Stochastic evaluation of voltage in distribution networks considering the characteristic of distributed generators

As the probabilistic load flow (PLF) approach is often applied in the assessment the voltage in the distribution system with the distributed generation, the intermittent power output of the distributed generators (DGs) should be more considered. The power variation characteristics of load and distributed generators should be treated separately. In this paper, taking the PV arrays for the typical example, the probability density function (PDF) of the DG is derived from the mathematical model of the power source and the PDF of its uncertain variables. The stochastic voltage evaluation via the PLF is processed by the 2 point estimate method (2 PEM). Besides, the possible network configurations with the relative probability are also considered, for analyzing the comprehensive case for the occurrence of network change. The proposed method will be tested with the modified IEEE 13-nodel feeder test system, and the data for the probabilistic evaluating features of all the nodal voltages distribution are obtained. The results can be used to help know the general and complete voltage effects.