Analysis of Power System Relay Protection Technology Through the analysis of the development status of China's power system relay protection technology, the task and basic requirements of relay protection are discussed. From the analysis of the wide application of current relay protection devices, some suggestions for the maintenance of protection devices are proposed, and the development trend of relay protection is discussed in light of the actual situation. 3.3 Application of protection devices Relay protection devices are widely used in high-voltage power supply systems, substations, etc. in factories, for line protection, main transformer protection, capacitor protection, etc. of high-voltage power supply systems. The application of the sub-bus relay protection device of the high-voltage power supply system installs the current quick-break protection for the segmented busbars that are not operated in parallel, but only when the circuit breaker is closed, it is automatically released after the closing. In addition, overcurrent protection should be installed, and protection should not be installed for power distribution stations with lower load levels. The application of substation relay protection device includes: 1 line protection: generally adopts two-stage or three-stage current protection, one of which is current quick-break protection, the second is time-limited current quick-break protection, and the third is over-current protection. 2 bus couple protection: need to install time-limited current quick-break protection and over-current protection. 3 main transformer protection: main transformer protection includes main protection and backup protection. The main protection is generally heavy gas protection and differential protection. The backup protection is composite voltage overcurrent protection and overload protection. 4 Capacitor protection: Protection of capacitors includes overcurrent protection, zero sequence voltage protection, overvoltage protection and voltage loss protection. With the rapid development of relay protection technology, the microcomputer protection device is gradually put into use. Due to the different manufacturers and the development time, the microcomputer protection presents a colorful and varied situation, but the basic principles and the objectives to be achieved are basically Consistent.
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1 Foreword Electricity, as the main energy source of today's society, plays an extremely important role in the development of the national economy and the improvement of people's living standards. The modern power system is a large system consisting of the generation, transmission, distribution and use of electricity. The rapid development of power systems has continuously put forward new requirements for the relay protection of power systems. In recent years, the rapid development of electronic technology and computer communication technology has injected new vitality into the development of relay protection technology. How to correctly apply relay protection technology to contain electrical faults and improve the operating efficiency and operation quality of power systems has become an urgent technical problem to be solved.
2 The status quo of relay protection development From the 1960s to the 1980s, the period of transistor relay protection technology flourished and widely applied. Since the mid-1970s, based on the integrated circuit protection investment of integrated operational amplifiers, integrated circuit protection technology has formed a complete series in the late 1980s, and gradually replaced transistor protection technology. The dominant position in the development, production and application of integrated circuit protection technology continues. By the early 90s. At the same time, China has begun research on computer relay protection since the late 1970s. Colleges and universities and research institutes have played a leading role, and have developed different types of different types of microcomputer protection devices. In 1984, the micro-machine protection device for transmission lines developed by the former Northeast Electric Power College was first identified and applied in the system, which opened a new page in the history of relay protection development in China, which opened the way for the promotion of microcomputer protection. In terms of main equipment protection, the generator loss-of-magnetism protection, generator protection and generator-transformer group protection, microcomputer line protection device, microcomputer phase voltage compensation mode high-frequency protection, and positive sequence fault component direction high-frequency protection have also passed. At this point, the microcomputer line protection devices of different principles and different models provide a new generation of relay protection devices with excellent performance, complete functions and reliable operation. With the research of microcomputer protection devices, many theoretical achievements have been made in microcomputer protection software and algorithms. At this time, China's relay protection technology has entered the era of microcomputer protection.
At present, relay protection is developing towards computerization and networking. Protection, control, measurement, data communication integration and artificial intelligence have brought arduous tasks to relay protection, and have also opened up a new world of research and development. With the continuous deepening of reform and opening up and the rapid development of the national economy, the power system relay protection technology will contribute to the great development of China's economy.
3 Configuration and application of power system relay protection 3.1 Relay protection The relay protection mainly uses the change of electrical quantity (current, voltage, power, etc.) in the short circuit or abnormal condition of the original power system to form relay protection. action. The task of the relay protection device is to safely when the power supply system is operating normally. Completely monitor the operation status of various equipments, provide reliable operation basis for the duty personnel; automatically, quickly and selectively remove the faulty parts when the power supply system fails, to ensure that the non-faulty parts continue to operate; When an abnormal operating condition occurs, it should be able to send a signal or alarm in a timely and accurate manner, and notify the on-duty personnel to deal with it as soon as possible.
3.2 Basic requirements for relay protection devices. When a fault occurs in the power supply system, the relay protection device should be able to selectively remove the faulty portion. First disconnect the circuit breaker closest to the fault point to ensure that other non-faulty parts of the system can continue to operate normally.
Sensitive. The sensitivity of the protection device is generally measured by the sensitivity factor. Within the protection range of the relay protection device, regardless of the position of the short-circuit point, regardless of the nature of the short-circuit, the protection device shall not cause a rejection action; however, when a failure occurs outside the protection zone, no malfunction should occur.
