Struct power_flow_data::Transformer

pub struct Transformer {

    pub i: BusNum,
    pub j: BusNum,
    pub k: BusNum,
    pub ckt: ArrayString<3>,
    pub cw: i8,
    pub cz: i8,
    pub cm: i8,
    pub mag1: f64,
    pub mag2: f64,
    pub nmetr: i8,
    pub name: ArrayString<15>,
    pub stat: i8,
    pub o1: OwnerNum,
    pub f1: f64,
    pub o2: Option<OwnerNum>,
    pub f2: Option<f64>,
    pub o3: Option<OwnerNum>,
    pub f3: Option<f64>,
    pub o4: Option<OwnerNum>,
    pub f4: Option<f64>,
    pub vecgrp: Option<ArrayString<15>>,
    pub r1_2: f64,
    pub x1_2: f64,
    pub sbase1_2: f64,
    pub r2_3: Option<f64>,
    pub x2_3: Option<f64>,
    pub sbase2_3: Option<f64>,
    pub r3_1: Option<f64>,
    pub x3_1: Option<f64>,
    pub sbase3_1: Option<f64>,
    pub vmstar: Option<f64>,
    pub anstar: Option<f64>,
    pub windv1: f64,
    pub nomv1: f64,
    pub ang1: f64,
    pub rata1: f64,
    pub ratb1: f64,
    pub ratc1: f64,
    pub cod1: i8,
    pub cont1: BusNum,
    pub rma1: f64,
    pub rmi1: f64,
    pub vma1: f64,
    pub vmi1: f64,
    pub ntp1: i16,
    pub tab1: isize,
    pub cr1: f64,
    pub cx1: f64,
    pub cnxa1: Option<f64>,
    pub windv2: f64,
    pub nomv2: f64,
    pub ang2: Option<f64>,
    pub rata2: Option<f64>,
    pub ratb2: Option<f64>,
    pub ratc2: Option<f64>,
    pub cod2: Option<i8>,
    pub cont2: Option<BusNum>,
    pub rma2: Option<f64>,
    pub rmi2: Option<f64>,
    pub vma2: Option<f64>,
    pub vmi2: Option<f64>,
    pub ntp2: Option<i16>,
    pub tab2: Option<isize>,
    pub cr2: Option<f64>,
    pub cx2: Option<f64>,
    pub cnxa2: Option<f64>,
    pub windv3: Option<f64>,
    pub nomv3: Option<f64>,
    pub ang3: Option<f64>,
    pub rata3: Option<f64>,
    pub ratb3: Option<f64>,
    pub ratc3: Option<f64>,
    pub cod3: Option<i8>,
    pub cont3: Option<BusNum>,
    pub rma3: Option<f64>,
    pub rmi3: Option<f64>,
    pub vma3: Option<f64>,
    pub vmi3: Option<f64>,
    pub ntp3: Option<i16>,
    pub tab3: Option<isize>,
    pub cr3: Option<f64>,
    pub cx3: Option<f64>,
    pub cnxa3: Option<f64>,
}

Each AC transformer to be represented in PSS/E is introduced through transformer data records that specify all the data required to model transformers in power flow calculations, with one exception.

That exception is a set of ancillary data, comprising transformer impedance correction records, which define the manner in which transformer impedance changes as off-nominal turns ratio or phase shift angle is adjusted. Those data records are described in Transformer Impedance Correction Records, ImpedanceCorrection.

Both two-winding and three-winding transformers are specified in the transformer data records. The data records for the two-winding transformer are common to the three-winding transformer; the data block for two-winding transformers is a subset of the data required for three-winding transformers.

