Eskom Centre of Excellence in HVDC Engineering
The Eskom Centre of Excellence (CoE) at the University of KwaZulu-Natal, which also serves as the Eskom Power Plant Engineering Institute (EPPEI) Specialization Centre in High Direct Current (HVDC) Engineering is a multi-disciplinary research center which focusses on research in technology relating to HVDC, power systems (including lines) and power electronics relating to AC systems.
The purpose of the Center is to contribute to the South African engineering and scientific expertise through its own fundamental and applied research, and through collaborative work with others. The multidisciplinary nature of our research is reflected in the past, current and future activities of the Centre’s research with industry and community-based development projects.
High Voltage Lab – Howard College
The following equipment is in the temperature controlled facility at the Howard College Campus:
- 400 kV/1000 V 150 kVA AC transformer
- 240 kV/380 V 120 kVA AC transformer (cascade)
- 100 kV/230 V 40 kVA AC transformer (pd free)
- 400 kV 500 pF CVD (31 mA @ 400 kV)
- 5 V / 380 V 30 kA / 394 A 150 kVA AC transformer
- 400 V / 500 V 200 kVA AC transformer
- 1 MV rated 8 stage impulse generator currently running at 7 stage approx peak of 650 kV
- Incline plane test (AC and DC)
Tests undertaken with estimated times:
- U50 – 60 minutes per standard 20 shot test
- Fast front – 60 minutes per standard 20 shot test
- Dry flashovers – 30 minutes per 5 flashover test and 1 minute withstand
- Wet flashovers – 30 minutes per 5 flashover test and 1 minute withstand
- High current AC (above 1 kA) – 60 minutes per test including setup and cooling. May require additional help to administer test
- High current AC (below 1 kA) – 30 minutes per test including setup
- Have calibrated current probes using this system
Advantages: Can undertake non-standard testing
Limitations: Clearances are not adequate for 400 kV
High Voltage Lab – Westville
The following equipment is in the facility at the Westville Campus:
- 500 kVdc Cockroft-Walton voltage multiplier
- 200 kVdc supply
- Corona cage
- Overhead line setup
- Tan delta: Hipotronics 2320 and Capacitors up to 200 kV
- Partial discharge measurement: Robinson DDX-7000 and 200 kV 1 nF coupling capacitor (31 mA @ 100 kV)
- Thermal camera
- Corona cameras
- Audio devices
Tests undertaken with estimated times:
- DC breakdown test on cables – 60-120 minutes per test
Advantages: Can undertake non-standard testing
Limitations:
- Current is limited to 50 mA so tan-delta can only test low capacitance systems, partial discharge is limited to 100 kV.
- Partial discharge is subject to interpretation due to sensitivity of the device and the laboratory.
- Clearances are not adequate for 550 kV.