In order to solve the problem that the impulse oscillating turn insulation test equipment cannot be applied to the detection of the turn insulation defect of iron core reactor and the incomplete turn insulation testing problem of the lightning impulse test

in this paper

a method of detecting the turn insulation defects of the iron core reactor based on the variable frequency resonance technique is proposed.The current relevant standards are analyzed in detail and the necessity of using high frequency voltage withstanding is proved.The circuit principle of variable frequency resonant for turn insulation defect detection and the method of determining the test capacity are given.Throughout the simulation analysis of an actual iron core reactor parameters

the time domain detection results before and after the short circuit of turn-to-turn and the changes of the amplitude-frequency characteristics of the test circuit are given

which verifies further that the voltage detuning can be used for detecting the turn insulation defects in dry-type iron core reactors.