Testing and protection of current transformer practical experiences in using the cpc 100

Abstract

We notice a recurrent underestimating in all transformer tests despite the huge influence of the accurate transducers on accounting systems. In addition, tests help to significantly reduce the risk of mixing up different instrument transformers or their connections. Tests can also help identify transportation damage inside a transformer. Last but not least, regularly scheduled tests are essential when it comes to detecting effects that can occur within the life cycle of a transformer such as shorted coils, loss of class accuracy due to material changes or changes to the load. Changing the power supply topology and thereby the primary time constant can lead to a situation where the transformer becomes unusable for protection, as it is saturated far earlier than desired due to transient operations. In this paper, we will look at the testing practices for current transformer used by the NATIONAL COMPANY OF ELECTRICITY AND GAS (SONELGAZ Algeria) and show that with the use of the CPC 100 many standard electrical tests for CTs can be performed with one single device saving testing time and labor costs.