Leakage flux

Flux generated in the transformer that is not related to the voltage transformation. The flux that links both the primary and secondary windings and contributes to transformation is called the main flux. There are primary leakage flux that links only the primary winding, and secondary leakage flux that links only the secondary winding. Leakage flux forms leakage reactance, and is represented in the equivalent circuit of the transformer by connecting reactance in series to both the primary and secondary sides. Leakage flux causes stray load losses due to eddy currents, so smaller leakage flux is desirable.