ObjectStab

Information

The ObjectStab package is a Modelica Library for Power Systems Voltage and Transient stability simulations and 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 according to [1].
• Fixed ratio transformers.
• On-load tap changing transformers (OLTC) modeled as detailed discrete
  models or using their corresponding continuous approximations according
  to [2].
• Static and dynamic loads, including induction motor according to [1] and generic exponential recovery loads according to [3].
• 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. Except where other references are given, the components are modeled according to the guidelines given in [1]. 

The component library has been validated using comparative simulations with EUROSTAG [4]. The library has been developed and tested using DYMOLA version 4.0b, 1999-11-05.

REFERENCES

[1] J. Machowski, J.W. Bialek, and J.R. Bumby, Power System Dynamics and Stability, Number ISBN 0-471-97174. Wiley, 1993.

[2] P.W. Sauer and M.A. Pai, "A comparison of discrete vs. continuous dynamic models of tap-changing-under-load transformers", in Proceedings of NSF/ECC Workshop on Bulk power System Voltage
Phenomena - III : Voltage Stability, Security and Control,  Davos, Switzerland, 1994.

[3] D. Karlsson and D.J. Hill, "Modelling and identification of nonlinear dynamic loads in power systems'', IEEE Transactions on Power Systems, vol. 9, no. 1, pp. 157-163, February 1994.

[4] J. Deuse and M. Stubbe, "Dynamic simulation of voltage collapses", IEEE Transactions on Power Systems, vol. 8, no. 3, pp. 894-904, August 1993.

[5] I. Romero Navarro, "Object-Oriented Modeling and Simulating of Power Systems using DYMOLA", Dept. of Industrial Electrical Engineering and Automation, Lund University, 1999. CODEN: LUTEDX/(TEIE-7138)1-151(1999).

Main Author:

Mats Larsson, Department of Industrial Electrical Engineering and Automation, Lund Institute of Technology, Sweden.

Some of the models are based on Dymola models developed in a Masters Thesis by Ines Romero Navarro [5].

       

Release Notes:

• Version 0.2 (November 15, 1999) - Fixed bug in Impedance and Admittance Load models
• Version 0.1 (November 7, 1999)
  The first version of the ObjectStab library is based on the following subpackages:
  • ObjectStab.Base
  • ObjectStab.Network
  • ObjectStab.Loads
  • ObjectStab.Generators
  • ObjectStab.Examples
  • ObjectStab.petrii1 (the Dymola Petri net library  translated from the Dymola source.)

The ObjectStab package is free software; it can be redistributed and/or modified under the terms of the Modelica license and the accompanying disclaimer.