Three-winding Transformer Model Using SSN User Coded Model

This circuit demonstrates a 3-phase OLTC transformer model designed for real-time simulation using SSN User's Coded Model

The model is compared to an SPS model for a 3-phase Y-Y-D transformer.

  Figure 1: 3-winding transformer model

Demonstration

The model is composed of two parts: (upper) a regular SPS model with a 3 winding transformer (Yg-Y-D) and (lower) a similar one made with an SSN user custom model.

If you look under the mask of the 3 winding SSN transformer, you will see that it is composed of 3 single-phase transformers.

One advantage of SSN custom models over SPS ones is that model parameters can be modified on-line because these parameters are Simulink signals.

In the demo, we change the tap ratio of the SSN transformer model as in OLTC transformers. Because this OLTC is implemented without internal switches, it is compatible with real-time simulation.

The model, therefore, could easily be modified to support saturation.

This demo now works WITHOUT internal S-function and is compatible with R2015a versions and above.