Substation-Level Grid Topology Optimization Using Bus Splitting

TL;DR

This paper introduces a novel substation-level topology optimization method incorporating bus splitting, which enhances grid efficiency and reduces costs through a tractable MILP formulation suitable for real-time power system operations.

Contribution

It develops an improved optimization framework that includes breaker-level bus splitting with a McCormick relaxation, enabling efficient real-time substation topology reconfiguration.

Findings

Reduces grid congestion and generation costs.

Demonstrates computational efficiency on IEEE test systems.

Provides economic benefits through topology optimization.

Abstract

Operations of substation circuit breakers are important for maintenance needs and topology reconfiguration in power systems. Bus splitting is one type of topology change where the two bus bars at a substation can become electrically disconnected under certain actions of circuit breakers. Because these events involve detailed substation modeling, they are typically not considered in routine power system operation and control. In this paper, an improved substation-level topology optimization framework is developed by expanding traditional line switching decisions by breaker-level bus splitting, which can further reduce grid congestion and generation costs. A tight McCormick relaxation is proposed to reformulate the bilinear terms in the resultant optimization problem to linear inequality constraints. Thus, a tractable mixed-integer linear program reformulation is attained that allows for efficient solutions in real-time operations. Numerical studies on the IEEE 14-bus and 118-bus systems demonstrate the computational performance and economic benefits of the proposed topology optimization approach.