Last Updated S022019

MEE504

Unit Name INSULATION COORDINATION  AND SUBSTATION EARTH GRID DESIGN
Unit Code MEE 504
Unit Duration 1 Term (online) or 1 Semester (on-campus)
Award

Graduate Diploma of Engineering ( Electrical Systems )

Duration : 1 year

Master of Engineering (Electrical systems

Duration : 2 years

 

Year Level One
Unit Creator / Reviewer Prof. Trevor Blackburn
Core/Elective: Core
Pre/Co-requisites Nil
Credit Points

3

Grad Dip course credit points = 24 

( 3 credits  x 8 ( units))

Master course credit points = 48

( 3 credits  x 12 (units)  + 12 ( thesis))

Mode of Delivery Online or on-campus. 
Unit Workload

10 hours per week

Lecture = 1 hour

Practical/ Lab = 1 hour ( where applicable )

Personal study recommended = 7 hours (guided and unguided)

Unit Description and General Aims

Power systems and substations in particular must operate so that the electrical equipment components are able to withstand the transient over-voltages that occur in them at various times. These transient over -voltages are greater than the normal power frequency voltage and so they, the transient impulse voltages, define the basic insulation level (BIL) of a power system. The dielectric strength or insulation withstand of the equipment must be designed (or coordinated) to be greater than the level of over -voltages that may impact on sensitive equipment. This will require the use of surge arresters as well as appropriate insulation design. This unit provides the fundamentals of the design procedures required to achieve insulation coordination. The scope of the coverage includes the sources and characteristics of transient over -voltages, including lightning and switching types, their propagation and attenuation characteristics. It will also cover the dielectric properties of the various types of insulation used in substations, including gas, liquid and solid types. The unit will cover the characteristics and design of protection devices and the basic statistical approach to insulation coordination design. The unit will also cover impulse voltage and current testing of equipment. Worker safety is a necessary factor in the design of substations and the course will also cover in detail earthing requirements in substations and safe clearances of live electrical components. ATP/EMTP software will be used to analyse system and equipment response to transient over -voltages . Students will acquire fundamental knowledge of high voltage techniques, insulation properties and design and test methods. They will undertake case studies of substation design projects for a range of distribution and transmission voltage levels appropriate to their individual and general work activities.

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Learning Outcomes

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

1. Determine the typical levels of over-voltages that will be expected in different types and voltage power networks
and how it impacts on equipment and subsequent general transmission system discontinuities.
Bloom’s Level 6
 
2. Understand the dielectric strengths and breakdown characteristics of electrical insulation (gases, liquids and solids) as used in electrical equipment and power systems.
Bloom’s Level 6
 
3. Discriminate between voltage distributions in distributed parameter windings for power frequency and transient overvoltage conditions.
Bloom’s Level 6
 
4. Apply the characteristics of overvoltage protection devices for equipment in HV substations and for LV equipment.
Bloom’s Level 6
 
5. Apply the principles of earthing system design techniques and regulations to the design of substation earth grids with regard to fault handling capacity and touch and step voltage limitations.
Bloom’s Level 6
 
6. Apply statistical methods to achieve proper insulation coordination design of substations.
Bloom’s Level 6
 
7. Specify the various impulse test requirements for equipment in substations.
Bloom’s Level 6
 
8. Use software packages to calculate transient overvoltages and their distribution and to design
earth grids with touch and step potential determinations.
Bloom’s Level 6

Student assessment

Assessment Type

(e.g. assignment 2000 word essay ( specify topic ) examination ( specify length and format))

When assessed Weighting (% of total unit marks) Learning Outcomes Assessed
Assessment 1
 
Type:Multi- choice test / Group work / Short answer
questions / Role Play / Self-Assessment / Presentation
 
Topic examples: Impact of lightning and switching overvoltages, new insulation materials, gas insulated
systems and transformers
 
After Topic 5 20% 1,2

Assessment 2 

 
Type:Report / Research / Paper / Case Study/ Site Visit/ Problem analysis/ Project / Professional
recommendation
 
Example:Report(Midterm Project)
[This will include a progress report; literature review,hypothesis, and methodology/ conclusions]
Word length: 1000
 
Topic examples: “Design of surge protection for a 110 kV substation against lightning and switching” and write an abstract on a topic related to “transient voltages and insulation coordination of a 500kV cable line”.

