Voltage unbalance emission limits for installations: general guidelines and system specific considerations

Guidelines for developing voltage unbalance emission limits for installations connected to EHV, HV, and MV power systems have recently been published as a technical report by the International Electrotechnical Commission (IEC). These guidelines, based on the work of Joint Working Group CIGRE/CIRED C4.103, are intended to provide a common basis for the development of similar guidelines or standards in specific countries. This paper reviews these international guidelines and the background to the development of specific recommendations made in the technical report. It also considers elements of these guidelines that may relate to specific network considerations, and therefore may be of interest to countries wishing to develop local guidelines or standards. Additional information relating to the evaluation of such specific considerations is referenced.