Power system automation technology paper 1
Analysis of Power System Automation Technology
With the rapid development of power electronics technology and microelectronics technology, the original concept of electric drive (electric drag) control can not fully grasp all the control devices that undertake the first-line tasks in modern production automation systems. Moreover, electric drive control has gone out of the factory and is widely used in transportation, farms, offices and household appliances. Its research object has been developed to motion control system, and the following only introduces the new development of electrical automation technology.
Electric power automation; Fieldbus; Wireless communication technology; Frequency converter/inverter
Introduction to 0
Nowadays, the innovative automation system controls the complex process, ensures the reliability and safety of the process operation, and establishes the corresponding foundation for the advanced maintenance strategy.
The rapid development of power process automation technology and the continuous improvement of control level have created conditions for the power industry to solve the contradiction between energy resources and environmental constraints. With the development of society and power industry, the importance of power automation is increasing day by day. The barriers between traditional information, communication and automation technologies are gradually disappearing. The latest technologies, including wireless network, field bus, frequency converter, man-machine interface and control software, have greatly improved the efficiency and safety performance of the process system.
Power system automation system generally refers to the electrician's secondary system, that is, power system automation refers to the automatic monitoring, coordination, adjustment and control of all components, local systems or the whole system of the power system locally or remotely through various devices with automatic detection, decision-making and control functions, so as to ensure the safe, stable and healthy operation of the power system and qualified power quality [1].
1 development of electric power automation
China began to develop substation automation technology in 1960s. After decades of development, substation automation technology has reached a certain level. In the reconstruction and construction of urban and rural power grids in China, not only the low-voltage substations are unattended, but also a large number of new automation technologies are adopted in the construction of ultra-high voltage substations of 220 kV and above, thus greatly improving the modernization level of power grid construction, enhancing the possibility of power transmission and distribution and power grid dispatching, and reducing the total cost of substation construction, which has become an indisputable fact. However, the development of technology is endless. With the development and maturity of intelligent switch, photoelectric current-voltage transformer, on-line state detection of primary operation equipment, substation operation training and simulation, and computer high-speed network in real-time system, it will have a far-reaching impact on the existing substation automation technology, and a fully digital substation automation system will appear soon.
2 the realization technology of electric power automation
Fieldbus is called computer local area network in the field of automation. With the rapid development of information technology, the structure of automation system has also changed. With the increasing complexity of industrial power grid and the copyright problem of industrial automation network, people have higher and higher requirements for the security of power grid. Fieldbus control technology, as a new control technology, will replace the past control mode and be applied to power automation.
3 wireless technology
Wireless communication technology has an attractive feature because it does not require complicated and expensive wiring in the factory area. On-site patrol and maintenance personnel can keep in touch with control management centers such as centralized control room to realize information sharing. In addition, wireless technology is highly flexible and easy to use, and can realize the visualization, parameter adjustment and diagnosis of remote devices or systems through remote links. The emergence and rapid progress of wireless technology are providing a new perspective for the power industry to observe problems, thus creating an exciting new era in the field of power process industry and asset management.
Although there are many wireless technologies at present, only a few of them are particularly suitable for the trend industry. This is because the process of wireless signal propagation through space, data capacity (bandwidth), anti-RFI (radio frequency interference) /EMI (electromagnetic interference) interference, sensitivity to physical barriers, expansibility, reliability and cost are different for different wireless technology networks. Therefore, many users tend to? Choose the right wireless technology according to the specific application? . Wireless technologies used for control mainly include GSM/GPRS (cellular), 9OOMHzRadios, Wi-Fi (802.1a/b/g), WIMAX(802. 16) and ZigBee (802./kloc-0). Among them, Wi-Fi and WIMAX applications have the fastest growth.
4 information technology
Power informatization includes two parts: power production, dispatching automation and management informatization. Automation of power plants and power stations has always been the focus of power informatization. Most hydropower plants, thermal power plants and substations are equipped with computer monitoring systems. A considerable number of hydropower plants have also realized unattended and few people are on duty after transformation. The wide application of automatic monitoring system for power generation production has greatly improved the automation level of production process. The level of power dispatching automation is even more advanced in the world. At present, SCADA, AGC, ems and other power dispatching automation systems have been built, and all provincial power dispatching institutions have established SCADA systems, and the three-level dispatching of power grid is 100% automated. Guo Ziming, director of automation department of North China Electric Power Dispatching Bureau, said that as early as 1970s, North China Electric Power Dispatching Bureau used transistor computers to dispatch electricity, from 12 1 to 176 and then to 176. By 1978, North China Electric Power Dispatching Bureau has basically realized the automation of power grid dispatching.
5 security technology
Electricity is one of the lifeblood of society, and the dependence of human society on the power system has reached an unimaginable level. The impact of power system catastrophe on society is immeasurable, so the most important thing of power system is the safety of operation, but this problem has not been well solved all over the world. The probability of power system disaster is very small, but the consequences are extremely serious. China's power system has also suffered serious stability damage accidents. Due to the demand of rapid economic development in China, the power industry will continue to develop at an unprecedented speed and scale. With the implementation of Three Gorges Power Station, West-to-East Power Transmission, North-South Mutual Power Supply and National Interconnection, China is bound to have the largest power system in the world.
