IEC TS 62749 ED3

Assessment of power quality - Characteristics of electricity supplied by public networks

Scope

IEC TS 62749:2026 specifies the expected characteristics of electricity at the point of supply of public low, medium and high voltage, 50 Hz or 60 Hz, networks, as well as power quality assessment methods. This document does not apply for systems operated above 230 kV.
The boundaries between the various voltage levels can be different for different countries or regions. In the context of this document, the following terms for system voltage are used:
- low voltage (LV) refers to UN ≤ 1 kV;
- medium voltage (MV) refers to 1 kV < UN ≤ 35 kV;
- high voltage (HV) refers to 35 kV < UN ≤ 230 kV.
Because of existing network structures, in some countries or regions, the boundary between medium and high voltage can be different.
While power quality is related to EMC in a number of ways, especially because compliance with power quality requirements depends on the control of cumulative effect of electromagnetic emission from all or multiple equipment and installations, this document is not an EMC publication (see also Annex E).

This third edition cancels and replaces the second edition published in 2020. This edition includes the following significant technical changes with respect to the previous edition:
- clarification that harmonic orders recommended in this document are up to 40th;
- 4.6 is modified accordingly;
- iteration that this document does not apply for systems operated above 230 kV;
- deletion of Annex C;
- improvement of 4.10;
- update of profiles and addition of new profiles;
- modifications to align with EN 50160:2022 and EN 50160:2022/AMD1:2025.