A Bi-level Robust Energy Storage Siting and Sizing Model of Distribution System with Energy Affordability Enforced

The energy affordability principles aim to enhance energy accessibility and reduce electricity expenditures for low-income communities. However, the advocated affordability policies impose new requirements on system operators, as few have been translated into technical utility models. Energy storage systems (ESS) are crucial in implementing energy affordability by regulating voltage profiles and reducing power loss. This paper proposes an energy affordability-embedded robust planning (EARP) model to relieve the energy burden of low-income loads through equitable ESS deployment. The proposed model innovatively enforces implicit energy affordability (EA) constraints into technical models with two steps. First, an energy affordability slackness component (EASC) variable is introduced to evaluate the smallest gaps between the given preliminary planning decisions and the desired affordability-satisfied decisions. Then, by relaxing the dispatch model with the EASC variable, the implicit EA constraints are converted into explicitly cutting planes using the duality theorem. The proposed bi-level EARP model is solved via an improved column & constraint generation (C&CG) algorithm. Case studies on the IEEE 33-Bus and 123-Bus systems verify the model's effectiveness in relieving energy burdens and achieving better sustainability in the long term compared with conventional bill assistance programs.