High Voltage Engineering AC at the University of the Witwatersrand
This SC aims to build up the Eskom skills base in electrical engineering by presenting courses and 4 conducting research in the area of high voltage (AC), which includes generation, transmission and distribution.
Generator stator insulation and generator rotor insulation integrity is crucial for reliable generator operation. Due to high temperatures, mechanical stresses, and vibration present in an operating generator, there is an inevitable steady degradation of the insulation condition. Partial discharge testing is one of the most important diagnostic tests conducted on generator insulation, but test result interpretation and estimation of remaining life is still a challenge. Generator transformers also operate in demanding environments, and their failure accounts for a large portion of the current Eskom unplanned capability loss factor (UCLF).
The transmission research focuses on the performance of transmission lines in environments that include lightning strikes, switching surges, power frequency overvoltages and pollution. Once again, the objective is to maintain reliable operation of Eskom’s large transmission network. Expertise in lightning performance of transmission lines is crucial for line designs that have acceptable lightning performance (a limited number of flashovers due to lightning). Switching surge performance is particularly important for live-line work where human safety must be ensured. Good pollution performance requires insulator selection that considers the pollution performance of various types of insulators (ceramic or polymeric). In addition to a reliable transmission network, reliable operation of large electrical networks involves maintaining acceptable transient stability, small-signal stability, voltage stability and frequency stability.
In the area of distribution, research focuses on improved monitoring and protection of equipment such as transformers, which have historically had limited monitoring. Stresses on transformers have increased due to electricity theft, non-linear loads, and unbalanced sharing of single-phase loads among the three phases. With increased penetration of renewable generation in distribution, better monitoring and control of transformers will be essential. The presence of non-linear loads increases the importance of power quality and electromagnetic compatibility studies.
This SC aims to build up the Eskom skills base in electrical engineering by presenting courses and 4 conducting research in the area of high voltage (AC), which includes generation, transmission and distribution.
Generator stator insulation and generator rotor insulation integrity is crucial for reliable generator operation. Due to high temperatures, mechanical stresses, and vibration present in an operating generator, there is an inevitable steady degradation of the insulation condition. Partial discharge testing is one of the most important diagnostic tests conducted on generator insulation, but test result interpretation and estimation of remaining life is still a challenge. Generator transformers also operate in demanding environments, and their failure accounts for a large portion of the current Eskom unplanned capability loss factor (UCLF).
The transmission research focuses on the performance of transmission lines in environments that include lightning strikes, switching surges, power frequency overvoltages and pollution. Once again, the objective is to maintain reliable operation of Eskom’s large transmission network. Expertise in lightning performance of transmission lines is crucial for line designs that have acceptable lightning performance (a limited number of flashovers due to lightning). Switching surge performance is particularly important for live-line work where human safety must be ensured. Good pollution performance requires insulator selection that considers the pollution performance of various types of insulators (ceramic or polymeric). In addition to a reliable transmission network, reliable operation of large electrical networks involves maintaining acceptable transient stability, small-signal stability, voltage stability and frequency stability.
In the area of distribution, research focuses on improved monitoring and protection of equipment such as transformers, which have historically had limited monitoring. Stresses on transformers have increased due to electricity theft, non-linear loads, and unbalanced sharing of single-phase loads among the three phases. With increased penetration of renewable generation in distribution, better monitoring and control of transformers will be essential. The presence of non-linear loads increases the importance of power quality and electromagnetic compatibility studies.