BLDC Motor Speed Control Project: Electrical Engineering

This report details a project focused on the speed control of a Brushless DC (BLDC) motor using a microcontroller. The project, conducted at YMCA University of Science and Technology, involved studying the characteristics of BLDC motors, particularly those with external permanent magnet rotors and three-phase driving coils. The primary objective was to develop a low-cost microcontroller-based speed control system using closed-loop control methods. The author, an Electrical Engineer, utilized an 8051 family microcontroller, a rectified power supply, and components like photodiode-IR transmitter sets and a matrix keypad for speed management. The project involved detailed analysis of motor operation, the application of PWM techniques, and the identification and resolution of issues related to motor rotation. The report highlights the engineering knowledge and skills applied, including the understanding of microcontrollers, PWM, and various control methods for BLDC motors, and also discusses collaborative work and future innovative plans.

Competency Demonstration Report
Career Episode 3

CE 3.1 Project Information
Name of the project: Study and project work on Brushless DC motor Speed Control
using Microcontroller
Location of the project: Faridabad, Haryana
Project Duration: Jan 2009-June 2009
Organization: YMCA University of Science and Technology
Role and Designation during the time: Electrical Engineer
CE 3.2 Project Background
CE 3.2.1 Characteristics of the project
I had conducted this particular venture work to study on Brushless DC motor (BLDC)
Speed Control using Microcontroller. Three phase BLDC motors that are controlled with use of
full bridge transistor based circuits are analyzed. BLDC motor is used of permanent magnet
external rotor, three phases of driving coils plus devices for Hall Effect which are used to sense
the rotor position. BLDC motor is driven of system that has permanent magnet wound up to
synchronous motor is being supplied with diverse frequency inverter restricted by shaft situation
sensor. I had described BLDC with distributed winding as well as particular form of PM-rotor by
means of particular stator margin. I had developed of speed management for BLDC motor by
utilize of closed loop manage method. I had use of rectified-power supply as well as 8051 family
microcontroller to control the speed.

CE 3.2.2 Objectives developed for the project
Following are the objectives of this project study:
 To study on low cost microcontroller based speed control of BLDC motor
 To manage three phase BLDC motor using full bridge transistor based circuits
 To describe BLDC motor with distributed winding and PM-rotor
 To develop speed control system for BLDC motor by closed loop control method
CE 3.2.3 My area of work
I had used a rectified power supply as well as microcontroller to design the Brushless
DC motor Speed Control. I had counted the number of rotations of motor a set of photodiode as
well as IR transmitter which are connected to the microcontroller. I had connected a matrix
keypad in order to manage the speed of motor. Optocoupler is to be associated in order to trigger
MOSFET to drive BLDC motor that is duly interfaced to microcontroller. I had started to choose
perfect kind of microcontroller for this particular project. I had also ensured that I had not
deviated from my scope of work. I had started to work on project report to prepare the
documentation once it was finished.

Dr. Dinesh Kumar
(Vice Chancellor)
Mr. Ashok Arora
(Dean of the Department)
Mr. Nitin Goyal
(Project Instructor and HOD)
Ruchi Verma
(B.tech Student)
CE 3.2.4 Project Group
Figure 1: People involved in the project
CE 3.2.5 My responsibilities throughout the project
I had duty to choose of correct kind of microcontroller for controlling the speed of BLDC
motor. I had studied about application of resistance, relays, rectifiers and filters. I had analyzed
as well as studied the modules of transmitter and infrared LED. I had conducted a detailed study
and analyzed the type of crystal oscillators that are used as converter. I had understood various
operational modes which are existing into BLDC motor as well as collection of proper operating
mode.

