How to deal with the failure of low voltage series reactor?

Low voltage series reactor is used more and more in the system software, which also causes some similar common faults in its operation. Based on many years of operation experience, several kinds of mechanical faults and their solutions are introduced in detail.

Surface discharge

After the series reactor is operated in the outdoor atmosphere for a period of time, there will be dirt deposition on its surface. In the fog or rain, the surface dirty layer will be damped, resulting in the increase of surface leakage current and heat generation. Because of the different volatilization speed of water, the dry and impetuous region appears on the surface, which results in the change of the local surface resistivity, and the local electric arc is produced at the final break of the current. With the increase of time, the arc will merge and form a dendritic discharge along the surface. As we all know, turn to turn short-circuit fault is the further development trend of dendritic charge and discharge, that is, the current in the short-circuit fault turn is greatly increased, and the insulation layer between turns is damaged due to the temperature rise.

In order to ensure that outdoor series reactors do not suffer from dendritic discharge and turn to turn short circuit fault, the application of hydrophobic coating can significantly inhibit surface discharge; the end embedded ring current sharing electrode can overcome the phenomenon of lower surface leakage current concentration; wearing a rain cap and an additional rain layer on top can to a certain extent inhibit the surface leakage current. In addition, in areas with serious environmental pollution, the frequency of cleaning the surface of series reactors and insulators should be increased.

Local temperature too high

When the temperature of series reactor is too high during operation, it will accelerate the aging of polyester film. When the rain water infiltrates into the lead-in line or the epoxy crack on the cross surface, it will lose the mechanical strength and cause the turn to turn short circuit to cause the fire.

The causes of series reactor temperature include: quality problems of welding products, additional resistance and scalding caused by welding resistance of terminal block and winding welding. In addition, due to the small design margin of temperature rise, the design value is close to the temperature rise limit specified in the national standard. In addition to the design scheme and production and manufacturing reasons, if the gas safety channel of the series reactor is blocked by dirt in the whole operation process, the heat pipe heat dissipation is not good, and part of the temperature will be too high, causing fire accidents.

For the above situation, the ventilation condition of series reactor should be improved, and the operating ambient temperature of series reactor should be reduced, so as to limit the temperature rise. In addition, it is required to shut down and maintain on time (be able to use drinking water column to clean the surface of the series reactor and the cooling air pipes of each vertical heat pipe), eliminate the surface scaling, keep the air pipes unobstructed, and carry out a detailed inspection on the opening of the insulation layer to properly handle the problems found.

Vibration and noise fault

The main reason of vibration is that the magnetic circuit is faulty and the iron core is not compressed or the clamp is loose during manufacturing and installation. Generally, it is only necessary to tighten the fastener again. After the fund of air core series reactor is put into operation, sometimes the communication noise (basic frequency is 100Hz) is very high, accompanied by the beat frequency and basic burning of rhythm sense. This is because the strong alternating flux of air core series reactor brings the resonance and eddy current caused by alternating electromagnetic force to the surrounding steel components, especially the embedded parts.

How to deal with the failure of low voltage series reactor?