Three Winding Transformer

Model of a three winding transformer. It is assumed, that node A is the node with highest, node B with intermediate and node C with lowest voltage.

The assumed mathematical model is inspired by ABB Schaltanlagenhanbuch [Gremmel1999], but with the addition of a central phase-to-ground admittance, cf. following picture.

Equivalent circuit diagram of a three winding transformer

“Star like” T-equivalent circuit diagram of a three winding transformer

Attributes, Units and Remarks

Type Model

All impedances and admittances are given with respect to the higher voltage side.

Attribute Unit Remarks
uuid    
id   Human readable identifier
rScA Ω Short circuit resistance in branch A
rScB Ω Short circuit resistance in branch B
rScC Ω Short circuit resistance in branch C
xScA Ω Short circuit impedance in branch A
xScB Ω Short circuit impedance in branch B
xScC Ω Short circuit impedance in branch C
gM nS No load conductance
bM nS No load susceptance
sRatedA kVA Rated apparent power of branch A
sRatedB kVA Rated apparent power of branch B
sRatedC kVA Rated apparent power of branch C
vRatedA kV Rated voltage at higher node A
vRatedB kV Rated voltage at higher node B
vRatedC kV Rated voltage at higher node C
dV % Voltage magnitude increase per tap position
dPhi ° Voltage angle increase per tap position
tapNeutr   Neutral tap position
tapMin   Minimum tap position
tapMax   Maximum tap position

Entity Model

Attribute Unit Remarks
uuid –  
id – Human readable identifier
operator –  
operationTime – Timely restriction of operation
nodeA – Higher voltage node
nodeB – Intermediate voltage node
nodeC – Lowest voltage node
parallelDevices – Amount of parallel devices of same attributes
type –  
tapPos – Current position of the tap changer
autoTap – true, if there is a tap regulation apparent and active

Caveats

Nothing - at least not known. If you found something, please contact us!

[Gremmel1999]Gremmel, H., Ed., Schaltanlagen. Cornelsen Verlag, 1999, Vol. 10, isbn: 3-464-48235-9.