Degaussing method and apparatus of the transformer core using DC

摘要

PPROBLEM TO BE SOLVED: To provide a demagnetizing apparatus capable of demagnetizing a transformer with simple constitution. PSOLUTION: The demagnetizing apparatus is constituted by incorporating a fault determination unit including a demagnetizing portion 2 which demagnetizes an iron core of the transformer, a fault determination portion 3 which applies an AC voltage to the transformer having the iron core demagnetized by the demagnetizing portion to determine whether the transformer has an inter-winding short circuit based upon an excitation current at the time, and a notification portion 5 which notifies a determination result of the fault determination portion. The demagnetizing part has an initial processing function of applying the DC voltage for a certain time to generate a positive saturation state, a function of applying a negative DC voltage thereafter, turning off the power source once the saturation state is generated, and waiting for counter electromotive force to reach 0 to acquire a time t1 from the start of application of the DC voltage till the counter electromotive force reaches 0, and a function of applying a positive DC voltage for a time half the t1 to achieve demagnetization. PCOPYRIGHT: (C)2011,JPO&INPIT