design practical, from the secondary system analysis and comparison of several aspects.1 System structureThe whole system level by the station management, industrial bus network layer and spacing layer is composed of three parts, the system of all monitoring, protective equipment are modular units of the structural design, according to the voltage substation level, the size can be flexible and user requirements. Because of the centralized system is no longer used, it is no longer here, the following describes only the structure of distributed systems.1.1 Function-oriented distributed systemsA function of each unit completed, the system functions can be divided into: AC and DC measurement unit, remote acquisition unit, remote control and operation unit, pulse energy collection units, such as the protection unit. The advantages of such systems is the functional unit with the communication bus between the complete separation of the electrical, any fault on the system unit has no effect on the rest of the system. The disadvantage is that multi-screen group, the relative complexity of the second wiring, poor scalability, decentralized units can not be installed.1.2 Interval-oriented distributed systemPower transmission line to substation is divided into a number of intervals, such as into the line spacing, transformer spacing, round layout. Relatively independent of the spacing of equipment, only through the Internet communication network stations with station-level computers to communicate. Interval of each layer by telemetry, remote, remote control, the protection of the distribution of multi-CPU configuration, and the introduction of computers in the design of local area network technology, the distribution function, as far as possible the principle of decentralization, which, though greatly improved the reliability of, any interval failure will not affect the other partitions, but the reliability of each interval is relatively low, if any interval a fault will affect the whole interval.1.3 Object-Oriented Distributed SystemsThat is, a unit of an object into each line, each round, each transformer, capacitors can be targeted. This is a true full-distributed substation automation system, which broke the original limits of the functions of the second device, in accordance with the requirements of substation automation reorganization. This object-oriented distributed systems in line with the International Electrotechnical Commissions technical specifications, is the future direction of development. It has the following features: greatly improved system reliability, partial failure does not affect the system; relatively independent modules, each affected small; data sharing good; system efficiency; multi-function integrated control approach, making the operation of equipment management very simple, low maintenance; anti-interference ability; good scalability; stations needed the Second cable greatly reduced, saving investment.2 Dual-bus network and a single network structureStand-level management and monitoring layer to protect the data and commands between the transmission network can be double or single network structure. Hub for the 110kV substation, a dual network structure to facilitate a large flow of data to ensure rapid delivery when all kinds of signals, and to improve its reliability. Dual-network approach, usually an independent group to monitor and protect the network, in the transmission line or electrical equipment fault protection actions, the network can be used to protect the rapid transmission of recorded wave data. Substation 110kV and below, as a result of a smaller scale, data throughput, 110kV and below a single network substation can well meet the requirements of data transmission.3 integration of monitoring and protectionSince the technology level of the special status of protection and management system problems, long-term protection and monitoring has been separated. However, with the electricity sector, the gradual changes in management and computer and digital communication technologys rapid development, low-voltage level (eg, 35kV, 10kV) substation, in order to reduce the investment cost, ease of operation and management and improve the level of automation, control and protection of suitable integration unit, which is characterized by: monitoring and protection together to protect the independence of TA and TA to monitor access, this is to ensure the accuracy of measurements, but also improves the reliability. Hardware standardization, the same as the unit of hardware, software is different from the same template can be interchangeable, the measurement accuracy is not affected after the swap will help users maintain and master. Object-oriented design, a complete sampling. The main protection and back-up protection of a strict separation of the main transformer protection and high and low pressure side of the back-up protection is a small unit, and backup protection for each side of the design, the same unit within the strict separation of the protection of exports. Flexible configuration unit may focus on group screen, the installation can also be dispersed. There are configuration functions, a variety of ways to protect the flexibility to access and removal.This structure has not been widely used at present because of: the professional management of the current power grids are separated from the protection and remote, using this structure to change the management system, operation and maintenance personnel at the same time demands a higher level. Reliable operation of such systems is one of the keys to the hardware unit to monitor the protection must adapt to poor working conditions, need to have a strong anti-jamming, anti-vibration capabilities, able to adapt to high temperature and high humidity of the working environment; second is to have a efficient and reliable fast data communications networks. Due to the design of the reasons, the integration of monitoring the protection of unit failure, there is no monitoring and the protection of a clear interface, it is difficult to find and distinguish the scope of failure.4 RS485 or CAN field bus networkDistributed system of communication there are serial communication bus mode and network mode, which is the most typical RS485, the latter applies to more typical substation environment Controller Area Network CAN.4.1 RS485 busRS2485 bus used in earlier substation integrated automation system, is still used in many systems, its shortcomings are: For smaller systems, there is sufficient transmission rate, real-time guaranteed, but with the system expansion to quickly lower the system performance. And safety of anti-poor and usually only suitable for internal use in the control room, can not be used to switch and switch between games, that does not apply to the installation of decentralized distributed systems. From the structure of the network there can be only one master node, and the rest are from the node, the I / O unit must be horizontal communication station-level computers, the system poor flexibility. Data communication is in response to type the command, the node only after receiving the master node in order to respond to the order, a number of important changes on a timely bit of information is not sent, real-time low. Error Detection and Correction feature no. Communication protocol by the manufacturers own, different systems difficult to interconnect devices.4.2 CAN bus networkThe use of a short frame transmission, and each frame has CRC error checking and other measures, anti-interference ability, just the use of low-cost twisted-pair transmission can guarantee BER 10-11.Farthest away from direct communication network up to 10km, at this time for the transfer rate 5kbit / s, and when the transmission distance of 40m, the transfer rate of up to 1Mbit / s.By multi-master mode, a network node can be found in the office any time to the network to send messages to other nodes, but also by point-to-point, point-to-multipoint broadcasting and global transmission of information, flexible means of communication.Node on the network can be configured to different priority levels, and the use of non-destructive decision-bus technology, when there are two nodes at the same time to send information to the network, the low-priority node will send its own moratorium, but the high-priority nodes continue to send it will not be affected, thus greatly saving time bus ruling conflict in order to ensure real-time nature of the whole system.Abnormal nodes on a network, a self-closing function of the bus and cut off the node and bus links, to ensure that other operations will not be affected bus.CAN network technical specifications in line with ISO11898, has good hardware support and an open environment.5 operating system backgroundSystem platforms and network operating system there are two major categories of WindowsNT and SCOUNIX, each with its own advantages and disadvantages.5.1 WindowsNT operating systemUpward compatibility of hardware, and do not need to manually optimize the allocation of hardware.Support software, and portability, and easy expansion of the secondary development and function. There are all-round multi-functional configuration of the system configuration, including system configuration, graphics, reports, curve, such as incident handling, allowing the system to generate modified very fast, flexible and convenient; a variety of configurations to generate and output statements, all of Excel-based electronic statements, easy to manage and interface with other tools; standard large-scale data systems SQLServer or Sybase as the real-time and historical database, the system capacity to ensure the data integrity and consistency, and easy to maintain seamless connectivity with other systems.Intuitive interface, high universality, the user generally will be used to reduce the workload of training. The stability of the system slightly worse, and sometimes more prone to occur as a result of the mandate of Death. Security is not high, susceptible to the intrusion of computer viruses. Based on the operating system, application software has some identifier, from the point of view of the confidentiality restrictions on the scope of its use.5.2 SCOUNIX systemMore stringent hardware compatibility, PC-general in the graphics card is not compatible with environment, even if compatible, and its lower resolution, most of 1024 768.Need to optimize the system configuration, this work could not do the general user. Less support software, application software, system configuration will have to prepare. English operating system environment, for domestic users is more difficult to master. More time to perfect the operation of experience and improvements in stability, safety, military, financial and other industries requiring high reliability of commonly used net