Design of BLDC Motor Controller

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 10 Issue: 11 | Nov 2023 www.irjet.net p-ISSN: 2395-0072
© 2023, IRJET | Impact Factor value: 8.226 | ISO 9001:2008 Certified Journal | Page 652
Design of BLDC Motor Controller
S. Suraj¹, P Gokul Raja², D.J. Arun³, Aravindan P⁴
¹²U.G Student, Dept. of Robotics and Automation, P.S.G College of Technology, Coimbatore – 641004
³⁴Project Associate, Dept. of Electrical and Electronics Engineering, P.S.G College of Technology, Coimbatore –
641004
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Abstract - This research paper demonstrates the
successful implementation of Brushless DC (BLDC) motor
control without the need for external position or speed
sensors. The sensorless method offers a cost-effective
solution with diverse applications. By varying the duty
cycle of Pulse-Width Modulation (PWM) signals sent to the
motor driver, remote speed adjustments are achieved via a
user-friendly IoT application. The integration involves an
Arduino Uno and an ESP8266 ESP-01 Wi-Fi module to
enable remote control. Users interact with the Blynk IoT
application, which features a slider for speed adjustment.
The Arduino translates the slider's position into specific
PWM duty cycle values, which, in turn, determine the
motor's speed. This opens up new possibilities for
automation, particularly within computer-integrated
manufacturing where it enables material-based speed
adjustments.
Key Words: electrical machines, brushless DC motors,
PWM, Wi-Fi Module, Control algorithm
1. INTRODUCTION
The widespread presence of DC motors in numerous
applications highlights their crucial role in our everyday
lives. Among these, the Brushless DC (BLDC) motor has
gained significant attention due to its inherent
advantages, which include noise reduction and improved
efficiency. BLDC motors are nowadays becoming more
and more popular in various applications due to their
superior controllability and performance such as high
efficiency due to reduced losses, compactness, long
operating life, high dynamic response, noiseless
operation, low maintenance, lower switching loss, low
rotor inertia and better speed versus torque
characteristics [7],[8]. In addition, the ratio of delivered
torque to the size of the motor is higher, making it useful
in applications where space and weight are critical
factors, especially in aerospace applications [1].
Moreover, in certain hazardous locations, the application
of DC brushed motors is limited because of the arcing
[6]. However, achieving precise control of BLDC motors
requires careful consideration of the motor's
specifications when choosing a suitable driver and
controller. Their efficient performance, along with
sensorless and sensor-based control methods, makes
them adaptable for various applications. To fully harness
the capabilities of a BLDC motor, it is essential to select
the driver and controller judiciously, taking into account
factors such as power requirements, voltage
compatibility, and control method. Furthermore, this
project investigates the incorporation of IoT technology
for remote control, enhancing the motor's usability and
accessibility. By examining the intricacies of BLDC motor
control and its alignment with the motor's specifications,
this project contributes to the expanding field of motor
control and automation.
2. CONTROL METHODS
First, the sensored control methods are discussed. One of
the control methods used for controlling BLDC motors is
the six-step commutation.
Fig -1: Phase voltage and sensor output waveforms [3]
It involves dividing the electrical cycle into six equal
intervals and energizing the stator windings in pairs
during each interval to create a rotating magnetic field.
The switching sequence used in this method is typically
determined based on the position of the rotor. This
position can be sensed using either Hall-effect sensors or
encoders. While the six-step commutation method offers
reliability and simplicity, it may not always yield optimal
efficiency. Another control method for BLDC motors is
field-oriented control (FOC), which is also known as
vector control. FOC is considered a more advanced
method that enables precise control of BLDC motors. It
achieves this by decoupling the electrical and magnetic
axes of the motor. To control the motor, FOC utilizes
feedback from Hall-effect sensors or encoders to adjust
both the amplitude and phase of the current applied to
the windings. This approach maximizes the efficiency

