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Nanduni I. Nimalsiri

Publications and source records attributed to Nanduni I. Nimalsiri.

2 recordsLinked to original sources

Plug-in Estimation Method for Topology and Admittance Estimation in Electric Grids

This paper proposes a scalable method for topology and admittance estimation in electric power grids. Our proposed plug-in estimation method incorporates precise phasor measurement unit data to estimate planned or unplanned grid topology and admittance parameter changes. Our plug-in estimation method decouples the problem into two stages: (i) constructing and averaging voltage coefficient matrices and current vectors from phasor data, and (ii) estimating admittance parameters via a least-squares regression approach with thresholding to recover the network topology. Rigidity matrix theory underpins the design of our plug-in estimation method --- to determine the data requirements (e.g., necessary and sufficient conditions) for accurate estimation of the grid topology and admittance parameters. By means of numerical simulations on the IEEE 13-node, 123-node, and European low voltage test feeders, we demonstrate the scalability of our plug-in estimation method and benchmark the computational time against a structured total least squares method. Our simulation results highlight the practicality of the proposed method for topology and admittance estimation in large-scale electric networks, including electric grids with partial topology information.

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A Survey of Algorithms for Distributed Charging Control of Electric Vehicles in Smart Grid

Electric vehicles (EVs) are an eco-friendly alternative to vehicles with internal combustion engines. Despite their environmental benefits, the massive electricity demand imposed by the anticipated proliferation of EVs could jeopardize the secure and economic operation of the power grid. Hence, proper strategies for charging coordination will be indispensable to the future power grid. Coordinated EV charging schemes can be implemented as centralized, decentralized, and hierarchical systems, with the last two, referred to as distributed charging control systems. This paper reviews the recent literature of distributed charging control schemes, where the computations are distributed across multiple EVs and/or aggregators. First, we categorize optimization problems for EV charging in terms of operational aspects and cost aspects. Then under each category, we provide a comprehensive discussion on algorithms for distributed EV charge scheduling, considering the perspectives of the grid operator, the aggregator, and the EV user. We also discuss how certain algorithms proposed in the literature cope with various uncertainties inherent to distributed EV charging control problems. Finally, we outline several research directions that require further attention.

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