Engineering Institute of Technology

 

Unit Name

POWER ELECTRONICS AND VARIABLE SPEED DRIVES

Unit Code

BEE208S

 

Unit Duration

Term

Award

Bachelor of Science (Engineering)

 

Duration 3 years

Year Level

Two or Three

Unit Creator/Reviewer

 

Core/Sub-discipline

Sub-discipline

Pre/Co-requisites

BEE108S

Credit Points

3

 

Total Program Credit Points 81 (27 x 3)

Mode of Delivery

Online or on-campus.

Unit Workload

(Total student workload including “contact hours” = 10 hours per week)

Pre-recordings / Lecture – 1.5 hours Tutorial – 1.5 hours

Guided labs / Group work / Assessments – 2 hours

Personal Study recommended - 5 hours

Unit Description and General Aims

 

The objective of this unit is for students to obtain a detailed knowledge of: the fundamental principles of power electronics; the devices used in power electronics; common circuits, such as converters, inverters, and switched mode power supplies; and, the controls applicable to these circuits. Information covered in this unit will also include variable speed drives for DC and AC motors, their protection, control, and applications in industry. Students will also undertake a project involving AC variable speed drive selection for typical applications, including their required settings and energy savings estimates.

Learning Outcomes

 

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

 

  1. Discuss the principles behind different power electronic devices, typical circuits based on the devices, and their applications.

  2. Design the basic parameters of a switched mode power supply (SMPS), including the selection of the components used.

  3. Explain the principles of controlling the output of rectifiers and their application in DC drives.

  4. Explain the different types of inverters and compare their relative advantages and disadvantages.

  5. Discuss the typical control methods of a pulse width modulated (PWM) AC drive focussing on their energy saving feature.

  6. Select an appropriate AC drive for a given application and work out its settings.

    Professional Development

    Completing this unit may add to students professional development/competencies by:

    1. Fostering personal and professional skills and attributes in order to:

      1. Conduct work in a professionally diligent, accountable and ethical manner.

      2. Effectively use oral and written communication in personal and professional domains.

      3. Foster applicable creative thinking, critical thinking and problem solving skills.

      4. Develop initiative and engagement in lifelong learning and professional development.

      5. Enhance collaboration outcomes and performance in dynamic team roles.

      6. Effectively plan, organise, self-manage and manage others.

      7. Professionally utilise and manage information.

      8. Enhance technologist literacy and apply contextualised technologist skills.

    2. Enhance investigatory and research capabilities in order to:

      1. Develop an understanding of systematic, fundamental scientific, mathematic principles, numerical analysis techniques and statistics applicable to technologists.

      2. Access, evaluate and analyse information on technologist processes, procedures, investigations and the discernment of technologist knowledge development.

      3. Foster an in-depth understanding of specialist bodies of knowledge, computer science, engineering design practice and contextual factors applicable to technologists.

      4. Solve basic and open-ended engineering technologist problems.

      5. Understand the scope, principles, norms, accountabilities and bounds associated with sustainable engineering practice.

    3. Develop engineering application abilities in order to:

      1. Apply established engineering methods to broadly-defined technologist problem solving.

      2. Apply engineering technologist techniques, tool and resources.

      3. Apply systematic technologist synthesis and design processes.

      4. Systematically conduct and manage technologist projects, work assignments, testing and experimentation.

Engineers Australia

The Australian Engineering Stage 1 Competency Standards for Engineering Technologists, approved as of 2013. This table is referenced in the mapping of graduate attributes to learning outcomes and via the learning outcomes to student assessment.

 

Stage 1 Competencies and Elements of Competency

1.

Knowledge and Skill Base

1.1

Systematic, theory based understanding of the underpinning natural and physical sciences and the engineering fundamentals applicable to the technology domain.

1.2

Conceptual understanding of the, mathematics, numerical analysis, statistics, and computer and information sciences which underpin the technology domain.

1.3

In-depth understanding of specialist bodies of knowledge within the technology domain.

1.4

Discernment of knowledge development within the technology domain.

1.5

Knowledge of engineering design practice and contextual factors impacting the technology domain.

1.6

Understanding of the scope, principles, norms, accountabilities and bounds of sustainable engineering practice in the technology domain.

2.

Engineering Application Ability

2.1

Application of established engineering methods to broadly-defined problem solving within the technology domain.

2.2

Application of engineering techniques, tools and resources within the technology domain.

2.3

Application of systematic synthesis and design processes within the technology domain.

2.4

Application of systematic approaches to the conduct and management of projects within the technology domain.

3.

Professional and Personal Attributes

3.1

Ethical conduct and professional accountability.

3.2

Effective oral and written communication in professional and lay domains.

3.3

Creative, innovative and pro-active demeanour.

3.4

Professional use and management of information.

3.5

Orderly management of self and professional conduct.

