A TIME-DOMAIN 3-PHASE POWER-SYSTEM IMPEDANCE MODELING APPROACH FOR HARMONIC FILTER ANALYSIS

This paper presents a time-domain method for impedance modeling of an unbalanced, three-phase. power transmission and distribution network using three-phase measurements of bus voltage and injected current waveforms. An impedance model seen at a bus where a harmonic filter is to be installed is calculated for each harmonic frequency and the effect of placing the filter at the bus is then analyzed at these frequencies. As the configuration or operating condition of the power system varies, the estimated model changes accordingly, provided updated measurements are available. Hence, the effect of the harmonic filter under different system configurations or operating conditions can be analyzed and the information from this analysis can be used for on-line harmonic filter control. Impedance models estimated by the proposed method have been applied in filter design and performance analysis with actual recorded data, and the results are presented in this paper.