大容量变压器直阻测试产生的剩磁危害及消除

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

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。

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