Synchronous Machine with Simplified Interface

 No. of Q-Axis Damper Windings

Choice

Select the appropriate number of q-axis windings.

 Armature Resistance As

Choice

Select Time Constant or Resistance. See Data Entry Formats for more details.

 Saturation

Choice

Select Enabled or Disabled.

The D-axis saturation is disabled by default.  When enabled, a saturation characteristic is applied as given by data points in the Saturation Curve section of the component properties.  See Saturation Curve for more details.

Armature Resistance [Ra]

REAL

Constant

Enter the armature resistance [pu].  

This is only enabled if the Armature Resistance As | Resistance is selected.

Armature Time Constant [Ta]

REAL

Constant

Enter the armature time constant.  

This is only enabled if the Armature Resistance As | time Constant is selected.

Stator Leakage Reactance [Xl]

REAL

Constant

Stator Leakage Reactance [pu]. Stator Leakage Reactance must be less than the Direct-Axis Reactance, Transient Reactance and Sub-Transient Reactance.

Unsaturated Reactance

REAL

Constant

Xd, Xq [pu]

Unsaturated Transient Reactance

REAL

Constant

Xd', Xq' [pu]

Unsaturated Transient Time (Open)

REAL

Constant

Tdo', Tqo' [s]

Unsaturated Sub-Transient Reactance

REAL

Constant

Xd", Xq" [pu]

Unsaturated Sub-Transient Time (Open)

REAL

Constant

Tdo", Tqo" [s]

Number of Data Points Available

Choice

Point # - Current

REAL

Constant

Enter the I data point for the mutual magnetizing inductance saturation curve.  See Saturation Curve for more details [pu]

Point # - PU Voltage

REAL

Constant

Enter the V data point for the mutual magnetizing inductance saturation curve.  See Saturation Curve for more details [pu]

Terminal Voltage Magnitude at Time = 0-

REAL

Constant

Terminal voltage magnitude at start-up [pu].

Terminal Voltage Phase at Time = 0-

REAL

Constant

Terminal voltage phase angle at start-up [deg].  

Care must be taken if the machine is connected through a Y-D transformer, with the bus side on Y and the machine on D.  If the bus phase angle is being determined from a conventional load flow program, Y-D transformations are not taken into account. Therefore, 30° must be subtracted from this angle if obtained from load flow calculations [rad]

 Terminal Real  Power at Time = 0-

REAL

Constant

Terminal active power at start-up [MW].

This parameter is available only if the Type of Settings for Initial Condition | Terminal Power Flow Condition is selected.

Terminal Reactive Power at Time = 0-

REAL

Constant

Terminal reactive power at start-up [MVAR].

This parameter is available only if the Type of Settings for Initial Condition | Terminal Power Flow Condition is selected.

Transition Time (Voltage Source Mode to Machine Mode)

REAL

Constant

The time when the machine is changed from a voltage source to a machine [s].

Transition Time (Fixed Mechanical Speed Mode to Rotor Dynamic Mode)

REAL

Constant

The time when the rotor is released [s].

Ramp Time to Rated (Start as a Source)

REAL

Constant

This parameter is used to provide a 'soft start', when starting from time = 0.0 as a source, so that network transients are minimized [s]. Only used when the machine is started as a Source.

 Output Initialized Field Voltage (Ef0)

Choice

Select Yes, or No.

If Yes, the required field voltage is used to initialize the exciter, so that the machine can be switched from source mode to machine mode smoothly. See Start-up and Initialization for more details

 Interface to Exciter?

Choice

Select Yes, or No.

If Yes, the parameters related to exciters will show.

 Terminal Information to Exciter

Choice

Select Terminal Voltage, Terminal Current or Both Voltage and Current. 

Some exciters need only the voltage and some need both voltage and real/reactive parts of the currents. This option will create an output scalar, a 2-element vector, or a 3-element vector (depending on the option chosen) to be passed to the exciter.  The exciter will use this information to initialize its internal variables so that an initialized output is provided to the machine when the machine is switched from a 'source' to a 'machine'. See Start-up and Initialization for more details.

This parameter is available only if the Interface to Exciter? | Yes is selected.

Smoothing Time Constant

REAL

Variable

Time constant used for smoothing out terminal measurements before supplying to exciter [s].

This parameter is available only if the Interface to Exciter? | Yes is selected.

Exciter Initialization Signal

Text

Give a variable name. 

This will change its assigned value from 0 to 1 when the machine is switched from a 'source' to a 'machine'. Use this variable in the exciter model to initialize it.

This parameter is available only if the Interface to Exciter? | Yes is selected.

Output Initialized Mechanical Torque (Tm0)

Choice

Select Yes or No.  

If Yes, the required mechanical torque is used to initialize the turbine and/or governor, so that the machine can be switched from 'locked-rotor' to 'free running' mode smoothly.  See Start-up and Initialization for more details

Interface to Governor/Turbine?

Choice

Select Yes or No.  

If Yes, the parameters related to Governor/Turbine will show.

Governor/Turbine Initialization Signal

Text

Give a variable name. 

This will change its assigned value from 0 to 1 when the machine is switched from a 'constant speed operation' to a 'normal machine'. Use this variable in any governor/turbine models to initialize them.

This parameter is available only if the Governor/Turbine? | Yes is selected.

Output Speed

Choice

Select per-unit or radians per second, depending on that needed by the Governor/Turbine models interfaced.

Real Power

REAL

Output

Real power output of the machine. (+) - power flowing out [pu]

Reactive Power

REAL

Output

Reactive power output of the machine. (+) - power flowing out [pu]

Neutral Voltage Real

REAL

Output

Voltage at the machine neutral (star) point [kV].

This parameter is available only if the External Neutral Connection | Disable is selected.

Neutral Current to Ground (kA)

REAL

Output

Machine neutral current [kA].

This parameter is available only if the External Neutral Connection | Disable is selected.

Load Angle; Gen +

REAL

Output

This is the phase difference between the internal voltage and the terminal voltage and is responsible for pushing the power in/out of machine.  This angle should not be confused with Internal Phase A Angle with Respect to sin(wt) as described below [rad]

Rotor Mechanical Angle

REAL

Output

This is a saw tooth wave from 0 to 2p radians.  The value indicates the position of the rotor [rad].

Internal Phase 'A' Angle with Respect to sin(wt)

REAL

Output

This is calculated as Wang = Phase angle of Terminal Voltage + Lang + Integral of (wpu - 1.0) x d(t).

Steady Electric Torque

REAL

Output

Smoothed output of the electrical torque of the machine [rad]