Transformers are static electrical devices.An electromagnetic induction device converts a certain level of AC voltage and current into another level of voltage and current at the same frequency. Transforming AC voltage, exchanging AC current, and transforming impedance is its main function. Leakage current is the tiny induced current generated around the insulating material by the electric field force, and it is commonly expressed in microamps. It is mostly found in coil windings, capacitors, cables and other components that have current flowing through them or in the insulating layer in the conductor. Although the insulating layer is conductive, almost no material is completely non-conductive. At both ends of any insulating material, a current will flow, so finding out why there is a leakage current is straightforward.
What are the five most common causes of transformer leakage that are listed below?
- Transformers are usually AC, and leakage currents are too high due to parasitic capacitance in windings. The insulation resistance is not too small, but rather the distance between the windings and the casing (body) is too close, resulting in a large capacitive leakage current.
- Some cheap silicon steel sheets will generate a large magnetic impedance, leading to excessive leakage current in the transformer.
- Transformers consist of a large number of silicon steel sheets superimposed on each other. If the superposition is not good and the gap is too large, leakage current can easily occur. To confirm whether there is a problem, recheck the iron core.
- Check the insulation, oil insulation, and winding insulation as well.
- There may have been a change in the wiring or it may have something to do with the design.