BLDC Motor Control using SPWM and FOC

Project overview

This project aims to control a 3-phase BLDC motor using an STM32F103C8T6 microcontroller. Initially, the motor will be driven using Sinusoidal Pulse Width Modulation (SPWM), with speed control via an ADC-connected potentiometer. Later, the project will implement Field-Oriented Control (FOC) for improved efficiency and performance.

Key Features

• SPWM-Based Motor Control: Generate three-phase sine wave signals using a precomputed sine table.

• Speed Control via ADC: Use a potentiometer to adjust motor speed by modifying the duty cycle of the SPWM signals.

• Hall Sensor Feedback: Utilize Hall sensors for accurate rotor position detection and proper commutation.

• Transition to FOC: Implement Field-Oriented Control for precise torque and speed regulation.

Components Needed

• STM32F103C8T6 Microcontroller: Main controller for generating SPWM and handling motor control logic.

• BLDC Motor with Hall Sensors: Three-phase motor with position feedback.

• MOSFET Driver Circuit: To drive the motor windings with appropriate PWM signals.

• Potentiometer: For adjusting motor speed via ADC input.

• Power Supply: Suitable voltage and current rating for the BLDC motor.

• Supporting Components: Resistors, capacitors, connectors, etc.

Project Plan

1. Set Up Development Environment

(i) Install vs code for firmware development.

(ii) Set up the STM32F103C8T6 development board.

2. Configure Hardware

(i) Connect the BLDC motor phases to the MOSFET driver circuit.

(ii) Attach Hall sensors to the STM32 for rotor position feedback.

(iii) Connect a potentiometer to an ADC pin for speed control.

3. Firmware Development

(i) Initialize Peripherals

• Configure timers for SPWM generation.
• Set up ADC for reading the potentiometer.
• Configure GPIOs for Hall sensor inputs.
• Setup Usart for debugging

(ii) Implement SPWM Control

• Use a sine wave lookup table to generate 3-phase PWM signals.
• Adjust duty cycle based on ADC input to control speed.

(iii) Hall Sensor-Based Commutation

• Read Hall sensor inputs to determine rotor position.
• Align SPWM signals with the correct commutation step.

4. Transition to FOC

• Implement Clarke and Park transformations for FOC.
• Use a PID controller for torque and speed regulation.
• Optimize performance by reducing torque ripple.

5. Testing and Validation

• Verify SPWM-based motor control and speed adjustment.
• Measure efficiency improvements after implementing FOC.
• Ensure smooth motor operation with minimal noise and vibration.

5. Future Enhancements

• Implement regenerative braking for energy recovery.
• Add closed-loop speed control using a feedback loop.