A new IEC standard for reactive energy has recently been published: the IEC 62053-24. This document is applicable for reactive energy meters of class 0,5 S, 1 S and 1. At NMi, this kind of meters can now be examined in conformity with the new standard.
Since many years the IEC standard 62053-23 is used. This standard was specifically designed for testing reactive energy meters. However, the document only contains the requirements for accuracy class 2 and 3, while modern electricity meters can easily handle a better accuracy. Up to now it was impossible to check these due to a lack of standards.
IEC 62053-24: increased accuracy
The new standard for better accuracy classes has recently been developed in the IEC TC13 working group. One of its characteristics is that the definition for reactive energy is based on the fundamental components of voltage and current. The new standard also contains accuracy tests under non-sinusoidal conditions, like the influence of 5th harmonics.
When reactive energy meters are examined in accordance with this new standard, NMi applies a specific reference standard that measures only the fundamental reactive power. By doing so, reactive energy meters can be perfectly examined according to the new IEC 62053-24 standard.