EFFECTS OF MODELING ON THE ACCURACY OF HARMONIC-ANALYSIS

Electronic switching in AC/DC converters results in the generation of harmonics. The level of these harmonics depends on the interaction of the interconnected AC and DC systems. In analysis methods for computing harmonic levels, the following issues have not been adequately researched: (1) modeling of the AC power system and its effect on the computed harmonic spectrum and (2) convergence of the solution method. This paper proposes a method which addresses these issues. The method is used to show that the choice of the AC system model is very critical since the harmonic distortion at the interface bus is the result of an interaction between the converter and the AC system. The method consists of a comprehensive model of a converter substation, the AC power system, and the DC system equivalent. A solution algorithm based on the Newton's method is proposed with improved convergence characteristics. A parametric study is presented in order to illustrate the effects of the AC power system model and the converter control system on the harmonic generation. © 1990 IEEE