Recent Feature Additions

Version 0.4.0¶

AC OPF Performance: AC PF Warm-Start + Interior-Point NR¶

The AC OPF solver now uses AC PF (Newton-Raphson) as its warm-start, replacing the previous flat-start approach. This fixes convergence failures on meshed/cyclic networks (e.g., IEEE-13) and dramatically improves performance:

When the AC PF solution satisfies voltage bounds, it is accepted directly. If bounds are violated, an interior-point NR with log-barrier terms refines the solution while maintaining strict feasibility.

MCP Server Migrated to v2¶

The MCP server now uses mcp>=2.0.0 with the new add_request_handler() API:

• Types from mcp_types package

• ListToolsRequest / CallToolRequest handler registration

• mcp.stdio_server for transport

Violation Detection & Automated Fix Engine¶

New gdm_flow.fix module provides iterative remediation of voltage and loading violations:

• detect_violations(system, solver="ldf") — runs power flow and identifies all out-of-band voltages and overloaded branches

• fix_violations(system) — iteratively applies strategies until violations are resolved or no progress is made

Four built-in strategies (applied in priority order):

CLI command: gdm-flow fix MODEL [--solver ldf] [--max-iter 10]

MCP scale_loads Tool¶

New MCP tool to uniformly scale all load P/Q before running solvers — useful for stress-testing at higher demand levels.

Code Quality & CI¶

• Codecov integration with coverage upload on every push to main

• 89% coverage enforcement in CI and pre-commit (pre-push stage)

• dashboard.py excluded from coverage (visualization-only code)

• Ruff lint + format enforced via pre-commit hooks

• All optional dependencies (mcp, plotting, opendss) installed in CI

Version 0.3.0¶

Split-phase (center-tapped transformer) support¶

All solvers now correctly handle center-tapped transformers and split-phase (S1/S2) buses:

• Y-bus: Kron-reduced 3-node admittance model with proper polarity — S1 in-phase with primary, S2 anti-phase. Includes S1-S2 coupling terms essential for NR convergence.

• AC OPF & AC PF: S1/S2 angle initialization propagates the primary phase angle through the secondary network via BFS, so transformers on phases B or C get correct starting angles.

• DC OPF: Linearization correction for S2 offset (negates v_nom for S2 buses).

• LinDistFlow: Phase angle map includes S1/S2, with center-tap detection and voltage-drop model for split-phase transformers.

Automatic parallel transformer aggregation¶

The CLI auto-detects and aggregates parallel single-phase transformers and regulators:

• Groups of 3 single-phase units → 3-phase equivalent

• Groups of 2 single-phase units → open-wye/open-delta equivalent

• Emits warnings when aggregation is applied

DistributionRegulator stamping in Y-bus¶

The Y-bus builder now stamps DistributionRegulator components (previously only DistributionTransformer was stamped), enabling correct voltage regulation modeling in NR-based solvers.

LinDistFlow geometry conversion¶

Added convert_geometry_to_matrix: bool = True parameter to solve_lindistflow(). When enabled, geometry-based branches are automatically converted to matrix impedance form before solving. The AC PF warm-start call uses convert_geometry_to_matrix=False to avoid mutating the system.

AC OPF NR warm-start always enabled¶

The Newton-Raphson warm-start (LinDistFlow → NR) is now always used regardless of system size, providing significant speedup on medium-sized systems (e.g., 135x on IEEE-123).

CLI compare command enhancements¶

The gdm-flow compare command now produces rich diagnostic output:

Solver results summary¶

Tested across three reference models: