PRTPRA4/101/0/2013

Tutorial letter 101/0/2013

Protection Technology IV (Practical)

PRTPRA4

Year Module

Department of Electrical and Mining Engineering

IMPORTANT INFORMATION:

This tutorial letter contains important information about your module.

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CONTENTS

Page

1  INTRODUCTION ............................................................................................................................ 3 

2  PURPOSE OF AND OUTCOMES FOR THE MODULE ............................................................... 3 

2.1  Purpose .......................................................................................................................................... 3 

2.2  Outcomes ....................................................................................................................................... 3 

3  LECTURER(S) AND CONTACT DETAILS .................................................................................... 3 

3.1  Lecturer(s) ...................................................................................................................................... 3 

3.2  Department ..................................................................................................................................... 3 

3.3  University ........................................................................................................................................ 4 

4  MODULE-RELATED RESOURCES .............................................................................................. 4 

4.1  Prescribed books ............................................................................................................................ 4 

4.2  Recommended books ..................................................................................................................... 4 

4.3  Electronic Reserves (e-Reserves) .................................................................................................. 4 

5  STUDENT SUPPORT SERVICES FOR THE MODULE ................................................................ 4 

6  MODULE-SPECIFIC STUDY PLAN ............................................................................................... 4 

7  MODULE PRACTICAL WORK AND WORK-INTEGRATED LEARNING ..................................... 4 

8  ASSESSMENT ............................................................................................................................... 4 

8.1  Assessment plan ............................................................................................................................ 4 

8.2  General assignment numbers ......................................................................................................... 5 

8.2.1  Unique assignment numbers .......................................................................................................... 5 

8.2.2  Due dates for assignments ............................................................................................................. 5 

8.3  Submission of assignments ............................................................................................................ 5 

8.4  Assignments ................................................................................................................................... 7 

9  OTHER ASSESSMENT METHODS ............................................................................................. 12 

10  EXAMINATION ............................................................................................................................. 12 

11  FREQUENTLY ASKED QUESTIONS .......................................................................................... 12 

12  SOURCES CONSULTED ............................................................................................................. 12 

13  CONCLUSION .............................................................................................................................. 12 

14  ADDENDUM ................................................................................................................................. 12 

PRTPRA4/101

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1 INTRODUCTION

Dear Student

Welcome to the subject Protection Technology IV (Practical) (PRTPRA4) at UNISA. This tutorial letter serves as a guideline to this subject. It provides you with general administrative information as well as specific information about the subject. Read it carefully and keep it safe for future reference. We trust that you will enjoy this course.

2 PURPOSE OF AND OUTCOMES FOR THE MODULE

2.1 Purpose

The purpose of this subject is for the student to apply the first principles of Protection Technology to calculate the Zbus using different models, calculations and theorems in a practical exercise.

2.2 Outcomes

The successful application of a fault current study where the fault current for all possible faults (three and single phase) are calculated on all the buses of a given network.

3 LECTURER(S) AND CONTACT DETAILS

3.1 Lecturer(s)

Your Lecturer for Protection Technology IV is Mr E Naude. He can be contacted at the following number for any theoretical questions: Tel nr : 0828067717 e-mail: enaude@gmail.co.za Contact Times: Mondays to Fridays 18h00 – 20h00

3.2 Department

Department of Electrical and Mining Engineering: electrical&mining@unisa.ac.za

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3.3 University

If you need to contact the University about matters not related to the content of this module, please consult the publication My studies @ Unisa that you received with your study material. This brochure contains information on how to contact the University (e.g. to whom you can write for different queries, important telephone and fax numbers, addresses and details of the times certain facilities are open).Always have your student number at hand when you contact the University.

4 MODULE-RELATED RESOURCES

4.1 Prescribed books

The same as for the theoretical part of the subject.

4.2 Recommended books

There are no recommended books for this module.

4.3 Electronic Reserves (e-Reserves)

There are no electronic reserves for this module.

5 STUDENT SUPPORT SERVICES FOR THE MODULE

Important information appears in your my Studies @ Unisa brochure.

