.Spot.ACabc.Transformers

Information

Transformer models in different abstraction levels.

All transformers allow the choice between Y- and Delta-topology both at primary and secondary side.
For Delta an additional phase-shift may be chosen in order to adapt to a given phase-numbering scheme.
The impedance parameters are defined 'as seen from the terminals', directly relating terminal voltage and terminal current. With this definition same parameters lead to same network properties, independent of topology. The necessary scaling is performed automatically.

In Delta-topology the conductor voltage is sqrt(3) higher, the current sqrt(3) lower, compared to the terminal voltage and current. Therefore the impedance relating conductor current and voltage is a factor 3 larger, the admittance a factor 1/3 smaller than the impedance and admittance as seen from the terminal.

If impedance parameters are given for the Deta-connected WINDINGS, choose:

  input values impedance parameters = 1/3 * (impedance parameters of windings)

In the abc-representation the following relations hold between terminal-voltage v_term and -current i_term on the one hand and conductor-voltage v_cond and -current i_cond on the other:

A) Y-topology.

  v_cond = v_term - {v_n, v_n, v_n};
  i_term = i_cond;
  i_n = sum(i_term);

where v_n denotes the voltage at the neutral point and i_n the current neutral to ground.

B) Delta-topology.

  v_cond = perm(-sh, v_term[{1,2,3}] - v_term[{2,3,1}]);
  i_term = perm(sh, i_cond[{1,2,3}] - i_cond[{3,1,2}]);

where perm denotes a permutation of phases corresponding to (-1,0,+1)*120deg phase shift.
The default value is sh = 0 and corresponds to a rotation of the dq-signals by 30deg in positive sense.

The winding scaled voltage- and current-variables v and i are related to the corresponding conductor quantities through the relation:

  v = v_cond/w
  i = i_cond*w

Contents

Name	Description
TrafoIdeal	Ideal transformer, 3-phase abc
TrafoStray	Ideal magnetic coupling transformer, 3-phase abc
TrafoMag	Magnetic coupling transformer, 3-phase abc
TrafoSatEff	Averaged saturation transformer, 3-phase dqo
TrafoSat	Saturation transformer, 3-phase abc
Trafo3Stray
Partials	Partial models
Parameters	Parameter data for interactive use