Analyze and discuss the operation and maintenance of relay protection in current power system

With the improvement of the national economy and the development of social economy and technology, the dependence is closely related to life, the production of electricity, this is the rapid development of electric power industry has created favorable conditions, but at the same time, along with the people to the requirement of power supply quality and efficiency of power system operation is increasing day by day, also let the electric power industry development face more severe challenges. In both opportunities and challenges of social development, ensure the safety of the power system operation and reliable, economic efficiency, the relay protection device has played an important role, especially in power grid operation caused by electrical equipment insulation damage in the process of abnormal operation or short circuit accident, etc., can damage electrical equipment life and affect the normal power supply, for the power production caused great economic losses, The relay protection device plays an important role in preventing the occurrence or expansion of power failures or accidents and provides a strong foundation for ensuring the safe and reliable operation of the power system.

As an important part of the power system, the relay protection device provides reliable basic guarantee for the safe, reliable, economical and efficient operation of the power system, and creates good conditions for effectively preventing the occurrence and expansion of accidents or faults in the operation of the power network. However, with the increasingly high requirements of power supply quality and power system operation efficiency, the task of relay protection is becoming more and more heavy. In order to effectively ensure the safety and economy of power system operation, we must pay attention to the operation and maintenance of relay protection in the power system. Is based on the operation and maintenance of relay protection analysis and discussion, and improve the reliability of relay protection measures, put forward some suggestions.

1. Characteristics of relay protection device

If you want to strengthen the operation and maintenance of relay protection, we must first understand the characteristics of relay protection device, so that it can meet the basic operation requirements. Relay protection device is mainly featured in the following aspects: 1) reliability. The reliability characteristic of relay protection device is its characteristic characteristic. When a fault occurs in the process of power system operation, the relay protection device will make reliable action to the fault within its protection range and effectively disconnect the expansion of the fault point. 2) Selectivity. Relay protection device in the operation of the power system failure, will selectively cut out of the fault, will be close to the point of failure of the switching equipment timely disconnect, effectively prevent the expansion of the fault, so that the other parts of the power system except the fault part can continue normal operation. 3) Agility. The sensitivity of relay protection device can be measured by over-sensitivity coefficient, which refers to its ability to respond to abnormal state or operation failure within the protection range. 4) Rapidity. When the system fails, the relay protection device can respond quickly and disconnect the switching equipment in time to ensure that the fault does not spread and expand. It also plays a very good role in reducing the damage degree of the fault components and lays the foundation for the realization of the safety and stability of the synchronous operation of the power system after the fault is removed.

2. Basic principles of relay protection operation and maintenance

The operation and maintenance principle of relay protection mainly has two aspects: 1) to ensure the safety of operation. To ensure the safety and stability of device operation is the basis and important principle of relay protection operation and maintenance. In the analysis and monitoring of state maintenance of relay protection device, maintenance items and periods should be adjusted reasonably and appropriately, and the management of relay protection operation and maintenance should be strengthened through improving effective management system. 2) Macro planning and gradual implementation. Of relay protection operation maintenance is a complex system, especially the state overhaul device has not formed mature system of the complete system, therefore, need to be under the overall macroscopic planning, hierarchical advancing step by step, to ensure that every step of relay protection operation maintenance is safe, reasonable implementation through the first pilot accumulated the necessary experience and further popularization and application.

3, relay protection device calibration content and cycle

In order to improve the reliability of relay protection, effectively ensure the safety and stability of power system operation, and make reliable action in time when the fault occurs, it is necessary to make effective inspection and verification of relay protection device and its secondary circuit regularly. The verification of relay protection device mainly includes the inspection of the whole group action of the protection device, the inspection of the electrical characteristics test and the mechanical part of the relay, the secondary power test, the voltage of the break and the measurement of the insulation resistance of the secondary circuit. And the secondary circuit of relay protection device and its examination content is mainly to ensure the integrity of single protection setting effective and reasonable storage, to ensure that the relay without exception, check the related devices of power supply and the LCD panel and light display is normal, check the device accurate ac sampling and packet and open the quantity is normal, inspect the switch and the linking piece position, ensure the operation of no Unusual smell or sound. Construction or renovation of secondary loop for the same period of the new relay protection device installation, need to do for the first time in one year after the operation of a comprehensive inspection, if discover the device running state, shall be determined according to actual situation make targeted maintenance project and shorten the repair cycle, appropriate if the relay protection device replacement without synchronous transform secondary loop, is in the device before put into operation, A complete overhaul is required, and subsequent overhaul can be carried out in a normal cycle. For 110kV microcomputer devices, full inspection can be done every six years and partial inspection can be cancelled.

