Speed Control System for BLDC Motors in Simulink

Project Overview

This project focuses on designing and simulating a speed control system for Brushless DC (BLDC) motors using MATLAB Simulink. The system uses a Permanent Magnet Synchronous Machine (PMSM) with a trapezoidal back-EMF and Hall sensors to achieve precise motor control.

Components Used

• Switching Logic Circuit
• Add Block
• Permanent Magnet Synchronous Machine (PMSM) with trapezoidal back-EMF and Hall sensors
• Bus Selector
• Scopes for Output
• Constant Input
• Gain Block
• PWM Drive Circuit
• 3-Phase PWM Inverter
• PID Controller
• MOSFET
• Power GUI (Discrete)
• DC Voltage Supply

Steps Followed

1. Select Permanent Magnet Synchronous Machine (PMSM):

   • Modify the back electromotive force (EMF) to a trapezoidal waveform.
   • Set the number of phases to 3.
   • Use a bus selector to monitor the output.

2. Configure Bus Selector for PMSM Parameters:

   • Access and monitor parameters like rotor speed, current, and voltage.

3. Switching Block for Hall Sensor Signals:

   • Process the three digital signals from the Hall sensors.
   • Generate three logic signals for the PWM drive circuit.

4. PWM Drive Circuit:

   • Convert logic signals into six device driving signals.
   • Control the three-phase inverter.

5. Three-Phase Inverter:

   • Convert DC power to three-phase AC power.

6. PID Control:

   • Use rotor speed as feedback.
   • Compare feedback with desired speed and calculate the error signal.
   • Use a PID controller to maintain the desired speed.

7. Connect PID Output to PWM Drive Circuit:

   • Adjust the six device driving signals in real-time.

Circuit Diagram

Subsystems

Switching Logic Circuit

PWM Drive Circuit

Results

When the rotor speed is set to 20 rad/s..