ASSESSMENT OF INSTRUMENT TRANSFORMER ACCURACY FOR POWER QUALITY MEASUREMENTS IN DISTRIBUTION GRIDS: RECENT ACTIVITIES AND FIRST RESULTS FROM 19NRM05 IT4PQ PROJECT

Extensive integration of renewables in the electrical energy distribution system is essential for the implementation of “green growth” strategies. However, it contributes to the degradation of the quality of the electrical power, as such power quality (PQ) monitoring holds greater and greater importance. Currently, there are no standards related to the characterisation of the instrument transformers (ITs) for PQ measurements, even if ITs can introduce significant errors in the PQ measurement chain. Therefore, a project has recently funded to investigate gaps in accuracy assessment and characterisation of ITs when used in PQ measurements and to work out specific performance indices, reference measurement systems and test procedures to evaluate the ITs accuracy and uncertainty contributions in PQ measurements. Guidelines and recommendations for the calibration of ITs used in PQ measurements will be provided to the Technical Committee IEC TC 38.