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ACIM Torque Estimator

Estimate electromechanical torque and power

Since R2020b

Libraries:
Motor Control Blockset / Controls / Control Reference
Motor Control Blockset HDL Support / Controls / Control Reference

Description

The ACIM Torque Estimator block generates electromechanical torque and power estimates for an induction motor. The block outputs the mathematically computed electromechanical torque for constant motor parameters. To measure an accurate torque value, we recommend that you use a physical sensor.

The block accepts feedback values of d- and q-axis stator current and mechanical speed as inputs.

Equations

If you select Per-Unit (PU) in the Input units parameter, the block converts the inputs to SI units before performing any computation. After calculating the output, the block converts the output back to per unit values.

These equations describe the computation of electromechanical torque and power estimates by the block.

Te=32p(LmLr)λrdisq

Pe=Teωm

For detailed set of equations and assumptions, see Mathematical Model of Induction Motor.

where:

  • p is the number of pole pairs available in the motor.

  • Lm is the magnetizing inductance of the motor (Henry).

  • Lr is the rotor inductance (Henry).

  • λrd is the d-axis flux linkage of the rotor (Weber).

  • isq is the stator q-axis current (Amperes).

  • ωm is the mechanical speed of the rotor (Radians/ sec).

Examples

Ports

Input

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Stator current along the d-axis of the rotating dq reference frame.

Data Types: single | double | fixed point

Stator current along the q-axis of the rotating dq reference frame.

Data Types: single | double | fixed point

Mechanical speed of the rotor.

Data Types: single | double | fixed point

Output

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Electromechanical torque of the rotor.

Data Types: single | double | fixed point

Electromechanical power of the rotor.

Data Types: single | double | fixed point

Parameters

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Number of pole pairs available in the induction motor.

Since R2025a

Motor parameters that the block uses to generate power and torque estimates. Set the parameter to one of these values:

  • Linear model with lumped parameters — Generate torque and power estimates using lumped circuit values for the machine inductances Ls ,Lr ,Lm , and the rated flux.

  • Non-linear model with D,Q-flux linkage LUTs — Generate torque and power estimates using d-axis and q-axis flux linkage lookup tables.

Inductance due to leakage flux linked to the stator winding (in Henry).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Linear model with lumped parameters.

Inductance due to leakage flux linked to the rotor winding (in Henry).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Linear model with lumped parameters.

Inductance due to the magnetizing flux (in Henry).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Linear model with lumped parameters.

Rated flux of the induction motor (in Weber).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Linear model with lumped parameters.

Since R2025a

The d-axis current lookup vector to use in the flux-linkage lookup tables (in percentage). The vector can have any number of elements.

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Non-linear model with D,Q-flux linkage LUTs.

Since R2025a

The q-axis current lookup vector to use in the flux-linkage lookup tables (in percentage). The vector can have any number of elements.

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Non-linear model with D,Q-flux linkage LUTs.

Since R2025a

The d-axis flux linkage lookup table data (in weber).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Non-linear model with D,Q-flux linkage LUTs.

Since R2025a

The q-axis flux linkage lookup table data (in weber).

Dependencies

To enable this parameter, set the Motor parameter input method parameter to Non-linear model with D,Q-flux linkage LUTs.

Unit of the input values.

Base voltage (in Volts) for per-unit system.

Dependencies

To enable this parameter, set Input units to Per-Unit (PU).

Base current (in Amperes) for per-unit system.

Dependencies

To enable this parameter, set Input units to Per-Unit (PU).

Base speed (in rpm) for per-unit system.

Dependencies

To enable this parameter, set Input units to Per-Unit (PU).

Base torque (in Nm) for per-unit system. See Per-Unit System page for more details.

This parameter is not configurable and uses a value that is internally computed using other parameters.

Dependencies

To display this parameter, set Input units to Per-Unit (PU).

Base power (in W) for per-unit system. See Per-Unit System page for more details.

This parameter is not configurable and uses a value that is internally computed using other parameters.

Dependencies

To display this parameter, set Input units to Per-Unit (PU).

Extended Capabilities

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

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced in R2020b

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