Sensitivity Analysis Approach of New Dynamic Harmonic Distortion Current Limits on Utility Grids

摘要

Harmonic levels in distribution power systems are expected to rise in the future. Understanding the consumer load composition of each individual circuit and maximum harmonic limits can help utilities plan and mitigate power quality issues. This paper presents a sensitivity analysis approach of IEEE Standard 519 total harmonic distortion (THD) current limits on an actual utility model. A new dynamic harmonic index method for characterizing distribution power circuits is proposed, which utilizes the short circuit ratio (SCR) as the main parameter. OpenDSS is used as a modeling platform to study the THD of the voltage (THDV), while increasing the harmonic spectrum of random consumer load points. The main goals are to: (1) identify voltage behavior in power utility networks when an increasing number of consumers operate at the Std. 519 limits, and (2) categorize utility circuits using available information. The short circuit at the point of common coupling, maximum demand load currents, and the circuit configuration are considered. Three actual utility circuits are analyzed and compared in terms of their SCR and one of these circuits is analyzed in depth as part of the sensitivity study. The proposed method is also compared with the conventional pure capacitor and tuned filler bank methods. Finally, a recommendation for new harmonic distortion current limits is provided.