Fields

i: BusNum

The bus number, or extended bus name enclosed in single quotes, of the bus to which the first winding is connected. The transformer’s magnetizing admittance is modeled on winding one. The first winding is the only winding of a two-winding transformer whose tap ratio or phase shift angle may be adjusted by the power flow solution activities; any winding(s) of a three-winding transformer may be adjusted. No default is allowed.

j: BusNum

The bus number, or extended bus name enclosed in single quotes, of the bus to which the second winding is connected. This winding may have a fixed, off-nominal tap ratio assigned to it. No default is allowed.

k: BusNum

The bus number, or extended bus name enclosed in single quotes, of the bus to which the third winding is connected. Zero is used to indicate that no third winding is present. Always equal to zero for a two-winding transformer.

ckt: ArrayString<3>

One- or two-character uppercase nonblank alphanumeric transformer circuit identifier; the first character of ckt must not be an ampersand (‘&’).

cw: i8

The winding data I/O code which defines the units in which the turns ratios windv1 and windv2 are specified (the units of rma1 and rmi1 are also governed by cw when |cod1| is 1 or 2):

• 1 for off-nominal turns ratio in pu of winding bus base voltage;
• 2 for winding voltage in kV. cw = 1 by default.

cz: i8

The impedance data I/O code that defines the units in which the winding impedances r1_2 and x1_2 are specified:

• 1 for resistance and reactance in pu on system base quantities;
• 2 for resistance and reactance in pu on a specified base MVA and winding bus base voltage;
• 3 for transformer load loss in watts and impedance magnitude in pu on a specified base MVA and winding bus base voltage. cz = 1 by default.

cm: i8

The magnetizing admittance I/O code that defines the units in which mag1 and mag2 are specified:

• 1 for complex admittance in pu on system base quantities;
• 2 for no load loss in watts and exciting current in pu on winding one to two base MVA and nominal voltage. cm = 1 by default.

mag1: f64

When cm is 1, mag1 is the magnetizing conductance in pu on system base quantities; when cm is 2, mag1 is the no load loss in watts. mag1 = 0.0 by default.

mag2: f64

When cm is 1, mag2 is the magnetizing susceptance in pu on system base quantities; when cm is 2, mag2 is the exciting current in pu on winding one to two base MVA (sbase1_2) and nominal voltage (nomv1). mag2 = 0.0 by default.

nmetr: i8

The nonmetered end code of either:

• 1 (for the winding one bus), or
• 2 (for the winding two bus). nmetr = 2 by default.

name: ArrayString<15>

An alphanumeric identifier assigned to the transformer. The name may be up to twelve characters. name may contain any combination of blanks, uppercase letters, numbers and special characters. name is twelve blanks by default.

stat: i8

The initial transformer status, where 1 designates in-service and 0 designates out-of-service. stat = 1 by default.

o1: OwnerNum

An owner number; (1 through the maximum number of owners at the current size level). Each transformer may have up to four owners. See Owner. By default, O1 is the owner to which bus “I” is assigned

f1: f64

The fraction of total ownership assigned to owner Oi; each Fi must be positive. The Fi values are normalized such that they sum to 1.0 before they are placed in the working case. By default, each fi is 1.0.

o2: Option<OwnerNum>

f2: Option<f64>

o3: Option<OwnerNum>

f3: Option<f64>

o4: Option<OwnerNum>

f4: Option<f64>

vecgrp: Option<ArrayString<15>>

Alphanumeric identifier specifying vector group based on transformer winding connections and phase angles. vecgrp value is used for information purpose only. vecgrp is 12 blanks by default.

r1_2: f64

The measured impedance of the transformer between the buses to which its first and second windings are connected (see also x1_2).

• When cz is 1, r1_2 is the resistance in pu on system base quantities;
• when cz is 2, r1_2 is the resistance in pu on winding one to two base MVA (sbase1_2) and winding one bus base voltage;
• when cz is 3, r1_2 is the load loss in watts. r1_2 = 0.0 by default.

x1_2: f64

The measured impedance of the transformer between the buses to which its first and second windings are connected (see also r1_2).

• When cz is 1, x1_2 is the reactance in pu on system base quantities;
• when cz is 2, x1_2 is the reactance in pu on winding one to two base MVA (sbase1_2) and winding one bus base voltage;
• when cz is 3, x1_2 is the impedance magnitude in pu on winding one to two base MVA (sbase1_2) and winding one bus base voltage. x1_2 has no default.

sbase1_2: f64

The winding one to two base MVA of the transformer. sbase1_2 = sbase (the system base MVA) by default.

r2_3: Option<f64>

The measured impedance of a three-winding transformer between the buses to which its second and third windings are connected (see also x2_3).

