IEEH PowerFactory Tools

A toolbox for Python based control of DIgSILENT PowerFactory.

• IEEH PowerFactory Tools
  • Field of Application
  • PowerFactory Interface
  • General Remarks on Export
  • Tutorials
  • Installation
  • Compatibility
  • Development
  • Acknowledgement
  • Attribution

Field of Application

This application is intended to use for an external usage ('engine mode') of the power flow calculation program DIgSILENT PowerFactory. Therefore, the Python-PowerFactory-API, provided by the company, is utilized.

The following functionalities are provided:

• Interface: collection of comfort functions for the work with the PowerFactory API
• Exporter: export of calculation relevant grid data from a PowerFactory project to the IEEH Power System Data Model (PSDM)
• Importer: import from external grid data into the PowerFactory environment [intended in future release]

Important: As the set of different elements, data types and attributes can differ between the various main versions (e.g. 2022) of PowerFactory, all functionalities are set up individual for main versions.

PowerFactory Interface

The toolbox builds up on the PowerFactoryInterface, that provides comfort functions to:

• connect to PowerFactory
• create and alter PowerFactory elements ("physical" elements, "organizational" elements, commands, etc.)
• collect PowerFactory elements of specific types
• execute PowerFactory commands
• ...

General Remarks

Please find below some important general remarks and assumptions to consider for the application.

General

A connection to PowerFactory is established via PowerFactoryInterface. After this initialization, a temporary unit conversion to default values is automatically performed to have a project setting independent behavior. The units are reset when the interface is closed. During an active connection, the following units apply:

• power in MW
• voltage in kV
• current in kA
• length in km

Exporter

The PowerFactoryExporter connects to PowerFactory via PowerFactoryInterface.

• The grid export follows the rules of usage recommended by PSDM:

  • The passive sign convention is used for all types of loads (consumer as well as producer).
  • The Rated Power is always defined positive (absolute value).

• By default, all assests of all active grids within the selected study case are to be exported, see example readme.

  • Assets can be excluded by writing do_not_export in the first line of the description field.

• The following type of elements are supported:

  • ElmLne - a symmetrical overhead line / cable
  • ElmTerm - a network terminal / bus
  • ElmCoup - a bus-bus switch (e.g. a circuit breaker in a detailed switching gear)
  • ElmTr2 - a symmetrical 2-winding transformers
  • ElmTr3 - a symmetrical 3-winding transformers (in future releases)
  • ElmLod - a general load (asym. / sym.)
  • ElmLodmv - a medium voltage load
  • ElmLodlv - a low voltage load
  • ElmLodlvp - a partial low voltage load
  • ElmPvsys - a PV system (generator)
  • ElmGenstat - a static generator
  • ElmXnet - an external grid representation
  • RelFuse - a fuse (bus-bus or bus-load)

• Remarks on export of loads:

  • The default load model of general loads (ElmLod) is of type const. impedance.
  • The default load model of medium-voltage loads (ElmLodmv) is of type const. power.
  • The default load model of low-voltage loads (ElmLodlv, ElmLodlvp) is of type const. current.
  • Be aware that the reference voltage of the load model must not match the nominal voltage of the terminal the load is connected to.
  • By default, the power factor direction of the rated power is set to "not defined", see docs at LoadPower - as_rated_power().
  • Connected consumer loads with an active and reactive power of zero leads to a RatedPower of NaN. Consider to exclude them for export.

• Remarks on export of transformer:

  • The impedances of all winding objects are referred to the high voltage side of the transformer.
  • The impedance of transformer earthing is an absolute natural value.
  • The zero sequence impedances are exported without considering the vector group, resulting zero sequence must be calculated separately by the user afterwards.
  • The zero sequence magnetising impedances are dependent on the wiring group, see docs at PowerFactoryExporter - create_transformer_2w().

• Remarks on export of fuses:

  • Branch like fuses are exported as switching state.
  • Element fuses does not apply a switching state by their own in PowerFactory but considered in export as applicable switching state.

• Remarks on export of the SteadyStateCase:

  • The operating points of the loads are specified by the controller and the associated load model in the topology for active or reactive power, see docs at PSDM.
  • By default a consumer load has a Q-controller of type CosPhiConst, except in the case where active and reactive power are explicitly specified in the load flow mask in PowerFactory, then it's QConst.
  • It is assumed, that a station controller (if relevant) is exclusively assigned to a single generator. The generator itself ought to be parameterized in the same way as the station controller to ensure that the exported operating point of Q is the same that set by the station controller.

Tutorials

Please consider the README in the example section. Here, Jupyter notebooks are provided to get in touch with the usage of this toolbox:

• for export: powerfactory_export.ipynb
• for control: powerfactory_control.ipynb

In addition, please see this interactive example how to import a PSDM grid representation in Matlab for grid calculation purposes.

Installation

Install via pip:

pip install ieeh-powerfactory-tools

Install via pdm:

pdm add ieeh-powerfactory-tools

Compatibility

Tools Version	PSDM Version	PowerFactory Version	Python Version
<= 1.3.1	1.1.0	2022	3.9, 3.10
1.4.x	1.1.0	2022	3.10
1.5.1	1.3.0	2022	3.10
2.1.0	2.2.0	2022	3.10

Starting with PowerFactory 2023, a new model for LV and MV loads is available as well as e.g. the result structure of harmonic load flow has changed. Also Python 3.11 can be used. Related adjustments are on schedule for the next mayor release 3.x

Development

Install pdm

• Windows

  (Invoke-WebRequest -Uri https://raw.githubusercontent.com/pdm-project/pdm/main/install-pdm.py -UseBasicParsing).Content | python -

• Linux/Mac:

  curl -sSL https://raw.githubusercontent.com/pdm-project/pdm/main/install-pdm.py | python3 -

• Or using pipx or pip:

  pipx install pdm

  pip install --user pdm

Clone powerfactory-tools

git@github.com:ieeh-tu-dresden/powerfactory-tools.git

cd powerfactory-tools

Install powerfactory-tools

• as a production tool

  pdm install --prod

• in development mode

  pdm install

For development in Visual Studio Code, all configurations are already provided:

• ruff
• black
• mypy

Acknowledgement

Please note that this work is part of research activities and is still under active development.

This code was tested with DIgSILENT PowerFactory 2021 SP5 (version < 1.4) and DIgSILENT PowerFactory 2022 SP2.

Attribution

Please provide a link to this repository:

https://github.com/ieeh-tu-dresden/powerfactory-tools

Please cite as:

Institute of Electrical Power Systems and High Voltage Engineering - TU Dresden, PowerFactory Tools - A toolbox for Python based control of DIgSILENT PowerFactory, Zenodo, 2022. https://doi.org/10.5281/zenodo.7074968.