Probabilistic Risk Assessment of Over-voltage Based on Voltage Sensitivity Analysis in Distribution Networks

To address the problem of over-voltage caused by the uncertainty of high penetrated distributed generations (DG) and load in distribution networks (DN), the voltage sensitivity-based probability analysis method for over-voltage assessment is proposed in this paper. Firstly, a voltage sensitivity analytical model for the DN is derived to quantify the impact of power fluctuations on node voltage. Then, to characterize the uncertainty characteristics of power fluctuation, the multivariate normal distribution function of DG and load forecasting error is established. Finally, based on the voltage sensitivity matrix, combined with the linear transformation of the multivariate normal distribution function, the probability distribution model of node voltage fluctuation is constructed. Based on the numerical analysis on the IEEE 33-node system, the proposed method for analyzing the probability of over-voltage can accurately reflect the probability risk of over-voltage.