• When cz is 1, r2_3 is the resistance in pu on system base quantities;
• when cz is 2, r2_3 is the resistance in pu on winding two to three base MVA (sbase2_3) and winding two bus base voltage;
• when cz is 3, r2_3 is the load loss in watts r2_3 = 0.0 by default. Ignored for a two-winding transformer.

x2_3: Option<f64>

The measured impedance of a three-winding transformer between the buses to which its second and third windings are connected (see also x2_3).

• When cz is 1, x2_3 is the reactance in pu on system base quantities;
• when cz is 2, x2_3 is the reactance in pu on winding one to two base MVA (sbas2_3) and winding one bus base voltage;
• when cz is 3, x2_3 is the impedance magnitude in pu on winding two to three base MVA (sbase2_3) and winding two bus base voltage. x2_3 has no default. Ignored for a two-winding transformer.

sbase2_3: Option<f64>

The winding two to three base MVA of a three-winding transformer; ignored for a two-winding transformer. sbase2_3 = sbase (the system base MVA) by default. Ignored for a two-winding transformer.

r3_1: Option<f64>

The measured impedance of a three-winding transformer between the buses to which its third and first windings are connected (see also x3_1).

• When cz is 1, r3_1 is the resistance in pu on system base quantities;
• when cz is 2, r3_1 is the resistance in pu on winding three to one base MVA (sbase3_1) and winding three bus base voltage;
• when cz is 3, r3_1 is the load loss in watts r3_1 = 0.0 by default. Ignored for a two-winding transformer.

x3_1: Option<f64>

The measured impedance of a three-winding transformer between the buses to which its third and first windings are connected (see also x3_1).

• When cz is 1, x3_1 is the reactance in pu on system base quantities;
• when cz is 2, x3_1 is the reactance in pu on winding three to one base MVA (sbas3_1) and winding three bus base voltage;
• when cz is 3, x3_1 is the impedance magnitude in pu on winding three to one base MVA (sbase3_1) and winding three bus base voltage. x3_1 has no default. Ignored for a two-winding transformer.

sbase3_1: Option<f64>

The winding three to one base MVA of a three-winding transformer. sbase3_1 = sbase (the system base MVA) by default. Ignored for a two-winding transformer.

vmstar: Option<f64>

The voltage magnitude at the hidden star point bus; entered in pu. vmstar = 1.0 by default. Ignored for a two-winding transformer.

anstar: Option<f64>

The bus voltage phase angle at the hidden star point bus; entered in degrees. anstar = 0.0 by default. Ignored for a two-winding transformer.

windv1: f64

When cw is 1, windv1 is the winding one off-nominal turns ratio in pu of winding one bus base voltage, and windv1 = 1.0 by default. When cw is 2, windv1 is the actual winding one voltage in kV, and windv1 is equal to the base voltage of bus “I” by default.

nomv1: f64

The nominal (rated) winding one voltage in kV, or zero to indicate that nominal winding one voltage is to be taken as the base voltage of bus “I”. nomv1 is used only in converting magnetizing data between per unit admittance values and physical units when cm is 2. nomv1 = 0.0 by default.

ang1: f64

The winding one phase shift angle in degrees. ang1 is positive for a positive phase shift from the winding one side to the winding two side (for a two-winding transformer). ang1 must be greater than -180.0 and less than or equal to +180.0. ang1 = 0.0 by default.

rata1: f64

The first winding’s first rating entered in MVA (not current expressed in MVA).

ratb1: f64

The first winding’s second rating entered in MVA (not current expressed in MVA).

ratc1: f64

The first winding’s third rating entered in MVA (not current expressed in MVA).

cod1: i8

The transformer control mode for automatic adjustments of the winding one tap or phase shift angle during power flow solutions:

• 0 for no control (fixed tap and phase shift);
• ±1 for voltage control;
• ±2 for reactive power flow control;
• ±3 for active power flow control;
• ±4 for control of a DC line quantity. If the control mode is entered as a positive number, automatic adjustment of this transformer winding is enabled when the corresponding adjustment is activated during power flow solutions; a negative control mode suppresses the automatic adjustment of this transformer winding. cod1 = 0 by default.

cont1: BusNum

The bus number, or extended bus name enclosed in single quotes, of the bus whose voltage is to be controlled by the transformer turns ratio adjustment option of the power flow solution activities when cod1 is 1.

cont1 should be non-zero only for voltage controlling transformer windings. cont1 may specify a bus other than “I”, “J”, or “K”; in this case, the sign of cont1 defines the location of the controlled bus relative to the transformer winding.