6 transmission technology
The device to realize variable frequency speed regulation is called frequency converter. Inverter is generally composed of rectifier, filter, drive circuit, protection circuit and controller (MCU/DSP). As one of the sharp tools of energy saving and emission reduction, frequency converter has been widely and maturely applied in power equipment. For inverter manufacturers, in the next 30 years, inverters, especially high-voltage inverters, will play an extremely obvious role in saving electricity and reducing consumption, and inverters will become the first choice for more and more power industry transformation technologies.
In the industry, ABB, the leader of power automation technology, has established the world's largest transformer production base and insulator manufacturing center. Since the establishment of 1998, the company has participated in many national key power construction projects, and won favorable comments from domestic and foreign users for its safe, reliable, efficient and energy-saving product performance. Its products include PLC, frequency converter, instruments, robots and other products, which have been well applied in the power industry.
7 man-machine interface
Power stations, substations and DC power panels are very important equipment. With the continuous development of science and technology, the improvement of enterprise search network and single chip microcomputer technology, the power industry has put forward higher precision and higher quality requirements for power stations and substations. DC power panel is a very important equipment in secondary equipment of power plants and substations, and it is responsible for providing DC control and protection power for power plants and substations. At the same time, it provides operating power for high-voltage switches and circuit breakers, so the reliability of DC power board will directly affect the safe operation of power station. The development of DC power supply panel has gone through a long time, from early DC generator and magnetic saturation DC charger to integrated circuit SCR controlled DC charger, single chip microcomputer controlled SCR charger, high frequency switching power supply charger and so on. And it is very mature at present.
The rectifier charging part of DC power board still adopts the most popular soft switching technology in the world at present, and finally converts power frequency alternating current into stable DC output. The core component of DC power board system control is V80 series programmable controller PLC, which processes the input and output analog quantities and switching values collected by the system, and finally controls the high-frequency switching power supply module to work more reliably according to the battery curve and the manual working requirements.
8 concluding remarks
Electrical automation technology is the most active, dynamic and promising comprehensive subject in the world today, and it is a synthesis of many high and new technologies. Its application range is very wide, almost permeating all sectors of the national economy. With the development of science and technology in China, electrical automation technology is also improving.
refer to
Wang Xiuli. Summary of China Power System Automation [J]. Water Conservancy and Electric Power Technology, 2005(02).
[2] Tang Liang. On the application of intelligent technology in power system automation [J]. Silicon Valley, 2008(02).
Xia Yongping, Tang Jianchun. On Power System Automation [J]. Silicon Valley, 20 10(06).
Power system automation technology paper II
Analysis of Power System Automation Technology
Abstract: What is the demand for electric energy supply in modern society? Safe, reliable, economical and high quality? And so on, correspondingly, the power system also constantly puts forward higher requirements for automation. Power system automation technology has been developing from low level to high level, and from local to whole. This paper expounds this in detail.
Keywords: electric power system; Automation; Automation
introduce
In recent years, with the continuous development of computer and communication technology, power system has developed into a system integrating computer, communication, control and power electronic equipment. The amount of information in power system automation processing is increasing, the observation range is getting wider and wider, and the objects of closed-loop control are getting richer and richer. In order to ensure the safe, stable and healthy operation of the power system, all components, parts and the whole system of the power system adopt devices with automatic detection, decision-making and control functions, and automatically monitor, adjust and control locally or remotely through signal and data transmission systems to achieve qualified power quality.
1 power system automation and intelligent control system
1. 1 power system automation
Power system automation mainly refers to the automatic management and automatic scheduling of the whole process of power transmission and production through equipment with automatic control function and automatic detection function. Using automation technology can realize remote and local automatic control, regulation and monitoring of power system, provide guarantee for the stability, safety and normal operation of power system, and meet the actual demand of power quality to the greatest extent. Realizing the system automation of power system is of great practical significance to improve the operation level of power system. Its automation mainly includes substation automation, distribution automation and dispatching automation. Realizing power system automation can ensure the stable and safe operation of power system, improve the power supply quality of power system, and realize the economic benefit and management efficiency of power enterprises.
1.2 combination of intelligent technology and power system automation
The development of intelligent technology provides a higher platform for the development of power system automation. The application of intelligent technology in power system automation can not only develop and improve power automation technology, but also effectively coordinate the instability of power system through the effective application of intelligent system. Considering that the development of power system is not very mature at present, it is necessary to apply intelligent technology to power system in order to meet the public's demand for cheap and convenient power network as much as possible. However, at present, the automation level of China's power system is not very high, the development of all aspects is not mature, and there are some problems and imperfections in different degrees.
