Last Updated | 2025S1 |
Unit Name | Power System Protection |
Unit Code | BEE308 |
Unit Duration | 1 Semester |
Award |
Bachelor of Science (Engineering) Duration 3 years |
Year Level | Two |
Unit Coordinator BEE Course Coordinator |
Dr Naser Hash Dr Hossein Tafti |
Core/Sub-discipline: | Sub-discipline |
Pre/Co-requisites | BEE204 |
Credit Points |
3 Total Course 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; 5 hours per week for 24 week delivery) 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 to: provide students with detailed knowledge of power system protection and its role in the safe and reliable operation of a power system; and, to impart the ability to choose and apply protection systems in a given context. Information covered in this unit will include: the different types of protective devices and their applications; the coordination between different protective devices and the different forms of grading that are possible; protection of individual types of equipment such as motors, generators, transformers, and switchgear; and, the approach to setting these protective devices. Students will also undertake project work involving protection applications and settings for a typical industrial power network.
Learning Outcomes
On successful completion of this Unit, students are expected to be able to:
- Explain the fundamentals of electrical power system protection and its components.
Bloom's Level 2 - Describe protection devices used in LV systems, relays, and IEDs.
Bloom's Level 2 - Evaluate short circuit current values of simple industrial systems using equivalent diagrams.
Bloom's Level 3 - Explain the time/current characteristics of DMT and IDMT types and calculate coordinated settings in practical circuits.
Bloom's Level 6 - Explain the concept of unit protection and compare its applications.
Bloom's Level 5 - Describe protection systems specific to each type of equipment.
Bloom's Level 3
Student Assessment
Assessment Type | When assessed | Weighting (% of total unit marks) | Learning Outcomes Assessed |
Assessment 1 Type: Weekly quizzes Description: Students will need to complete multiple-choice quiz questions to demonstrate a good understanding of the fundamental concepts. |
Weekly | 10% | All (Topics 2 to 11) |
Assessment 2 Type: Test (Invigilated) Description: Students will need to answer some short and/or long answer questions and/or solve some numerical problems. |
During Topic/Week 7 | 20% | 1, 2, 3, 4 (Topics 1 to 6) |
Assessment 3 Type: Practical (Report) & Pre-recorded Presentation Description: Students will need to complete a practical project using software. It requires research on the state-of-art solutions in the field. |
End of Topic/Week 9 | 30% | 1, 2, 3, 4, 5 (Topics 1 to 9) |
Assessment 4 Type: Exam (Invigilated) Description: An examination with a mix of theoretical short/detailed answer questions and some engineering problems. |
Exam Week | 40% | All (All topics) |
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
Required textbook(s)
- J. L. Blackburn, T. J. Domin, Protective Relaying: Principles and Applications, 3rd Edition. CRC Press, 2006. eBook ISBN 9780429115691
Reference Materials
- Number of peer-reviewed journals and websites (advised during lectures)
For example:
- Simple, easy to follow explanations can be seen from the webpage:
- Protection System in Power System by electrical4u.com Online Electrical Engineering
Unit Content
One topic is delivered per contact week.
Topics 1 and 2
Basics of Power System Protection
- Objectives of protection systems
- Attributes of protection systems
- Functional components in a protection system
- Protection – basic approaches: fuses, release integrated with breakers, and relays
- Instrument transformers and their application in protection
- Reliable, battery-based power supply for protection systems
- Fuses and their application in the protection of feeders
- Types of protective release integrated systems with LV circuit breakers
Topics 3 and 4
Faults: Types and Calculation of Fault Current
- Reason for faults in electrical circuits
- Types of faults
- Principle of fault current calculation
- Limiting the fault current magnitude – methods of determining this
- Ohmic and per unit impedance, and the calculation of impedance per unit values
- Equivalent diagrams for fault current evaluation
- Calculation of 3-phase fault current using reduction of equivalent diagram
- Maximum and minimum fault currents, implication for protection design
- Symmetrical components and application in calculating the current for unbalanced faults
Topics 5 and 6
Protection Relays and IEDs, Their Setting and Coordination
- Types of protection relays based on construction
- Time-current characteristics and relay types based on the characteristic
- Intelligent electronic devices - essential components
- IEC/ANSI equations for time/current characteristics
- Determining current setting based on circuit parameters and fault current values
- Grading of protection needs and methods (current, time, energy, impedance, direction)
- Current/time grading and the different approaches used
- Calculation of coordinated setting on current relays using a spreadsheet program
Topics 7 and 8
Principles of Unit Protection and Protection of Feeders
- Unit or differential protection
- Comparison with other methods of protection
- Applications of unit protection and pitfalls
- Protection Requirements for Bushfire mitigation
- Feeder protection using current relays
- Feeder protection using unit principle
- Protection by comparison of phase angle
- Distance protection and comparison with unit protection
- Distance protection with PLCC or other inter-communication for fast operation
Topic 9
Transformer Protection
- Transformer faults
- Over-current protection
- Differential protection
- Earth fault/REF protection
- Temperature based protection
- Gas protection
- Mounted DGA monitoring for early detection
Topics 10 and 11
Protection of Electrical Switchgear and Rotating Machines (Generators and Motors)
- Busbar protection in outdoor and indoor substations using current relays and unit protection
- LV busbar protection with optical (arc) sensing
- LV busbar protection with zone selective relaying and communication interlinks
- Faults in motors
- Winding protection using unit protection approach
- Thermal protection
- Stall protection
- Over-current, earth fault and negative sequence current protection
- Generator faults
- Protection using current relays
- Winding protection using unit approach and sensitive earth fault protection
- Temperature based protection
- Loss of field and pole-slip protection
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
- ETAP
- PSCAD
Hardware
- N/A
Unit Changes Based on Student Feedback
- The assessment structure is updated based on the action items of the Learning and Teaching Committee (Dec 2024)