FAQ

  • Data format under Windows: 
    Problem: SIMSEN is not able to read values from ASCII data files. The reason is a decimal symbol (example: 1,5 or 1;5 instead of 1.5).
    Solution: Go to the Control Panel of Windows. Open the International Settings and set the Decimal Symbol to “.”
  • Direction of the three-phase elements in-line:
    Problem: Warnings about in-line three-phase elements (Transmission Line, Current Variator or Circuit Breaker) when entering the simulation mode. These elements need a three-phase element connected to their secondary terminal in order to calculate the voltages and the power on their primary terminal (1).
    Solution: Invert the direction of the element to make sure that its terminal 2 is connected to the terminalo 1 of another element. If this is not possible, add a three-phase electrical load with high impedance (R=1e8). This element is able to calculate its voltage by itself.
  • Connections:
    Problem: An error message ‘wire not ending on element or crossing’ is displayed when entering the simulation mode. Then, a red circle is displayed at the end of the corresponding wire.
    Solution: Delete the concerned wire and make sure that its end points are exactly connected to the end points of an element (not to the displayed crossing points). Check if you did not define more than one wire between two elements.
  • Neutral terminals:
    Problem: An error message ‘State variables numbering failure’ is displayed when entering the simulation mode.
    Solution: You tried to connect ground circuits between different voltage circuits, in parallel with a transformer for example. Be aware that it is not possible to connect ground circuits belonging to different voltage levels. Remove the corresponding wires and elements.
  • The simulation stops:
    Problem: The simulation stops after a while, especially when using GTO Thyristors or IGBT’s.
    Solution: This problem is due to a numerical divergence. Reduce the integration step and try again.
  • The parameter Fs in the Thyristor and the Triac:
    Problem: Some users asked about the parameter Fs in the Thyristor or Triac. This parameter was used to calculate the time duration of the pulse on the gates in function of the angular duration Thimp of the pulse and the frequency Fs. If Fs is set to 0, no pulse are given.
    Solution: The parameter Fs has been removed from the two models. The parameter Thimp has been replaced by the parameter dTimp (in sec), which correspond to the time duration of the pulse on the gate. The internal command of the semiconductors has also been removed. Please check the command of these semiconductors.
  • Unit confusion, SI or per unit:
    Problem: Some users encounter problems when reading quantities or specifying initial conditions. The unit of the quantities may differ depending on the place where they are used. If ‘Writing = PU’ is set in the General Data of an element, are the read and/or written values also in per unit? 
    Solution: The units mentioned in the section ‘List of quantities and parameters’ of the elements remain valid whatever the specified value of ‘Writing = ‘. Respect the mentioned units in the different sections. For instance, the mechanical are set in [rpm] in the initial conditions, but are read in [rad/s], the angles are set in [deg] in the initial conditions but are read or written in [rad]. Be careful with the units used and refer to the help file of the element.
  • Initial values for the Ths angle in the voltage supplies:
    Problem: Some users wanted to specify or initialize the Ths angle of the voltage supplies.
    Solution: The current version 2.2.10 of SIMSEN allows setting these angles directly from the main file in the
    – INITIAL CONDITIONS section. Refer to the help file of the element.