Three-Phase Source

Implement three-phase source with internal R-L impedance

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Libraries:
Simscape / Electrical / Specialized Power Systems / Sources

Description

The Three-Phase Source block implements a balanced three-phase voltage source with an internal R-L impedance. The block connects the three voltage sources in Y with a neutral connection that you can internally ground or make it accessible. You can specify the source internal resistance and inductance either directly by entering R and L values or indirectly by specifying the source inductive short-circuit level and X/R ratio.

Examples

Three-Phase Series Compensated Network

The use of three-phase blocks to study transients on a series-compensated 735-kV transmission system

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Ports

Conserving

A — A-phase

specialized electrical

Specialized electrical conserving port associated with the A-phase of the block.

B — B-phase

specialized electrical

Specialized electrical conserving port associated with the B-phase of the block.

C — C-phase

specialized electrical

Specialized electrical conserving port associated with the C-phase of the block.

N — Neutral connection

specialized electrical

Specialized electrical conserving port associated with the neutral connection of the block.

Dependencies

To enable this port, set Configuration to Yn.

Parameters

Parameters

Configuration — Internal connection of three voltage sources

Yg (default) | Yn | Y

The internal connection of the three internal voltage sources. The block icon changes according to the source connection:

Y	The block connects the three voltage sources in Y to an internal floating neutral.
Yn	The block connects the three voltage sources in Y to a neutral connection which is accessible through a fourth terminal.
Yg	Default. The block connects the three voltage sources in Y to an internally grounded neutral.

Source

Specify internal voltages for each phase — Option for internal voltages for each phase

off (default) | on

Option to specify the internal voltage for each phase.

Phase-to-phase voltage (Vrms) — Internal phase-to-phase voltage

25e3 (default)

Internal phase-to-phase voltage, in volts RMS.

Dependencies

To enable this parameter, clear the Specify internal voltages for each phase parameter.

Phase angle of phase A (degrees) — Phase angle of phase A

0 (default)

Phase angle of the internal voltage that phase A generates, in degrees. The three voltages are generated in a positive sequence. For this reason, phase B and phase C internal voltages lag phase A by 120 degrees and 240 degrees, respectively.

Dependencies

To enable this parameter, clear the Specify internal voltages for each phase parameter.

Line-to-neutral voltages [Va Vb Vc] (Vrms) — Internal line-to-neutral voltages

[25e3 25e3 25e3]/sqrt(3) (default)

Internal line-to-neutral voltage of phase A, B, and C, in volts RMS.

Dependencies

To enable this parameter, select the Specify internal voltages for each phase parameter.

Phase angle of line-to-neutral voltages [phia phib phic] (deg) — Phase angle of line-to-neutral voltages

[0 -120 +120] (default)

Phase angles of the internal voltages generated by phase A, B, and C, in degrees.

Dependencies

To enable this parameter, select the Specify internal voltages for each phase parameter.

Frequency (Hz) — Source frequency

60 (default)

Source frequency, in hertz (Hz).

Impedance

Internal — Option to model internal RL inductance

on (default) | off

Whether to model an internal RL inductance.

Specify short-circuit level parameters — Option to specify internal impedance

off (default) | on

Whether to specify internal impedance using the inductive short-circuit level and X/R ratio.

Dependencies

To enable this parameter, select the Internal parameter.

Source resistance (Ohms) — Source internal resistance

0.8929 (default)

Source internal resistance, in ohms (Ω).

Dependencies

To enable this parameter, clear the Internal and Specify short-circuit level parameters parameters.

Source inductance (H) — Source internal inductance

16.58e-3 (default)

Source internal inductance, in henries (H).

Dependencies

To enable this parameter, clear the Internal and Specify short-circuit level parameters parameters.

3-phase short-circuit level at base voltage(VA) — Three-phase inductive short-circuit power

100e6 (default)

Three-phase inductive short-circuit power, in volts-amperes (VA), at specified base voltage. The block uses this value to compute the internal inductance L.

