Suggestions for overall EMC co-ordination with regard to rapid voltage changes

A Cigré / Cired joint working group (JWG C4.108 - Flicker Objectives) was established in 2007 to prepare a technical report addressing numerous aspects of the flicker problem, one of which is rapid voltage changes. This work was initiated following the conclusion of the now-complete Cigré / Cired joint working group JWG C4.103 - Emission Limits for Disturbing Installations which found significant worldwide variation in utility company practices related to rapid voltage changes. One of the work items assigned to JWG C4.108 was to assess the phenomenon and propose a unified approach suitable for overall EMC co-ordination. The JWG has found that clear evidence of an EMC problem is difficult to establish and that definitions, measurement specifications, and assessment procedures may be unsatisfactory at this time. The intent of this paper is to inform Cired experts of the technical aspects and recommendations developed by the JWG at the time of this writing.