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# Sequence Analyzer (Phasor)

Compute sequence components (positive, negative, and zero) of three-phase phasor signal

## Library

Control and Measurements/Measurements

## Description

The Sequence Analyzer (Phasor) block computes the three-sequence phasor components (positive sequence u1, negative sequence u2, and zero sequence u0) of a three-phase phasor signal as follows:

$\left[\begin{array}{c}{u}_{1}\\ {u}_{2}\\ {u}_{0}\end{array}\right]=\frac{1}{3}\left[\begin{array}{ccc}1& a& {a}^{2}\\ 1& {a}^{2}& a\\ 1& 1& 1\end{array}\right]\left[\begin{array}{c}{u}_{a}\\ {u}_{b}\\ {u}_{c}\end{array}\right]$

where $\alpha$ is the complex operator performing a 2$\pi /3$ rotation:

$a={e}^{\frac{j2\pi }{3}}$

## Dialog Box and Parameters

Sequence

Select the sequence components: Positive, Negative, Zero, or all three sequences Positive, Negative, and Zero.

## Inputs and Outputs

abc

The three-phase phasor signal [ua ub uc].

mag u

Returns the magnitude of the selected sequence phasor component.

angle u

Returns the angle, in degrees, of the selected sequence phasor component.

## Characteristics

 Direct Feedthrough Yes Dimensionalized No

## Example

The power_PhasorMeasurementspower_PhasorMeasurements example shows the use of the Sequence Analyzer (Phasor) block.