Linear Transformer (3 Windings)

Purpose

Single-phase transformer with winding resistance and optional core loss

Library

Electrical / Transformers

Description

../../_images/lineartrafo3.svg

This transformer models three coupled windings on the same core. The magnetizing inductance \(L_{\mathrm{m}}\) and the core loss resistance \(R_{\mathrm{m}}\) are modeled as linear elements. Their values are referred to the primary side. A stiff solver is recommended if \(R_{\mathrm{m}}\) is not infinite.

The electrical circuit for this component is given in Fig. 214.

../../_images/lineartrafo31.svg

Fig. 214 Electrical circuit of a linear transformer (3 windings)

In the transformer symbol, the primary side winding is marked with a little circle. The secondary winding is marked with a dot at the outside terminal, the tertiary winding with a dot at the inside terminal.

Parameters

Leakage inductance

A three-element vector containing the leakage inductance of the primary side \(L_1\), the secondary side \(L_2\) and the tertiary side \(L_3\). The inductivity is given in henries \((\mathrm{H})\).

Winding resistance

A three-element vector containing the resistance of the primary winding \(R_1\), the secondary winding \(R_2\) and the tertiary winding \(R_3\), in ohms \((\Omega)\).

No.of turns

A three-element vector containing the number of turns of the primary winding \(n_1\), the secondary winding \(n_2\) and the tertiary winding \(n_3\).

Magnetizing inductance

The magnetizing inductance \(L_{\mathrm{m}}\), in henries \((\mathrm{H})\). The value is referred to the primary side.

Core loss resistance

An equivalent resistance \(R_{\mathrm{m}}\) representing the iron losses in the transformer core. The value in ohms \((\Omega)\) is referred to the primary side.

Initial current

A three-element vector containing the initial currents on the primary side \(i_1\), the secondary side \(i_2\) and the tertiary side \(i_3\), in amperes \((\mathrm{A})\). The currents are considered positive if flowing into the transformer at the marked terminals. The default is [0 0 0].