The impact of lightning surges on petrochemical complexes and countermeasures

Flicker is caused by a short-term disappearance of the grid voltage or power supply. The reasons include short circuits in the wiring or electrical equipment, etc., and it is restored within a short time thanks to devices such as automatic reclosing or automatic transfer switches. Anti-vibration and electrical protection devices, contactors, etc. are used. For more discussions, see -----http://bbs.hcbbs.com/viewthread.php?tid=121788

For large petrochemical companies, dual-circuit power supply is commonly used. Under normal circumstances, a sudden shake causes no major problem, but two consecutive shakes usually result in the vehicle stopping.

During operation, power systems can experience sudden and significant voltage fluctuations or brief power outages followed by restoration due to reasons such as lightning strikes, short-circuit faults, reclosing operations, faults in the external or internal power grid, and the startup of large-scale equipment. This phenomenon is commonly referred to as \"voltage fluctuation\". The International Electrotechnical Commission (IEC) defines it as a voltage drop to 90%–1% of the rated value, lasting for 10 ms–1 min. The root-mean-square value of the power frequency voltage at a certain point in the power supply system suddenly drops to 1%–90% of its rated value, and then returns to normal after a short duration of 10 ms to 1 minute. Flicker mainly occurs in the following situations: ① Sudden drops or rises in voltage, lasting from 0.5 cycles to 1 minute, with the voltage rising or falling to 110–180% or 10–90% of the nominal value. ②Voltage flicker refers to regular changes in the voltage waveform or a series of random variations in the voltage amplitude; it is generally manifested as the visual perception resulting from lighting abnormalities caused by voltage fluctuations as perceived by the human eye. ③Short-term power outages, which are interruptions in power supply lasting from 0.5 cycles to 3 seconds (such as automatic switching over and reclosing functions).

Given that the production of petrochemical plants follows its own set of operational principles, as well as technical and safety requirements, it is necessary to conduct a thorough and systematic evaluation from various aspects such as safety, process operations, control systems, environmental protection, and equipment before implementing any technical upgrades aimed at preventing voltage fluctuations. This evaluation is needed to ensure that such measures do not introduce new safety risks or exacerbate existing hazards in the plant. Secondly, it is necessary to carefully analyze the key equipment and factors that affect the safe operation of production units during grid fluctuations, in order to minimize the number of devices that require special measures. Finally, after implementing technical upgrades to prevent power fluctuations in the electrical grid, it is necessary to promptly revise, supplement, and improve the accident response plans for production facilities, in order to avoid unnecessary issues during operational processes, especially when dealing with accidents.

I heard about voltage fluctuations for the first time; it seems to refer to the ordinary short-term power outages we experience.

It’s best to install a UPS, that is, an uninterruptible power supply, which can also serve as a backup power source: lol

Anti-fluctuation contactors can address the issue of voltage fluctuations in control circuits, while DC supplies and UPS systems can deal with voltage fluctuations in the main circuit. The Dayton H600 DC supply has advantages when used with high-power inductive loads.