Static voltage bilayer optimization for distribution networks based on Sobol’ method

Abstract In active distribution networks, the uncertainty of a large number of distributed power sources makes the voltage stability problem of distribution networks more and more prominent. The existing optimization methods tend to deal with the economy and voltage stability of distribution networks as independent objectives, with less consideration of their connection, making it difficult to realize the efficient use of flexible resources. The paper introduces upper and lower connection factors and proposes a two-layer optimization model for distribution network voltage using the Sobol’ method. First, taking into account the uncertainty of distributed power sources and loads in active distribution networks, a probabilistic tidal current calculation model for active distribution networks is constructed, based on which the impact of load fluctuations on the L index is quantitatively analyzed by the global sensitivity of the Sobol’ method. Secondly, the upper and lower connection factors are calculated based on the sensitivity analysis results. The upper economic objective and the lower stability objective are connected through the connection factors to establish a two-layer optimization model to solve the flexible resources in the system optimally. Finally, simulations on the modified IEEE33 node system validate that the proposed optimization model enhances distribution network security while considering economic factors.