Research on multidimensional risk assessment system of renewable energy distribution network based on value at risk

In order to reflect the impact of source-load uncertainty on the overall operation risk of the power system in the future time interval, this paper establishes a multi-dimensional risk assessment system for renewable energy distribution networks based on value-at-risk. Firstly, the output probability model and load probability model of wind power photovoltaic are established, and then the sampling combination and power flow calculation are carried out based on the Monte Carlo method, and the corresponding node voltage and branch power flow results are obtained. Calculate the two risk indicators of branch power limit and node voltage limit at each prediction time of the distribution network, and use them as the first dimension risk assessment index; secondly, based on the value-at-risk theory to quantitatively evaluate the system risk, calculate the second dimension risk assessment Index; Finally, calculate the third dimension risk assessment index, calculate the comprehensive risk index through the entropy weight method, and comprehensively and reasonably analyze the operation risk of the distribution network under the access of different amounts of renewable energy. Finally, the rationality of the proposed model and method is verified by IEEE33 example system.