If cont1 is entered as a positive number, the ratio is adjusted as if bus cont1 is on the winding two side of the transformer; if cont1 is entered as a negative number, the ratio is adjusted as if bus |cont1| is on the winding one side of the transformer. cont1 = 0 by default.

rma1: f64

rma1 is the upper limit (and rmi1 the lower limit) of either:

• Off-nominal turns ratio in pu of winding one bus base voltage when |cod1| is 1 or 2 and cw is 1; rma1 = 1.1 and rmi1 = 0.9 by default.
• Actual winding one voltage in kV when |cod1| is 1 or 2 and cw is 2. No default is allowed.
• Phase shift angl e in degrees when |cod1| is 3. No default is allowed.
• Not used when |cod1| is 0 or 4; rma1 = 1.1 and rmi1 = 0.9 by default.

rmi1: f64

The lower limit to rma1’s upper limit. See rma1 for details.

vma1: f64

vma1 is the upper limit (and vmi1 the lower limit) of either:

• Voltage at the controlled bus (bus |cont1|) in pu when |cod1| is 1. vma1 = 1.1 and vmi1 = 0.9 by default.
• Reactive power flow into the transformer at the winding one bus end in Mvar when |cod1| is 2. no default is allowed.
• Active power flow into the transformer at the winding one bus end in MW when |cod1| is 3. no default is allowed.
• Not used when |cod1| is 0 or 4; vma1 = 1.1 and vmi1 = 0.9 by default.

vmi1: f64

The lower limit to vma1’s upper limit. See vma1 for details.

ntp1: i16

The number of tap positions available; used when cod1 is 1 or 2. ntp1 must be between 2 and 9999. ntp1 = 33 by default.

tab1: isize

The number of a transformer impedance correction record if this transformer winding’s impedance is to be a function of either off-nominal turns ratio or phase shift angle, or 0 if no transformer impedance correction is to be applied to this transformer winding. See ImpedanceCorrection. tab1 = 0 by default.

cr1: f64

The load drop compensation impedance for voltage controlling transformers entered in pu on system base quantities; used when cod1 is 1. cr1 + jcx1 = 0.0 by default.

cx1: f64

See cr1 for details.

cnxa1: Option<f64>

Winding connection angle in degrees; used when cod1 is 5. There are no restrictions on the value specified for cnxa1; if it is outside of the range from -90.0 to +90.0, cnxa1 is normalized to within this range. cnxa1 = 0.0 by default.

windv2: f64

When cw is 1, windv2 is the winding two off-nominal turns ratio in pu of winding two bus base voltage, and windv2 = 1.0 by default. When cw is 2, windv2 is the actual winding two voltage in kV, and windv2 is equal to the base voltage of bus j by default.

nomv2: f64

The nominal (rated) winding two voltage in kV, or zero to indicate that nominal winding two voltage is to be taken as the base voltage of bus j. nomv2 is present for information purposes only; it is not used in any of the calculations for modeling the transformer. nomv2 = 0.0 by default.

ang2: Option<f64>

The winding two phase shift angle in degrees. ang2 is positive for a positive phase shift from the winding two side to the “T” (or star) point bus. ang2 must be greater than -180.0 and less than or equal to +180.0. ang2 = 0.0 by default. Ignored for a two-winding transformer.

rata2: Option<f64>

The second winding’s first rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

ratb2: Option<f64>

The second winding’s second rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

ratc2: Option<f64>

The second winding’s third rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

cod2: Option<i8>

The transformer control mode for automatic adjustments of the winding two tap or phase shift angle during power flow solutions:

• 0 for no control (fixed tap and phase shift);
• ±1 for voltage control;
• ±2 for reactive power flow control;
• ±3 for active power flow control. If the control mode is entered as a positive number, automatic adjustment of this transformer winding is enabled when the corresponding adjustment is activated during power flow solutions; a negative control mode suppresses the automatic adjustment of this transformer winding. cod2 = 0 by default. Ignored for a two-winding transformer.

