This paper reviews the common practice and analytical models for the representation of aggregate linear load in harmonic propagation and distortion studies. Simulation results in this paper demonstrate the high sensitivity of harmonic propagation and distortion to the model type used to represent the load. Comparison of the several load models in the literature shows a significant difference on the system impedance around the dominant resonance. The paper recommends a comprehensive modeling approach that accounts for all major components of the modern load including electronic load and background distortion.

This paper presents a review of characteristics and modeling of major power electronic types of harmonic sources for the power system harmonic analysis. The power electronic switching types of harmonic sources to be reviewed include static power converters, static var compensators (SVCs), and cycloconverters. Discussions and comments for applications of these harmonic sources in harmonic modeling and simulation also will be described.

This paper presents three harmonic simulation test systems. The purpose is to demonstrate guidelines for the preparation and analysis of harmonic problems through case studies and simulation examples. The systems can also be used as benchmark systems for the development of new harmonic simulation methods and for the evaluation of existing harmonic analysis software.