Voltage-sensitive distribution factors for contingency analysis and topology optimization
This work addresses the computational and accuracy limitations in power grid contingency analysis and topology optimization, particularly for tasks like busbar splitting, though it is incremental as it builds on existing linearization methods.
The paper tackled the problem of conventional distribution factors failing to capture voltage variations and reactive power in power grid topology optimization by introducing generalized distribution factors from a voltage-sensitive linearization of AC power flow equations, resulting in close agreement with full AC solutions and significantly outperforming traditional DC approximations.
Topology optimization is a promising approach for mitigating congestion and managing changing grid conditions, but it is computationally challenging and requires approximations. Conventional distribution factors like PTDFs and LODFs, based on DC power flow, fail to capture voltage variations, reactive power, and losses, thereby limiting their use in detailed optimization tasks such as busbar splitting. This paper introduces generalized distribution factors derived from a voltage-sensitive linearization of the full AC power flow equations. The proposed formulation accurately reflects reactive power flows, Ohmic losses, and voltage deviations while remaining computationally efficient. We derive and evaluate generalized PTDFs, LODFs, and topology modification factors using matrix identities. We discuss potential applications including voltage-aware N-1 security analysis and topology optimization with a focus on busbar splitting. Numerical experiments demonstrate close agreement with full AC solutions, significantly outperforming the traditional DC approximation.