2 Power system automation technology
2. 1 substation automation
At present, the development of substation automation in China has achieved certain results, greatly reducing the operating cost of substations and enhancing the possibility of power grid dispatching and transmission and distribution. The control strategy is developing towards optimization, adaptation, intelligence, coordination and regionalization. Substation automation has been widely used in substations at all levels because of its stable operation and high degree of automation. Using automation technology can replace manual telephone operation and manual monitoring, thus greatly improving the level of safe operation and work efficiency.
2.2 Power grid dispatching automation
Power grid dispatching automation mainly includes core computer control system and real-time analysis and calculation software system. Power grid dispatching automation technology can automatically dispatch the power market by analyzing and monitoring the security and operation state of the power grid system in the process of power production, so as to meet the actual operation requirements of the power market. Microcomputer, power electronic device and remote communication are more and more used in control means. The information collection part of power plant and substation is a remote terminal, and the dispatching terminal is mainly used to dispatch the information collected by the remote terminal.
2.3 Substation integrated automation
Through the application of modern electronic technology, information processing technology and computer technology, the substation equipment and instruments are optimized and combined, and the comprehensive management of measurement, automatic control and monitoring of the main lines and related equipment of the substation is realized. The goal is optimization, coordination and intelligence, such as excitation control and power flow control. This technology has the characteristics of simple maintenance, debugging and operation, which greatly enhances the protection performance of substation and fundamentally realizes the remote monitoring and management means of substation.
2.4 Distribution network automation
Distribution network automation technology combines distribution lines and distribution substations. Like synthetic distribution network, it has the characteristics of dispersion, many points and wide coverage. This technology can monitor the operation state of distribution network in real time, so as to improve and optimize the operation mode of distribution network. When the distribution network fails and abnormal operation occurs, the distribution network automation technology can find the fault in time and take effective measures.
3 Intelligent technology in power system
3. 1 fuzzy control
Fuzzy control mainly adopts a fuzzy macro-control system, which has the characteristics of easy operation, nonlinearity, randomness, simplification and uncertainty, making the supervised fuzzy relationship model very simple and feasible, and has great advantages. The superiority of fuzzy control method is embodied in every place, including household appliances, which makes the control operation very easy to master and very simple. This intelligent technology of fuzzy theory has very practical value in the automatic control of power system, because it can simulate people's decision-making process and fuzzy reasoning process.
3.2 Linear Optimal Control
Optimal control is an important part of modern control theory, and it is also an embodiment of applying optimization theory to control problems. Linear optimal control is the most widely used and mature branch of many modern control theories. Lu Qiang and others put forward the problem of using optimal excitation control means to improve the transmission capacity and dynamic quality of long-distance transmission lines, and obtained a series of important research results. This study points out that the optimal excitation control mode should be directly used to replace the classical excitation mode in large units. The linear optimal controller of power system has been widely used in power production and played an important role.
3.3 Expert System Control
Expert system has a wide range of applications in power system, including identifying power system in warning state or emergency state, providing emergency treatment, system restoration control, extremely slow state transition analysis, load shedding, system planning, voltage and reactive power control, fault point isolation, distribution system automation, dispatcher training, short-term load forecasting of power system, static and dynamic security analysis, and advanced man-machine interface. Although expert system has been widely used in power system. But there are still some limitations.
3.4 Neural Network Control
Neural network control is developed from artificial neural network, which is mainly used for learning and model structure, and has been widely popularized and realized. At present, people are most concerned about the nonlinearity of neural network control, as well as its robustness, processing ability and autonomous learning ability. Neural network is a neural network composed of a large number of simple neurons connected in a certain way. According to different specific problems, various neural network structures and their training algorithms have been applied in power systems. The main theoretical research of neural network includes the hardware realization and learning algorithm of neural network.
4 intelligent technology and automation development trend
At present, automation is gradually developing from a single unit to some areas or even the whole system, and the single function is gradually developing to integration and multi-function. The control strategy is developing in the direction of adaptation, optimization, regionalization and intelligence. With the continuous progress of science and technology in China, intelligent technology has been widely used in various fields, and its significance is particularly important for power systems. Although intelligent technology has been widely used in power system, according to the current development trend, intelligent technology based on computer software and hardware will be more comprehensively applied in power system. In addition, intelligent technology and automation technology will be more closely combined and will be well applied in power grid system.
5 concluding remarks
With the development of computer technology, control technology and information technology, power system automation is facing unprecedented changes. Multimedia technology and intelligent control will quickly enter the field of power system automation, and the development of information technology will not only promote the development of power system monitoring, but also promote the development of power system control to a higher level.
refer to
[1] Xia Shujun, Cheng, Application of automation technology in power system distribution network [J]. New technologies and products in China, 20 10 (2): 78-79.
[2] Zhu Lin, Xu Xiuying, Xiao Zhongtu. On the application ability of power system and its automation technology [J] Wind of science and technology, 20 10 (4): 36-37.
Zeng Lin, Tao Jin. Research on the application of automation intelligent technology in power system [J]. Journal of Beijing University of Electric Power (Natural Science Edition), 201(10): 94-97.
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