Phase tap changer

The com.powsybl.iidm.network.PhaseTapChanger interface is used to model a phase tap changer device on a transformer. It can be added to both two windings transformers and three windings transformers.

# Characteristics

Attribute Type Unit Required Default value Description
LowTapPosition int - no 0 The position index of the tap changer’s low tap
TapPosition int - yes - The position index of current tap
Regulating boolean - no false true if the ratio tap changer is regulating, false otherwise. This is a State variable.
TargetDeadband double - no Double.NaN The deadband used to avoid excessive update of controls
RegulationMode enum - no FIXED_TAP The regulation mode of the phase tap changer. May be CURRENT_LIMITER, ACTIVE_POWER_CONTROL or FIXED_TAP
RegulationValue double MW or A yes - The target value, depending on the regulation mode
RegulationTerminal Terminal - no - The terminal where regulation is done

Each step of a phase tap changer has the following attributes:

Attribute Type Unit Required Default value Description
$r_{\phi, tap}$ double % yes - The resistance deviation in percent of nominal value
$x_{\phi, tap}$ double % yes - The reactance deviation in percent of nominal value
$g_{\phi, tap}$ double % yes - The conductance deviation in percent of nominal value
$b_{\phi, tap}$ double % yes - The susceptance deviation in percent of nominal value
$\rho_{\phi, tap}$ double p.u. yes - The voltage ratio in per unit of the rated voltages
$\alpha_{\phi, tap}$ double $^{\circ}$ yes - Angle difference

# Model

A phase tap changer is regulating if Regulating is set to true.

Remote control can be modeled by setting a distant terminal as the regulation terminal.

Three regulation modes are available:

• CURRENT_LIMITER: the tap changer adapts the step position to limit the current on the regulation terminal
• ACTIVE_POWER_CONTROL: the tap changer adapts the step position to regulate the active power on the regulation terminal
• FIXED_TAP: no tap changer step modification is allowed

For more information about how phase tap changers are taken into account in the transformers model, please refer to the two windings transformers documentation and the three windings transformers one.

# Examples

This example shows how to add a phase tap changer to a two windings transformer:

twoWindingsTransformer.newPhaseTapChanger()
.setLowTapPosition(-1)
.setTapPosition(0)
.setRegulating(true)
.setRegulationMode(PhaseTapChanger.RegulationMode.CURRENT_LIMITER)
.setRegulationValue(25)
.setRegulationTerminal(twoWindingsTransformer.getTerminal2())
.beginStep()
.setAlpha(-10)
.setRho(0.99)
.setR(1.)
.setX(2.)
.setG(0.5)
.setB(0.5)
.endStep()
.beginStep()
.setAlpha(0)
.setRho(1)
.setR(1.)
.setX(2.)
.setG(0.5)
.setB(0.5)
.endStep()
.beginStep()
.setAlpha(10)
.setRho(1.01)
.setR(1.)
.setX(2.)
.setG(0.5)
.setB(0.5)
.endStep()