Estimation and utilization of aggregate harmonic load model

Abstract

Detailed harmonic analysis is desirable to study the adverse impact of increasing harmonic loads on the power system. Harmonic loads needs to be modeled accurately for such analysis. Conventionally Constant current model is used to model the harmonic loads for analysis. However, recently to incorporate cross coupling effect among harmonics, Frequency Coupling Matrix (FCM) based model is suggested in literature. So far FCM model is mostly used to represent individual non-linear devices obtained either analytically or through measurements under test conditions. However, techniques for determining aggregate FCM model are not discussed in literature. To address this, technique based on artificial disturbance using distributed generation sources to determine aggregate FCM is proposed in this paper. This model accurately captures the attenuation effect of distorted bus voltages on the load harmonic injections. Further, FCM based method is used to analyze a 11 bus radial distribution system and the results are compared with constant current model based method.