Variable Speed Motor Drives
It is estimated that electrical drives and other rotating equipment consume about 50% of the total electrical energy consumed in the world today (and this figure increases to 70% if you only consider industry.) The cost of maintaining electrical motors can be a significant amount in the budget item of manufacturing and mining industries. This course gives you a thorough understanding of electrical motor’s protection, control and maintenance and gives you the tools to maintain and troubleshoot electrical motors.
You will gain a fundamental understanding of the protection, control and maintenance of electric motors and drives. Typical applications of electric motors in manufacturing, materials handling, process control are covered in detail. The concluding section of the course gives you the fundamental tools in troubleshooting motors confidently and effectively.
Upon completion of the course participants will be able to:
Anyone associated with the use of electrical motors in the industrial or automation environment. The course will also benefit those working in system design as well as site commissioning, maintenance and troubleshooting.
INTRODUCTION TO VARIABLE SPEED DRIVES
· The Need for Variable Speed Drives
· Fundamental Principles of Speed Control
· Efficiency, Torque, Inertia, Horsepower/Power Factor
· Torque-Speed Curves
· How the motor produces Torque
· Types of Variable Speed Drives
3-PHASE AC INDUCTION MOTORS
· Basic Construction and Physical Configuration
· Principles of Operation and Performance
· Equivalent Circuit and Fundamental Equations
· Starting, Acceleration, Running and Stopping
· Power, Torque and Thermal Rating
POWER ELECTRONIC CONVERTERS
· Definitions and Basic Principles
· Power Diodes and Thyristors
· Principles of Communication
· Power Electronic Rectifiers
· Power Electronic Inverters
· Gate Commutated Converters
· Gate Controlled Devices - GTO, FCT, GTR, FET, IGBT
ELECTROMAGNETIC COMPATIBILITY (EMC)
· Sources of Electromagnetic Interference
· Harmonics on the Power Supply side of AC Converters
· The Effect of Harmonic Distortion on other connected Equipment
· Methods of reducing the effect of Supply side Harmonics
· Electric Motor Protection
· Thermal Overload Protection – Current Sensing
· Thermal Overload Protection - Direct Temperature Sensing
PROTECTION OF MOTORS AND CONVERTERS
· AC Frequency Converter Protection
· Fault Diagnostics
· Electric Motor Protection
· Thermal Overload Protection - Current Sensors
· Thermal Overload Protection – Direct Temperature
CONTROL SYSTEM FOR AC VARIABLE SPEED DRIVES
· The Overall Control System
· Power Supply to the Control System
· DC Bus Charging System
· VSD Control Loops (Open-Loop, Closed- Loop)
· Vector control and its applications
· Current Feedback in AC Variable Speed Drives
· Speed Feedback from the Motor
THE SELECTION OF AC CONVERTERS FOR VARIABLE SPEED DRIVE APPLICATIONS
· The Basic Selection Procedure
· Loadability of Converter Fed induction Motors
· Operation in the Constant Power Region
· The Nature of the Machine Load
· Starting and Stopping VSDs (Motor Braking)
· How to Calculate Acceleration Torques and Times
· How to Select the correct Motor and Converter for Pump and Fan Loads
· How to Select the correct Motor and Converter for Constant Torque Loads, such as conveyors
· Summary of the Selection Procedure
INSTALLATION AND FAULT FINDING TECHNIQUES
· General Installation and Environmental Requirements
· Power Supply Connections and Earthing
· Where to install the Contactors in the Power Circuit
· Installing AC Converters into Metal Enclosures
SPECIAL TOPICS
· PWM Rectifier for AC Converters
· Soft Switching
· The Matrix Converter
A variety of methodologies will be used during the course that includes:
· (30%) Based on Case Studies
· (30%) Techniques
· (30%) Role Play
· (10%) Concepts
· Pre-test and Post-test
· Variety of Learning Methods
· Lectures
· Case Studies and Self Questionaires
· Group Work
· Discussion
· Presentation
To be advised as per the course location. This rate includes participant’s manual, and-Outs, buffet lunch, coffee/tea on arrival, morning & afternoon of each day.
Daily Course Timings:
08:00 - 08:20 Morning Coffee / Tea
08:20 - 10:00 First Session
10:00 - 10:20 Coffee / Tea / Snacks
10:20 - 12:20 Second Session
12:20 - 13:30 Lunch Break & Prayer Break
13:30 - 15:00 Last Session