Credibility-based Risk Assessment of the Active Distribution Networks

Abstract

A large number of distributed generations(DGs) and controllable loads are introduced into the active distribution networks(ADNs), and the power grid structure is more complicated, which makes the risk assessment of the ADNs using traditional evaluation methods unable to meet the accuracy requirements. Therefore, a credibility-based risk assessment method of the ADNs is proposed. Firstly, the probabilistic and severity indicators of the system are studied. Then, the uncertainty of Monte Carlo (MC) sampling results and the randomness of distributed power supply and load are considered. Next, the credibility of the assessment results is calculated, which is the comprehensive rate of change of each risk indicator compared to the risk indicator of the previous year n and the weighted value of the distribution model and the mean and standard deviation of the samples. Finally, based on the above content, the credibility-based risk assessment model of the ADNs is established. Real-time credibility is compared with set credibility as a criterion for convergence, thus the randomness of MC sampling is greatly reduced and the evaluation time is shortened. Through the risk assessment of the ADNs in a certain area of Jiangsu, the results show that the credibility-based risk assessment of the ADNs can greatly improve the accuracy and efficiency of risk assessment of the distribution network.