Position Generator

Generate position ramp of fixed frequency

• Library:

• Motor Control Blockset / Controls / Control Reference

• 

Description

The Position Generator block generates a position ramp signal (with a frequency that is identical to that of the reference voltage signal) using the position increment value of the reference signal.

We recommend that you use fixed-step discrete solver for this block to enable code generation and ensure accurate simulation.

Ports

Input

∆θ — Position increment value

scalar

Position increment value of a fixed frequency reference voltage signal (in either per unit, radians, or degrees). These equations describe how the block computes the position increment:

• $$\Delta \theta \text{ (per unit) }=\text{ Frequency }\times \text{ Sample Time}$$

• $$\Delta \theta \text{ (radians) }=\text{ 2}\pi \times \text{ Frequency }\times \text{ Sample Time}$$

• $$\Delta \theta \text{ (degrees) }=\text{ 360}\times \text{ Frequency }\times \text{ Sample Time}$$

Data Types: single | double | fixed point

Reset — External reset signal

scalar

External pulse that resets the position ramp output based on the value of the External reset parameter.

Dependencies

To enable this port, set External reset to either active high resets to zero or active high resets to initial condition.

Data Types: single | double | fixed point

Output

θe — Reference voltage position

scalar

Position or phase value of the reference voltage signal (in either per unit, radians, or degrees).

Data Types: single | double | fixed point

Parameters

Theta Units — Unit of θ

Per-unit (default) | Radians | Degrees

Unit of the input position increment value and the output reference voltage position.

Initial theta output — Initial value of θe

0 (default) | scalar

Output position ramp value (in either per unit, radians, or degrees) at initial time (0 seconds).

External reset — Output value on reset

none (default) | active high resets to zero | active high resets to initial condition

Output position ramp value (in either per unit, radians, or degrees) at the time when the block receives an active high external reset pulse. You can reset the output to either zero or to equal the value of the Initial theta output parameter.

Model Examples

Sensorless Field-Oriented Control of PMSM

Implements the field-oriented control (FOC) technique to control the speed of a three-phase permanent magnet synchronous motor (PMSM). For details about FOC, see Field-Oriented Control (FOC).

Run 3-Phase AC Motors in Open-Loop Control and Calibrate ADC Offset

Uses open-loop control (also known as scalar control or Volts/Hz control) to run a motor. This technique varies the stator voltage and frequency to control the rotor speed without using any feedback from the motor. You can use this technique to check the integrity of the hardware connections. A constant speed application of open-loop control uses a fixed-frequency motor power supply. An adjustable speed application of open-loop control needs a variable-frequency power supply to control the rotor speed. To ensure a constant stator magnetic flux, keep the supply voltage amplitude proportional to its frequency.

Field-Oriented Control of Induction Motor Using Speed Sensor

Implements the field-oriented control (FOC) technique to control the speed of a three-phase AC induction motor (ACIM). The FOC algorithm requires rotor speed feedback, which is obtained in this example by using a quadrature encoder sensor. For details about FOC, see Field-Oriented Control (FOC).

Field-Weakening Control (with MTPA) of PMSM

Implements the field-oriented control (FOC) technique to control the torque and speed of a three-phase permanent magnet synchronous motor (PMSM). The FOC algorithm requires rotor position feedback, which is obtained by a quadrature encoder sensor. For details about FOC, see Field-Oriented Control (FOC).

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™.