Interval power flow analysis via multi-stage affine arithmetic for unbalanced distribution network

Integrating large numbers of intermittent energy resources, such as photovoltaic generations and wind turbines, brings huge uncertainty to the operation of distribution network. In this paper, an interval power flow method via multi-stage affine arithmetic is proposed to address the impact of distributed generation output power and load uncertainty on the power flow solution for the unbalanced distribution network, which acquires affine expression of bus voltage by solving the fixed component, first-order perturbation and non-linear perturbation of the bus complex voltage respectively. Multi-numerical results based on modified IEEE 123 nodes test feeder are presented and discussed, demonstrating that the proposed method achieves much better performance than existing ones in both precision and computation aspects.