Documentation

Velocity Controller

Discrete-time velocity controller

  • Library:
  • Simscape / Power Systems / Simscape Components / Control / General Machine Control

Description

The Velocity Controller block implements a velocity controller in discrete-time.

You provide measured and reference rotor velocities (w and wref) as inputs to the block. The block then outputs a reference torque Tref to be given to an electric drive.

To prevent windup in the integrator, feed the saturated reference torque Tref_sat from the electric drive back to the velocity controller.

Equations

You can control the rotor angular velocity with discrete sample time Ts using one of three common approaches:

  • Proportional-integral (PI) control, with proportional and integral gains Kp_w and Ki_w:

    Tref=(Kp_w+Ki_wTszz1)(wrefw)

  • Proportional (P) control, with proportional gain Kp_w:

    Tref=Kp_w(wrefw)

  • P-PI control characterized by a double velocity feedback loop as shown in the following figure:

    Here, the PI Controller block is structured as in the PI control strategy, and Kv is the proportional gain for a P controller.

Ports

Input

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Desired or reference velocity, in rad/s.

Data Types: single | double

Measured mechanical velocity, in rad/s.

Data Types: single | double

Saturated torque reference used for integral anti-windup gain, in N*m.

Data Types: single | double

External reset signal (rising edge) for the integrator.

Data Types: single | double

Output

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Unsaturated reference torque, in N*m.

Data Types: single | double

Parameters

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Type of controller.

Proportional gain of PI or P controller.

Integral gain of PI controller.

Dependencies

This parameter is enabled when the Control type is set to PI control or P-PI control.

Proportional gain of P controller.

Dependencies

This parameter is enabled when the Control type is set to P-PI control.

Anti-windup gain of PI controller.

Dependencies

This parameter is enabled when the Control type is set to PI control or P-PI control.

Time interval between samples. If the block is inside a triggered subsystem, inherit the sample time by setting this parameter to -1. If this block is in a continuous variable-step model, specify the sample time explicitly. For more information, see What Is Sample Time? (Simulink) and Specify Sample Time (Simulink).

Specify the discretization sample time when the zero-cancellation is active and simulation sample time is set to -1.

Dependencies

This parameter is enabled when:

  • Control type is set to PI control or P-PI control.

  • Sample time is set to -1.

Enable or disable zero-cancellation on the feedforward path.

Dependencies

This parameter is enabled when the Control type is set to PI control or P-PI control.

Model Examples

References

[1] Naouar, M. W., A. A. Naassani, E. Monmasson, and I. Slama-Belkhodja. "FPGA-based predictive current controller for synchronous machine speed drive." IEEE Transactions on Power Electronics. Vol. 23, Number 4, 2008, pp. 2115–2126.

Introduced in R2017b

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