Compute Parameter

Extend functionality of blocks by enabling additional inputs

Since R2024a

• 

Libraries:
Motor Control Blockset / Signal Management

Description

The Compute Parameter block extends the functionality of compatible blocks available in the current model. The block customizes itself according to the settings of a compatible block and provides the parameters needed by the compatible block through either an output bus or multiple output signals.

You can use the Compute Parameter block parameters dialog box to select a compatible block by providing its relative path. The dialog box can also list the relative paths of all compatible blocks available in the current model, which you can then copy to the Relative path of compatible block that needs functional extension field in the dialog box.

For example, when you configure the Compute Parameter block to connect with Flux Observer block, the Compute Parameter block provides an output in the form of a bus. You can then connect this bus to the additional input port ParameterBus available in the Flux Observer block.

For the other compatible blocks, you can connect the Compute Parameter output signals to the corresponding additional input ports available in the compatible blocks.

Therefore, the block provides a functional extension to the compatible blocks by enabling them to accept parameter values at run-time. The block supports these compatible blocks:

• Flux Observer

• Quadrature Decoder

• I-F Controller

It is recommended that you run this block at a rate that is slower than the task rate of compatible block to minimize the computation load in hardware targets.

Examples

Swap Motors with Single Deployment of Sensorless FOC Algorithm

Run a permanent magnet synchronous motor (PMSM) in an industrial drive application setup using a sensorless field-oriented control (FOC) algorithm. The example uses a sensorless Flux Observer to estimate the motor position. Industrial drives enable you to replace a motor with a new one without repeated deployment of code. An industrial drive setup needs only nameplate parameters to adapt the software to the new motor.

• Open Example

Ports

Input

N_pp — Number of pole pairs available in motor

scalar

Number of pole pairs available in the motor.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer or I-F Controller block in the current model.

Data Types: single | double | fixed point

R — Stator winding resistance

scalar

Stator phase winding resistance of the motor (in ohms).

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

Data Types: single | double | fixed point

L_d — Stator winding inductance along d-axis

scalar

Stator winding inductance of the motor along the d-axis (in henries).

Dependencies

To enable this port:

• Set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

• Set the Motor selection parameter of the Flux Observer block to PMSM.

Data Types: single | double | fixed point

L_ls — Stator leakage inductance

scalar

Leakage inductance of the induction motor stator winding (in henries).

Dependencies

To enable this port:

• Set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

• Set the Motor selection parameter of the Flux Observer block to ACIM.

Data Types: single | double | fixed point

L_lr — Rotor leakage inductance

scalar

Leakage inductance of the induction motor rotor winding (in henries).

Dependencies

To enable this port:

• Set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

• Set the Motor selection parameter of the Flux Observer block to ACIM.

Data Types: single | double | fixed point

L_m — Magnetizing inductance of induction motor

scalar

Magnetizing inductance of the induction motor (in henries).

Dependencies

To enable this port:

• Set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

• Set the Motor selection parameter of the Flux Observer block to ACIM.

Data Types: single | double | fixed point

f_cutoff — Cutoff frequency of internal highpass filter

scalar

Cutoff frequency (in hertz) of the internal highpass filter that filters noise.

The Flux Observer block uses an internal first-order IIR highpass filter. Specify a frequency at this port that is lower than the lowest frequency corresponding to the minimum speed of the motor. For example, you can enter a value that is one-tenth of the lowest electrical frequency of the stator voltages and currents. You can adjust the value you specify at this port to determine a more accurate cutoff frequency that generates the desired block output.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Flux Observer block in the current model.

Data Types: single | double | fixed point

NumSlits — Number of slits per phase

scalar

The number of slits available in each phase of the quadrature encoder.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Quadrature Decoder block in the current model.

Data Types: single | double | fixed point

CountsPerSlit — Number of counts generated for every slit

scalar

The number of counts that the quadrature encoder generates for every slit. A count indicates a slit position. For example, set this port to 4 (quadrature mode) if you want the encoder to generate four counts corresponding to 00, 10, 11, and 01 slit positions or values. If you select the quadrature mode:

Encoder counts per revolution (post-quadrature) = Encoder counts per slit ✖ Encoder slits

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Quadrature Decoder block in the current model.

Data Types: single | double | fixed point

ω₁ (RPM) — Speed (after motor starts) at which I-F control stops

scalar

Speed (after motor starts) until which the I-F controller remains active (in RPM). When the motor speed exceeds this value, the I-F controller becomes inactive and the Status block output turns true.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

ω₂ (RPM) — Speed required to re-enter I-F control

scalar

After exiting I-F control (and entering closed-loop control), speed required to reactivate the I-F controller (in RPM). When the motor speed falls below this value, the I-F controller becomes active again and the Status block output turns false.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

Imax (A) — Maximum motor current during I-F control

scalar

Maximum current (in amperes) that is supplied to the motor when I-F control is active.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

Max(Δω/Δt) (RPM/s) — Maximum rate of speed change during I-F control

scalar

Maximum rate at which motor speed can change (in RPM/s) when I-F control is active.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

I_DecayRate (A/s) — Maximum rate of current decay during I-F control

scalar

Maximum rate at which motor current can decay (in amperes/s) when I-F control is active.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

T_Idle (s) — Time of constant speed and current

scalar

Time (in seconds) during which both motor speed and current remains constant when I-F control is active.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

ζ — Speed oscillation damping coefficient value

scalar

Value of the speed oscillation damping coefficient that the I-F Controller block should use.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the I-F Controller block in the current model.

Data Types: single | double | fixed point

Output

ParameterBus — Computed parameters for flux observer and I-F controller

bus

Computed parameters for the Flux Observer and I-F Controller blocks.

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of either the Flux Observer or the I-F Controller block in the current model.

Data Types: single

CountsPerRev — Number of counts per revolution

scalar

Number of counts the quadrature encoder generates for each revolution.

CountsPerRev = Encoder slits ⨯ Encoder counts per slit

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Quadrature Decoder block in the current model.

Data Types: single

1/CountsPerRev — Inverse of number of counts per revolution

scalar

The block outputs the inverse of the number of counts the quadrature encoder generates for each revolution at this port.

1/CountsPerRev = 1/(Encoder slits ⨯ Encoder counts per slit)

Dependencies

To enable this port, set the Relative path of compatible block that needs functional extension parameter to indicate the relative path of the Quadrature Decoder block in the current model.

Data Types: single

Parameters

Relative path of compatible block that needs functional extension — Relative path of compatible block

blank (default) | string

Relative path of the compatible block from the current model that needs functional extension.

Get a list of supported block paths in the model — Obtain list of compatible block paths

button

Click this button to obtain a list of relative paths of all compatible blocks in the current model. The block displays this list in the Supported block paths section.

Copy and paste the relevant path from the list in the Relative path of compatible block that needs functional extension parameter to configure this block.

Supported block paths — List of compatible block paths

display cell

This section displays the list of relative paths of the compatible blocks in the current model.

Extended Capabilities

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

Version History

Introduced in R2024a