Dynamic Line Rating For Transmission Congestion — Simulation & Power Modeling

Abstract — Dynamic Line Rating For Transmission Congestion

Dynamic Line Rating For Transmission Congestion: Power Electronics, MATLAB/Simulink & Circuit Modeling Integrated Analysis: MATLAB/Simulink · MOSFET/IGBT Gate Drivers · SPWM/SVPWM · THD Spectrum · ~13506 Words Chapter 1: Power Electronics Overview, System Specifications & Topology Modeling As power grids experience increasing renewable penetration and rapid load growth from AI data centers and electrification, alleviating line congestion becomes critical to unlocking additional grid capacity. This work investigates Dynamic Line Rating (DLR), a congestion mitigation method that adjusts power line current limits in response to meteorological conditions. Unlike traditional approaches that impose predefined time-varying limits, we propose a novel optimization framework that embeds the transient-state heat equation governing conductor temperature dynamics, enabling direct constraints on conductor temperature rather than simplified steady-state approximations. We derive a closed-form solution to the heat equation, enabling a finite-dimensional reformulation of the dynamics. We then leverage a distributed decomposition method, a bi-level Alternating Direction Method of Multipliers (ADMM) algorithm with provable convergence, aided by regularity properties of the heat equation solution. These modeling and algorithmic innovations allow us to conduct the first large-scale evaluation of DLR using multi-period AC optimal power flow. Numerical experiments on the 2000-bus Texas grid demonstrate that DLR allows significant reduction in generation cost in congested systems over Static Line Rating (SLR) and Ambient Adjusted Ratings (AAR). The transient temperature formulation provides additional grid flexibility and headroom benefits with minimal computational overhead.

Analytical & State-Space Control Methodology

The increasing demand for efficient and reliable power transmission has highlighted the limitations of Static Line Ratings (SLR), which impose conservative thermal limits on transmission lines based on worst-case weather assumptions. This leads to underutilization of network capacity by increasing congestion costs and lowering system efficiency. Dynamic Line Ratings (DLR) leverage real-time weather data (ambient temperature, wind speed, and solar radiation) to adjust line ratings dynamically, increasing effective line ampacity. Recognizing its potential, the Federal Energy Regulatory Commission (FERC) has advocated for broader DLR adoption to enhance grid flexibility and reduce operational costs [ 1 , 2 ] . However, deploying real-world DLR solutions presents two major challenges. First, it requires high-resolution weather data and/or temperature monitoring technologies. Second, it adds computational complexity to the Optimal Power Flow (OPF) problems used for electricity dispatch. In this work, we assume full access to this data and focus on performance assessment.

Simulink Waveforms & Power Quality Findings

In Optimal Power Flow (OPF) problems, operators minimize generation costs while satisfying system constraints, e.g., voltage levels, angle limits, and transmission capacities. The most accurate formulation, Alternating Current OPF (ACOPF) , captures nonlinear nonconvex power flow physics but is strongly NP-hard . To reduce complexity, the industry often uses the linear Direct Current (DCOPF) approximation, although its accuracy degrades under heavily loaded conditions.

Scope & Practical Applications

• High-efficiency DC-DC converters and isolated resonant topologies (LLC / DAB)
• Sinusoidal and Space Vector PWM inverters for grid integration & industrial motor drives
• MOSFET / IGBT gate driver optimization with active Miller-clamp shoot-through protection
• Power quality conditioning with Total Harmonic Distortion (THD) strictly compliant with IEEE 519
• Complete Simscape .SLX model files, parameter calculation scripts, and IEEE dissertation reports