Transformer iron core demagnetization method

• Main Authors: HAO ZHIGUO, ZHANG XIAOJING, LIU ZHIYUAN, ZOU HONGSEN, YU XIAOJUN, WEI PENG, YIN LEI, ZHANG BAOHUI, TAN TINGYUE
• Format: Patent
• Language: English
• Published: 27.01.2016
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; INDUCTANCES; MAGNETS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS

The invention discloses a transformer iron core demagnetization method and especially provides a method for demagnetizing the iron core of a transformer after the DC resistance test. According to the invention, the voltage is applied onto the primary winding of a transformer by a DC power supply for three times, wherein the voltage-applying amplitude is the same each time and the polarity thereof is alternately changed. The voltage-applying duration is determined based on the acquired current waveform of the primary side of the transformer. During the first two times, the current applied onto the primary winding of the transformer reaches a forward peak value and a reverse peak value respectively. During the third time, the current applied onto the primary winding of the transformer occupies only half of the duration from the forward peak value to 63.2% of the reverse peak value. Through the above three voltage application processes, the iron core of the transformer is demagnetized. Based on the above method, the demagnetization duration is greatly shortened and the demagnetization effect is ensured at the same time. Meanwhile, the demagnetization equipment is small in power and good in practicality.