Induction Machine Measurement

Per-unit measurement from induction machine

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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 Setting	Output 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 (rad)	power_factor_angle = atan2(pu_Qt, pu_Pt)
Power factor	cos(power_factor_angle)

Examples

Three-Phase Asynchronous Machine Starting

Model a wye-delta starting circuit for an induction machine. When the supply is connected to the machine via switch S1, switch S2 is initially off resulting in the machine being connected in a wye configuration. Once the machine is close to synchronous speed, switch S2 is operated thereby reconnecting the machine in a delta configuration. The higher impedance seen by the supply when the motor is in wye configuration reduces the starting current, and causes less disruption to other connected loads.

• Open Model

Ports

Input

pu — Input port

physical

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

o — Per-unit measurement output

physical

Physical signal associated with the per-unit measurement output.

Parameters

Output — Per-unit measurement

Electrical torque (default) | 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

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

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2013b