Model system tests on a new numeric method of power system frequency measurement

A numeric technique for the evaluation of power system frequency has been implemented on a TMS320C31 digital signal processor. The frequency measuring equipment has been tested on programmable relay testing equipment, using known reference signals, and on a micromachine based power system simulator. The results show the frequency measuring equipment gives fast and accurate measurement under both steady-state and dynamic conditions. The response of the equipment to instantaneous changes in phase and amplitude is found to be undesirable if the algorithm is to be applied to frequency measuring protection relays.