Bi-level framework for planning assessment of distribution grids based on smart grid technologies and conventional grid upgrades

Nowadays, the Distribution System Operators face challenges with the selection of the most cost-effective network expansion measures that have to be undertaken due to the growing integration of Distributed Energy Resources (DERs). In this paper, the main goal is to develop a comprehensive framework for conducting a cost analysis of grid expansion plans that consider both conventional and innovative smart grid solutions. The planning framework consists of three main stages. At the pre-processing stage, the future scenario is defined, identifying grid contingencies and specifying the available grid upgrade equipment. Next, the core of the framework, is a bi-level optimization process that optimizes both capital and operational costs of the candidate solutions. At the final post-processing stage, the most cost-effective solutions for the predefined scenario are generated. The framework is applied for an IEEE low voltage test grid simulating three different DER future scenarios. From the results, it is evident that the framework can defer the replacement of existing assets and installation of smart grid technologies by leveraging flexibilities of load shifting methods.