Unit Description and General Aims

The objective in presenting this unit is to impart to students a comprehensive knowledge of controls meant to regulate the power flow to electrical machinery used in typical industrial operations. The subject matter covered in this unit will include: the different production processes used in industry and the control requirements for machinery used in these processes; speed control of different types of motors used in manufacturing activities such as metal forming, rolling, manufacturing of paper, etc.; the control of heaters used in machinery such as moulding and extrusion presses; and the control of heating furnaces and welding controllers. The scope of the unit will also include a study of power electronic devices, their basic control strategies and characteristics, the equipment configurations in which these devices find applications, and the control functions used in power electronic equipment to achieve precise operational control.

Learning Outcomes

On successful completion of this Unit, students are expected to be able to:

1. Describe the different types of manufacturing processes and their control requirements with an emphasis on lowering the power consumption. 
   Bloom’s Level 4

2. Detail power electronic device types used for controlling the output of electrical equipment industrial applications. 
   Bloom’s Level 4

3. Describe the circuits for rectification and inversion and their application in motor controls. 
   Bloom’s Level 4

4. Specify the use of DC and AC motors in different industry segments and the control strategies adopted.
   Bloom’s Level 6

5. Specify the use of Robots in different industry segments and the control strategies adopted. 
   Bloom’s Level 6

6. Evaluate the principles of industrial heating and welding and their control requirements. 
   Bloom’s Level 5

Student assessment

Overall requirements: Students must achieve a result of 50% or above in the exam itself to pass the exam and must pass the exam to be able to pass the unit. An overall final unit score of 50% or above must be achieved to pass the unit once all assessment, including the exam, has been completed.

Prescribed and Recommended Readings

Textbook

Bralla, JG 2007, Handbook of Manufacturing Processes - How Products, Components and Materials are Made, Industrial Press, ISBN 978-1-60119-933-1. (available on the EIT eLibrary)

Recommended

• Phipps, CA 1999, Variable Speed Drive Fundamentals, 3rd edn, Fairmont Press Inc., ISBN 978-1-61583-295. Online version available at: http://app.knovel.com/hotlink/toc/id:kpVSDFE001/variable-speed-drive/variable-speed-drive
• Rashid, MH 2011. Power Electronics Handbook - Devices, Circuits, and Applications. 3rd edn. Elsevier. Online version available at: http://app.knovel.com/hotlink/toc/id:kpPEHDCAE1/power-electronics-handbook/power- electronics-handbook
• Manesis S., Nikolakopoulos, G., 2018, Introduction to Industrial Automation, Boca Raton CRC Press

Reference

Erickson, CJ 1994, Handbook of Electrical Heating for Industry, IEEE, ISBN 13: 9780780304208.

Notes and Reference texts

Knovel library: http://app.knovel.com

IDC notes and Reference texts as advised. Other material advised during the lectures

Unit Content

One topic is delivered per contact week, with the exception of part-time 24-week units, where one topic is delivered every two weeks.

Topic 1

Industrial manufacturing processes and control methods

1. Basics of industrial manufacturing (batch processes and assembly lines)
2. Metal forming (hot and cold)
3. Metal cutting/stamping
4. Forging and casting
5. Machine tools (Turning, shaping/planning, drilling, boring, grinding, and milling)
6. Die casting and moulding operations
7. Automation in manufacturing
   1. Introduction to CNC
   2. The ten steps in CNC programming
   3. Advantages and disadvantages of CNC technology

Topic 2

Advanced Manufacturing Processes and Technologies

1. Heat treatment
2. Welding
3. Heating furnaces
4. Melting furnaces
5. Plating and coating
6. Interlocks and controls in different machines
7. Introduction to Robotic technology
   1. Robot applications
   2. Robot safety
   3. Robot selection considerations

Topic 3

Power electronic devices used in industrial equipment

1. Principle of operation and characteristics of semiconductor diodes
2. Principle of operation and characteristics of power transistors
3. Principle of operation and characteristics of thyristors and triacs
4. Principle of operation and characteristics of GTO devices
5. Principle of operation and characteristics of IGBTs and IGCTs
6. Important specifications of semi-conductor devices and their relevance in selection

Topic 4

Rectifiers and their control

1. Half wave, full wave and bridge rectifiers with diodes and their waveform (single and 3 phase)
2. Half-controlled and fully controlled 3 phase rectifiers and waveform
3. Pulse circuit for thyristor control
4. Snubber circuits and their design
5. Protection of devices using semi-conductor fuses
6. Power factor and harmonic problems in the supply circuit due to rectifier operation

Topic 5

Inverters and their control

1. Inversion by switching and inversion by voltage synthesis
2. GTO thyristors as inverters
3. Transistors and IGBTs as inverters
4. Voltage and current source inverters
5. Pulse-width modulation type voltage source inverters
6. Line commutated inverters for high power motors

Topic 6

DC motors and their control

1. DC motor operating principle
2. DC motor types based on field supply (shunt, series, compound)
3. Speed/torque characteristics
4. DC motor control and constant torque/constant power mode of control
5. Armature voltage control using thyristor rectifiers
6. Field voltage control
7. 4-quadrant operation

Topics 7 and 8

AC motors and control

1. Single phase AC motors-operating principle
2. 3 phase motors-types
3. 3 phase motor operating principle (rotating magnetic field)
4. Starting of cage motors-controls (direct and assisted starting)
5. Soft starters using power thyristors
6. Slip ring motors construction
7. Starting using rotor resistance control
8. Synchronous motors and their starting
9. Speed control of AC motors VVVF type
10. 4-quadrant AC drives
11. Braking using resistance and regenerative braking
12. Slip power recovery type of drives for wound rotor motors

Topic 9

Welding control

1. Basics of electric welding
2. Resistance welding (spot, seam) and controls
3. Current control for DC arc welding using rectifiers
4. AC Arc welding and control of welding machines
5. Overview of robotic welding (an application in different industries)
6. Sensors for welding robots
7. System issues in robotic welding

Topics 10

Heaters, furnaces, and control methods

1. Resistance heating
2. Control of resistance heaters (on/off and voltage control methods)
3. Radiant heating and its control
4. Induction furnace and its application in melting
5. High frequency induction heating and control
6. Dielectric heating
7. Power source for induction/dielectric heaters

Topics 11

Advanced Technologies in Industrial Operations

1. Heating furnaces and temperature control (heat treatment operations)
2. Arc furnace for melting and control of arc current/length
3. Industrial Internet of Things (Advantages, Applications and challenges in manufacturing)
4. Practical examples of industrial applications of the robots (Robotic arms in picking and placing, shearing machine, Metal plate rolling Mill machine)
5. Industrial mobile robots (Automated guided vehicles)

Topic 12

Unit Review

In the final week students will have an opportunity to review the contents covered so far. Opportunity will be provided for a review of student work and to clarify any outstanding issues. Instructors/facilitators may choose to cover a specialized topic if applicable to that cohort.

Software/Hardware Used

Software

• Software: MATLAB
• Version: N/A
• Instructions:  N/A
• Additional resources or files: N/A

Hardware

• N/A

Unit Changes Based on Student Feedback