变压器电容隔直装置预防性试验初探

Preliminary Study on the Preventive Test of Transformer Neutral DC Current Blocking Device

当直流电流窜入变压器内部时,会引起变压器的直流偏磁,进而引发变压器噪声偏大、无功损耗增加等问题。在变压器中性点加装隔直装置可减小直流进入变压器带来的各种问题,但如何对隔直装置进行预防性试验是摆在试验人员面前的一道难题。试验人员根据丰富的现场经验,探索性地制定了隔直装置的预防性试验项目,并对运行于广州电网的13台变压器隔直装置进行检查,发现了几起故障和隐患,对验证预防性试验具有一定的现场实用性和借鉴作用。

When the DC current flows into inside of transformer, it will cause DC bias of transformer, and such problems as big noise and increase of reactive power loss. Various problems brought by the DC current into the transformer can be reduced by way of adding the blocking device in the neutral point of transformer, but the problem is how to perform the preventive test to the device. The preventive test items for the device is set up in accordance with field experience and the blocking device for 13 units of transformers operated at Guangzhou grid is inspected and the fault as well as hidden trouble are found. Verification of preventive test has a definite practical value and reference.