The easiest way to learn all about AC Variable Frequency Drives and get Certified
Are you interested in knowing more about AC Variable Frequency Drives (known as VFDs for short) These are also called by other names like Variable Speed Drives, AC Drives, Inverter Drives, Frequency Drives, Adjustable Speed Drives and other similar terms.
A Variable Frequency Drive is an important part of any manufacturing plant or facility today. Nowadays you see them being increasingly used in all kinds of places, not just manufacturing plants and industries, but also in office buildings, warehouses and other commercial places. The reason is easy. They are the best thing that ever happened to the ac induction motor, as you can now control these motors in a variety of ways, which were not at all possible earlier. For years together, the ac motor, the workhorse of all manufacturing as well as all kinds of activity of any kind, was labeled as a "constant speed machine". But with the advent of this new technology, we could easily adjust speed as well as other parameters of these motors easily.
However, the information that is available on how to use these drives is not very easily available. Of course there ARE several sources of information, but are problematic. Why? Read on below:
Source 1: The internet
Of course, there is a lot of "free information" out there that is on the internet, but it is difficult to verify, collate and understand. To do this would also require literally spending endless hours surfing, and trying to find something that can actually be used in your work. What is your time worth? Multiply that by the hours that you would have to spend collecting all this information. Also some of this information may be incorrect as well as outdated. You also don't get a Certificate for your labors.
Source 2: Textbooks
You could buy a textbook on the subject from any of the bookstores; the only problems being that the information is very likely outdated and secondly many of these are written in a way that is difficult to understand for the practising engineer or technician like you. Seriously, do you have the time to solve some complex vector mathematics, differential equations and the like? Or would you want to find out quickly how to select and use a commercially available VFD for your application? Also no Certificate gets issued if you read the book.
Source 3: Vendor literature & training courses
Would you ask a barber whether you need a haircut? What would be the answer? No prizes for guessing! If you ask a vendor (nothing against them, they are the ones who develop the technology behind these wonderful devices), the chances are that you will not get UNBIASED answers. Suppose a standard V/f drive is good enough for your application. Would a typical vendor tell you that? Or would he/she try to "upsell" you to a more advanced one? I think you get the point....
Vendor specific training programs will cover only the models and types of VFDs that the vendor sells.
So, we at Abhisam Software (who develop a lot of e-learning courses for engineers and technicians), thought about it and decided that we should have an UNBIASED, VENDOR NEUTRAL, COMPLETE TRAINING COURSE WITH CERTIFICATION about this wonderful technology which is also
a) Easy to understand with graphics and animations to explain key concepts
b) Having a complete, unbiased and current vendor neutral information
c) Not too long winded and boring, without skipping anything important
d) Easily accessible- Either download it to your PC/laptop or access it online based on the version that you select
d) Having an associated exam and Certification with an electronic badge- display your competence to the world!
So we decided to make this software based training program for it, which we call an XPRTU. (It makes an expert out of you).
The Abhisam AC VARIABLE FREQUENCY DRIVES E-learning Course XPRTU!
Read on below to see the Table of Contents
Module 1 – Basic Concepts
Introduction to the Course
Introduction to AC Motor Drives
Better Load Matching
Focus on AC Motors
What you will learn
VFDs, VSDs, ASDs, VVVF Converters, Inverters
An ac induction motor
An AC Induction Motor working
Speed Control of ac induction motors
Speed of an AC Induction Motor
Power, Speed and Torque
Torque for different types of loads
Locked Rotor Torque
Motor characteristics and types
Design A Motor
Design B Motor
Design C Motor
Design D motor
Design E Motor
Which type is best for my application?
Load torque characteristics for different kind of loads
Load torque characteristics Animation
Classification of loads
Constant Torque loads
Variable Torque loads
Constant Power loads
Four Quadrant Operation
Overview of AC motor controls
DOL starter (Direct On Line starter)/Across the line starter
Star (Wye) and Delta connections
Control with a VFD
Why use VFDs?
