Advanced Electrical Drive Controls, Types and Implementation”

1. Presented by
Dr. R. RAJA, M.E., Ph.D.,
Associate Professor, Department of EEE,
Muthayammal Engineering College, (Autonomous)
Namakkal (Dt), Rasipuram – 637408
MUTHAYAMMAL ENGINEERING COLLEGE
(An Autonomous Institution)
(Approved by AICTE, New Delhi, Accredited by NAAC, NBA & Affiliated to Anna University),
Rasipuram - 637 408, Namakkal Dist., Tamil Nadu, India.
“Advanced Electrical Drive Controls, Types
and Implementation”

2. Contents
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 Block Diagram of Electrical Drive
 Types of Electrical Drives
 Based on Supply
• AC Motor drives
• DC Motor drives
 Based on Number of Motors
• Individual
• Multi Motor
• Group Drive
 Based on Speed
• Constant Speed drive
• Variable Speed drive
 Based on Control Parameters
• Vector Control Drive
• Constant Power Drive
• Constant Torque Drive
 Advantages of Electrical Drives
 Disadvantages of Electrical Drives
 Applications of Electrical Drives

3. Introduction
 An electrical drive is defined as an electronic device designed to control
certain parameters of the motor for controlling the electrical energy into
mechanical power in a precise controllable way.
 Electrical power systems employed for motion control are called “Electrical
Drives”.
 It consists of a classy electronic system or a combination of different systems
for the purpose of motion control.
 Motion is provided with the help of prime movers.
 Example of prime movers are Petrol engines, Diesel engines, gas or steam
turbines, steam engines, hydraulic motors, and electric motors.
 Drives power systems employing electric motors are known as electric drives.
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4. Block Diagram of Electrical Drive
 A modern electrical drive capable of variable controlled speed is made of
some important parts as shown in the below block diagram.
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5. Source: Source can be DC or AC source.
Power converter: AC to DC, AC to AC, DC to DC, DC to AC converters.
Motor: Converts electrical energy in to mechanical energy, it is the heart of the
electrical system.
Commonly used motors are
 DC motors – series, shunt/parallel DC motor, compound and permanent magnet
DC motor.
 Induction motors – wound rotor and linear, squirrel cage.
 Brush less dc motors
 Stepper motors.
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Contd..

6. 10/28/2021 6
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Contd..
Load: It can be a machine to accomplish a given task. Example is Pump, Fan,
Machine tools.
Controller: The power required for the motor is supplied by the controller.
Sensor: Depending upon the type of control required, various inputs from sensors
are taken. An example is a speed, current.

7. Types of Electrical Drives
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8. AC Motor drives
 AC drive is a device used to control the speed of an electric motor such as a
three-phase induction motor by changing the frequency of the electrical supply
to the motor.
 AC drive is also called Variable Frequency Drive (VFD) or Variable Speed
Drive (VSD).
DC Motor drives
 It is basically speed control system of a DC electrical motor that supplies
voltage to the motor to operate at desired speed.
 DC drives are classified as analog DC drives and digital DC drives.
 Digital DC drive can offer precision control.
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Based on Supply

9. Based on Number of Motors
Individual
 There will be a separate drive motor for various parts of a machine.
 Example: Lathe machine.
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10. Multi Motor
 Separate motors are provided for actuating different parts of a machine.
 Example: Cranes.
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Contd..

11. Group Drive
 In a group drive, one motor is used as a drive for two or several machines.
 The motor is connected by a single shaft, other machines are connected to the
shaft by belts and pulleys.
 Group drive is most economical.
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Contd..

12. Based on Speed
Constant Speed drive
 Machine tools require more or less constant speed drives, squirrel cage
induction motor along with the manual controls are used.
Variable Speed drive
 The main purpose of variable speed drive is to control speed along with
acceleration, deceleration, torque and finally the direction of machine.
 They are used to reduce power consumption.
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13. Based on Control Parameters
Vector Control Drive
 Vector control is most accurate than any other kind of variable frequency drive
(VFD).
 In this control mode, torque and speed controlled using pulse width modulation
(PWM) techniques in an inverter.
 These are used for AC synchronous and induction motors.
Constant Power Drive
 When a motor while carrying rated current in its armature provides constant
power at all speeds in a certain range of speed control it is known as constant
power drive in that range of speed control.
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14. Constant Torque Drive
 Constant torque load type drive is distinctive when fixed volumes are being
handled.
 Examples are screw compressors, feeders, and conveyors.
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Contd..

15. Advantages of Electrical Drives
 Enough overload capacity without loss of life of machine.
 Four quadrant operation.
 Modifiable torque-speed characteristics.
 No requirement of warming up period.
 Higher efficiency.
 Easy control.
 Clean operation, no pollution.
 Wide range of speed control.
 Electric braking can be employed
 They can be started instantly and immediately can be fully loaded.
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16. Disadvantages of Electrical Drives
 High initial cost due to the presence of power converters and controller
electronics.
 Regular maintenance and high attention are required.
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17. Applications of Electrical Drives
 Industrial Production,
 Manufacturing, and
 Process Control.
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18. Thank You
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