Analysis Of The Causes Of Insulation Aging Due To Overheating Of The Core In A Constant Voltage Transformer

During long-term operation, if the 3 phase constant voltage transformer iron core remains under high temperatures, it will cause gradual degradation of the internal insulation system. Under the influence of an alternating magnetic field, the magnetic core generates hysteresis and eddy current losses, both of which are converted into heat. If the structural design between the silicon steel sheets in the core is inadequate or the laminated insulation is faulty, eddy current losses will increase significantly, causing localized or overall temperature rise.

Simultaneously, if the constant voltage transformer for home load is excessive or the power supply system experiences harmonics, current surges, or other anomalies, the windings and core will bear additional loads, leading to continuous heat accumulation. This accumulated heat is difficult to dissipate through the cooling system, further exacerbating the temperature rise of the core and windings.

As the temperature remains high, the internal chemical structure of the insulation materials (such as paper insulation layers and oil-impregnated paper) begins to change. The molecular chains in the polymer or paper dielectric break or recombine under thermal effects, causing a decrease in insulation performance and a reduction in mechanical strength. Over time, this leads to a decrease in dielectric strength and a weakening of the breakdown resistance.