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Measurement methods and test procedures for assessing accuracy of instrument transformers for power quality measurements

Short Name: IT4PQ, Project Number: 19NRM05
Power substation

Characterising Instrument transformers to develop new standards for more reliable power quality measurements

Renewable electricity can cause grid-injected disturbances, damaging power quality (PQ). PQ represents the grids ability to supply constant, stable power and PQ problems cost EU industry and commerce around €150 billion annually. To reduce network currents and voltages down to a level compatible with PQ measurement instruments requires the use of Instrument Transformers (ITs). However current international standards fail to account for IT performance in the presence of disturbances and do not detail specific IT characterisation tests, making it impossible to perform PQ measurements in electricity grids with a known level of confidence


Building upon the EMRP projects SmartGrid II and FutureGrid the project has defined accuracy and uncertainty limits for ITs in PQ measurements, developed reference measuring systems and traceable test procedures and assessed IT performance with multiple influence factors. At the end of the project in 2023 recommendations will be given to IEC TC38 to incorporate into new standards. Increased confidence in PQ measurements will allow electricity utilities and industries to take appropriate actions to help prevent or solve any PQ related issues.

Project website
Measuring Harmonics With Inductive Voltage Transformers in Presence of Subharmonics

IEEE Transactions on Instrumentation and Measurement

Improving Harmonic Measurements with Instrument Transformers: a Comparison Among Two Techniques

2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)

Instrument Transformers for Power Quality Measurements: a Review of Literature and Standards

2021 IEEE 11th International Workshop on Applied Measurements for Power Systems (AMPS)

A simplified procedure for the Accurate Frequency Response Identification of Voltage Transformers

Proceedings of the 24th IMEKO TC-4 International Symposium, September 14-16, 2020

Measurement Methods and Procedures for Assessing Accuracy of Instrument Transformers for Power Quality Measurements

Conference on Precision Electromagnetic Measurements CPEM 2020 Proceedings

Other Participants
Alma mater studiorum Università di Bologna (Italy)
Ricerca sul Sistema Energetico – RSE S.p.A. (Italy)
Technische Universität Dresden (Germany)
Università degli studi della Campania Luigi Vanvitelli (Italy)