The hazards of a microcomputer-based protection device ‘freezing’ and the measures to take

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In actual operation, microcomputer-based protection devices can experience crashes. Although the probability of this occurring is very low, its consequences are severe. Take the capacitor protection device as an example: if the microcomputer-based protection device for capacitors fails to function, and the capacitors are installed outdoors, then in the event of an internal fault in the capacitors, or during rainy weather when bird feathers become wet and fall on the exposed switches of the capacitors, the protection system will not operate, which can lead to abnormal tripping and a loss of voltage across the entire busbar. Especially in the case of Scenario 2, if a short-circuit fault occurs in a 35 kV line and the microcomputer-based protection device shuts down, failing to provide protection, it will cause the switch on the power supply side of the bus connected to that line to trip, thereby expanding the scope of the power outage. Because the other end of the line connected to that 35 kV bus bar could cause a loss of voltage throughout the entire station or power outages for important users. 4. Measures to be taken 　4.1 After performing operations to shut down or restart the equipment, and during the inspection process, it is essential to check the status of the protection devices, and promptly restore the operation menu of these devices to the main menu interface. 4.2 During inspection tasks, it is essential to check the operating status of the microcomputer-based protection devices as an important part of these inspections. To assess the performance of such devices, one can also examine the data from the related equipment in the background monitoring system to see whether it is being updated regularly within a certain time frame (1–5 seconds). If data such as voltage, current, active power, and reactive power do not get updated at all, this should raise concerns. 　 4.3 Once a \"freeze\" occurs, the power switch of the microcomputer protection device can be turned off and then turned on again. Two scenarios may arise: A. After the power switch is turned on, the device operates normally, and the relevant data on the backend system is updated properly ； B. After turning on the power switch, if the microcomputer-based protection device still remains in a frozen state, then, if possible, the duty personnel should take immediate action to transfer the relevant loads through switching operations, thereby shutting down the equipment associated with the faulty protection device. If this is not possible, they should contact the dispatch team to have those devices shut down (operational regulations clearly stipulate that it is strictly prohibited for equipment to operate without protection). This article is from http://www.weijizongbao.com/jishu/543.html; please indicate the source when reproducing it