Analysis of Common Faults of AC-DC Integrated Power Supply
Power system generally includes AC power supply, DC power supply, storage battery, UPS, etc. Under normal circumstances, unattended substations adopt AC-DC integrated power supply system, which requires little or no maintenance. In the AC-DC integrated power supply system, the AC power supply panel is usually used for the secondary lighting and heating circuit of substation equipment; The DC charging screen converts AC power supply into DC power supply; The DC feeder screen is used in the secondary control loop of substation equipment. Usually, the two power supplies are mutually standby; The battery panel is the backup power supply of the DC power supply panel. When the AC power supply of the complete set of electrical manufacturers fails, the battery panel acts as the DC power supply panel.
In daily work and production, the AC-DC integrated power supply system is usually very stable, and sometimes it will fail due to maintenance or human factors, which will affect production. Once, due to cross operation during maintenance, the electric holding switch in substation misoperated. After analyzing this incident, we all know that the storage battery exists as a backup power supply, which is very important. However, this point was ignored when arranging the maintenance. During the inspection, no objection was raised until the maintenance operation on the same day. In the final analysis, the person who submitted the maintenance plan made mistakes, and the person who checked at different levels did not have the same problem.
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A seemingly simple fault, some people even think that it is a low-level fault that can’t be lower, and it may have been staged in different places. Similar failures, in addition to the limited personal ability, the complete set of electrical manufacturers can not make correct judgments, and there are also a great part of management omissions, process errors, and lack of experience. In the continuous work and study, I have read many similar cases. If we can share resources and learn from the experience of our predecessors, we will avoid many unnecessary mistakes.
Hainan distribution box?
There are many ways to solve this problem. For example, two feeder branches of AC/DC integrated power supply in the same loop pass through the same transformer for detection. Or modify it in the program, and set the branches forming the same loop into the same loop in the software; Or just disconnect a feeder branch, so that it does not form a loop. As far as the current application is concerned, a method will be more troublesome in construction and installation, and some loops may not be determined during construction and installation, or there may be changes, so it is not particularly practical; The second method is controlled by software, which is more practical and reliable if the program is set well. The third method is also feasible, but for some operation and maintenance departments, complete sets of electrical manufacturers may not allow single-loop power supply based on some considerations. Therefore, personally, I recommend the second method.
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