MATPOWER-Release-Notes-8.1.md

What's New in MATPOWER 8.1

Released Jul 12, 2025

Below is a summary of the changes since version 8.0 of MATPOWER. See the CHANGES.md file for all the gory details. For release notes for previous versions, see Appendix H of the MATPOWER User's Manual.

New Features:

• Three-Phase Proof-of-Concept Enhancements
  • New utility, mp.case_utils.convert_1p_to_3p(), converts a standard single-phase MATPOWER case to an equivalent balanced three-phase case. Thanks to Wilson González Vanegas.
  • New off-nominal tap ratio parameter in prototype three-phase transformer model. Thanks to Wilson González Vanegas.
  • New prototype three-phase shunt model. Thanks to Wilson González Vanegas.
  • Support for three-phase prototype data in savecase().
• MP-Opt-Model 5.0 includes:
  • New, redesigned classes for building and solving mathematical programming/optimization models. The new classes mp.opt_model and mp.set_manager and subclasses replace refactored opt_model and mp_idx_manager which are deprecated, but retained for backward compatibility.
  • Support for quadratic constraints and quadratically constrained quadratic programming (QCQP) models and solvers. Thanks to Wilson González Vanegas.
  • Support for the open-source HiGHS solver for LP, QP and MILP problems based on the HiGHSMEX interface.
  • New relax_integer option to facilitate easily solving the LP or QP relaxation of a mixed integer LP or QP model.
  • Support for Artelys Knitro solver for LP and QP problems. Thanks to Wilson González Vanegas.
  • Support for Artelys Knitro 15.x.
  • Support for conversion between objects and structs to facilitate workarounds for Octave's inability to save and load classdef objects. For details, see the MP-Opt-Model 5.0 release notes.
• MOST Pro 1.4.1, available by contacting info@matpower.org, adds support for MATPOWER DC lines as described in Section 7.6.3 of the MATPOWER User's Manual. Please note: MATPOWER 8.1 includes MOST 1.3.1, and MOST Pro 1.4.1 is a paid upgrade.
• MP-Test 8.1 adds functions to assist with code for debugging and enhances handling of Inf values in test results. For details, see the MP-Test 8.1 release notes.
• New functions:
  • mp.case_utils.convert_1p_to_3p -- Converts a single-phase case to a three-phase case.
  • mp.load_dm -- Loads a data model object.
  • save2psse_rop -- Saves data from a MATPOWER case to a PSS/E ROP (Raw Operating Point) file. Thanks to Irabiel Romero.
• New options:
  • highs.opts overrides default options for the HiGHS solver.

New Case Files:

• One new distribution system case. Thanks to Paul S. Moses.
  • case1197 -- 1197-bus radial distribution system case.
• One new transmmission system case. Thanks to Mory Najafi.
  • case59 -- 59 bus, 14 generator Australian network case.

New Documentation:

Three live scripts illustrate the use of new features.

• convert_1p_to_3p_ex1.mlx (in examples) illustrates the use of the new single-phase to three-phase conversion capabilities.
• milp_example1.mlx (in mp-opt-model/examples) illustrates the use of MP-Opt-Model and the new mp.opt_model class to build and solve an optimization (MILP) model.
• qcqp_example1.mlx (in mp-opt-model/examples) illustrates the new quadratic constraint features and two methods of building and solving a quadratically-constrained quadratic programming (QCQP) model.

Other Improvements:

• Add shunt loss columns (psh_fr, qsh_fr, psh_to, qsh_to) to branch data model. In pretty-printed output, separate branch loss summary into series and shunt losses and add series loss columns to branch detail output. Thanks to Wilson González Vanegas.
• The save2psse function now creates distinct generator IDs for cases with multiple generators at a single bus. Thanks to Irabiel Romero.
• MIPS 1.5.2 adds a feature detection function for \mips{}. For details, see the MIPS 1.5.2 release notes.
• MOST 1.3.1 fixes bugs in most_summary() and some tests, and includes unit commitment tests for HiGHS solver. For details, see the MOST 1.3.1 release notes.
• Include HiGHS solver, if available, in DC OPF tests.
• Add rebuild() method to mp.data_model, used to update the data model internals after making changes to data in the data tables of the elements.
• Make optional the mpopt argument to mp.task.run().

Bugs Fixed:

• Fix typos that cause fatal errors with GNU Octave 10.x.
• Fix typo in units of min and max reactive power shadow price in summary section of legacy OPF output.
• Optional 'soln_fname' input to run_mp(), hence also to run_pf(), run_cpf(), and run_opf(), was being ignored.
• Fix bug #256 to make opf.use_vg option compatible with generators at PQ buses.
• Build load and shunt connectivity using bus column in main table (i.e. bus numbers), not source_uid column (i.e. row indices in original bus table).

Incompatible Changes:

• See the MP-Opt-Model 5.0 release notes for incompatible changes related to MP-Opt-Model.