Some problems in substation automation system

2022-09-19
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At present, substation automation system has been widely used in substations at all levels, with a high degree of automation and stable operation. In actual operation, it gives full play to the characteristics of advanced technology and reliable operation. The wide application of substation automation system in county-level substations has played a positive and vital role in upgrading the protection and monitoring system, improving the automation degree of substations, realizing dispatching automation and automatic meter reading, building unattended substations and reducing personnel and increasing efficiency

2. Problems in actual operation

2.1 background monitor

2.1.1 whether to set background monitor

at present, there are two views on whether to set background monitor in county-level substation automation system: one is to set background monitor, the other is not to set background monitor. The first view is that the current substation is still on duty with many or few people, and the setting of background monitoring machine is convenient for on-site monitoring and management, the installation and commissioning of monitoring and protection system, the test and adjustment of protection setting value and the inquiry of accident records; The second view is that the substation will eventually become unattended, so there is no need to set up a background monitoring machine. In fact, due to the condition of primary equipment, the fact that most county bureaus have not yet established dispatching automation systems, and the inability to immediately realize unattended, the newly-built and reconstructed substations still have watchkeepers. Even if it can be truly unattended in the future, it will take a long time. Therefore, from the actual needs, the substation should be equipped with background monitoring machines. Therefore, when ordering the substation automation system, The background monitoring machine and corresponding monitoring software should be ordered at the same time to prevent reordering and increase investment if they cannot meet the actual needs

2.1.2 operation management of background monitoring machine

practice shows that the operation management of background monitoring machine is very important. In the actual operation, there have been many times that the background monitoring machine is paralyzed and unable to work due to human factors and the monitoring machine itself. Some substations occur several times within a year, no matter how much you sneer, mostly due to human factors, which seriously affects the overall operation of the substation. Therefore, in order to prevent this kind of situation, first, we should formulate and strictly implement the operation and management system of the background monitor of the substation, restrict the personnel on duty, prevent the use of the background monitor to play games and play games, and prevent the unauthorized use of floppy disks and CDs to infect the monitor with viruses. Once the background monitor is paralyzed for human reasons, we should strictly punish it according to the system and never tolerate it, At the same time, warn others that the experimental machine should be properly grounded. Second, strengthen the regular and irregular inspection of the management department of the county bureau, and deal with problems immediately if found, so as to avoid future problems. Third, set up password management methods for the operating system and monitoring software. Only the management department of the county bureau and the substation master master the password, and the ordinary personnel on duty do not master the password, so as to prevent random access to the operating system and start and stop the monitoring software, and prevent the use of the software and hardware resources of the background monitoring machine from being damaged. Fourth, the operating system is encapsulated with monitoring software, such as the background monitoring software of df1331 automation system produced by Dongfang Electronics, which has the function of encapsulating the operating system after startup. The encapsulated operating system of monitoring software means that when the background monitoring machine is started for the first time, the monitoring machine automatically starts the operating system and continues to start the monitoring software until it is started to the monitoring software interface. If the monitoring software is stopped, a password needs to be entered. Only those who master the password can stop the monitoring software and enter the operating system. At present, the background monitoring software of some substation automation systems does not have this function, which should be solved jointly with the manufacturer's technicians. The function of monitoring software encapsulating the operating system is very effective in preventing the background monitoring machine from being used and damaged by others. Chinalco Shandong enterprise is an old central enterprise located in Zibo City. When selecting the background monitoring software, we should pay attention to the selection of products with this function to improve the safety and reliability of the background monitoring system

2.1.3 the background monitoring machine should choose the industrial control machine

because the background monitoring machine requires real-time operation, the amount of data processed is relatively large, the response speed is fast, and it is in a strong electromagnetic environment, so the general ordinary computer can not meet the requirements, and the high-performance industrial control machine should be selected. The high-performance industrial control computer can work in a strong electromagnetic environment, has strong anti-interference performance, can run in real time, and the hardware equipment has good working stability, which can meet the requirements of the substation background monitoring system. At present, in some substations, due to the large use of commercial computers, home computers and other computers, the background monitoring machine has been damaged and can not work. High performance industrial computer can ensure the safe and stable operation of substation background monitoring system

