Variable Frequency Drive Training

Practical Approaches and Problem-Solving Solutions

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Dececember 4-5,2006
Vancouver, BC
Best Western Hotel and Conference Centre (Richmond, BC)

December 5-6, 2006
Edmonton, AB
The Coast Terrace Inn

December 11-12, 2006
Toronto, ON
Park Plaza Hotel (Airport)

December 12-13, 2006
Ottawa, ON
Chimo Hotel

Variable Frequency Drive Training - Click Here For Your FREE On-Site Training Quotation

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DAY 1 - VFD PROGRAM DESCRIPTION

Introduction to the basic work principles of rotating direct and alternating current machines and their construction. Students will be introduced to the main features of Direct and Alternating current motors and learn how to calculate the produced torque and power for each type of motor. Professor Nigim will also present their construction and operational characteristics to enable informative judgment on their application environment.

• Direct current ‘DC’ motor current and Torque Calculation
• Induction Motor ‘IM’ Current and Torque Calculation

Learn how to select a starting current limiting control unit and why it is needed for small and large motors.

• Why soft starters are needed?
• Basic elements of soft starters ‘reduced voltage starters’

This section will introduce the subject of semiconducting elements and how they are controlled and used to regulate the flow of power to the motor and the various commercial configurations in use in many today drives.

• Switching elements
• Converters configurations ‘Rectifiers’ convert AC to DC source
• Inverters configurations, convert DC to AC source
• Back to Back Conversion/Inversion systems
• Voltage Source Inverters
• Current Source Inverters

This session will explain how variable frequency drives are designed to operate at different speed settings and still deliver constant torque and or power to the mechanical load.

• Battery driven DC and IM motors drives
• Mains driven DC and IM motors drives
• Open and closed ‘speed and current’ control loops
• Field oriented and vector control of IM

Many variable frequency drive application failures are due to improper use. This session will focus on the main issues that should be considered when installing drives in industrial premises.

• Power Factor Correction
• Cable Length
• Losses caused by inverters
• Harmonics
• Electrical Protection

This session will introduce the main criteria for selecting variable frequency drives and their required maintenance for sustainable operation.

• Mechanical loads characteristics
• Safe operation and initialization
• Required routine maintenance
• Drive interface with process controllers
• IEC and NEMA standards

This seminar topic will discuss the impact of VFDs when installed in an industrial environment as related to the power system and to the electric motor.

Topics such as Harmonics, Line transients, power surges and other power quality issues will be discussed providing the student an insight of how these everyday electric power disturbances will create undesirable effects if not mitigated.

• Power Harmonics
• Transients
• Surges
• Long motor feeder cables
• Bearing currents
• Electro Magnetic Compatibility, noise issues

Inverters today have an extremely fast switching time and this step change in voltage can cause communication issues, high motor stress and even damaging current flow through motor bearings. The student will learn how and why the VFD can create these problems and see the effect of damage that can occur if left unchecked.

The cable between the motor and the VFD behaves significantly different when on sine wave power versus VFD power. The student will learn the impact of the cable from very short length to extremely long distances.

The previous section shows all the potential problems with VFDs and Motors on VFDs. This section will demonstrate to the student how to address and prevent these problems so that they do not create undesirable effects in the industrial system. Each of the above problems will be discussed with recommended solutions for each issue. The cost impact of these options will also be provided giving the student some degree of weighing the benefits of the options versus the cost of the consequence. The result of this seminar will allow the student to be able to properly apply a new VFD with the required options in a plant providing years of trouble free operation.

• Application issues
• Speed range
• Torque Capability
• Min Speed
• Max Speed
• Reversing
• Stopping/Braking

A demonstration of how a variable frequency drive and electric motor behaves and operates when an Under-voltage dip occurs, a short Power loss of up to 2 seconds occurs and when an Extended power loss occurs. The demonstration will also show the feature of an auto restart upon return of power, starting into a rotating motor and effects of operation upon an interlock trip such as a vibration switch etc.

This topic will discuss the application selection and sizing issues with VFDs and Motors when variable speed drives are used. The effect of the speed range, minimum speed, normal speed, maximum speed and torques through out the speed range will be discussed. The student will learn the reason why different VFD and motor selections may occur even on similar applications.

Stopping of a motor will be discussed. It is sometimes critical to stop a motor faster than it would normally stop if power was just removed (open a contactor) for personnel safety issues or to limit equipment damage. The issues of using an Emergency Stop circuit and the different results that can be achieved on a VFD application will be discussed. The student will realize why a different logic may be required depending on the result that is desired, i.e. People protection, Equipment Damage of just a safe quick stop is required.

The final session of this presentation will state the reason and advantages for the 12 or so most common specified VFD options that are purchased today. The student will see why these options are commonly specified and provide the solid basis for reliable trouble free long life VFD installations.

SPECIAL NOTE: Along with the above seminar material:

Each student will receive a detailed VFD specification and Check list to use to ensure that all the above issues are addressed.

The student will also receive an electronic copy of the Basics of AC Drives and the Basics of AC Motors. These two books are more than 100 pages, providing valuable information for the student for future reference.

GENERAL INFORMATION

When and Where
The The Variable Frequency Drives Training Course forum will be held as follows:

Dececember 4-5, 2006
Vancouver, BC
Best Western Hotel & Conference Centre
7551 Westminster Highway, Richmond, BC
Tel: 604-273-7878

Dececember 5-6, 2006
Edmonton, AB
The Coast Terrace Inn
4440 Gateway Blvd.
Tel: 780-437-6010

Dececember 11-12, 2006
Toronto, ON
Park Plaza Hotel
33 Carlson Court
[near the airport]
Tel: 416-675-1234

Dececember 12-13, 2006
Ottawa, ON
Chimo Hotel
1199 Joseph Cyr St
Gloucester, ON
Tel: (613) 744-1060

A special bedroom rate (non-commissionable) has been arranged with these hotels. To receive this rate, inform the hotel that you are a delegate with the Canadian Electricity Forum when making your reservation.