# Power (Phasor)

Compute active and reactive powers using voltage and current phasors

## Library

Control and Measurements/Measurements

## Description

The Power (Phasor) block computes the active power P and reactive power Q of a pair of voltage-current signals. P and Q are computed as follows:

`$P+jQ=\frac{1}{2}\left(V×{I}^{\ast }\right)$`

I* = complex conjugate of I.

Sign conventions are defined as

## Dialog Box and Parameters

The block has no parameters.

## Inputs and Outputs

`V`

The phasor (complex signal) voltage, in volts peak.

`I`

The phasor (complex signal) current, in amperes peak.

`P`

Returns the active power, in watts.

`Q`

Returns the active power, in vars.

## Characteristics

 Direct Feedthrough Yes Dimensionalized Yes

## Example

The `power_PhasorPowerMeasurements` example shows the use of the Power (Phasor) block.