Advantages of using a VFDs
Disadvantages of VFDs
Industrial applications of VFDs
Self Assessment Test
Module 2 - Inside a VFD
Introduction to the module
DC Link Block
How it all works together
VFD parts & VFD components
Switching frequency of diodes
Full Wave Rectifier
Three Phase Rectifiers
Thyristors (Silicon Controlled Rectifiers-SCRs)
Thyristor Firing Angle
Three Phase Thyristor Rectifiers
DC link block
Soft Charge Circuit
Working model of a transistor
Transistor as an amplifier
Transistor as a switch
Pulse Width Modulation
How does PWM work
PWM Waveform Generation
Changing the PWM amplitude
Changing the PWM frequency
Noise effects of PWM inverters
Module 3 - VFD Functions
Introduction to the module
Schematic of a typical VFD
Starting/Stopping of the motor
Motor Thermal Overload Protection
Braking- Electrical or Mechanical?
Electrical Braking using VFDs
Motoring and regeneration
Open Loop Control
Closed Loop Control
Control schemes in VFDs
Sensorless vector control
Flux Vector control (Closed loop)
Anti-windmill protection and Flying Start
How does DTC work?
Advantages and Disadvantages of DTC
Module 4 - Energy Saving using VFDs
Types of Loads
Pumps, Fans and Blowers
Traditional flow control
Control of Centrifugal Pumps
Centrifugal Pump basics
Pump Characteristic Curve
Throttling the flow
Effect of discharge throttling
Throttled Flow Curve
Other energy savings due to VFDs
Shorter Duty Cycles
Module 5 - Specifying, Selecting and Installing VFDs
Selection Process Flowchart
Evaluate VFD benefits versus traditional motor controls
VFD features for maximum benefit
Derating of VFDs
Harmonics due to VFD installations
Total Harmonic Distortion
Problems due to harmonics
What could be the PCC? Says who?
Measurement of harmonics
Harmonics in PWM type drives
Mitigation of harmonics
Number of Starts
Fuse Disconnects & Bypasses
Panels and Enclosures
Installation in Panels & Enclosures
Maximum Cable lengths
Module 6 - Using VFDs with DCS/PLC systems
VFDs used in process plants
Agitator Control via DCS Example
Self Assessment Test
Choose from any of the Versions Below
Earn Certificates and Badges
When you complete this e-learning course, you can take the associated exam and earn a Certificate of Competency, as well as an electronic badge, that you can display online on places such as LinkedIn and Facebook.
Still Have Questions? No Problem, Here's A List Of Our Most Frequently Asked Questions.
What is this? Is it just a power point presentation?
No, it is NOT a power point presentation at all! It is a full fledged, comprehensive e-learning course that we call as an XPRTU. It has text, graphics, animations, exercises that form a complete learning course. You can view a demo version here.
How will I get access to the course?
The course is available in three versions. The Online Version gives you a one year access to the course via the internet via any browser. The Download version is a Windows program that you can download and install on your own Windows OS (Windows XP, Vista, 7, 8/8.1/10). The Enterprise version is ideal for organizations that need to train larger numbers . You can buy any of these versions immediately via our e-commerce partner,Fastspring. Credit Cards, Bank payments are accepted.
What Operating Systems will it work on?
The Standard Download version will work on any Windows systems (Windows XP, Vista, 7, 8, 8.1 or 10). The Online and Enterprise versions are accessible from any device (including Macs) that have a browser.
How do I get Certified?
Simply take the Abhisam online exam within the validity of the license period. On passing you get an Electronic Certificate (pdf) as well as a Badge (issued via Credly), that you can display online on places such as LinkedIn or Facebook. This shows the world, including your prospective employers, customers or clients that you are competent in the subject. Our Badges conform to the Mozilla Open Badges standard and can be added to your backpack.
What is the ordering process?
When you click on the Buy Now button, you will be taken to the Fast Spring secured payment site. Ordering is completely secure. You can pay online by either Credit Card or wire transfer/manual order. Note that you will get the license key to activate only after payment is approved.