cont2: Option<BusNum>

The bus number, or extended bus name enclosed in single quotes, of the bus whose voltage is to be controlled by the transformer turns ratio adjustment option of the power flow solution activities when cod2 is 1. cont2 should be nonzero only for voltage controlling transformer windings.

cont2 may specify a bus other than i, j, or k; in this case, the sign of cont2 defines the location of the controlled bus relative to the transformer winding. If cont2 is entered as a positive number, or a quoted extended bus name, the ratio is adjusted as if bus cont2 is on the winding one or winding three side of the transformer; if cont2 is entered as a negative number, or a quoted extended bus name with a minus sign preceding the first character, the ratio is adjusted as if bus |cont2| is on the winding two side of the transformer. cont2 = 0 by default. Ignored for a two-winding transformer.

rma2: Option<f64>

rma2 is the upper limit (and rmi2 the lower limit) of either:

• Off-nominal turns ratio in pu of winding two bus base voltage when |cod2| is 1 or 2 and cw is 1; rma2 = 1.1 and rmi2 = 0.9 by default.
• Actual winding one voltage in kV when |cod2| is 1 or 2 and cw is 2. No default is allowed.
• Phase shift angle in degrees when |cod2| is 3. No default is allowed.
• Not used when |cod2| is 0; rma2 = 1.1 and rmi2 = 0.9 by default. Ignored for a two-winding transformer.

rmi2: Option<f64>

The lower limit to rma2’s upper limit. See rma2 for details. Ignored for a two-winding transformer.

vma2: Option<f64>

vma2 is the upper limit (and vmi2 the lower limit) of either:

• Voltage at the controlled bus (bus |cont2|) in pu when |cod2| is 1. vma2 = 1.1 and vmi2 = 0.9 by default.
• Reactive power flow into the transformer at the winding two bus end in Mvar when |cod2| is 2. No default is allowed.
• Active power flow into the transformer at the winding two bus end in MW when |cod2| is 3. No default is allowed.
• Not used when |cod2| is 0; vma2 = 1.1 and vmi2 = 0.9 by default. Ignored for a two-winding transformer.

vmi2: Option<f64>

The lower limit to vma1’s upper limit. See vma1 for details. Ignored for a two-winding transformer.

ntp2: Option<i16>

The number of tap positions available; used when cod2 is 1 or 2. ntp2 must be between 2 and 9999. ntp2 = 33 by default. Ignored for a two-winding transformer.

tab2: Option<isize>

The number of a transformer impedance correction record if this transformer winding’s impedance is to be a function of either off-nominal turns ratio or phase shift angle, or 0 if no transformer impedance correction is to be applied to this transformer winding. See ImpedanceCorrection. tab2 = 0 by default. Ignored for a two-winding transformer.

cr2: Option<f64>

The load drop compensation impedance for voltage controlling transformers entered in pu on system base quantities; used when cod2 is 1. cr2 + jcx2 = 0.0 by default. Ignored for a two-winding transformer.

cx2: Option<f64>

See cr2 for details. Ignored for a two-winding transformer.

cnxa2: Option<f64>

Winding connection angle in degrees; used when cod2 is 5. There are no restrictions on the value specified for cnxa2; if it is outside of the range from -90.0 to +90.0, cnxa2 is normalized to within this range. cnxa2 = 0.0 by default.

windv3: Option<f64>

When cw is 1, windv3 is the winding three off-nominal turns ratio in pu of winding three bus base voltage, and windv3 = 1.0 by default. When cw is 2, windv3 is the actual winding three voltage in kV, and windv3 is equal to the base voltage of bus k by default. Ignored for a two-winding transformer.

nomv3: Option<f64>

The nominal (rated) winding three voltage in kV, or zero to indicate that nominal winding two voltage is to be taken as the base voltage of bus j. nomv3 is present for information purposes only; it is not used in any of the calculations for modeling the transformer. nomv3 = 0.0 by default. Ignored for a two-winding transformer.

ang3: Option<f64>

The winding three phase shift angle in degrees. ang3 is positive for a positive phase shift from the winding two side to the “T” (or star) point bus. ang3 must be greater than -180.0 and less than or equal to +180.0. ang3 = 0.0 by default. Ignored for a two-winding transformer.

rata3: Option<f64>

The third winding’s first rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

ratb3: Option<f64>

The third winding’s second rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

ratc3: Option<f64>

The third winding’s third rating entered in MVA (not current expressed in MVA). Ignored for a two-winding transformer.

cod3: Option<i8>

The transformer control mode for automatic adjustments of the winding three tap or phase shift angle during power flow solutions:

• 0 for no control (fixed tap and phase shift);
• ±1 for voltage control;
• ±2 for reactive power flow control;
• ±3 for active power flow control. If the control mode is entered as a positive number, automatic adjustment of this transformer winding is enabled when the corresponding adjustment is activated during power flow solutions; a negative control mode suppresses the automatic adjustment of this transformer winding. cod3 = 0 by default. Ignored for a two-winding transformer.

cont3: Option<BusNum>

The bus number, or extended bus name enclosed in single quotes, of the bus whose voltage is to be controlled by the transformer turns ratio adjustment option of the power flow solution activities when cod3 is 1. cont3 should be nonzero only for voltage controlling transformer windings.

cont3 may specify a bus other than i, j, or k; in this case, the sign of cont3 defines the location of the controlled bus relative to the transformer winding. If cont3 is entered as a positive number, or a quoted extended bus name, the ratio is adjusted as if bus cont3 is on the winding one or winding two side of the transformer; if cont3 is entered as a negative number, or a quoted extended bus name with a minus sign preceding the first character, the ratio is adjusted as if bus |cont3| is on the winding three side of the transformer. cont3 = 0 by default. Ignored for a two-winding transformer.

rma3: Option<f64>

rma3 is the upper limit (and rmi3 the lower limit) of either:

• Off-nominal turns ratio in pu of winding three bus base voltage when |cod3| is 1 or 2 and cw is 1; rma3 = 1.1 and rmi3 = 0.9 by default.
• Actual winding one voltage in kV when |cod3| is 1 or 2 and cw is 2. No default is allowed.
• Phase shift angle in degrees when |cod3| is 3. No default is allowed.
• Not used when |cod3| is 0; rma3 = 1.1 and rmi3 = 0.9 by default. Ignored for a two-winding transformer.

rmi3: Option<f64>

The lower limit to rma3’s upper limit. See rma3 for details. Ignored for a two-winding transformer.

vma3: Option<f64>

vma3 is the upper limit (and vmi3 the lower limit) of either:

• Voltage at the controlled bus (bus |cont3|) in pu when |cod3| is 1. vma3 = 1.1 and vmi3 = 0.9 by default.
• Reactive power flow into the transformer at the winding three bus end in Mvar when |cod3| is 2. No default is allowed.
• Active power flow into the transformer at the winding two bus end in MW when |cod3| is 3. No default is allowed.
• Not used when |cod3| is 0; vma3 = 1.1 and vmi3 = 0.9 by default. Ignored for a two-winding transformer.

vmi3: Option<f64>

The lower limit to vma3’s upper limit. See vma3 for details. Ignored for a two-winding transformer.

ntp3: Option<i16>

The number of tap positions available; used when cod3 is 1 or 2. ntp3 must be between 2 and 9999. ntp3 = 33 by default. Ignored for a two-winding transformer.

tab3: Option<isize>

The number of a transformer impedance correction record if this transformer winding’s impedance is to be a function of either off-nominal turns ratio or phase shift angle, or 0 if no transformer impedance correction is to be applied to this transformer winding. See ImpedanceCorrection. tab3 = 0 by default. Ignored for a two-winding transformer.

cr3: Option<f64>

The load drop compensation impedance for voltage controlling transformers entered in pu on system base quantities; used when cod3 is 1. cr3 + jcx3 = 0.0 by default. Ignored for a two-winding transformer.

cx3: Option<f64>

See cr3 for details. Ignored for a two-winding transformer.

cnxa3: Option<f64>

Winding connection angle in degrees; used when cod3 is 5. There are no restrictions on the value specified for cnxa3; if it is outside of the range from -90.0 to +90.0, cnxa3 is normalized to within this range. cnxa3 = 0.0 by default.