A novel fuzzy number based method to model aggregate loads for harmonic load-flow calculation

Harmonic distortion is a growing problem in power systems due to the increasing use of power electronic devices and loads. A possibilistic methodology for harmonic load-flow calculations based on fuzzy numbers has recently been proposed by the authors as an alternative to probabilistic approaches for modeling uncertainties in linear and nonlinear loads. This paper presents a methodology to aggregate uncertainly known bus loads, whose magnitudes and composition are described through fuzzy parameters, into a fuzzy admittance and injected harmonic currents of a possibilistic harmonic load-flow calculation. Interaction between fuzzy parameters (the possibilistic counterpart of probabilistic dependence) is properly modeled. A numerical example is given in the last section.