Reactors are used more and more in the system, and they often cause some similar faults in operation. Based on years of operation experience, the author introduces several common faults and treatment methods.
Creep discharge
After the reactor is operated under outdoor atmospheric conditions for a period of time, there will be dirt deposits on the surface. In the case of heavy fog or rain, the surface layer is damp, resulting in an increase in surface leakage current and heat generation. Due to the different speed of water evaporation, a dry area appears locally on the surface, causing a change in local surface resistance, and a current forms a local arc at the interruption. As time elapses, the arc will merge to form a dendritic discharge along the surface. The turn-to-turn short circuit is a further development of dendritic discharge, that is, the current in the short-circuit line 剧 increases sharply, and the temperature rise causes the wire 匝 insulation to be damaged.
In order to ensure that the outdoor reactor does not suffer from dendritic discharge and inter-turn short circuit fault, the coating of hydrophobic paint can greatly suppress surface discharge; the end of the annular current sharing electrode can overcome the leakage current concentration at the lower end surface; wear rainproof The cap and the additional rain layer can suppress the surface leakage current to a certain extent. In addition, in areas with serious pollution, the frequency of cleaning the surface of the reactor and the surface of the insulator should be increased.
Local temperature is too high
When the reactor is operated, the temperature is too high, and the polyester film is accelerated. When the rainwater is infiltrated into the lead wire or the horizontal epoxy cracking, the aging is accelerated, and the mechanical strength is lost, causing the short circuit between the turns to cause the fire to burn.
The cause of the temperature rise of the reactor is: the quality of the welding, the welding resistance of the terminal and the winding weld produces additional resistance and heat. In addition, due to the small design margin of temperature rise, the design value is very close to the temperature rise limit specified by the national standard. In addition to design and manufacturing reasons, if the air passage of the reactor is blocked by foreign matter during operation, resulting in poor heat dissipation, it may cause local temperature to cause fire.
In the above case, the reactor ventilation conditions should be improved to reduce the temperature of the operating environment of the reactor, thereby limiting the temperature rise. At the same time, it is regularly shut down and maintained (the tap water column can be used to flush the surface of the reactor and each vertical heat dissipating air passage) to remove the dirt accumulated on the surface area, keep the air passage unblocked, and inspect the external insulation state in detail, and find the problem in time.
Vibration noise failure
When the iron core reactor is in operation, the vibration becomes large, causing loose fasteners and increased noise. The main cause of vibration is the failure of the magnetic circuit and the fact that the core is not pressed or the clamp is loose during manufacturing. Generally only need to tighten the fasteners again. Sometimes the air reactor is subjected to AC noise (the fundamental frequency is 100 Hz) after being put into operation, and the ground is heated with a rhythmic beat frequency. This is because the powerful alternating magnetic flux of the air-core reactor operates to bring resonance and eddy currents and heat to the surrounding steel components, especially the basic embedded parts. This is a fundamental problem in the design and installation of infrastructure. It can only be shut down for complete renovation.