A method for aggregation of harmonic emission characteristics of power electronics and model order reduction

The increasing integration of power electronics (PEs), including electric vehicle chargers (EVCs) and photovoltaic inverters (PVIs), into modern power systems has raised concerns about harmonic emissions. As nonlinear loads, these devices will introduce harmonic pollution that may degrade grid stability and device performance. Traditional harmonic modelling methods are often complex and computationally expensive, especially when dealing with large-scale systems. This paper proposes a method for aggregating the harmonic emission characteristics of PEs and a model order reduction approach. The data-driven equivalent harmonic Norton aggregation model (EHNAM) is introduced to assess harmonic emissions of PVIs and EVCs under various operating conditions. The model dynamically updates its parameters based on real-time climate and charging data, simplifying harmonic analysis without compromising accuracy. A case study of an EV charging station connected in the IEEE 33-node distribution system demonstrates the effectiveness of the model. The results are compared with those of a detailed MATLAB/Simulink model, showing that EHNAM provides a computationally efficient yet accurate solution for large-scale harmonic analysis. This method contributes to the assessment and mitigation of harmonics in systems with extensive PEs.