EXTERNAL SYSTEM MODELING FOR POWER TRANSMISSION-SYSTEM HARMONIC-ANALYSIS USING THE BILINEAR THEOREM

A method is proposed which easily and accurately determines the relati ve importance of external system equivalents on the harmonic impedance of a transmission network. Oversimplifications of external systems ca use errors in transfer impedance for harmonic analysis. The bilinear t heorem provides an economical and accurate method of determining the a ppropriate locations for network simplification. This method needs thr ee system constants to be computed and then changes in transfer impeda nce due to variations in equivalent impedance of external system can b e checked without extensive network solutions. Using this technique, w e can also fix the errors bounds and reduce the high error range of th e equivalent impedance. This method permits the modeling of larger tra nsmission systems with a known accuracy for harmonic analysis, filter designs and switching studies.