6 MODULE-SPECIFIC STUDY PLAN

Use your my Studies @ Unisa brochure for general time management and planning skills.

7 MODULE PRACTICAL WORK AND WORK-INTEGRATED LEARNING

This module covers the practical part.

8 ASSESSMENT

8.1 Assessment plan

The assignments are as follows: Assignment 1: Registration Form for PROTECTION TECHNOLOGY IV

(Annexure A) Assignment 2: Send in your portfolio.

PRTPRA4/101

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Submission of both assignments is compulsory.

The final mark is based on all the assignment marks obtained and their contribution towards the final mark are as shown in the table below:

ASSIGNMENT NUMBER CONTRIBUTION TOWARDS FINAL SUBJELE

MARK 1 (Compulsory) 10 % 2 (Compulsory) 90%TOTALS = 100 %

Submission of Assignment 1 “allows” you complete a practical assignment, which is the examination for this subject. Ensure that you understand this principle. Failure to submit Assignment 1 by the due date, will result in you being barred from handing in a practical assignment and you will have to reregister for this subject. If in doubt, contact your lecturer before the submission date!!!!

8.2 General assignment numbers

Assignments are numbered consecutively per module, starting from 01.

8.2.1 Unique assignment numbers

Assignment 1: (Compulsory)

742596

Portfolio: (Compulsory)

879483

8.2.2 Due dates for assignments

THE CUT-OFF SUBMISSION DATES FOR THE ASSIGNMENTS ARE :

Assignment 1 (Annexure A- Registration form) (Compulsory)

16 April 2013

Assignment 2 – Results of experiments Portfolio(Compulsory)

1 October 2013

8.3 Submission of assignments

A practical assignment must be submitted. The practical experiments, which much be completed, is included in this tutorial letter. A mentor must be chosen and the mentor form must accompany the assignment when it is sent in. (See ANNEXURE B)

For detailed information and requirements as far as assignments are concerned, see the brochure my Studies @ Unisa that you received with your study material.

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To submit an assignment via myUnisa: Go to myUnisa. Log in with your student number and password. Select the module. Click on assignments in the menu on the left-hand side of the screen. Click on the assignment number you wish to submit. Follow the instructions.

PRTPRA4/101

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8.4 Assignments

ANNEXURE A – ASSIGNMENT 1

REGISTRATION FORM FOR PROTECTION TECHNOLOGYS IV PRACTICAL - COMPLETION OF PRACTICAL ASSIGNMENT

2013

PLEASE COMPLETE IN CLEAR BLOCK LETTERS & SEND IN AS A NORMAL ASSIGNMENT

FROM Surname/Initials

:

STUDENT NUMBER :

POSTAL ADDRESS :

POSTAL CODE :

TEL NO (WORK) :

TEL NO (HOME) :

MOBILE :

e-mail :

……………………..SIGNATURE OF LEARNER DATE: …………………….

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ASSIGNMENT 2

Practical Assignment

1.1 INTRODUCTION

As this is a very theoretical subject consisting only of calculations, it is very difficult to do practical experiments. The most useful practical assignment will be to undertake a complete fault-study on a typical small power system. This can be done by using any available software program that will perform this study on a computer. I am sure that very few students have access to such a program and it will therefore be required that you do the fault study by doing all the calculations by hand.

What is a fault study?

A fault study is an exercise where the fault currents for all possible faults (three-phase, single-phase to earth, phase to phase and phase to phase to earth), are calculated on all the buses.

1.2 PROCEDURE

Draw the positive-, negative- and zero-sequence diagrams for the network and then do the following:

Determine Zbus(pos), Zbus(neg) and Zbus(zero).

Calculate the fault-currents on all the buses for all types of faults.

1.3 GENERAL

(Use the example in the textbook for reference)

Marks will not be allocated for correct answers. The following will be used as guidelines for mark allocation:

Correctness of sequence-diagrams (20%)

Correct method used to determine Z-buses (10%)

Correct method used to determine fault-currents (10%)

Completeness of the exercise (60%)

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1.4 FAULT STUDY

Do a fault study on the power system shown in Figure 1.

