February 14, 2022

Abstract: Due to increasing penetration of Inverter-based Resources (IBRs), harmonic distortion is a growing power quality challenge. To improve the accuracy of harmonic studies including IBRs, detailed models are required, but data from manufacturers are difficult to obtain or proprietary. This paper compares the ideal current-source IBR model with a generic impedance-based model, that does not require detailed knowledge of the control system. Harmonic studies are carried out on a region of the GB power system model using both the ideal and the impedance-based IBR models. The results show that the use of impedance-based IBR models impacts network impedances and harmonic levels at low frequencies, when compared to the ideal current source model. For high-order frequencies, the results of the two models are similar. By modeling IBRs using the impedance-based model and the harmonic contributions from the distribution network, the obtained voltage Total Harmonic Distortions (THDs) at selected busbars are comparable with measurement data.

Citation: Z. Deng, G. Todeschini and K. L. Koo: ‘Comparison between Ideal and Frequency-dependent Norton Equivalent Model of Inverter-Based Resources for Harmonic Studies’, IEEE Innovative Smart Grid Technologies Conference Asia (ISGT Asia), 2-5 December 2021, Virtual Edition.

doi: 10.1109/ISGTAsia49270.2021.9715634