VbyF Controller

R2026b

Implement V/F (open-loop or scalar) control for three-phase motors

Since R2023b

• 

VbyF Controller block

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Libraries:
Motor Control Blockset / Control / Induction Machine / Controllers
Motor Control Blockset / Control / Synchronous Machine / Controllers

Description

The VbyF Controller block implements V/F (open-loop or scalar) control for a three-phase permanent magnet synchronous motor (PMSM) or an AC induction motor (ACIM).

You can specify reference speed, motor rated speed, number of motor pole pairs, motor rated voltage, minimum block output voltage, and number of discrete time steps for initial ramp up via the block parameters dialog (default) or as input ports by setting the Parameters input method parameter to Input ports.

When you start up the motor, the block uses the N_Ramp input to identify the number of block samples that it needs to gradually ramp up the motor speed to the reference speed.

$$N_{Ramp}=\frac{T_{ramp}}{Discretestepsize(s)}$$

The block's output voltage amplitude varies according to the reference motor speed (ω_ref), while keeping the ratio of rated voltage to rated frequency constant.

$$V_{abc\_amplitude}= \left(\frac{V_{rated}}{f_{rated}}\right)f^{ref}=\left(\frac{V_{rated}}{{\omega }_{rated}}\right){\omega }_{ref}$$

where:

• V_{abc_amplitude} is the amplitude of the output voltage V_abc.

• V_rated is the amplitude of rated phase voltage of the motor.

• f_rated is the rated frequency of the motor.

• f^ref is the reference frequency of the motor.

• ω_rated is the rated speed of the motor.

• ω_ref is the reference speed of the motor.

The V/F control technique does not require any feedback from the motor. This control technique ensures a constant stator magnetic flux by keeping the motor phase voltage proportional to its frequency. For more information about this technique, see Open-Loop Motor Control.

Note

• It is recommended that you use this block to start the motor and run it at lower speeds and then switch to other control methods, such as field-oriented control (FOC), to operate the motor at higher speeds.

• If you specify 16-bit fixed-point inputs, the block might not produce an accurate output due to insufficient resolution.

Examples

Swap Motors with Single Model Deployment of Sensor-Based FOC Algorithm

Run a permanent magnet synchronous motor (PMSM) in an industrial drive application setup using position-sensor-based field-oriented control (FOC). Industrial drives enable you to swap motors in real-time without repeated deployment of code. An industrial drive setup needs a fixed inverter and software that has the ability to adapt the control algorithm according to the new motor using only the updated nameplate parameters.

• Open Example

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

Generate Motor Control Models for Selected Algorithm and Hardware

Use Motor Control Blockset™ to generate a Simulink® model that is configured for a specific hardware and motor control technique.

• Open Live Script

Estimate Battery Current of PMSM in Open-Loop Control Using Arduino Hardware

Use Simulink® Support Package for Arduino® Hardware to estimate the battery current of a permanent magnet synchronous machine (PMSM) in open-loop control using Motor Control Blockset™. This example also shows how to actuate a PMSM motor and calculate phase currents that are indirectly used to estimate the current of the battery.

Ports

Input

ω_m^ref — Reference speed

scalar

Reference mechanical speed for V/F control.

Data Types: single | double | fixed point

ω_m^rated — Motor rated speed

scalar

Rated mechanical speed of the motor.

Dependencies

To enable this port, set Parameters input method to Input ports.

Data Types: single | double | fixed point

N_pp — Number of motor pole pairs

scalar

Number of pole pairs available in the three-phase motor.

Dependencies

To enable this port, set Parameters input method to Input ports.

Data Types: single | double | fixed point | uint | int

V_rated — Rated phase voltage amplitude of motor

scalar

Amplitude (peak value) of the rated phase voltage of the motor corresponding to the rated speed of the motor.

Dependencies

To enable this port, set Parameters input method to Input ports.

Data Types: single | double | fixed point

V_min — Minimum output voltage

scalar

Minimum amplitude (peak value) of the block output voltage that should be applied to the motor.

Dependencies

To enable this port, set Parameters input method to Input ports.

Data Types: single | double | fixed point

N_Ramp — Steps for initial ramp up

scalar

Number of discrete time steps used for initial ramp up of motor speed.

Dependencies

To enable this port, set Parameters input method to Input ports.

Data Types: uint

Enable — Enable block outputs

scalar

Signal that enables block outputs:

• 1 — Enables block outputs.

• 0 — Reset internal integrators.

Changing the Enable signal value from 1 to 0 stops the V/F control being implemented using internal integrators; however, the V_abc output of the block may retain the previously calculated value.

