A Low-Cost Measurement Setup to Test Low-Power Voltage Transformers in the 9 kHz - 150 kHz Frequency Range

The increasing integration of renewable resources in the energy mix of countries leads to a certain degradation of the quality of electricity due to the use of electronic power converters. The latter, composed of switching components, can introduce high frequency harmonics up to 150 kHz into the network. However, the international standards and state-of-art literature of instruments transformers (ITs) do not adequately cover or even address methods, techniques, parameters, and metrological requirements to be followed during power quality (PQ) measurements in case of frequencies greater than tens of kilohertz. In this framework, this paper proposes a new method and a measurement setup, performed with economical instrumentation, for characterizing two medium voltage (MV) low-power voltage transformers (LPVTs) in the extended frequency range 9 - 150 kHz. In detail, this work applies the “sinc-approach” which is a new characterization procedure, previously designed by the authors, that has several advantages enumerated later. After the description of the scenario behind this work, the measurement setup, tests, and results are described in depth in order to propose a preliminary simple and low-cost harmonic characterization procedure of LPVTs in the frequency range from 9 kHz to 150 kHz.