Documentation

AC Voltage Source

Implement sinusoidal voltage source

Library

Fundamental Blocks/Electrical Sources

Description

The AC Voltage Source block implements an ideal AC voltage source. The generated voltage U is described by the following relationship:

U=Asin(ωt+ϕ),  ω=2πf,  ϕ=Phase in radians.

Negative values are allowed for amplitude and phase. A frequency of 0 and phase equal to 90 degrees specify a DC voltage source. Negative frequency is not allowed; otherwise the software signals an error, and the block displays a question mark in the block icon.

Dialog Box and Parameters

Parameters Tab

Peak amplitude

The peak amplitude of the generated voltage, in volts (V).

Phase

The phase in degrees (deg).

Frequency

The source frequency in hertz (Hz).

Sample time

The sample period in seconds (s). The default is 0, corresponding to a continuous source.

Measurements

Select Voltage to measure the voltage across the terminals of the AC Voltage Source block.

Place a Multimeter block in your model to display the selected measurements during the simulation. In the Available Measurements list box of the Multimeter block, the measurement is identified by a label followed by the block name.

Measurement

Label

Voltage

Usrc:

Load Flow Tab

The Load Flow tool of the powergui block uses the parameters on this tab. These load flow parameters affect only model initialization. They do not affect simulation.

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

Generator type

Specify the generator type of the voltage source. The default value is swing.

Select swing to implement a generator controlling the magnitude and phase angle of its terminal voltage. Specify the reference voltage magnitude and angle in 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. Specify P in the Active power generation P parameter of the block. Specify V in 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. Specify P and Q in the Active power generation P and Reactive power generation Q parameters of the block, respectively.

Active power generation P

Specify the desired active power generated by the source, in watts. This parameter is available if you specify Generator type as PV or PQ.

Reactive power generation Q

Specify the desired reactive power generated by the source, in vars. This parameter is available only if you specify Generator type as PQ.

Minimum reactive power Qmin

This parameter is available only if you specify Generator type as PV. This parameter indicates the minimum reactive power the source can generate while keeping the terminal voltage at its reference value. Specify the reference voltage as 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.

Maximum reactive power Qmax

This parameter is available only if you specify Generator type as PV. This parameter indicates the maximum reactive power the source can generate while keeping the terminal voltage at its reference value. Specify the reference voltage with 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.

Examples

The power_acvoltage example uses two AC Voltage Source blocks at different frequencies connected in series across a resistor. The sum of the two voltages is read by a Voltage Measurement block.

Introduced before R2006a

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