Evaluating the long-term impact of a continuously increasing harmonic load demand on feeder level voltage distortion

The increasing implementation of nonlinear devices within residential homes may have a significant impact on feeder level harmonic distortion. Within this paper the authors analyze the long-term distortion possibilities on a distribution feeder due to a large number of residential customers producing harmonic currents near and above the IEEE 519 recommendations. Field experiments were performed to develop a function that defines the relationship between the harmonic current produced by a single residential customer and their corresponding harmonic impedance. Utilizing an expanded version of the IEEE 13 Node Test Feeder with residential customers represented by a Norton equivalent circuit with the nested harmonic impedance function, the authors applied the current injection method to evaluate how an increasing harmonic demand will affect future harmonic voltage distortion. The evaluation results provide a foundation for utility companies to forecast feeder level harmonic distortion based upon feeder impedance and the existing levels of harmonic distortion.