Probabilistic load flow incorporating generator reactive power limit violations with spline based reconstruction method

• A PLF method is proposed in which the violations of the reactive power limits of the generators are adequately represented.
• The 7PEM along with the spline based reconstruction technique is proposed for constructing the PDF of the resulting multimodal distributions.
• The effect of standard deviation and system size on the absolute maximum error is also analyzed.
• It has been tested on the IEEE-118-300 bus test systems for unimodal and multimodal load distributions and validated by comparing with MCS studies.
• The correlation among the loads and limits on power generation/absorption of the slack bus has also been considered.

The increase in the penetration of intermittent generation and uncertainty in load patterns calls for the need to include these uncertainties in the conventional power flow programs. Consideration of the generator reactive power limit violation is an essential aspect in load flow studies for planning. In this paper, a probabilistic load flow method is proposed in which the violation of the reactive power limits of the generators are adequately represented. The seven point estimate method along with the spline based reconstruction technique is proposed for constructing the probability density function of the resulting multimodal distributions. The proposed load flow method has been tested on the IEEE-118 bus and IEEE-300 bus test systems for unimodal and multimodal load distributions, with and without correlation, and the accuracy of the results has been validated by comparing these results with those obtained by Monte Carlo simulation studies. Further, the effect of slack bus power limits has also been studied in this work.