Saturable Transformers
Purpose
Single-phase transformers with two resp. three windings and core saturation
Library
Electrical / Passive Components
Description

These transformers model two or three coupled windings on the same
core.
The core saturation characteristic is piece-wise linear and is modeled using the
Saturable Inductor. The magnetizing current
and flux
value pairs are
referred to the primary side. To model a transformer without saturation enter 1 as
the magnetizing current values and the desired magnetizing inductance
as the
flux values. A stiff Simulink solver is recommended if the iron losses are not
negligible, i.e.
is not infinite.
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 vector containing the leakage inductance of the primary
side
, the secondary side
and, if applicable, the tertiary side
. The
inductivity is given in henries (H).
-
Winding resistance
- A vector containing the resistance of the primary winding
, the secondary winding
and, if applicable, the tertiary winding
,
in ohms (
).
-
No. of turns
- A vector containing the number of turns of the primary winding
, the secondary winding
and the tertiary winding
, if applicable.
-
Magnetizing current values
- A vector of positive current values in amperes (A)
defining the piece-wise linear saturation characteristic of the transformer legs.
The current values must be positive and strictly monotonic increasing. At least
one value is required.
-
Magnetizing flux values
- A vector of positive flux values in Vs defining the
piece-wise linear saturation characteristic. The flux values must be positive and
strictly monotonic increasing. The number of flux values must match the number
of current values.
-
Core loss resistance
- An equivalent resistance
representing the iron losses in
the transformer core. The value in ohms (
) is referred to the primary side.
-
Initial current
- A vector containing the initial currents on the primary side
,
the secondary side
and the tertiary side
, if applicable. The currents are
given in amperes (A) and considered positive if flowing into the transformer at
the marked terminals. The default is [0 0 0].