A Practical Approach to Estimate Harmonic Distortions in Residential Distribution System

Harmonic pollutions in residential distribution system has become an emerging concern for utility companies. It is however difficult for the utility to have a systematic understanding on the severity of the distortion due to the lack of monitoring infrastructure. To address this issue, this paper proposes a practical solution to estimate harmonic distortions in residential distribution systems. The measurement is first taken at several representative service transformers and a unified harmonic model is developed for the secondary residential system. Then a probabilistic harmonic load flow algorithm is proposed with the network model provided by the utility. Importantly, the available harmonic measurements are considered, which significantly reduce the uncertainty of the estimation. Finally, the proposed method is verified using a real three-phase four-wire residential system in North America. Practical issues are also discussed to show the robustness and limitations of the proposed method.