EFFECT OF WAVE-FORM DISTORTION ON PROTECTIVE RELAYS

The technical literature is filled with theoretical and empirical refe rences to harmonics in power systems, but few have made an effort to d efine the influence of these waveform distortions on protective relays . It is felt that one important reason for this omission is that the w ide variety of measurement principles used for relays produce differen t results, and the scope of such an appraisal becomes gargantuan. In s pite of this fact, this paper will make an effort to 1) examine severa l electromechanical, solid-state, and microprocessor measurement conce pts, 2) describe the theoretical expectations of harmonic influence, a nd 3) present laboratory confirmation of these results.