and torque output of the motor. Space Vector PWM
(SVPWM) is often used in conjunction with FOC for
achieving precise control of BLDC motors. This technique
involves optimizing the selection of voltage vectors to
maximize the motor's performance and efficiency. In
SVPWM, rotor position detection is typically done using
Hall sensors. These sensors play a crucial role in
accurately executing the PWM control strategy.
Sensorless control is an alternative method for
controlling BLDC motors that offers a cost-effective
solution. It eliminates the need for encoders or Hall-
effect sensors, thereby reducing component costs. In
sensorless control, the rotor position and speed are
estimated using the motor's back electromotive force
(back-EMF). As the rotor rotates, the motor generates a
back-EMF voltage in the windings, and this voltage
varies with the rotor's position. By analyzing the
waveform of the back-EMF and employing complex
algorithms, the controller can deduce the precise
position of the rotor.
One of the advantages of sensorless control methods is
their reduced component cost and increased reliability.
However, implementing sensorless control methods
accurately can be more challenging, particularly at lower
speeds and during startup. This is because these
methods require sophisticated algorithms and careful
tuning to ensure precise control. Despite these
challenges, sensorless control methods have gained
popularity in various applications, especially in
situations where sensor placement is impractical or cost-
prohibitive.
3. SELECTION OF CONTROLLER AND DRIVER
Choosing the appropriate motor driver and controller is
of utmost importance when aiming to achieve optimal
performance with a BLDC motor. The process of
selection primarily relies on the specific specifications of
the motor, encompassing voltage, rated current, and
power. Let us delve into how these factors exert an
influence on the decision-making regarding the driver
and controller:
The voltage rating assumes a significant role in this
regard as the driver and controller ought to be
compatible with the motor's voltage rating. It is crucial
to carefully choose the components that regulate the
power demands of the motor in order ensure safe
operation. Moreover, the driver should possess a current
rating that coincides with or surpasses the motor's rated
current. This particular criterion ensures that the driver
is fully equipped to supply the indispensable current to
effectively drive the motor, all the while avoiding the
perils of overheating or overloading. Furthermore, the
power rating of the motor plays a pivotal role in
determining the type of driver and controller that is
necessitated. In instances where the power rating of the
motor is relatively high, it may be imperative to employ
more robust and capable drivers and controllers, as they
are proficient in handling the augmented power
demands. Lastly, the chosen control method, whether it
be sensored or sensorless, should impeccably align with
the motor's specifications and application requirements.
Fig -2: Brushless Motor Controller DC 12-36V 500W
PWM Driver Board (Sensorless)
The process of selecting the most suitable motor driver
and controller is undeniably intricate, as it necessitates
thorough consideration of various factors such as voltage
rating, rated current, power rating, and control method.
4. WORKING
The functioning of a brushless DC (BLDC) motor is a
complex and synchronized process that involves a
meticulously coordinated sequence of signals to the
motor windings. This sequence is made to ensure that
the rotor spins in the desired direction and at the desired
speed. To understand the working of a BLDC motor, it is
important to examine each step of the process in detail.
Fig -3: BLDC Motor Control diagram [3]
In a sensored BLDC motor control system, position
sensors, such as Hall-effect sensors, play a crucial role in
providing feedback on the rotor's position. This
information is essential for determining the appropriate
phase sequence that needs to be energized in the stator
windings. By accurately sensing the position of the rotor,
the controller can effectively calculate the optimal timing
for commutation.

