Research on Voltage Rise Risk Assessment Model and Method for Distribution Network with Distributed Generation

Distributed generation (DG) has great influences on the operation of distribution network. Voltage rise is one of the important influences. To evaluate the potential voltage rise risk of distribution network with DG, a modified 2-point estimate method is proposed to calculate the probabilistic load flow so that the probabilistic statistic values of voltages can be obtained. Combing with theory of semi-invariant and Cornish-Fisher series expansion, the probability distribution function curves and the probability of voltage rise are obtained. The probabilistic evaluation index and evaluation criterion for voltage rise risk of the distribution network with DG are proposed in the paper. Finally, the rationality and effectiveness of voltage rise risk assessment method are verified with IEEE 39-bus distribution network. The simulation results show that the voltage rise risk in distribution network with DG is related to the access capacity and location of DG.