Two windings transformer

The com.powsybl.iidm.network.TwoWindingsTransformer interface is used to model a two windings power transformer. A two windings power transformer is connected to two voltage levels (side 1 and side 2) that belong to a same substation. A ratio tap changer and/or a phase tap changer can be associated with a two windings power transformer.

Characteristics

Attribute Type Unit Required Default value Description
id string - yes - Unique identifier of the transformer
name string - yes - Human-readable name of the transformer
double yes - The nominal series resistance at the side 2 of the transformer
double yes - The nominal series reactance at the side 2 of the transformer
double S yes - The nominal magnetizing conductance at the side 2 of the transformer
double S yes - The nominal magnetizing susceptance at the side 2 of the transformer
double kV yes - The rated voltage at side 1
double kV yes - The rated voltage at side 2

Two windings transformers can also have current limits defined for each end.

Model

Two windings transformer are modeled with the following equivalent model:

Power line model

With the series impedance and the shunt admittance and the voltage ratio and the angle difference and potentially parameters from the current step of a ratio tap changer and/or a phase tap changer, we have:

Using the above notation, the equations of the two windings transformer, in complex notations, are as follow:

Examples

This example shows how to create a two windings transformer in the network:

TwoWindingsTransformer twoWindingsTransformer = substation.newTwoWindingsTransformer()
    .setId("TWT2")
    .setName("My two windings transformer")
    .setVoltageLevel1("VL1")
    .setVoltageLevel2("VL2")
    .setNode1(1)
    .setNode2(2)
    .setR(0.5)
    .setX(4)
    .setG(0)
    .setB(0)
    .setRatedU1(24)
    .setRatedU2(385)
    .add();