Commutation is a fundamental aspect of BLDC motor
operation. It involves the controller determining the
precise timing for energizing the stator windings in the
correct sequence. This sequence of energizing the
windings creates a rotating magnetic field, which
interacts with the permanent magnets on the rotor. This
interaction is what ultimately leads to the generation of
torque and the rotation of the rotor. To facilitate the
commutation process, the motor controller generates
gate signals for the power electronic switches, typically
six MOSFETs, in the three-phase inverter. These gate
signals are responsible for controlling the timing and
duration of current flow through the motor windings. By
carefully manipulating these signals, the controller can
effectively switch the MOSFETs in the inverter, directing
the current through the stator windings.
The torque production in a BLDC motor is a result of the
interaction between the magnetic field and the rotor's
permanent magnets. By switching the MOSFETs in the
inverter, the controller will direct the current through
the stator windings such that it generates a torque,
causing the rotor to turn. This torque production is a
crucial aspect of BLDC motor operation, as it is what
enables the motor to perform useful work. Throughout
the operation of the BLDC motor, the controller
continuously monitors the motor's characteristics. This
monitoring allows the controller to make necessary
adjustments to the commutation and timing to maintain
the desired speed and torque. Feedback mechanisms,
such as back-EMF voltage, play a vital role in fine-tuning
the motor's operation. By utilizing these feedback
mechanisms, the controller can make precise
adjustments to ensure optimal motor performance.
In certain applications, speed control is a significant
requirement. To achieve speed control in a BLDC motor,
the duty cycle of the Pulse-Width Modulation (PWM)
signals sent to the motor can be varied. By effectively
regulating the average voltage thereby the power
delivered to the motor through the manipulation of the
PWM signals, the speed of the motor can be controlled.
This speed control capability adds advantage to the
operation of BLDC motors, making them suitable for a
wide range of applications. Understanding the details of
these processes is crucial for maximizing the
performance and functionality of BLDC motors in
various applications.
5. SPEED CONTROL USING IOT
In this particular segment, the primary focus revolves
around the remote manipulation and regulation of the
rotational velocity of a Brushless Motor encompassing
state-of-the-art Internet of Things (IoT) technology. This
cutting-edge technology encompasses the integration of
an Arduino Uno, an ESP8266 ESP-01 Wi-Fi module, and
the Brushless Motor Controller DC 12-36V 500W PWM
Driver Board. The ultimate objective is to establish a
wireless connection between the motor controller and
the aforementioned components through the ESP8266
Wi-Fi module, allowing the regulation and alteration of
the motor's speed through the manipulation of the Pulse
Width Modulation (PWM) signal's duty cycle. This
intricate process comprises a series of pivotal steps, each
holding significant importance in the overall
functionality and success of the project.
In order to ensure efficient operation of the motor, it is of
utmost importance to connect it in strict accordance
with the manufacturer's specifications. This entails
providing the motor with the appropriate power supply
and establishing the necessary connections, although
specific details regarding these procedures are not
explicitly mentioned within this context.
Within the motor controller, a designated pin is
specifically allocated for the purpose of regulating the
motor's rotational velocity. This particular pin is linked
to one of the Arduino Uno's PWM pins, thereby enabling
the user to adjust the duty cycle of the PWM signal,
consequently facilitating the desired changes in the
motor's speed. The seamless integration of the ESP8266
ESP-01 Wi-Fi module with the Arduino Uno serves as a
pivotal enabler in establishing a stable and reliable
connection between the motor controller and the Blynk
IoT application via Wi-Fi. This amalgamation ultimately
paves the way for the realization of remote speed
control, thereby enhancing convenience and
accessibility.
Fig -4: Blynk IoT Dashboard in (a) Website (b) Mobile
Application

The effective utilization of the Blynk IoT application
represents a crucial aspect of this project. This user-
friendly application serves as a platform for creating a
highly intuitive and visually appealing user interface that
facilitates the regulation of the motor's speed. The
provided source code establishes seamless
communication between the Blynk IoT app and the
motor controller, thereby granting the user the ability to
effortlessly control the motor's speed through the
utilization of a slider interface.
The successful execution of the project necessitates the
development of the Arduino code and uploading them
onto the Arduino Uno. This code is specifically designed
to configure the hardware components and establish a
stable connection with the Blynk application. Upon
execution, the code effectively maps the position of the
slider within the Blynk IoT app to the desired motor
speed, subsequently adjusting the PWM duty cycle in a
precise and efficient manner. It is important to note that
the Wi-Fi-connected ESP8266 module acts as a vital
communication bridge between the Blynk application
and the motor controller, thereby effectively translating
the user's slider inputs into precise and accurate speed
adjustments through the utilization of PWM control.
6. SETUP AND CIRCUIT DIAGRAMS
The process of setting up the hardware components for
the motor begins with providing a regulated power
supply within the specified voltage range of 12-36V. This
ensures that the motor receives the appropriate amount
of power. To establish the connections, the VCC and
ground (GND) pins of the motor controller should be
connected to the corresponding voltage and ground
terminals. This ensures the proper flow of electricity.
Additionally, the MA, MB, and MC pins of the motor
controller need to be connected to each phase of the
motor.
Fig -5: Demonstration of Speed Control using Blynk IoT
Mobile Application
The Arduino Uno, a widely used microcontroller board,
plays a crucial role in controlling the motor's speed. To
enable speed adjustments, the VR (speed control) port of
the motor controller should be connected to one of the
Arduino Uno's PWM pins, such as Pin 9. This connection
allows the Arduino Uno to regulate the speed of the
motor by utilizing pulse-width modulation (PWM)
techniques. By varying the width of the pulses, it can
effectively control the amount of power delivered to the
motor, thereby adjusting its speed accordingly.
Fig -6: Diagram representing circuit connections for
speed control of motor using IoT
The ESP-01 module serves as the key component
responsible for enabling Wi-Fi connectivity, which
allows for remote control of the motor. To establish
communication with the ESP-01 module, several pins
need to be properly connected. The TX pin and RX pin of
ESP-01 should be connected to digital pins of Arduino
UNO board to enable communication between the Wifi
Module and the controller. Lastly, the EN pin (Enable) of
the ESP-01 module is utilized to enable or disable the
module.
To create a user-friendly dashboard for controlling the
motor's speed, the Blynk IoT app can be used. This app is
available for download on various app stores, making it
easily accessible to users. By configuring the hardware
and establishing a connection with the Blynk app using
the Blynk AUTH token, users can effectively control the
motor's speed. The code implemented in the Arduino
Uno maps the slider values from the Blynk IoT app to
control the motor's speed. By uploading the code to the
Arduino Uno, users gain remote control over the motor's
speed, allowing for convenient and flexible adjustments.
The Wi-Fi-connected ESP8266 module facilitates the
communication between the Blynk app and the motor
controller. It serves as a bridge, translating the slider
inputs from the app into precise speed adjustments
through the implementation of PWM control. This
seamless communication and control process ensures a
smooth and efficient user experience.