3.6

Effective team membership and team leadership.

Graduate Attributes

Successfully completing this Unit will contribute to the recognition of attainment of the following graduate attributes aligned to the AQF Level 7 criteria, Engineers Australia Stage 1 Competency Standards for Engineering Technologists and the Sydney Accord:

 

Graduate Attributes

(Knowledge, Skills, Abilities, Professional and Personal Development)

EA Stage 1 Competencies

Learning Outcomes

A. Knowledge of Science and Engineering Fundamentals

A1. Breadth of knowledge of engineering and systematic, theory-based understanding of underlying principles, and depth of knowledge across one or more engineering sub- disciplines

 

1.1, 1.3

 

1, 3, 4, 5

A2. Knowledge of mathematical, statistical and computer sciences appropriate for engineering technology

 

1.2

 

2, 6

A3. Discernment of knowledge development within the technology domain

1.4

1, 3, 4, 5

A4. Knowledge of engineering design practice and contextual factors impacting the technology domain

 

1.5

 

2, 6

B. Problem Solving, Critical Analysis and Judgement

B1. Ability to research, synthesise, evaluate and innovatively apply theoretical concepts, knowledge and approaches across diverse engineering technology contexts to effectively solve engineering problems

 

1.4, 2.1, 2.3

 

2, 6

B2. Technical and project management skills to design complex systems and solutions in line with developments in engineering technology professional practice

 

2.1, 2.2, 2.3, 3.2

 

2, 6

C. Effective Communication

C1. Cognitive and technical skills to investigate, analyse and organise information and ideas and to communicate those ideas clearly and fluently, in both written and spoken forms appropriate to the audience

 

3.2

 

1, 3, 4, 5

C2. Ability to engage effectively and appropriately across a diverse range of cultures

3.2

 

D. Design and Project Management

D1. Apply systematic synthesis and design processes within the technology domain

2.1, 2.2, 2.3

2, 6

D2. Apply systematic approaches to the conduct and management of projects within the technology domain

 

2.4

 

2, 6

E. Accountability, Professional and Ethical Conduct

E1. Innovation in applying engineering technology, having regard to ethics and impacts including economic; social; environmental and sustainability

 

1.6, 3.1, 3.4

 

2, 6

E2. Professional conduct, understanding and accountability in professional practice across diverse circumstances including team work, leadership and independent work

 

3.3, 3.4, 3.5, 3.6

 

Unit Competency and Learning Outcome Map

This table details the mapping of the unit graduate attributes to the unit learning outcomes and the Australian Engineering Stage 1 Competency Standards for the Engineering Technologist.

 

 

 

Graduate Attributes

A1

A2

A3

A4

B1

B2

C1

C2

D1

D2

E1

E2

 

Engineers Australia Stage 1 Competency Standards for Engineering Technologist

1.1

 

 

 

 

 

 

 

 

 

 

 

1.2

 

 

 

 

 

 

 

 

 

 

 

1.3

 

 

 

 

 

 

 

 

 

 

 

1.4

 

 

 

 

 

 

 

 

 

 

1.5

 

 

 

 

 

 

 

 

 

 

 

1.6

 

 

 

 

 

 

 

 

 

 

 

2.1

 

 

 

 

 

 

 

 

 

2.2

 

 

 

 

 

 

 

 

 

 

2.3

 

 

 

 

 

 

 

 

 

2.4

 

 

 

 

 

 

 

 

 

 

 

3.1

 

 

 

 

 

 

 

 

 

 

 

3.2

 

 

 

 

 

 

 

 

 

3.3

 

 

 

 

 

 

 

 

 

 

 

3.4

 

 

 

 

 

 

 

 

 

 

3.5

 

 

 

 

 

 

 

 

 

 

 

3.6

 

 

 

 

 

 

 

 

 

 

 

 

Unit Learning Outcomes

LO1

 

 

 

 

 

 

 

 

 

LO2

 

 

 

 

 

LO3

 

 

 

 

 

 

 

 

 

LO4

 

 

 

 

 

 

 

 

 

LO5

 

 

 

 

 

 

 

 

 

LO6

 

 

 

 

 

Student Assessment

 

 

Assessment Type

When Assessed

Weighting

 

(% of total unit marks)

Learning Outcomes Assessed

 

Assessment 1

Type: Multi-choice test / Group work / Short answer questions / Practical / Remote Lab / Simulation

Example Topic: Power electronic devices and switched mode power supply.

Students will complete a quiz with MCQ type answers to

30 questions to demonstrate a detailed knowledge of power electronic devices and switched mode power supply design.

 

Week 5

 

15%

 

1, 2

 

Assessment 2

Type: Multi-choice test / Group work / Short answer questions / Practical / Remote Lab / Simulation

Example Topic: DC and AC variable speed drives.

Students will complete a test with about 20 questions each to be answered in less than 100 words and explanatory diagrams to demonstrate a detailed knowledge of the basic principles of DC and AC variable speed drives.

 

Week 9

 

20%

 

3, 4, 5

 

Assessment 3

Type: Multi-choice test / Group work / Short answer questions / Practical / Remote Lab / Simulation / Project / Report

Example Topic: A project involving AC variable speed drive selection for typical applications, including their required settings and energy saving estimates.

 

Week 11

 

20%

 

6

 

Assessment 4

Type: Examination Example Topic: All topics

An examination with a mix of detailed essay type questions and numerical problems to be completed within 2 hours.

 

Final Week

 

40%

 

All

 

Attendance / Tutorial Participation

Example: Presentation, discussion, group work, exercises, self-assessment/reflection, case study analysis, application.

Continuous

5%

-

Prescribed and Recommended Readings

 

Required textbook(s)

EIT reference book on Variable Speed Drives (Course code VSD)

 

Reference Materials

Number of peer-reviewed journals and websites (advised during lectures). An example of such webpage is: https://en.wikipedia.org/wiki/Vector_control_(motor)

Vector control (motor).

 

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.

 

Topics 1 and 2

Power electronic devices, typical applications, and circuits

  1. Power diodes, their types and working principles

  2. Power transistors, their types and working principles

  3. Thyristors, their types and working principles

  4. Gate turn off thyristors, their types and working principles

  5. IGBT and IGCT, their construction and working principles

  6. Uncontrolled and controlled rectifiers, their output waveforms and output voltage calculation

  7. Inverters: Devices used and output waveforms; effect of load inductance

 

Topics 3 and 4

Switched mode power supply circuits, design, and component ratings

  1. Need for switched mode power supply

  2. Working principle of a switched mode power supply

  3. Typical circuit of a switched mode power supply

  4. Output wave form of a switched mode power supply

  5. Effect of a filter on the output waveform

  6. Design aspects of a switched mode power supply

  7. Component selection

  8. Control of switched mode power supply

  9. Stability issues

 

Topics 5 and 6

Rectifiers, their types, control methods, and DC drives in industry

  1. Common devices used for power rectifier circuits

  2. Uncontrolled rectifier; single and 3 phase circuits of different configurations

  3. Output voltage and waveforms of an uncontrolled rectifier

  4. Controlled rectifier and control methods

  5. Output waveform of different controlled rectifiers

  6. Comparison of different devices used as controlled rectifiers

  7. DC drives: principles of speed control by armature voltage and by field weakening

  8. Applying controlled rectifiers for variable speed DC drives

  9. Common industrial applications of DC drives, their advantages and short comings

 

Topic 7

Inverter basic principle, voltage and current source inverters, and line-commutated inverters

  1. Basic principle of an inverter using switching as the basis of getting an AC output from DC input

  2. Voltage source and current source inverters

  3. Line commutated inverters

  4. Comparison of different types and their applications

  5. Waveforms obtainable with different types of inverters

 

Topics 8 and 9

Pulse width modulated AC drives, open loop drives, vector control drives, and sensor-less vector control drives

  1. Pulse width modulation principle

  2. Importance of carrier frequency in a PWM inverter

  3. Simple circuit applying PWM such as UPS with fixed output frequency/voltage

  4. Importance of DC bus and choice of DC bus voltage

  5. Advantage of a PWM circuit and limitations

  6. PWM application to AC motors using VVVF principle

  7. Problems when applying PWM AC drives with high carrier frequency

  8. Control strategies to obtain coordinated V/F control in open loop drives

  9. Performance improvement using feedback methods

  10. Vector control principles/applications

  11. Sensorless vector control principles/applications

 

Topics 10 and 11

Typical applications of AC drives, drive selection for different applications, energy saving calculations, and drive settings

  1. Typical applications of different forms of inverters for control of LV and HV AC motors

  2. Need for variable speed AC drives and benefits (when compared to DC drives)

  3. AC drives with induction and synchronous motors – the main differences

  4. Torque speed characteristics of different mechanical equipment

  5. Energy saving calculations when using variable speed drives

  6. Selection of a PWM AC drive for a given application by comparing motor and load torque

  7. Selection of a suitable motor for use with an AC drive

  8. Special requirements of motors when driven by AC PWM drives

  9. Bearing problems and need to use insulated bearings

  10. Retrofitting a VSD in an existing installation and interfacing with C&I systems

  11. Harmonic problems and EMI

  12. Typical setting options available and how to determine the settings in a given application

 

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.

The Engineering Institute of Technology (EIT) is dedicated to ensuring our students receive a world-class education and gain skills they can immediately implement in the workplace upon graduation. Our staff members uphold our ethos of honesty and integrity, and we stand by our word because it is our bond. Our students are also expected to carry this attitude throughout their time at our institute, and into their careers.