Digital models of coupling capacitor voltage transformers for protective relay transient studies

The authors describe the development by EPRI of digital coupling capacitor voltage transformer (CCVT) models that are intended for digital simulation of fault transients. Experimental techniques for laboratory measurements of the CCVT parameters are outlined. A sensitivity study was performed to identify the influence of various CCVT parameters on the transient behavior relevant for the relaying studies. Digital models of three different CCVTs are given and their transient behavior is compared to the behavior of the actual transformers. >