7. CONCLUSION
This paper successfully demonstrated the precise control
of a Brushless DC (BLDC) motor using a sensorless
method, thereby eliminating the requirement for
external position or speed sensors. Moreover, using the
Internet of Things (IoT) technology, specifically an
Arduino Uno and an ESP8266 ESP-01 Wi-Fi module,
grants the ability to remotely control the speed of the
motor through the Blynk IoT application. This innovative
amalgamation of sensorless BLDC motor control and IoT
connectivity opens up a vast array of possibilities for
automation, particularly within the realm of computer-
integrated manufacturing. By employing coding and
classification systems such as DCLASS, MCLASS, and the
OPTIZ coding system, it can be made possible to
customize the motor's speed according to specific code
of the material which is based on the material properties.
This capability proves to be particularly advantageous in
tapping applications, as it facilitates the adjustment of
the motor's speed based on the properties of the
material, thereby optimizing efficiency and precision.
8. REFERENCES
[1] José Carlos Gamazo-Real, Ernesto Vázquez-Sánchez,
and Jaime Gómez-Gil, "Position and Speed Control of
Brushless DC Motors Using Sensorless Techniques and
Application Trends," Sensors 2010, 10(7), 6901-6947.
[2] Damond Goodwin, "Field-oriented Control (Vector
Control) for Brushless DC Motors," March 19, 2023.
[3] Amol R. Sutar, G. G. Bhide, and J. J. Mane,
"Implementation and Study of BLDC Motor Drive
System," International Journal of Engineering Sciences &
Research Technology, 5(5), May 2016.
[4] Ciurys Marek Paweł, Dudzikowski Ignacy, Pawlak
Marcin, "Laboratory tests of a PM-BLDC motor drive,"
Department of Electrical Machines, Drives and
Measurements, Faculty of Electrical Engineering,
Wrocław University of Technology, Poland, 2015
Selected Problems of Electrical Engineering and
Electronics (WZEE).
[5] Anjana Elizabeth Thomas and Salim Paul, "Digital
Signal Controller Based Digital Control of Brushless DC
Motor," International Journal of Electronics
Communication and Computer Engineering, Volume 4,
Issue 4, ISSN (Online): 2249–071X, ISSN (Print): 2278–
4209.
[6] Wael A. SALAH, Dahaman ISHAK, Khaleel J.
HAMMADI, Soib TAIB, "Development of a BLDC motor
drive with improved output characteristics," PRZEGLĄD
ELEKTROTECHNICZNY (Electrical Review), ISSN 0033-
2097, Vol. 87, No. 3, 2011.
[7] G. Madhusudhana Rao et al., "Speed Control of BLDC
Motor Using DSP," International Journal of Engineering
Science and Technology, Vol. 2(3), 2010.
[8] Bhim Singh, B P Singh, (Ms) K Jain, "Implementation
of DSP Based Digital Speed Controller for Permanent
Magnet Brushless DC Motor," IE(I) Journal-EL, Vol. 84,
June 2003.

Design of BLDC Motor Controller

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