The ObjectStab package is a free Modelica Library for Power Systems. Contrary to special-purpose tools for the same type of simulations like PSS/E, Eurostag and SIMPOW, the ObjectStab library has an open architecture so that all models can be customized to fit the individual users' needs.  The library is intended for research and educational use.

After joining this group you can download the newest version of the library from the files section.

The library presently contains the following component models :

• Generators with constant frequency and voltage as slack or PV nodes, or using 3rd or 6th
  order dq-models with excitation and prime mover control systems.
• Transmission lines in pi-link or series impedance representation.
• Reactive power compensation devices; shunt reactors, shunt capacitances and series capacitances.
• Fixed ratio transformers.
• On-load tap changing transformers (OLTC) modeled as detailed discrete models or using their corresponding continuous approximations according.
• Static and dynamic loads, including generic exponential recovery loads.
• Buses.
• Faulted lines and buses including fault impedance.

Standard assumptions for multi-machine transient stability simulations are made, i.e., generator stator and network time constants are neglected and voltages and currents are assumed to be sinusoidal and symmetrical. 

The component library has been validated using comparative simulations with EUROSTAG. The library has been developed and tested using DYMOLA version 5.0, 2002-09-19.