# Three-Phase Programmable Voltage Source

Implement three-phase voltage source with programmable time variation of amplitude, phase, frequency, and harmonics

Libraries:
Simscape / Electrical / Specialized Power Systems / Sources

## Description

Use this block to generate a three-phase sinusoidal voltage with time-varying parameters. You can program the time variation for the amplitude, phase, or frequency of the fundamental component of the source. In addition, two harmonics can be programmed and superimposed on the fundamental signal.

### Examples

The `power_3phsignalseq` circuit illustrates the use of the Three-Phase Programmable Voltage Source block to produce a step variation of the positive-sequence voltage and to inject harmonics into the circuit.

A 25 kV, 100 MVA short-circuit level, equivalent network feeds a 5 MW, 2 Mvar capacitive load. The internal voltage of the source is controlled by the Discrete 3-phase Programmable Voltage Source block.

A positive sequence of 1.0 pu, 0 degrees is specified for the fundamental signal. At t = 0.05 s a step of 0.5 pu is applied to the positive-sequence voltage magnitude, then at t = 0.1 s, 0.08 pu of fifth harmonic in negative sequence is added to the 1.5 pu voltage.

The three-phase voltage and current are measured at the output of the source impedance. Two Discrete Sequence Analyzer blocks are used to measure the positive-sequence fundamental component and the negative-sequence fifth harmonic of the three-phase voltage.

## Ports

### Conserving

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Electrical conserving port associated with the neutral terminal.

Electrical conserving port associated with the phase A terminal.

Electrical conserving port associated with the phase B terminal.

Electrical conserving port associated with the phase C terminal.

## Parameters

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To edit block parameters interactively, use the Property Inspector. From the Simulink® Toolstrip, on the Simulation tab, in the Prepare gallery, select .

### Parameters

The amplitude in volts RMS phase-to-phase, the phase in degrees, and the frequency in hertz of the positive-sequence component of the three voltages. Default is `[100 0 60]`.

Phase B and phase C internal voltages lag phase A by 120 degrees and 240 degrees, respectively ([0 -120 +120]).

Specify the parameter for which you want to program the time variation. Select `None` (default) if you do not want to program the time variation of the source parameters. Select `Amplitude` if you want to program the time variation of the amplitude. Select `Phase` if you want to program the time variation of the phase. Select `Frequency` if you want to program the time variation of the frequency.

The time variation applies to the three phases of the source except when the Type of variation parameter is set to ```Table of amplitude-pairs```. In that case you can apply a variation to phase A only.

Specify the type of variation that is applied to the parameter specified by the Time variation of parameter. Select `Step` to program a step variation. Select `Ramp` to program a ramp variation. Select `Modulation` to program a modulated variation. Select `Table of amplitude-pairs` to program a series of step changes of amplitudes at specific times.

The `Table of amplitude-pairs` option is available only when the Time variation of parameter is set to `Amplitude`.

`Table of amplitude-pairs` is the default when Time variation of is set to `Amplitude`. `Step` is the default when Time variation of is set to `Phase` or `Frequency`.

#### Dependencies

To enable this parameter, set Time variation of to `Amplitude`, `Phase`, or `Frequency`.

If selected, the programmed time variation of the amplitude is applied only to phase A of the Three-Phase Programmable Voltage Source block.

#### Dependencies

To enable this parameter, set Time variation of to `Amplitude` and Type of variation to `Table of amplitude-pairs`.

Specifies the amplitude variation points taken by the voltage source during the simulation. The specified values are in pu, based on the positive-sequence amplitude of the voltage source. The corresponding times where the variation will take place are defined by the Time values parameter.

#### Dependencies

To enable this parameter, set Time variation of to `Amplitude` and Type of variation to `Table of amplitude-pairs`.

Specifies the transition times, in seconds, of the amplitude variation defined in the Amplitude values (pu) parameter.

#### Dependencies

To enable this parameter, set Time variation of to `Amplitude` and Type of variation to `Table of amplitude-pairs`.

Specify the amplitude of the step change. The variation of amplitude is specified in pu of the positive-sequence amplitude.

#### Dependencies

To enable this parameter, set Type of variation to `Step`.

Specify the rate of change, in volt/seconds. The rate of change of voltage is specified in (pu of the positive-sequence voltage)/second.

#### Dependencies

To enable this parameter, set Type of variation to `Ramp`.

Specify the amplitude of the modulation for the source parameter that is specified in the Time variation of parameter. When the varying quantity is the voltage amplitude, the amplitude of the modulation is specified in pu of the positive-sequence amplitude.

#### Dependencies

To enable this parameter, set Type of variation to `Modulation`.

Specify the frequency of the modulation for the source parameter that is specified in the Time variation of parameter.

#### Dependencies

To enable this parameter, set Type of variation to `Modulation`.

Specify the time, in seconds, when the programmed time variation takes effect and the time when it stops.

If selected, two harmonics can be programmed to be superimposed on the fundamental voltage of the source.

Specify the order, amplitude, phase, and the type of sequence (1 = positive-sequence; 2 = negative-sequence; 0 = zero-sequence) of the first harmonic to be superimposed on the fundamental signal. The voltage of the harmonic is specified in pu of the positive-sequence voltage.

Specify `1` for the harmonic order and `0` or `2` for the sequence to produce a voltage imbalance without harmonics.

#### Dependencies

To enable this parameter, select the Fundamental and/or Harmonic generation parameter.

Specify the order, amplitude, phase, and the type of sequence (1 = positive-sequence; 2 = negative-sequence; 0 = zero-sequence) of the second harmonic to be superimposed on the fundamental signal. The voltage of the harmonic is specified in pu of the positive-sequence voltage.

Specify `1` for the harmonic order and `0` or `2` for the sequence to produce a voltage imbalance without harmonics.

#### Dependencies

To enable this parameter, select the Fundamental and/or Harmonic generation parameter.

Specify the time, in seconds, when the harmonic generation is superimposed on the fundamental signal and the time when it stops.

#### Dependencies

To enable this parameter, select the Fundamental and/or Harmonic generation parameter.

The load flow parameters are used to define block parameters for use with the Load Flow tool of the Powergui block. These load flow parameters are used for model initialization only. They have no impact on the block model and on the simulation’s performance.

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

Specify the generator type of the voltage source.

Select `swing` (default) to implement a generator controlling magnitude and phase angle of its terminal voltage. The reference voltage magnitude and angle are specified by 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.

Select `PV` to implement a generator controlling its output active power P and voltage magnitude V. P is specified by the Active power generation P parameter of the block. V is specified by the Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the voltage source terminals. You can control the minimum and maximum reactive power generated by the block by using the Minimum reactive power Qmin and Maximum reactive power Qmax parameters.

Select `PQ` to implement a generator controlling its output active power P and reactive power Q. P and Q are specified by the Active power generation P and Reactive power generation Q parameters of the block, respectively.

Specify the active power that you want generated by the source, in watts.

#### Dependencies

To enable this parameter, set Generator type to `PV` or `PQ`.

Specify the reactive power that you want generated by the source, in vars.

#### Dependencies

To enable this parameter, set Generator type to `PQ`.

Minimum reactive power that can be generated by the source while keeping the terminal voltage at its reference value. This reference voltage is specified in the Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the source terminals. 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 that can be generated by the source while keeping the terminal voltage at its reference value. This reference voltage is specified in the Swing bus or PV bus voltage parameter of the Load Flow Bus block connected to the source terminals. 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`.

## Version History

Introduced before R2006a