Electrical engineering courses

MV, HV AND EHV SWITCHGEAR TESTING AND COMMISSIONING M

Ref No: 2015055

INTRODUCTION  Testing is an essential activity in any engineer’s career. Whatever your role in industry -electrical designer, purchase engineer, manufacturer, installation contractor or maintenance engineer, a solid knowledge of tests to be carried out on a given piece of electrical equipment and interpretation of results obtained is a necessity. This manual is designed to familiarize you with various aspects of testing general electrical equipment and high voltage testing in particular. Examples will be cited from various international standards regarding the procedure for conducting of tests and interpreting the test results. The need for keeping proper records of tests conducted both in the initial stages and later during routine maintenance will be discussed. Some of the tests are too complex to be performed on a routine basis or may require specialized equipment which may not be normally available to user industries or even manufacturers. This is where the services of an independent and accredited test lab is useful.  The role of such labs will be briefly discussed.    OBJECTIVES    At the end of the seminar, each delegate will have good knowledge of: • Types of HV & MV tests performed • Good industry practice in performing the tests • The need for testing of MV and HV electrical equipment • Various types of HV equipment encountered in industry • Stage wise testing performed on electrical equipment • Testing equipment used • Need for good record keeping on tests conducted • Role of standards on testing approach, test basis and interpretation of results • National test labs and their importance in quality assurance


1- INTRODUCTION 

  • 1.1 Electrical system 
  • 1.2 HV AND MV equipment 
    • 1.2.1 Voltage Classification 
  • 1.3 Use of HV and MV equipment 
    • 1.3.1 High voltage equipment 
    • 1.3.2 Medium voltage equipment 
    • 1.3.3 Common HV and MV equipment 
  • 1.4 Need for testing 
  • 1.5 Purpose of testing 
  • 1.6 Categories of tests 
  • 1.7 Variations to test voltages and results 
    • 1.7.1 Altitudes above sea level 
    • 1.7.2 Temperature conditions 
    • 1.7.3 Tolerances 

2- INSULATION TESTING 

  • 2.1 Need for insulation 
  • 2.2 Principles of insulation testing 
    • 2.2.1 Capacitive current (Ic) 
    • 2.2.2 Dielectric absorption current (Ida) 
    • 2.2.3 Resistive (leakage) current (Ir) 
  • 2.3 Purpose of insulation testing 
  • 2.4 Testing the insulation of equipment 
  • 2.5 Insulation resistance test voltages 
  • 2.6 Types of testers 
  • 2.7 Construction of a tester 
  • 2.8 Connecting a tester 
  • 2.9 Test procedure 
  • 2.10 Precautions to be taken when measuring insulation 
  • 2.11 Polarization index 
  • 2.12 Step voltage test 
  • 2.13 Readings and interpretation 
  • 2.14 Dryness of insulation using absorption ratio 

3- HIGH POTENTIAL TESTS 

  • 3.1 Purpose of hi-pot testing 
    • 3.1.1 AC high potential testing (also called an over-potential test) 
    • 3.1.2 Power factor testing 
    • 3.1.3 AC hertz test 
    • 3.1.4 Resonant test 
  • 3.2 AC and DC hi-pot tests 
  • 3.3 Test equipment construction and connections 
  • 3.4 Safety precautions to be taken 
  • 3.5 Test voltages as per applicable standards 

4- OIL TESTING 

  • 4.1 Transformer oil – dielectric properties and uses 
  • 4.2 The need for testing transformer oil 
  • 4.3 Dielectric test 
  • 4.4 Improvement of oil by filtration 
  • 4.5 Oil filtration units 
  • 4.6 Test of acidity 
  • 4.7 Other tests 
    • 4.7.1 Interfacial tension test (IFT) 
    • 4.7.2 Color 
    • 4.7.3 Relative density 
    • 4.7.4 Dielectric dissipation factor 
    • 4.7.5 Water content 
    • 4.7.6 Flash point 
    • 4.7.7 Viscosity 
    • 4.7.8 Pour point 
    • 4.7.9 Specific resistance 
  • 4.8 Dissolved gas analysis 
    • 4.8.1 Features and importance 
    • 4.8.2 Basic gas analysis inferences 
    • 4.8.3 DGA study methods 
    • 4.8.4 DGA case studies 
  • 4.9 Precautions to be taken when sampling oil 