CE 3.3 Distinctive Activity
CE 3.3.1 Comprehending the Theory of the project
BLDC motor is a DC motor that is curved within out, such that the field is on the rotor as
well as armature is on stator. It is a type of DC motor, permanent magnet AC motor that
characteristics of existing take off the DC motor. I had used of electronic commutation for
conducting this project work. I had used some of the components for implementing the project
such as BLDC motor, inverter, microcontroller and hall sensors. I had used of different control
measures for BLDC motor. I had focused on two of the methods: sensor less as well as sensor
based control. The sensors are utilized for controlling the speed of machine, current location of
rotor required to conclude the interaction intervals. I had also used of PWM method to control
speed of motor. Within the DC motor, electronic switches are doing the commutation and pre-
programmed commutation interval is defined to fro brushless DC motor. This particular project
is dealt with control method in order to reduce speed of oscillations. I had conducted all the work
with use of microcontroller programming.
I had analyzed that there are various modes of working are obtainable and they are
applied to regulate single or dual brushed DC motors. I had determined that rating of current is
varied with cooling as well as without cooling, and the varied value is 3A to 4.5A respectively. I
had observed that recommended motor has a working range between 6-24V. There is a direct
control on speed as well as direction into serial model of operations. I had controlled speed and
direction of the motor coupled together. I had estimated that PWM step limit (1-225) as well as
dead band is controlled by user.

Figure 2: BLDC motor transverse section
CE 3.3.2 Engineering Knowledge and Skills applied in the project
I have deeper considerate of 8051 microcontroller as well as PWM technique for
controlling the operation of brushless DC motor. I have knowledge to analyze model of
microcontroller from 8000 series to determine which will be suitable for the project work. I had
researched different brushless DC motor and go through various models for conducting work. I
had also known what details should require to provide to third party to accelerate power as well
as speed of the BLDC motor. It resulted to increase the flux value of the motor winding and
provide a significant impact on flux value of rotor that controls the device.
CE 3.3.3 Accomplishment and task performed
Within the analog control mode, I had possessed control over speed as well as direction
of the BLDC motor. I had taken help of different control voltages so that I could able to control
the speed and direction of the motor. I had determined that accepted input voltage ranges were to
be 0-5V. I had analyzed that there is a dead band situated approximately 2.5V, with 0V as full

speed turn around as well as 5V as full speed forward. I had used of R/C control mode to control
speed and direction. I had accepted that the pulse range is 0.5-2.5ms. It is determined that the
dead-band is around 1.5ms and proportional reverse speed control is being provided by down
pulse of 1ms. I had pulsed of around 2ms offer forward speed control. I had determined that full
speed forward pulses are from 2ms to 2.5ms as well as full speed reversed pulses are from 1ms
to 0.5ms furthermore 25ms period pulses are delighted similar to 1.5ms pulse as well as origin
the motor to discontinue.
CE 3.3.4 Identified issues and their solutions
CE 3.3.4.1 Issues
The issues are raised when the control was turned on and the result was that the motor
would not rotate properly. The shaft of the motor was vibrated into the place when motor phases
were energized into wrong sequences. It was possible that the Hall Effect sensor wires were not
connected wrongly.
CE 3.3.4.2 Solution
All the connections of the motors were checked properly. I had entirely analyzed the
model of the microcontroller to make sure that perfect microcontroller is selected for the project
work.
CE 3.3.5 Plan to produce creative and innovative work
The motor drives need rotor location sensor to carry out phase commutation as well as
current power. In order to perform this, a steady supply of location information is necessary;
therefore position sensor with advanced resolution such as shaft encoder is being used. I had
information of six phase commutation instants per electrical cycle is required, consequently I had

used of Hall Effect sensors. In order to measure position of motor as well as speed,
accelerometers were being applied.
CE 3.3.6 Collaborative work
I had contributed towards the project work and ensured to utilize the engineering skills to
acquire during the years of my study. I had utilized the technical skillet to acquire during my
Bachelor’s degree study. I had made ensure that my course is backed up the realistic and
mathematical analysis. I had taken responsibility and exploited of engineering skill sets to create
sure that constituent selection, scheming as well as prototyping is to be completed on point.
CE 3.4 Project review
CE 3.4.1 Project overview
The project was based on study on low cost microcontroller based speed control of the
BLDC motor. The motor used of magnetic exterior rotor with three phases of the driving coils
plus the devices of the Hall Effect which are used to intellect the rotor position. There is
commencement of coils; one phase after other and the Hall Effect sensors drives the electronics
devices.
CE 3.4.2 My contribution to work
I required analyzing and acquiring an understanding of 8051 Microcontrollers and
utilizing to manage the operation Brushless DC motors with use of PWM technique. I had
realized that this study was critical to perform when there is selection of correct type of DC
motor for conducting the project work.