Software for
STATIC AND TRANSIENT ELECTRIC POWER SYSTEMS SIMULATION

The STEPSS software is made up of three modules:

  • PFC (for Power Flow Computation) performs a power flow computation in order to determine the initial operating point of a dynamic simulation
  • RAMSES (for RApid Multiprocessor Simulation of Electric power Systems) simulates the dynamic evolution of the power system in response to disturbances/actions specified by the user
  • CODEGEN (for CODE GENerator) translates a model described by the user in a text file into its equivalent in FORTRAN 2003 language. The latter has to be compiled and linked to a user-defined executable version RAMSES.

RAMSES

  • differential/algebraic equations solver developed at the Univ. of Liège by P. Aristidou and T. Van Cutsem
  • simulation under the phasor approximation
  • significant speed-up obtained from decomposition (Schur-complement) and localization techniques
  • parallel processing on standard multicore computers.

CODEGEN

  • receives user-defined models written in a simple homemade language
  • translates them into FORTRAN 2003 code, to be compiled and linked to the rest of RAMSES
  • 4 types of models : excitation control of sync. mach. / torque control of sync. mach. / injectors / two-ports
  • models freely shared by users -> open-source simulation software.

Each of the three modules can be used separately. For instance:

  • PFC alone: a power flow computation is run to inspect the power system state and/or save the corresponding power flow solution for use by RAMSES
  • PFC alone: a sequence of power flow computations is performed until obtaining the desired power system state. The corresponding power flow solution is saved for use by RAMSES
  • RAMSES alone: with the initial power flow solution produced by PFC or by the user, several dynamic simulations are run starting from that initial state, i.e. without invoking PFC each time
  • CODEGEN alone: a model is built and saved for future incorporation in a user-defined version of RAMSES.

LICENSE TERMS
         STEPSS can be used free of charge for non-commercial/non-profit purposes, in a version limited to 1000 buses and 2 cores.
         Please read the detailed license terms in the documentation

SOFTWARE DOWNLOAD AND INSTALLATION
         Please check the Installation section in the documentation for accessing the software

USER GUIDE
         Please refer to the documentation       Still under construction !
         Click on "Help - User guide" in the program interface





Example 1: A simple 5-bus system

An academic system aimed at illustrating various notions of dynamics, control and stability wtih synchronous machines

  • Detailed description of the system : in this PDF file
  • input files : in this zip file
  • configuration file to load in RAMSES when starting : sim.cfg (included in zip file)

Example 2: The Kundur test system

A well-known two-area system illustrating the notion of interarea mode of oscillation

  • Detailed description of the system : refer to the famous book "Power System Stability and Control", Prabha Kundur, McGraw-Hill, 1993 (see Chapter 12)
  • input files : in this zip file
  • configuration file to load in RAMSES when starting : sim.cfg (included in zip file)

Example 3: The IEEE Nordic test system

A test system set up and documented by the Task Force on "Test Systems for Voltage Stability and Security Analysis" of the IEEE PES Power System Dynamic Perfomance Committee.

  • detailed models, data and simulation results are given in the technical report which can be downloaded from the IEEE PES Resource Center, No PES-TR 19. See also orbi.ulg.ac.be/handle/2268/141234 or orbi.ulg.ac.be/handle/2268/171162
  • input files : in this zip file. It contains a variants.pdf file explaining the various combinations of input files
  • configuration file to load in RAMSES when starting : sim_nothing.cfg, sim_trip.cfg or sim_short_trip.cfg (included in zip file).