Measurement Uncertainty of Current Harmonics During the Assessment of Compliance to Grid Code Requirements

This paper improves the impact of measurement uncertainty on harmonic grid code compliance assessment by characterization of the current transformers at a renewable power producer. Field data was collected to evaluate the CT ratio error for magnitude and phase angle up to the 60
^th
harmonic. The test setup made use of certified instruments and applied IEC standards to derive CT ratio correction factors per harmonic order and per CT to reduce the combined uncertainty of the measurement chain.