5- TESTING OF TRANSFORMERS 

  • 5.1 General 
  • 5.2 Routine tests 
  • 5.3 Guarantees and tolerances 
  • 5.4 Visual inspection 
  • 5.5 Winding resistance measurements 
  • 5.6 Turns ratio measurement 
  • 5.7 Polarity and vector group check 
  • 5.8 Impedance voltage and load losses 
  • 5.9 No load losses and current measurement 
  • 5.10 Insulation resistance tests 
  • 5.11 Dielectric tests 
  • 5.12 RIV Corona measurements 
  • 5.13 Partial discharge measurements 
  • 5.14 Impulse tests 
  • 5.15 Tests on OLTC 
  • 5.16 Type tests 
  • 5.17 Special tests 
    • 5.17.1 Measurement of zero sequence impedance 
    • 5.17.2 Short circuit test 
    • 5.17.3 Other special tests 
  • 5.18 Tests on bushings 
    • 5.18.1 Main insulation (C1) test connections 
    • 5.18.2 Test procedure 
    • 5.18.3 Test results and inference 
    • 5.18.4 Hot collar test 
    • 5.18.5 Test connections 
    • 5.18.6 Test procedure 
    • 5.18.7 Test results 
    • 5.18.8 Other tests on bushings 

6- CT TESTING 

  • 6.1 Instrument transformers 
  • 6.2 Current transformer types 
  • 6.3 Burden and accuracy classes 
  • 6.4 Other technical parameters 
  • 6.5 Polarity 
  • 6.6 Magnetization curve 
  • 6.7 Metering and protection CT requirements 
  • 6.8 Major tests on a CT 
  • 6.8.1 Type tests 
  • 6.8. 2 Routine tests 
  • 6.8. 3 Special tests 
  • 6.9 Test procedures 
    • 6.9.1 Short time current Ith withstand test 
    • 6.9.2 Temperature rise test 
    • 6.9.3 Impulse tests 
    • 6.9.4 RIV test 
    • 6.9.5 Partial discharge test 
    • 6.9.6 PF voltage tests 
    • 6.9.7 Inter-turn over-voltage test 
    • 6.9.8 Chopped impulse test on primary winding 
    • 6.9.9 Capacitance and dielectric dissipation factor 
    • 6.9.10 Transmitted over voltages measurement 
    • 6.9.11 Ratio verification test 
    • 6.9.12 Accuracy class verification 
    • 6.9.13 Polarity test 
    • 6.9.14 Test for CT magnetizing curve 
    • 6.9.15 Short circuit test 
    • 6.10 Safety precautions 

7- VT TESTING 

  • 7.1 Types of voltage transformers 
  • 7.2 Basic technical terms 
  • 7.3 Connection of voltage transformers 
  • 7.4 Tests on voltage transformers 
    • 7.4.1 Type tests 
    • 7.4.2 Routine tests 
    • 7.4.3 Special tests 
  • 7.5 Test procedures 
    • 7.5.1 Temperature rise test 
    • 7.5.2 Short-circuit withstand capability test 
    • 7.5.3 Impulse test on primary winding 
    • 7.5.4 Lightning impulse test 
    • 7.5.5 Switching impulse test 
    • 7.5.6 Wet test for outdoor type transformers 
    • 7.5.7 RIV test 
    • 7.5.8 Power frequency withstand test 
    • 7.5.9 Partial discharge test 
    • 7.5.10 Chopped impulse test on primary winding 
    • 7.5.11 Capacitance and dielectric dissipation factor 
    • 7.5.12 Transmitted over voltages measurement 
    • 7.5.13 Ratio and accuracy class verification test 

