
The iron core of toroidal transformer is wound by continuous oriented silicon steel tape. During the operation of toroidal transformer, external force damage or aging of insulation of screws may cause insulation damage between silicon steel sheets and increase of eddy current, resulting in local overheating of transformer iron core.
When the toroidal transformer is in operation, the hysteresis loss of the iron core, eddy current loss and copper loss of the coil are converted into heat, so that the temperature rises, the heat to the surrounding by radiation, conduction and other ways of diffusion, when the heat and heat dissipation reach a state of equilibrium, the temperature of each part tends to be stable. Iron loss (hysteresis loss and eddy current loss) is a basic constant loss, related to the toroidal transformer structure, so in operation can not reduce or eliminate iron loss; The copper loss varies with the load.
If the insulation of several turns adjacent to the toroidal transformer is damaged or aged, there will be a closed short-circuit circulation, which reduces the number of turns of the winding. The short-circuit circulation generates high heat and increases the temperature of the transformer, which will burn the ring transformer in serious cases.
External causes of high toroidal transformer temperature