International Electrotechnical Commission

Electromagnetic compatibility (EMC) – Part 3-7: Limits – Assessment of emission limits for the connection of fluctuating installations to MV, HV and EHV power systems - Edition 2.0
 N TR 61000-3-7

Annotation

This technical report outlines principles which are intended to be used as the basis for determining the requirements for connecting large fluctuating loads (producing flicker) to public power systems. The primary objective is to provide guidance for engineering practices which will ensure adequate service quality for all connected consumers.

Since the guidelines outlined in this report are necessarily based on certain simplifying assumptions, there is no guarantee that this approach will always provide the optimum solution for all flicker problems. The recommended approach should be used with flexibility and judgment as far as engineering is concerned, when applying the given assessment procedures in full or in part.

The final decision regarding the connection of fluctuating installations will always rest with the utility.

Problems related to voltage fluctuations fall into two basic categories:

– flicker effect from light sources;

– risk of the voltage magnitude being outside accepted tolerances.

This report primarily focuses on controlling or limiting flicker, but a clause is included to address voltage magnitude changes and their effects.

NOTES

1 This report uses the following terms for system voltage:

In the context of this report, the function of the network is more important than its rated voltage. For example, a HV system used for distribution may be given a "planning level" (see clause 3) which is situated between those of MV and HV systems.