Harmonic distortion caused by non-linear household loads: Measurement and modelling

This study presents the modeling and validation of non-linear household loads in a single-family house in the Dominican Republic for harmonic analysis using a comprehensive methodology. Actual measurement data from seven non-linear household loads were captured with a METREL MI 2883 power quality analyzer, with the laptop charger exhibiting the highest harmonic distortion, showing a Total Harmonic Distortion of current (THD I ) of 126.97 %, and the fridge with the lowest, at 14.25 %. These data were then modeled in MATLAB/Simulink for real-time execution on an Opal RT 5700XG simulator. A novel approach for accurately replicating harmonic waveforms and characteristics of real loads is introduced, enabling precise evaluation of Active Harmonic Filters (AHFs) and control strategies in Hardware-in-the-Loop Simulation (HILS) configurations. Validation tests confirmed the reliability of the methodology, with percentage deviations consistently below 3 % between Simulink and measured values, and an average RN_RMSE of 2.19 % between MATLAB/Simulink and RTDS simulations. Specifically, RN_RMSE values ranged from 0.82 % for the microwave oven to 3.28 % for the smartphone charger, with the highest accuracy observed in the microwave oven and the largest deviation in the smartphone charger. The methodology consistently achieved deviations below 5 % across all validation scenarios. These results establish the effectiveness of the proposed methodology in achieving high-fidelity modeling non-linear household loads. The primary contribution of this work lies in advancing beyond traditional approaches reliant on generic models, providing a practical and accurate framework for the design and optimization of harmonic mitigation strategies aligned with real-world conditions.