Importance of quality AC power distribution and understanding of EMC standards IEC 61000-3-2, IEC 61000-3-3 and IEC 61000-3-11

The aim of this technical paper is to bring out the importance of regulations on AC power distributions on AC power distribution and understanding of the international EMC standards IEC 61000-3-2 (1998) that deals with the limitation of harmonic currents injected into the public mains supply, IEC 61000-3-3 (1994) and IEC 61000-3-11 (2000) those deal with measure of the ability of the product to cause voltage fluctuations and lightning to flicker at frequencies which cause human discomfort. The paper discusses the cause and effects of power harmonics, voltage fluctuations and flicker, in the power distribution system. The paper explains how the switched-mode power conversion technology based power supplies can cause a variety of undesirable effects in the power distribution system. It also presents how the power quality of the AC mains deteriorate due to voltage fluctuations caused by phase-controlled AC input operated electrical devices. The sources of "flicker" and its effects on human safety are also highlighted. An overview of EMC standards, IEC 61000-3-2 and IEC 61000-3-3/IEC 61000-3-11 is presented in this paper. Finally, experimental results of a product evaluated for EMC compliance as per IEC 61000-3-2 and IEC 61000-3-3 are also presented.