Overview of IEEE C37.92-2005 Standard for Analog Inputs to Protective Relays From Electronic Voltage and Current Transducers

The paper gives an overview of the new IEEE standard C37.92, which defines a low-voltage (11.3 V max) analog signal interface between new types of electronic sensors, and microprocessor-based protective relays or intelligent electronic devices. The application requirements are described; the technical specifications of the interface are summarized. The paper explains electromagnetic-environment considerations. The new interface standard offers simplicity and low cost, ease of adaptation of existing relay designs, and the opportunity to transform and combine signals from existing conventional instrument transformers in hybrid protection schemes