.PowerSystems.System

Information

The model System represents a global reference for the following purposes:

It allows the choice of

• nominal frequency (default 50 or 60 Hertz, but arbitrary positive choice allowed)
• system frequency or initial system frequency, depending on frequency type
• frequency type: parameter, signal, or average (machine-dependent) system frequency
• lower and upper limit-frequencies
• common phase angle for AC-systems
• synchronous or inertial reference frame for AC-3phase-systems
• transient or steady-state initialisation and simulation modes
  For 'transient' initialisation no specific initial equations are defined.
  This case allows also to use Dymola's steady-state initialisation, that is DIFFERENT from ours.
  Note: the parameter 'sim' only affects AC three-phase components.

It provides

• the system angular-frequency omega
  For fType Parameter this is simply a parameter value.
  For fType Signal it is a positive input signal.
  For fType Average it is a weighted average over the relevant generator frequencies.
• the system angle theta by integration of

   der(theta) = omega 

• the reference angle thetaRef for defining the coordinate-orientation:
  thetaRef = theta if refType == Synchron (reference frame is synchronously rotating with theta).
  thetaRef = 0 if refType == Inertial (inertial reference frame, not rotating).
  
• the angle thetaRel = theta - thetaRef

Note: Each model using System must use it with an inner declaration and instance name system in order that it can be accessed from all objects in the model.
When dragging the 'System' from the package browser into the diagram layer, declaration and instance name are automatically generated.

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