Tap-Changing Transformer
A single-phase transformer with switching windings.
blockType: AcausalElectricPowerSystems.Passive.Transformers.TapChanging
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Description
Block Tap-Changing Transformer It is a single-phase transformer with switching windings. You can change the ratio of the transformer turns during the simulation using the control input.
Use this unit to adjust or change the output voltage of a linear transformer during simulation. To simulate the saturation effect, use the block Nonlinear Transformer.
The principle of operation
The signal on the input port c is used to change the position of the transformer winding switch.
If the signal on port c exceeds the positive value of the parameter Control threshold, t, then the position of the winding switch p increases by one.
If the signal on port c is lower than the negative value of the parameter Control threshold, t, then the position of the winding switch p is lowered by one.
This figure shows the reaction of the winding switch to the control signal.
On the diagram:
-
— the nominal number of winding turns of the winding switch.
-
— percentage change in the number of turns per step step. Set this value using the Change per tap (%) parameter.
-
and — minimum and maximum allowable switching indexes. Set these values using the Minimum tap index (nominal=0) and Maximum tap index (nominal=0) parameters.
To select the winding of the winding switch, use the Tap-changer location parameter. The overall transformation coefficient depends on this parameter. :
-
Primary winding
-
Secondary winding
where — nominal transformation coefficient.
The equivalent scheme
The equivalent scheme is shown in the figure.
Here:
-
RpandRs— sequential resistances of the primary and secondary windings, respectively. Changing the position of the winding switch affects these values. -
LlpandLls— the scattering inductance of the primary and secondary windings, respectively. Changing the position of the winding switch affects these values. -
RmandM— magnetization resistance and inductance, respectively. Changing the position of the winding switch affects these values. -
n— the transformation coefficient. -
GpandGs— the scattering conductivity of the primary and secondary windings, respectively. Changing the position of the winding switch does not affect these values.
Ports
Non-directional
1+ — positive terminal 1 of the pass line:q[<br>] electricity
The electrical port represents terminal 1 of the line with positive polarity.
1− — negative terminal 1 of the pass line:q[<br>] electricity
The electrical port represents terminal 1 of the line with negative polarity.
2+ — positive terminal 2 of the pass line:q[<br>] electricity
The electrical port represents terminal 2 of the line with positive polarity.
2− — negative terminal 2 of the pass line:q[<br>] electricity
The electrical port represents terminal 2 of the line with negative polarity.
c — pass control signal:q[<br>] scalar
An input signal that controls the position of the winding switch.
Parameters
Main
Turns ratio (primary/secondary) — pass transformation coefficient:q[<br>] 1 (default)
The transformation coefficient is at the nominal position of the winding switch. The transformation coefficient is defined as the number of turns of the primary winding divided by the number of turns of the secondary winding.
Primary leakage induction — leakage inductance on the primary winding
0.0001 Gn (default)
The inductance, which represents the magnetic flux loss of the primary winding.
Secondary leakage induction — leakage inductance on the secondary winding
0.0001 Gn (default)
The inductance, which represents the losses on the magnetic flux of the secondary winding.
Magnetization induction — magnetization inductance
100e-6 Gn (default)
The magnetization inductance for the transformer.
Primary series resistance — primary winding resistance
0.0 (default)
The series resistance of the primary winding.
Secondary series resistance — secondary winding resistance
0.0 (default)
The series resistance of the secondary winding.
Primary leakage conductivity — primary winding scattering conductivity
0.0 (default)
The scattering conductivity of the primary winding. Set this value to non-zero to achieve numerical convergence in some circuit topologies.
Secondary leakage conduction — scattering conductivity of the secondary winding
0.0 (default)
The scattering conductivity of the secondary winding. Set this value to non-zero to achieve numerical convergence in some circuit topologies.
Tap
Tap-changer location — winding of the winding switch
Primary(by default) | Secondary
Specify on which winding the switch of the windings is located: primary or secondary.
Minimum tap index (nominal=0) — minimum position of the winding switch
-5 (default)
The minimum allowable position of the winding switch.
Maximum tap index (nominal=0) — maximum position of the pass winding switch:q[<br>] 5 (default)
The maximum allowable position of the winding switch.
Change per tap (%) — step of changing the position of the
1% (default)
The percentage change in the number of turns of the winding switch per position step. Set this value so that the absolute percentage change at the minimum and maximum position indices is less 100%.
Control threshold — pass shift threshold:q[<br>] 0.5 (default)
The control value at which the position of the winding switch changes. To reduce the position of the winding switch, apply a control signal less than this value. To increase the position of the winding switch, apply a control signal greater than this value.