Figure 1

G1: 1 000 MVA 15 kV Xd” = X2 = 0,18p.u X0 = 0,07p.u

G2: 1 000 MVA 15 kV Xd” = X2 = 0,2p.u X0 = 0,1p.u

G3: 500 MVA 13,8 kV Xd” = X2 = 0,15p.u X0 = 0,05p.u

G4: 750 MVA 13,8 kV Xd” = 0,3p.u X2 = 0,4p.u

X0 = 0,1p.u

T1: YNd11 1 000 MVA 765/15 kV X = 0,1p.u

T2: YNd11 1 000 MVA 765/15 kV X = 0,1p.u

T3: YNy0 500 MVA 765/15 kV X = 0,12p.u

T4: YNyn0 750 MVA 765/15 kV X = 0,11p.u

L1-2: X1 = 50 X0 = 150

L1-3: X1 = 40 X0 = 100

L3-2: X1 = 40 X0 = 100

Use Sb = 1 000 MVA and the pre-fault voltage on the transmission lines of 765 kV.

1 3

2

G1 T1

T3

T4

T2

G2

G3

G4

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ANNEXURE B

1. POLICY FOR PRACTICAL ASSIGNMENTS a. All experiments have to be performed. b. In order to receive a pass mark, the student need to receive a sub-minimum of 50%. c. All students must have their own practical guide and components. d. Every student must do his own practical, however students are allowed to receive help in a constructive

manner. e. Practical experiments must be built by the student himself and the relevant answers supplied on the

respective answer sheet for that experiment. f. Use standard symbols and notation, as used in the theoretical notes and practical guide, on the answer

sheet. g. Where applicable, the construction of your practical assignment will be evaluated on the following criteria: i) neatness; ii) correct layout of components; iii) correct wiring techniques; iv) correct operation of circuit; v) student's knowledge of the circuit; and vi) insight into the practical work. h. All the experiments need to be certified by the student's mentor (see the form attached), as the student's

own work. Refer to paragraph 3 for the very important information regarding the appointment of your mentor.

i. Students need to take every safety precaution (especially where the experiment involves 220-V and 380-V

alternating current). UNISA cannot be held responsible for any damage to equipment or harm to any person. In cases where the student is in doubt about any safety aspect, contact Unisa for assistance.

2. INTERACTION WITH THEORETICAL WORK You are advised to conduct the experiments only after the relevant theory has been covered. 3. APPOINTMENT OF MENTOR Your mentor plays a very important role in the successful completion of your assignment. The functions of your

mentor are the following: (a) help you in a constructive manner and (b) verify that it is your own work. Your mentor should thus be appointed in order to fulfill the above mentioned task. Your mentor must preferably be professionally registered with ECSA (Engineering Counsel of South

Africa) for us to accredit his authorisation of your work. If the person acting as your mentor is not registered with ECSA, then someone who is professionally registered with ECSA, should also authorise your assignment. The mentor must supply his particulars as requested on the authorisation form attached to each experiment, for us to accept his authorisation.

PRTPRA4/101

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UNISA, Programme Group Engineering,

SUBMIT THIS FORM WITH THE RESULTS OF YOUR PRACTICAL EXPERIMENTS

Protection Technology IVII - PRACTICAL

Mentor Appointment

Student number: ................................................

Student name: ....................................................

Employer: ..........................................................

Particulars of mentor:

Name: ...........................................

Address: ........................................

.........................................

.........................................

.........................................

Employer: .........................................................

Telephone number:.............................................. (W)

............................................... (H)

Qualifications:.....................................................................................

Capacity at work:................................................................................

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9 OTHER ASSESSMENT METHODS

None

10 EXAMINATION

Use your my Studies @ Unisa brochure for general examination guidelines and examination preparation guidelines.

11 FREQUENTLY ASKED QUESTIONS

The my Studies @ Unisa brochure contains an A-Z guide of the most relevant study information.

12 SOURCES CONSULTED

None

13 CONCLUSION

Please ensure that you have all the tutorial letters and prescribed book available before starting with your studies.

14 ADDENDUM

None