Capacitance-coupled voltage transformer monitoring

A system to monitor the health of a capacitance-coupled voltage transformer (CCVT) of an electric power delivery system, comprising:

• a CCVT in electrical communication with the electric power delivery system, the CCVT comprising a stack of capacitors and an electrical contact to a first ground connection;
• a first current measurement device disposed between the stack of capacitors and the first ground connection, the first current measurement device to provide a first electrical signal corresponding to a first current flowing through the CCVT;
• a step-down transformer comprising a primary winding electrically connected to the stack of capacitors;
• a second current measurement device electrically coupled to the step-down transformer, the second current measurement device to provide a second electrical signal corresponding to a second current flowing through the step-down transformer;
• an intelligent electronic device (IED) in electrical communication with the first and second current measurement devices, to:
• receive the first electrical signal from the first current measurement device;
• receive the second electrical signal from the second current measurement device;
• calculate a health factor for a common frequency from the first and second electrical signals;
• compare the health factor against a health range;
• and
• when the health factor exceeds the health range, signal an alarm.