8- DUCTER TESTING 

  • 8.1 Need for the instrument 
  • 8.2 Description of instrument 
  • 8.3 Working principle 
  • 8.3.1 Kelvin bridge 
  • 8.3.2 Wheatstone bridge 
  • 8.3.3 Four wire instrument 
  • 8.4 Milli-ohmmeter vs micro-ohmmeter 
  • 8.5 Breaker contact resistance measurement 
  • 8.6 Transformer resistance measurement 
  • 8.7 Precautions during measurements 

9- TESTS ON OTHER MAJOR EQUIPMENT 

  • 9.1 Other major equipment 
  • 9.2 HV/MV switchgear and breakers 
    • 9.2.1 Routine tests 
    • 9.2.2 Type tests 
    • 9.2.3 Lightning impulse voltage tests 
    • 9.2.4 Power-frequency voltage tests 
    • 9.2.5 Testing for internal faults 
  • 9.3 MV motors 
  • 9.4 MV capacitors 
    • 9.4.1 Routine tests 
    • 9.4.2 Type tests 
    • 9.4.3 Test procedures 
  • 9.5 Disconnectors 
    • 9.5.1 Type tests 
    • 9.5.2 Routine tests 
    • 9.5.3 Procedures 

10- FIELD TESTS 

  • 10.1 Need for field tests 
  • 10.2 General safety procedures 
    • 10.2.1 Basic precautions 
    • 10.2. 2 Test area safety practices 
    • 10.2.3 Control and measurement circuits 
    • 10.2.4 Grounding and shorting 
    • 10.2.5 Spacing 
    • 10.2.6 High-power testing 
    • 10.2.7 General 
  • 10.3 Transformers 
    • 10.3.1 Visual and mechanical inspection 
    • 10.3.2 Electrical tests 
    • 10.3.3 Acceptance criteria 
  • 10.4 Switchgear 
    • 10.4.1 Visual and mechanical inspection 
    • 10.4.2 Electrical tests 
    • 10.4.3 Acceptance criteria 
  • 10.5 High voltage disconnectors 
    • 10.5.1 Visual and mechanical checks 
    • 10.5.2 Electrical checks 
    • 10.5.3 Test values 
  • 10.6 MV cables 
    • 10.6.1 Visual and mechanical inspection 
    • 10.6.2 Electrical tests 
    • 10.6.3 Acceptance criteria 
  • 10.7 MV bus ducts 
    • 10.7.1 Visual and mechanical inspection 
    • 10.7.2 Electrical tests 
    • 10.7.3 Acceptance criteria 
  • 10.8 Instrument transformers 
    • 10.8.1 Visual and mechanical inspection 
    • 10.8.2 Electrical tests 
    • 10.8.3 Acceptance criteria 
  • 10.9 Rotating machinery 
    • 10.9.1 Visual and mechanical inspection 
    • 10.9.2 Electrical tests 
    • 10.9.3 Acceptance criteria 
    • 10.10 Surge arresters 
    • 10.10.1 Visual and mechanical inspection 
    • 10.10.2 Electrical tests 
    • 10.10.3 Acceptance criteria 
    • 10.11 Outdoor bus structures 
    • 10.11.1 Visual and mechanical inspection 
    • 10.11.2 Electrical tests 
    • 10.11.3 Acceptance criteria 
    • 10.12 Engine generators 
    • 10.12.1 Visual and mechanical inspection 
    • 10.12.2 Electrical tests 
    • 10.12.3 Acceptance criteria 
    • 10.13 Maintenance tests 
    • 10.13.1 Multiplication factors 
    • 10.13.2 Recommended schedule 

• Instrumentation & Control Engineers
• Consulting Engineers
• Electrical Engineers
• Project Engineers
• Maintenance Engineers
• Power System Protection & Control Engineers
• Building Service Designers
• Data Systems Planners & Managers
• Electrical & Instrumentation Technicians 

Trainees shall receive a portfolio containing a comprehensive course manual.

Attendees shall receive a certificate of attendance from AMAD Tech.