# Induction Machine Measurement

Per-unit measurement from induction machine

Libraries:
Simscape / Electrical / Electromechanical / Asynchronous

## Description

The Induction Machine Measurement block outputs a per-unit measurement associated with a connected Induction Machine Squirrel Cage or Induction Machine Wound Rotor block. The input of the Induction Machine Measurement block connects to the pu output port of the induction machine block.

You set the Output parameter to a per-unit measurement associated with the induction machine. Based on the value you select, the Induction Machine Measurement block:

• Directly outputs the value of an element in the input signal vector

• Calculates the per-unit measurement by using values of elements in the input signal vector in mathematical expressions

The Induction Machine Measurement block outputs a per-unit measurement from the induction machine according to the output value expressions in the table. For example, when you set Output to Stator d-axis voltage, the block directly outputs the value of the pu_vds element in the input signal vector. However, when you set Output to Slip, the block calculates the slip value by subtracting the value of the pu_velocity element from 1.

Output Parameter SettingOutput Value Expression

Electrical torque

pu_torque

Rotor velocity

pu_velocity

Stator d-axis voltage

pu_vds

Stator q-axis voltage

pu_vqs

Stator zero-sequence voltage

pu_v0s

Stator d-axis current

pu_ids

Stator q-axis current

pu_iqs

Stator zero-sequence current

pu_i0s

Slip

1-pu_velocity

Apparent power

$\sqrt{pu_P{t}^{2}+pu_Q{t}^{2}}$

Real power

pu_Pt = (pu_vds*pu_ids) + (pu_vqs*pu_iqs) + 2(pu_v0s*pu_i0s)

Reactive power

pu_Qt = (pu_vqs*pu_ids) – (pu_vds*pu_iqs)

Terminal voltage

$\sqrt{pu_vd{s}^{2}+pu_vq{s}^{2}}$

Terminal current

$\sqrt{pu_id{s}^{2}+pu_iq{s}^{2}}$

power_factor_angle = atan2(pu_Qt, pu_Pt)

Power factor

cos(power_factor_angle)

## Ports

### Input

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Physical signal vector associated with per-unit measurements from a connected induction machine. The vector elements are:

• pu_torque

• pu_velocity

• pu_vds

• pu_vqs

• pu_v0s

• pu_ids

• pu_iqs

• pu_i0s

### Output

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Physical signal associated with the per-unit measurement output.

## Parameters

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Per-unit measurement from induction machine. Options are:

• Electrical torque

• Rotor velocity

• Stator d-axis voltage

• Stator q-axis voltage

• Stator zero-sequence voltage

• Stator d-axis current

• Stator q-axis current

• Stator zero-sequence current

• Slip

• Apparent power

• Real power

• Reactive power

• Terminal voltage

• Power factor angle

• Power factor angle

## Version History

Introduced in R2013b