April 2026 monthly summary for powsybl-core focusing on delivering data-quality improvements and export readiness. Implemented BaseVoltage optimization for lines to improve voltage representation accuracy and added a safe default for missing ratedS values in PowerTransformerEnd within TwoWinding transformers, ensuring mandatory fields are satisfied for CGMES exports. These changes reduce modeling errors, improve grid analysis reliability, and strengthen data integrity across transformer representations.

In March 2026, delivered focused improvements in powsybl-core that reduce complexity, improve correctness of exports, and enhance CGMES interoperability. These changes reduce maintenance risk, ensure compliance with equipment-type constraints, and improve how fictitious injections are represented for downstream consumers. The work strengthens reliability for power system simulations and integrations with external tools.

January 2026 monthly summary for powsybl-core: Focused on documenting enhancements to support asymmetrical short-circuit calculations; improved homopolar extensions documentation and corrected the three-winding transformer section's title and formatting to enhance clarity and accuracy. These changes improve developer onboarding, reduce ambiguity, and support stable downstream integration.

November 2025 monthly summary for powsybl-core focusing on documentation quality improvements and CGMES handling robustness. Delivered clearer transformer documentation, strengthened SynchronousMachine handling with robust isCondenser-based kind detection and improved conversion logic, and expanded tests and documentation to improve reliability and interoperability with downstream tools.

October 2025 monthly summary for powsybl-core: Focused on expanding topology modeling capabilities to support more flexible network designs and automated configuration workflows. Delivered Busbar Connection Enhancements with NODE_BREAKER Topology, enabling connections from existing connectables to newly created busbar sections within a voltage level, with support for NODE_BREAKER topology and options to connect coupling devices. Implemented new report messages to cover various connection scenarios and updated developer/user documentation to reflect these capabilities. This work aligns with strategic goals to improve automation, interoperability, and scalability in high-voltage network modelling.

September 2025 monthly focus: Strengthened CGMES integration in powsybl-core by enabling automatic discovery of NamingStrategy implementations, hardening naming strategy attributes, and improving export data quality with a robust default naming for unnamed temporary limits. These changes reduce manual configuration, improve data consistency for CGMES exports, and lay groundwork for future extensibility. Tests and documentation accompany the changes to ensure maintainability and clarity for downstream consumers.

July 2025 performance highlights: Delivered enhancements to CGMES data handling and stabilized developer onboarding by addressing repository build context issues across core and Python bindings. These changes improve data accuracy for CGMES-powered workflows, reduce build-time friction for new contributors, and strengthen overall reliability for downstream systems.

June 2025 monthly summary for powsybl-core: Implemented end-to-end Load Flow Solved Values workflow and enhanced topology change error handling, enabling more accurate state representation and robust topology edits while preserving backward compatibility and preparing for iIDM v1.14 updates.