Christos Zachariades - Academia.edu (original) (raw)
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Papers by Christos Zachariades
IEEE Transactions on Power Delivery
This paper reports on a method combining the use of finite element simulations and external measu... more This paper reports on a method combining the use of finite element simulations and external measurements to provide preliminary condition diagnosis of oil-filled cable sealing ends (CSEs) without requiring downtime. Good agreement has been obtained between the predictions from the electric field and thermal simulations and the measurements on a 132 kV oil-filled CSE. The electrostatic computation combined with electric field measurements can provide information regarding the electric field distribution inside the CSE and help in identifying potential issues with the CSE design, the materials or the cable termination process. The thermal computation combined with thermal imaging can reveal potential problems, such as high resistance connection to the busbar, and provide information regarding the cooling efficiency of the liquid dielectric. The method presented can provide the starting point for prioritizing maintenance operations on CSEs.
Thesis the University of Manchester 2014, Nov 21, 2014
IEEE Sensors Journal
High Frequency Current Transformer (HFCT) sensors are widely used for Partial Discharge detection... more High Frequency Current Transformer (HFCT) sensors are widely used for Partial Discharge detection due to their versatility, high sensitivity and wide bandwidth. This paper reports on a Finite Element Analysis (FEA) methodology that can be employed to optimize HFCT performance. The FEA model consists of accurate 3D representations of the sensor components. Two different FEA software modules were used in order to cover the wide operating frequency range of the sensor. The simulation computes the frequency response of the sensor in the range 0.3 MHz-50 MHz for various HFCT geometric and material parameters, specifically the number of winding turns, spacer thickness, aperture size and core material. A prototype HFCT was constructed and the measured response compared with that of the simulation. The shapes of the responses were similar, with the simulated sensitivity being higher than the measured sensitivity by 1 dB on average. The measured low frequency cutoff of the sensor was found to be only 0.05 MHz lower than that of the simulation.
IEEE Transactions on Power Delivery, 2015
2015 IEEE Electrical Insulation Conference (EIC), 2015
2015 IEEE Electrical Insulation Conference (EIC), 2015
IEEE Transactions on Power Delivery
This paper reports on a method combining the use of finite element simulations and external measu... more This paper reports on a method combining the use of finite element simulations and external measurements to provide preliminary condition diagnosis of oil-filled cable sealing ends (CSEs) without requiring downtime. Good agreement has been obtained between the predictions from the electric field and thermal simulations and the measurements on a 132 kV oil-filled CSE. The electrostatic computation combined with electric field measurements can provide information regarding the electric field distribution inside the CSE and help in identifying potential issues with the CSE design, the materials or the cable termination process. The thermal computation combined with thermal imaging can reveal potential problems, such as high resistance connection to the busbar, and provide information regarding the cooling efficiency of the liquid dielectric. The method presented can provide the starting point for prioritizing maintenance operations on CSEs.
Thesis the University of Manchester 2014, Nov 21, 2014
IEEE Sensors Journal
High Frequency Current Transformer (HFCT) sensors are widely used for Partial Discharge detection... more High Frequency Current Transformer (HFCT) sensors are widely used for Partial Discharge detection due to their versatility, high sensitivity and wide bandwidth. This paper reports on a Finite Element Analysis (FEA) methodology that can be employed to optimize HFCT performance. The FEA model consists of accurate 3D representations of the sensor components. Two different FEA software modules were used in order to cover the wide operating frequency range of the sensor. The simulation computes the frequency response of the sensor in the range 0.3 MHz-50 MHz for various HFCT geometric and material parameters, specifically the number of winding turns, spacer thickness, aperture size and core material. A prototype HFCT was constructed and the measured response compared with that of the simulation. The shapes of the responses were similar, with the simulated sensitivity being higher than the measured sensitivity by 1 dB on average. The measured low frequency cutoff of the sensor was found to be only 0.05 MHz lower than that of the simulation.
IEEE Transactions on Power Delivery, 2015
2015 IEEE Electrical Insulation Conference (EIC), 2015
2015 IEEE Electrical Insulation Conference (EIC), 2015