A COMPARISON OF FREQUENCY-MEASUREMENT METHODS FOR UNDERFREQUENCY LOADSHEDDING

A comparison of frequency measurement methods for the purpose of under frequency load shedding is presented in this paper. Comparison is made under the assumptions of the presence of DC offset, high order harmon ics and noise in the measured signal. The major constraints have been the accuracy of frequency measurement, time needed to measure the freq uency and complexity of implementation in terms of computational requi rements. A method for efficient, low-cost implementation of frequency relay which can be used at domestic consumer installations is proposed and its implementation is described. (C) 1998 Elsevier Science S.A. A ll rights reserved.