大容量变压器直阻测试产生的剩磁危害及消除

大容量变压器直流电阻试验后,会在变压器铁心中留有剩磁,本文对变压器直流电阻试验后产生的剩磁原因以及由于剩磁的存在对变压器的投运造成的危害进行了分析,提出了目前几种消磁的技术手段和措施,对比分析了消磁取得的效果并通过实例进行了验证。结果表明:采用正反向直流衰减法可消除 90%以上的变压器直流电阻测试所造成的剩磁。

Hazard and elimination of residual magnetism produced by direct-current resistance test on large capacity transformer

After direct-current resistance test on large capacity transformer,residual magnetism willbe left in transformer core,so analyzes the causes and the hazard of residual magnetism ontransformer commission. puts forward several current degaussing technical measures. comparativelyanalyzes degaussing effects and verifies by the examples. The result shows that using positive andnegative DC currents attenuation method,can eliminate more than 90% of the remanence producedby transformer DC resistance test.