Data Types: single | double | fixed point

Output

V_abc — Motor phase voltages

vector

Stator phase a, b, and c voltages that drive the motor.

Data Types: single | double | fixed point

θ_e — Estimated rotor electrical position

scalar

Estimated rotor electrical position, in per-unit.

Dependencies

To enable this port, select the Output electrical position (PU) parameter.

Data Types: single | double | fixed point

Parameters

Speed unit — Unit of the speed inputs

RPM (default) | Radians/Sec | Degrees/Sec | Per unit based on dialog

Units of the ω_m^ref and ω_m^rated inputs.

Select Per unit based on dialog to use per-unit system for the two speed inputs. For more information about the per-unit system, see Per-Unit System.

Per unit speed (RPM) — Base speed of the motor for per-unit computations

1200 (default) | scalar

Rated speed of the motor (in rpm) that the block uses in the per-unit computations. For more information about the per-unit system, see Per-Unit System.

Dependencies

To enable this parameter, set Speed unit to Per unit based on dialog.

Discrete step size (s) (-1 for inherit) — Sample time after which block executes again

50e-6 (default) | scalar

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

Parameters input method — Method for providing motor parameters to the block

Specify via dialog (default) | Input ports

Method by which you provide motor parameters to the block.

• Specify via dialog — Specify motor parameters using the block parameters dialog. The block exposes two input ports: ω_m^ref and Enable.

• Input ports — Provide motor parameters through input ports. The block exposes seven input ports: ω_m^ref, ω_m^rated, N_pp, V_rated, V_min, N_Ramp, and Enable.

Rated Speed (RPM) — Rated mechanical speed of the motor

4000 (default) | scalar

Rated mechanical speed of the motor, in RPM.

Dependencies

To enable this parameter, set Parameters input method to Specify via dialog.

Pole-pairs — Number of motor pole pairs

4 (default) | scalar

Number of pole pairs in the three-phase motor.

Dependencies

To enable this parameter, set Parameters input method to Specify via dialog.

Rated Voltage (V) — Amplitude of rated phase voltage of the motor

24 (default) | scalar

Amplitude (peak value) of the rated phase voltage of the motor corresponding to the rated speed, in volts.

Dependencies

To enable this parameter, set Parameters input method to Specify via dialog.

Minimum Voltage (V) — Minimum output voltage amplitude of the block

2.4 (default) | scalar

Minimum amplitude (peak value) of the block output voltage applied to the motor, in volts.

Dependencies

To enable this parameter, set Parameters input method to Specify via dialog.

Initial speed ramp count (Nramp) — Number of steps for initial speed ramp-up

40000 (default) | scalar

Number of discrete time steps that the block uses for the initial ramp-up of motor speed at startup.

Dependencies

To enable this parameter, set Parameters input method to Specify via dialog.

Output electrical position (PU) — Enable the electrical position output port

off (default) | on

Select this parameter to enable the θ_e output port, which provides the estimated rotor electrical position in per-unit.

Reference speed limit mode — Method for limiting the reference speed input

Acceleration limit (default) | Disabled | Lowpass filter

Method that the block applies to limit the rate of change of the reference speed input.

• Disabled — No speed reference limiting is applied.

• Lowpass filter — The block applies an IIR lowpass filter to the reference speed input.

• Acceleration limit — The block limits the rate of speed change to the value specified by the Acceleration limit (RPM/sample) parameter.

Acceleration limit — Maximum rate of change of reference speed per sample

2000 (default) | scalar

Since R2026b

Maximum allowable rate of change of the reference speed per sample. The unit of this parameter matches the unit selected in Speed unit.

Dependencies

To enable this parameter, set Reference speed limit mode to Acceleration limit.

Filter coefficient value — IIR lowpass filter coefficient for reference speed limiting

0.0001 (default) | scalar

Since R2026b

Coefficient of the IIR lowpass filter that the block applies to the reference speed input.

Dependencies

To enable this parameter, set Reference speed limit mode to Lowpass filter.

Extended Capabilities

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™.

Restrictions

If you specify 16-bit fixed-point inputs, the block might not produce an accurate output due to insufficient resolution.

Version History

Introduced in R2023b

R2026b: Block enhancements for reference speed limiting and filter configuration

The block includes the following enhancements:

• The Acceleration limit parameter now uses the same unit as the Speed unit parameter.

• A new Filter coefficient value parameter is available when you set Reference speed limit mode to Lowpass filter. Use this parameter to configure the IIR lowpass filter coefficient for the reference speed input.