 

After Topic 8

25% 4,5,6,7,8

Assessment 3

Type:Report(Final Project)
[If a continuation of the midterm, this should complete the report by adding sections on: methodology,implementation /evaluation, verification/ validation,conclusion/ challenges and recommendations/ future work. If this is a new report, all headings from the midterm and the final reports must be included.]
Word length: 2000
 
Topic examples: "Design the earth grid of a substation " and write an abstract on a topic related to “transient overvoltages in wind farm resulted from the lightning”.
After Topic 11 35% 1,2,3,5,8

Practical Participation

Type: Example: May be in the form of quizzes, class tests, practical assessments , remote labs, simulation software or case studies

Final Week 15% 8

Attendance / Tutorial Participation

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

Continuous 5% 1 -8

 

Prescribed and Recommended readings

Required textbook(s)
  • C. R. Bayliss, B. J. Hardy, Transmission and Distribution Electrical Engineering, 4th Edition. Elsevier, 2011 - ISBN: 978-008096913-8 (available via the eLibrary)
  • J. Glover, M. Sharma, Power System Analysis and Design, 6th Edition. Thomson-Engineer, 2016 – ISBN: 978-1305636187
 
 
Reference Materials:
  • J. C. Das,Transients in Electrical Systems, 2011 (ISBN 978-0-07-162248-6)
  • J. A. Matinez-Velasco, Power System Transients Parameter Determination, 2010 (ISBN 978-1-4200-6529-9)
  • Greenwood, Allan: “Electrical Transients in Power Systems” 2nd ed. 1991, John Wiley.
  • Hileman, Andrew R: “Insulation Coordination for Power Systems”, 1999, Marcel Dekker.
  • Kuffel, E and Zaengl, W S: “High Voltage Engineering” 1984, Pergamon Press.
  • IEEE Std. 1313.1/2: “Insulation Coordination, Principles and Rules”.
 

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

Over voltages and insulation in power systems
 
1. Historical developments of power system voltages
2. Overvoltages and their impact
3. Lightning properties and OV generation
4. Transient recovery voltages and switching
 

Topic 3 and 4

Impact of transient OVs on windings
 
1. Surge properties of distributed parameter lines and cables
2. Surge propagation on lines and cables
3. Reflection and transmission coefficients of travelling waves
4. Non-linear voltage distribution in windings

 

 

Topics 5 and 6

Insulation properties and protection
1. Dielectric properties of materials
2. Basic insulation levels and clearance requirements in substations
3. Surge protection: surge arresters and similar devices
4. Insulation coordination methods

 

Topics 7 and 8

Earthing/grounding systems and personnel protection in substations
1. Earthing/grounding system fundamentals
2. Grid system and electrode earthing
3. Touch, step and transferred potentials and permissible levels
4. Current handling capacity design of earthing conductors
5. Power system earthing regulations and design requirements

 

Topics 9 and 10

Calculation methods in design
1. Use of ATP for transient analysis
2. Use of earthing software for grid design and potential calculations

 

Topic 11

Impulse testing

1. Marx generators and lightning impulses
2. Surge current generators

 

Topic 12

  1. Project and Revision
  2. In the final week students will have an opportunity to review the contents covered
  3. so far. Opportunity will be provided for a review of student work, to clarify any outstanding issues, and to work on
  4. finalising the major assessment report.

 

Software/Hardware Used

Software

  • Software: Microsoft Excel, Matlab/Simulink

  • Version: N/A

  • Instructions:  N/A

  • Additional resources or files: N/A

Hardware

  • N/A