Experimental investigation on the performances of electronic current transformers

Before becoming qualified engineering application product, and realizing large-scale engineering application target smart substation, electronic current transformer (ECT) must first accept comprehensive and strict performance tests. The sand-glass test scheme of ECT is proposed. This test scheme includes thirty-three test contents, combining with the type tests, the special tests and the field tests. These tests not only provide reliable guarantee for electronic current transformers running safety and quality in smart grid, and establish the valuable basis for forming the standard and test methods of ECT. The developed optical current transformers have passed the above complete and strict product tests. The optical current transformers are large-scale used in 220kV smart substation in Liaoning Province. It is the first smart substation all using optical current transformer in china. The substation includes ninety-nine optical current transformers. Test and operation results show that the optical current transformers have satisfactory measurement accuracy and operation reliability. The steady-state measurement accuracy of optical current transformer excels IEC 0.2S level measurement requirements, and the transient measurement accuracy excels IEC 5TPE level protection requirements.