Representation of large asynchronous load areas for harmonic penetration studies

This paper illustrates the first phase of a research work carried out to validate a simple model proposed by the authors, for large asynchronous load areas representation in harmonic penetration studies. The validation methodology has started out with an investigation conducted on asynchronous load typologies existing in italian power system load areas. Afterwords, measurement results, as obtained from several tests on LV fed low rated motor groups, expressed in terms of equivalent impedance as a function of the frequency (for values up to 700 Hz), have been compared with those calculated using the proposed model. A calibration of the model has been finally performed by using it in a harmonic load-flow program to match experimental results obtained for a large distribution network.