2.1.4 the background monitoring machine should be equipped with uninterruptible power supply

in some substations, the background monitoring machine is not equipped with uninterruptible power supply, and the station transformer AC power supply is used. Using the AC power supply of station transformer has the following disadvantages: first, when the system is powered off, the background monitor loses power and cannot work; Second, the AC voltage of the occupancy transformer fluctuates greatly. Sometimes the voltage quality is unqualified, sometimes the voltage is high, and the computer is burned. Sometimes the voltage is low. The computer cannot work and cannot provide qualified power to the background monitoring machine; Third, when the primary fuse of the station transformer is blown, the background monitor loses power; Fourth, when the 10kV system is grounded, the AC power supply of the station transformer is seriously disturbed by harmonics, which affects the normal operation of the background monitor. At present, some manufacturers produce DC inverter and AC inverter. The DC battery in the station is used as the DC power supply of the inverter, which is supplied to the background monitoring machine after inverter and ac. the capacity is selected as 500 - the maximum power is calculated automatically at the end of the test Up Lower yield strength Hysteresis loop method Gradual approximation method Non proportional tensile strength Tensile strength Compressive strength Determine the elongation strength at any point Constant load extension at any point Modulus of elasticity Elongation Maximum value of stripping interval Min Average value Net energy Turn back energy Total energy Flexural modulus Breakpoint displacement x% load Breakpoint load x% displacement Wait 1000VA. The configuration of this inverter does not need to purchase another DC battery, which saves investment and has good effect

2.1.5 the real-time data and accident records in the background monitoring system cannot be stored

at present, the background monitoring system of some substation automation systems cannot store real-time data and accident records. With the continuous development of hard disk production technology, large capacity hard disk has appeared and been widely used. The monitoring software should have the function of storing real-time data according to the optional time interval, and should have the function of storing accident records, which is convenient for saving, searching, browsing and printing historical data and accident records

2.2 the protection and monitoring system does not have a fault filter device

at present, the protection and monitoring system in some substations does not have a fault filter device. As a substation automation system, the fault filter device should be a necessary device. When the distribution line trips, the fault filter device can record the change of current in 10 or more cycles before and after the fault trip and the fault current value, so as to analyze the cause of the fault

2.3 accident and warning sound signals of the protection and monitoring system

the accident and warning sound signals of the protection and monitoring system of some substations are controlled by the background monitoring system. When the background monitoring machine cannot work, the accident and warning sound signals cannot be sent, and the personnel on duty cannot be prompted to deal with the accident or fault, which seriously affects the safe operation of the substation. This kind of situation has occurred several times, causing the PT to burn out, I don't know if the switch trips due to accident

in this case, contact the manufacturer and deal with it together, so as to separate the accident of the protection monitoring system and the warning audio signal, which are not controlled by the background monitoring system, so as to prevent the failure of the protection accident and the warning audio signal when the background monitoring machine is not working

2.4 sending and receiving processing of telecontrol data and information of protection monitoring system

2.4.1 sending of telecontrol data and information

the telecontrol data and information of some substation automation systems are sent to the dispatching master station through the background monitoring system. When the background monitoring system cannot work normally, the telecontrol data and information cannot be sent, which is not conducive to the sending of telecontrol data and information, The telecontrol data and information shall be sent directly to the dispatching master station in the communication unit of the protection and monitoring system, which is not controlled by the background monitoring system. Since the transmission of telecontrol data and information is controlled by the background monitoring system, several substations have stopped sending telecontrol data and information to the dispatching master station because the background monitoring machine cannot work normally. This situation can only be handled by the manufacturer

2.4.2 sending, receiving and processing of telecontrol data and information

at present, some substation automation systems have weak ability to send, receive and process telecontrol data and information, mainly manifested in: they cannot upload protection setting values, main transformer gears, etc., and cannot correctly receive and process the switch remote control operation, modification of setting values, main transformer gear adjustment and other functions of the dispatching master station. Due to the existence of this problem, the automation of substation is greatly affected, which is not conducive to the remote operation of equipment

3. Summary

the above problems are some of the more serious problems in the actual operation of the substation automation system. Some of them can be handled by themselves, while most of them need to be handled by the manufacturer, while some of them cannot be handled by the manufacturer. The existence of these problems is not conducive to the safe, reliable and stable operation of the substation. When selecting the substation automation system, we should pay attention to whether the above problems exist and whether the overall function of the substation automation system is complete. Substation automation system is the core of substation. It is very important to choose a high-quality substation automation system for the safe, reliable and stable operation of substation

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