Flux Observer

Compute electrical position, magnetic flux, and electrical torque of rotor

  • Library:
  • Motor Control Blockset / Sensorless Estimators

Description

The Flux Observer block computes the electrical position, magnetic flux, and electrical torque of a PMSM by using the per unit voltage and current values along the α- and β-axes in the stationary αβ reference frame.

Equations

These equations describe the computation of the electrical position, magnetic flux, and electrical torque by the block.

ψ1α= (VαIαR)dt

ψ1β= (VβIβR)dt

ψ= ψ1α2+ψ1β2

Te=32P(ψ1αIβψ1βIα)

θe tan1ψ1βψ1α

where:

  • Vα and Vβ are the α-axis and β-axis voltages.

  • Iα and Iβ are the α-axis and β-axis current.

  • R is the stator resistance of the motor.

  • P is the number of motor pole pairs.

  • ψ is the magnetic stator flux.

  • Te is the electrical torque of the rotor.

  • θe is the electrical position of the rotor.

Ports

Input

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Voltage component along the α-axis in the stationary αβ reference frame.

Data Types: single | double | fixed point

Voltage component along the β-axis in the stationary αβ reference frame.

Data Types: single | double | fixed point

Current along the α-axis in the stationary αβ reference frame.

Data Types: single | double | fixed point

Current along the β-axis in the stationary αβ reference frame.

Data Types: single | double | fixed point

The pulse (true value) that resets the block algorithm.

Data Types: single | double | fixed point

Output

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The electrical position of the rotor as estimated by the block.

Dependencies

To enable this port, set Block output to Position.

Data Types: single | double | fixed point

The magnetic flux of the rotor as estimated by the block.

Dependencies

To enable this port, set Block output to Flux.

Data Types: single | double | fixed point

The electrical torque of the rotor as estimated by the block.

Dependencies

To enable this port, set Block output to Torque.

Data Types: single | double | fixed point

Parameters

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Motor parameters

Select the unit of the α and β-axes voltage and current input values.

Select one or more quantities that the block should compute and display in the block output.

Note

You must select at least one value. The block displays an error message if you click Ok or Apply without selecting any value.

Number of pole pairs available in the motor.

Dependencies

To enable this parameter, set Block output to Torque.

Stator phase winding resistance of the motor in ohms.

The fixed time interval in seconds between two consecutive instances of block execution.

Datatypes

Unit of the electrical position output.

Dependencies

To enable this parameter, set Block output to Position.

Data type of the electrical position output.

Dependencies

To enable this parameter, set Block output to Position.

Unit of the magnetic flux output.

Dependencies

To enable this parameter, set Block output to Flux.

Data type of the magnetic flux output.

Dependencies

To enable this parameter, set Block output to Flux.

Unit of the electrical torque output.

Dependencies

To enable this parameter, set Block output to Torque.

Data type of the electrical torque output.

Dependencies

To enable this parameter, set Block output to Torque.

References

[1] O. Sandre-Hernandez, J. J. Rangel-Magdaleno and R. Morales-Caporal, "Simulink-HDL cosimulation of direct torque control of a PM synchronous machine based FPGA," 2014 11th International Conference on Electrical Engineering, Computing Science and Automatic Control (CCE), Campeche, 2014, pp. 1-6. (doi: 10.1109/ICEEE.2014.6978298)

[2] Y. Inoue, S. Morimoto and M. Sanada, "Control method suitable for direct torque control based motor drive system satisfying voltage and current limitations," The 2010 International Power Electronics Conference - ECCE ASIA -, Sapporo, 2010, pp. 3000-3006. (doi: 10.1109/IPEC.2010.5543698)

Introduced in R2020a