Power System Blocks

Powsybl (Power System Blocks) is an open source framework written in Java, that makes it easy to write complex software for power systems’ simulations and analysis. Its modular approach allows developers to extend or customize its features.

Powsybl is part of the LF Energy Foundation, a project of The Linux Foundation that supports open source innovation projects within the energy and electricity sectors.

Open source

Powsybl in an open source framework licensed under the Mozilla Public License 2.0. The source code is hosted on GitHub in two different repositories:


Powsybl provides IIDM (iTesla Internal Data Model), a complete grid model (substations, voltage levels, AC and DC lines, two and three windings transformers, generators, loads, shunt and static VAR compensators…). The grid model can be extended with extensions to complete the modelling of the equipments. It also provides importers and exporters for several common exchange formats (Entso-E CIM/CGMES, UCTE-DEF…).

Powsybl provides several API for power systems’ simulations and analysis (power flow computations, security analysis, remedial action simulations, short circuits computations, sensitivity computations, time domain simulations…). These simulations can run either on a personal computer or on a server, but they can also run on a supercomputer like in the iTesla project with Curie supercomputer. The separation of the simulation API and the implementations allows developers to provide their own implementation.

Powsybl is available as a command line tool or in a complete desktop application, based on the GSE (Grid Study Environment) project. The GSE project is part of the powsybl framework. It provides a JavaFX UI to help developers writing desktop applications based on the powsybl framework. The GSE is fully customizable and extendable with plugins. All the features of powsybl are also exposed as web services.