1160 / 2020-09-29 17:52:02

The Defective Causes Analysis for a Batch of Current Transformers based on Simulation Tests

current transformer,constant voltage and current,dissolved gas,manufacturing process,simulation test

  Recently, quality problems were found successively in more than ten current transformers (CTs), which were produced in a same batch, in Guangming switch station of Inner Mongolia province. Both the capacitance and dielectric loss did not meet the requirement of criteria. And the contents of dissolved gas in oil in those CTs exceeded the warming value. However, no abnormality was found in all parts of the transformer during the disassembling process. In view of this, two defective models were prepared by using the LB6-110W type of transformers separately. One of them was improper dried whereas the other was simply oil-immersed without using vacuum. The development process of defects in current transformer was studied. It was believed that the unsatisfactory vacuum immersion oil is the main cause for the failure of this batch of CTs. Based on this research, corresponding technical suggestions were put forward.