Quick action. It means that the protection device should cut off the short circuit fault as quickly as possible. The time to cut off the fault is shortened to reduce the damage of the short circuit current to the electrical equipment, and the recovery of the system voltage is accelerated, thereby creating favorable conditions for the self-starting of the electrical equipment, and also improving the stability of the parallel operation of the generator.
reliability. If the protection device fails to meet the reliability requirements, it will become the root cause of the expansion of the accident or direct failure. In order to ensure the reliability of the protection device, it is necessary to ensure that the design principle, setting calculation, installation and debugging of the protection device are correct. At the same time, the components of the protection device are required to be reliable in quality, proper in operation and maintenance, and simplified and effective in system to improve the reliability of protection. Sex.
4 The maintenance personnel of the relay protection device shall patrol and inspect the relay protection device at regular intervals, and make a record of the operation of each instrument. During the operation of relay protection, when an abnormal phenomenon is found, monitoring should be strengthened and reported to the competent authority.
Establish a post responsibility system, so that each panel has staff on duty. Everyone has a job and every post. On duty personnel, the operation of the protection device is generally only allowed to open or disconnect the pressure plate, switch the switch and unload the fuse, etc., and the electrical safety work regulations should be strictly observed in the work process.
Do a good job of cleaning the relay protection device. The cleaning work must be carried out by two people to prevent accidental operation of the equipment, pay attention to keep a safe distance from the live equipment, avoid personal electric shock and cause short circuit of the secondary circuit and grounding accident. The current and voltage sampling values ​​of the microcomputer protection are recorded once a week, and the microcomputer-protected printer is periodically checked and printed every month.
Regular inspection and maintenance of relay protection devices: 1 Check whether the symbols and names of the components of the secondary equipment are complete; 2 Check whether the transfer switch, various buttons, and actions are flexible and free of card, and the action is flexible. Contact contact with sufficient pressure and burns; 3 check the control room light plate, red and green indicating whether the light bulb is intact; 4 check the gauges on the various cabinets, relays and terminal screws for looseness; 5 check voltage transformers, current transformers Whether the secondary lead terminal is intact; 6 whether the wiring is neat, whether the fixed clip is detached or not; 7 Check whether the operating mechanism of the circuit breaker is normal.
According to the annual periodic evaluation of relay protection devices, the equipment is divided into three categories according to the plot: after the operation inspection, the technical condition is good and no defects, and the equipment that can ensure safe and economic operation is a kind of equipment; the equipment is basically intact and the individual parts are Although there are general defects, it can still operate safely, and does not endanger personal and equipment safety as a second-class equipment. Equipment with major defects, endangering safe operation, reduced output, and three types of equipment with serious "three leaks". If it is found that the relay protection is defective, it must be dealt with in time, and it is strictly forbidden to operate in hidden danger. The establishment of equipment defect accounts for defective relay protection devices is conducive to future maintenance work.
5 Power system relay protection development trend Relay protection technology is developing towards computerization, networking, intelligence, protection, control, measurement and data communication. With the rapid development of computer hardware, the requirements of the power system for microcomputer protection are also constantly improving. In addition to the basic functions of protection, it should also have long-term storage space for large-capacity fault information and data, fast data processing functions, and powerful communication. Capabilities, the ability to share system-wide data, information and network resources with other protection, control devices and scheduling, high-level language programming, etc., enable the PC to have the functionality of a PC. In order to ensure the safe operation of the system, each protection unit and the coincidence device must work in coordination. Therefore, the network protection of the microcomputer protection device must be realized, which is completely feasible under the current technical conditions. Under the condition of computerization and networking of relay protection, the protection device is actually a high performance. For the needs of measurement, protection and control, the secondary voltage of all equipment of the outdoor substation, such as transformers and lines, The current must be directed to the main control room with a control cable. The large amount of control cable that is laid has a large investment and makes the secondary circuit very complicated. However, if the above-mentioned computer device integrated with protection, control, measurement, and data communication is installed in the vicinity of the protected equipment of the outdoor substation, and the voltage and current amount of the protected device are converted into digital quantities in the device, By sending it to the main control room via a computer network, a large number of control cables are dispensed with.
in conclusion. With the development of power systems and the advancement of computer communication technology, the development of relay protection technology has become computerized, networked, integrated, and intelligent, which poses new challenges for relay protection workers. Only the relay protection device is regularly inspected and maintained, and its operation status is inspected on time. The fault is found and handled in time to ensure the normal operation of the system without faults and improve the reliability of power supply.
References [1] Wang Cuiping. Maintenance and testing of relay protection devices [J]. Keyuan Forum.
[2] Yan Xingchoo. Extreme application of relay protection technology [J]. Science and Technology Information, 2007.
[3] Zhou Peihua. Discussion on the development trend of power system relay protection[J].科技咨询导报,2007