Documentation

Asynchronous Machine Measurement

Per-unit measurement from asynchronous machine

Library

Machines

Description

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

You set the Output parameter to a per-unit measurement associated with the asynchronous machine. Based on the value you select, the Asynchronous 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 Asynchronous Machine Measurement block outputs a per-unit measurement from the asynchronous 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

pu_Pt2+pu_Qt2

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

pu_vds2+pu_vqs2

Terminal current

pu_ids2+pu_iqs2

Power factor angle (rad)

power_factor_angle = atan2(pu_Qt, pu_Pt)

Power factor

cos(power_factor_angle)

Parameters

Output

Per-unit measurement from asynchronous machine. The default value is Electrical torque.

Ports

The block has the following ports:

pu

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

  • pu_torque

  • pu_velocity

  • pu_vds

  • pu_vqs

  • pu_v0s

  • pu_ids

  • pu_iqs

  • pu_i0s

o

Per-unit measurement output port.

Introduced in R2013b

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