Bernard E. Lenehan

A New High-Speed Distance-Type Carrier-Pilot Relay System

This paper outlines the reasons for application of pilot relay equipment, particularly of the carrier-current type. A one-cycle carrier-pilot-relay scheme is described which now makes available the desirable high-speed and back-up characteristics of step-type distance protection combined with the 100 per cent simultaneous tripping feature possible with a pilot circuit. Impedance and over current supervised single-phase directional elements are utilized for controlling carrier on phase and ground faults, respectively.

A new single-side-band carrier system

This new method of single-side-band generation is based on the frequency addition principle. Apparatus consists of linear modulators combined with wide-range phase-splitting circuits to produce the signals.

Transactions section: Preprint of corresponding pages from the current annual AIEE transactions volume

POWER consumers often are supplied from high-voltage distribution or sub-transmission circuits through transformer banks. When such consumers are to be charged on the basis of high-voltage or primary supply, some way of including the transformer losses is desirable without resorting to the difficulties and expense of direct primary-circuit metering.