4. Specific maintenance of relay protection operation

The specific maintenance of relay protection operation mainly includes: 1) strengthen the monitoring of abnormal phenomena in the operation of relay protection device, and report the specific situation to the competent department in time. 2) In the maintenance process, the necessary split switch operation should be carried out after consultation with the relevant person in charge, so as to avoid the failure of human factors and make the maintenance counterproductive. 3) Timely find out the cause of relay protection action switch trip, further understand the situation of protection action, and return to all dropped signals after fault elimination and Li Tong of West Yunnan resumes operation, and make real-time and effective records of all contents such as fault occurrence, cause analysis and specific elimination measures. 4) for the operation of the relay protection device, the personnel on duty only switch switch or conversion, pressure plate connected or disconnected and insurance unloading, etc., can not do redundant illegal operations, if there is not in the operation of the abnormal situation, should be promptly disconnected switch and contact the relevant person in charge. 5) According to the provisions of "Electrical Safety Work Regulations" and combined with the equipment drawings of the site, carry out regular maintenance of the traditional substation secondary equipment according to the relevant provisions, to ensure that the relay protection device and its secondary circuit wiring is intact.

5. Effective measures to improve the reliability of relay protection

Improve the reliability of the relay protection is the main purpose of the relay protection operation maintenance, the operation of the relay protection maintenance everywhere embodies the to improve the reliability of the relay protection purpose, effectively improve the reliability of the relay protection measures, is important way to prevent the failure of the power system and expand, offering reliable guarantee for the safety and stability of power system running. For this aspect, the author puts forward some suggestions based on his own views:

1) Increase investment in relay protection. In the support of science and technology, new technology and equipment emerge in endlessly, to improve the reliability of relay protection operation, not as long as pay attention to the maintenance of device parameter, and a reasonable choice relay protection device, there will be a highly skilled in the operation of the new device is applied in the power system, improve the electrical equipment of the power system operation, such as for the application of integrated automation system, It can be used with relay protection to fully improve the reliability of relay protection.

2) Strengthen the daily maintenance of relay protection operation. The phenomenon of breakdown in the operation of the power system is a random, not certainty, it will be more careful in the daily operation and monitoring, especially for can effectively prevent failure or accident and expansion of daily monitoring of relay protection, for the abnormal situation timely found running malfunction and real-time processing measures are taken to restore the stable operation of power system, Of great importance. Therefore, to strengthen the daily maintenance of relay protection operation, the protection efficiency and quality, and the secondary loop relay protection devices are regularly check and inspection, timely find problems and solve, improve the ability of fault handling, comprehensively enhance the level of relay protection operation maintenance and stability for power system operation safety, economic and efficient implementation to create a good condition.

3) Strengthen the training of maintenance personnel's quality and business skills. To improve the reliability of the relay protection, we should pay attention to the maintenance of relay protection device, and the comprehensive quality of maintenance personnel and business skills, requires a high degree of maintenance staff to grasp the high maintenance technology and have rich experience in maintenance, timely fault make accurate analysis to the system, can the health status of relay protection device to do comprehensive evaluation, also can make reasonable maintenance decision, Effective optimization of maintenance process and plan, these are the embodiment of the technical quality of maintenance personnel, is the basis and key to ensure the quality of maintenance. Therefore, it is necessary to strengthen the quality of maintenance personnel and business skills training, through preaching, learning and other means to strengthen the safety awareness of maintenance personnel, improve the maintenance personnel's sense of responsibility and enthusiasm, and through professional skills training and effective assessment, improve the comprehensive quality and business skills of maintenance personnel, So that the maintenance work from the theory to the actual operation have an overall grasp and understanding, familiar with the maintenance operation process and rules and regulations requirements, effectively improve the quality of maintenance. At the same time, effective incentive reward and punishment system and sound post responsibility system should be adopted to improve the responsibility of maintenance personnel at the same time, to ensure the implementation of specific maintenance work, to provide reliable guarantee for the efficient operation of relay protection.

6. Conclusion

To sum up, the operation of the relay protection maintenance, for the relay protection device in the protection of electric power system safe and efficient operation lay a more solid foundation, is an important way of promoting the relay protection function, the analysis of the operation of the relay protection maintenance and research is very important, the electric power industry to achieve efficient and safe and stable operation of power system economy, It is necessary to provide the occurrence and expansion of power system operation accidents, and it is necessary to pay more attention to the operation analysis of relay protection in the power system, so as to create good basic conditions for promoting the healthy and rapid development of the power industry.