AC/DC Fundamental Power Flow Solver – Sequential Newton-Raphson Implementation for Hybrid Grids
Year: 2026
Type: software
Abstract: This repository provides a MATLAB-based implementation of a sequential AC/DC power flow solver for hybrid transmission systems. The method combines a DC power flow with an AC power flow solved sequentially using a Newton-Raphson formulation, coupled through a simplified converter model with constant efficiency losses. The tool is fully flexible and can be used for: Hybrid AC/DC systems Pure AC power flow studies Pure DC power flow studies depending on the selected configuration. The framework is designed for flexibility and reproducibility, using Excel-based input templates to define both grid topology and operating conditions. AC/DC coupling is handled implicitly through consistent bus numbering, enabling straightforward modelling of converter-connected systems without additional configuration. The implementation is computationally efficient and scalable. It has been successfully tested on large-scale systems (up to ~7000 buses), making it suitable for both small benchmark cases and realistic transmission grids. Key features include: Sequential Newton-Raphson solver for both DC and AC subsystems Support for standalone AC or DC simulations Automatic detection of AC/DC coupling via shared bus indices Excel-based input/output interface for reproducible workflows Export of converter operating points for post-processing and small-signal analyses Robust performance for large-scale systems This tool is intended for research and educational applications in power systems, particularly in the analysis of hybrid AC/DC grids, multi-terminal HVDC systems, and large-scale network studies. This AC/DC power flow tool has been developed as a complementary module to a small-signal converter-driven stability analysis tool. In particular, it is intended to interface with the repository ISSA (Innovative Software for Stability Analysis), providing the steady-state operating point required for subsequent linearisation and stability studies.
Institution: Universitat Politècnica de Catalunya
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7155372138