This equation computers the internal inductance L (in H) from the inductive three-phase short-circuit power Psc (in VA), base voltage Vbase (in Vrms phase-to-phase), and source frequency f (in Hz):

$$L=\frac{V_{base}^2}{Psc}\cdot \frac{1}{2\pi f}.$$

Dependencies

To enable this parameter, select the Internal and Specify short-circuit level parameters parameters.

Base voltage (Vrms ph-ph) — Phase-to-phase base voltage

25e3 (default)

Phase-to-phase base voltage, in volts RMS. Use this parameter to specify the three-phase short-circuit level. Default is 25e3. The base voltage is usually the nominal source voltage.

Dependencies

To enable this parameter, select the Internal and Specify short-circuit level parameters parameters.

X/R ratio — X/R ratio at nominal source frequency

7 (default)

X/R ratio at nominal source frequency or quality factor of the internal source impedance.

This equation computes the internal resistance R (in ohms) from the source reactance X (in ohms) at specified frequency, and X/R ratio:

$$R=\frac{X}{\left(X/R\right)}=\frac{2\pi fL}{X/R}.$$

Dependencies

To enable this parameter, select the Internal and Specify short-circuit level parameters parameters.

Load Flow

The Load Flow tool of the powergui block uses the parameters in this section. These load flow parameters are used for model initialization only, they have no impact on the block model and on the simulation performance.

The configuration of the Load Flow tab depends on the option you select for the Generator type parameter.

Generator type — Generator type of the voltage source

swing (default) | PV | PQ

Specify the generator type of the voltage source:

• swing — Implement a generator controlling magnitude and phase angle of its terminal voltage. The Swing bus or PV bus voltage and Swing bus voltage angle parameters of the Load Flow Bus block connected to the voltage source terminals specify the reference voltage magnitude and angle.

• PV — Implement a generator controlling its output active power P and voltage magnitude V. The Active power generation P parameter of the block specifies the value of the output active power P. The Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the voltage source terminals specifies the value of the voltage magnitude V. You can control the minimum and maximum reactive power of this block by using the Minimum reactive power Qmin and Maximum reactive power Qmax parameters.

• PQ — Implement a generator controlling its output active power P and reactive power Q. The Active power generation P and Reactive power generation Q parameters of the block specify the values of the output active power P and reactive power Q, respectively.

Active power generation P (W) — Desired active power

10e3 (default)

Desired active power that the source generates, in watts.

Dependencies

To enable this parameter, set Generator type to PV or PQ and clear theSpecify internal voltages for each phase parameter.

Reactive power generation Q (var) — Desired reactive power

0 (default)

Desired reactive power that the source generates, in vars.

Dependencies

To enable this parameter, set Generator type to PQ and clear theSpecify internal voltages for each phase parameter.

Active power generation [Pa Pb Pc] (W) — Desired active power that each phase of source generates

[10e3, 10e3, 10e3] (default)

Desired active power that each phase of the source generates, in watts.

Dependencies

To enable this parameter, set Generator type to PV or PQ and select theSpecify internal voltages for each phase parameter.

Reactive power generation [Qa Qb Qc] (var) — Desired reactive power that each phase of source generates

[0, 0, 0] (default)

Desired reactive power that each phase of the source generates, in vars.

Dependencies

To enable this parameter, set Generator type to PQ and select theSpecify internal voltages for each phase parameter.

Minimum reactive power Qmin or [Qamin,Qbmin Qcmin] (var) — Minimum reactive power that source can generate

-inf (default)

Minimum reactive power that the source can generate while keeping the terminal voltage at its reference value. The Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the source terminals specifies this reference voltage. The default value is -inf, which means that there is no lower limit on the reactive power output.

Dependencies

To enable this parameter, set Generator type to PV.

Maximum reactive power Qmax or [Qamax,Qbmax Qcmax] (var) — Maximum reactive power that source can generate

inf (default)

Maximum reactive power that the source can generate while keeping the terminal voltage at its reference value. The Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the source terminals specifies this reference voltage. The default value is inf, which means that there is no upper limit on the reactive power output.

Dependencies

To enable this parameter, set Generator type to PV.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced before R2006a