The GICTransformer model is used in combination with the GICLine model for the calculation of geomagnetically induced current (GIC). The GICLine model contains the source representing the induced voltage. Transformers with a connection to ground provide a return path for the resulting current.

Power transformers are represented by their dc equivalent circuits, and only windings with connection to ground are included in the analysis. The model is a resistor network for the purposes of computing GIC in transformers. Only frequency domain models are necessary.


Following are presented the commands and properties of the GICTransformer Model


%R1

Optional. Percent Resistance, each phase, for H winding (1), (Series winding, if Auto). Default is 0.2. 


Alternative way to enter R1 value. It is the actual resistances in ohmns that matter. MVA and kV should be specified.

%R2

Optional. Percent Resistance, each phase, for H winding (1), (Series winding, if Auto). Default is 0.2. 


Alternative way to enter R1 value. It is the actual resistances in ohmns that matter. MVA and kV should be specified.

basefreq

Base Frequency for ratings.

busH

Name of High-side(H) bus. Examples:

BusH=busname

BusH=busname.1.2.3

busNH

Name of Neutral bus for H, or first, winding. Defaults to all phases connected to H-side bus, node 0, if not specified and transformer type is either GSU or YY. (Shunt Wye Connection to ground reference)For Auto, this is automatically set to the X bus.

busNX

Name of Neutral bus for X, or Second, winding. Defaults to all phases connected to X-side bus, node 0, if not specified. (Shunt Wye Connection to ground reference)

busX

Name of Low-side(X) bus, if type=Auto or YY. 

emergamps

Maximum or emerg current.

enabled

{Yes|No or True|False} Indicates whether this element is enabled.

faultrate

Failure rate per year.

K

Mvar K factor. Default way to convert GIC Amps in H winding (winding 1) to Mvar. Default is 2.2. Commonly-used simple multiplier for estimating Mvar losses for power flow analysis. 


Mvar = K * kvLL * GIC per phase / 1000 


Mutually exclusive with using the VarCurve property and pu curves.If you specify this (default), VarCurve is ignored.

KVLL1

Optional. kV LL rating for H winding (winding 1). Default is 500. Required if you are going to export vars for power flow analysis or enter winding resistances in percent.

KVLL2

Optional. kV LL rating for X winding (winding 2). Default is 138. Required if you are going to export vars for power flow analysis or enter winding resistances in percent..

like

Make like another object

MVA

Optional. MVA Rating assumed Transformer. Default is 100. Used for computing vars due to GIC and winding resistances if kV and MVA ratings are specified.

normaamps

Normal rated current.

pctperm

Percent of failures that become permanent.

phases

Number of Phases. Default is 3.

R1

Resistance, each phase, ohms for H winding, (Series winding, if Auto). Default is 0.0001.

R2

Resistance, each phase, ohms for X winding, (Common winding, if Auto). Default is 0.0001. 

repair

Hours to repair.

Type

Type of transformer: {GSU* | Auto | YY}. Default is GSU.

VarCurve

Optional. XYCurve object name. Curve is expected as TOTAL pu vars vs pu GIC amps/phase. Vars are in pu of the MVA property. No Default value. Required only if you are going to export vars for power flow analysis. See K property.