Reference & Theory

Quick Reference

• Glossary — A-Z of power systems terminology
• Units & Conventions — Per-unit system, sign conventions, base values

Foundations

Start here if you're new to power systems:

• Complex Power — Real, reactive, and apparent power (P, Q, S)
• Impedance & Admittance — R, X, Z, G, B, Y explained
• Bus Types — Slack, PV, and PQ buses
• Y-Bus Matrix — Building the network admittance matrix

Analysis Methods

• Power Flow Theory — Mathematical foundations of AC/DC power flow
• Newton-Raphson Method — The iterative solver for power flow
• OPF Formulations — DC-OPF, SOCP, and AC-OPF mathematics
• State Estimation Theory — WLS estimation, bad data detection, observability

Planning & Markets

• Contingency Analysis — N-1 security and reliability
• LMP Pricing — Locational marginal prices in electricity markets
• Reliability Theory — LOLE, EUE, Monte Carlo methods

Algorithms

GAT implements established power systems algorithms:

Power Flow

• Newton-Raphson — Standard AC power flow
• Fast Decoupled — P-θ/Q-V decoupled iteration
• DC Power Flow — Linearized real power flow

Optimal Power Flow

• DC-OPF — Linear economic dispatch
• SOCP Relaxation — Convex branch-flow model (Farivar-Low)
• AC-OPF — Full nonlinear OPF (penalty L-BFGS + IPOPT backends)

State Estimation

• Weighted Least Squares — Classical SE formulation
• Bad Data Detection — Chi-squared and largest normalized residual

Reliability

• Monte Carlo — Sequential/non-sequential simulation
• Analytical — LOLE, EENS, EIR calculation
• Multi-area — Corridor-constrained adequacy

Data Formats

• Arrow schema — Canonical folder layout with system, buses, generators, loads, and branches.
• gat convert format — Command-line helper that auto-detects imports and converts via Arrow when crossing MATPOWER, PSS/E, CIM, or PandaPower boundaries.
• MATPOWER — .m file format
• PSS/E — RAW file support

Literature

Key references for implemented algorithms:

Textbooks

• Grainger & Stevenson, Power System Analysis
• Wood, Wollenberg & Sheblé, Power Generation, Operation and Control
• Kundur, Power System Stability and Control

Papers

• Zimmerman, Murillo-Sánchez, Thomas (2011) — MATPOWER
• Billinton & Allan — Reliability Evaluation of Power Systems
• NERC TPL Standards — Transmission Planning

FAQ

See the FAQ for common questions about power systems analysis and GAT usage.