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In the development of ultra high-voltage (UHV) vacuum circuit breakers (VCB), higher current-rating and improved thermal performance become more and more important to provide safe function and reliability in spite of scale-down and increasing performance demanded of modern devices. Due to the high complexity of heat generation and loss processes, it is not easy to predict temperature-rise of the breaker...
In Gas Insulated Switchgear (GIS) the loop resistance is a key parameter which can characterize the contact condition of the conductive circuit. The current method to measure loop resistance was mostly proposed and used in routine test, commissioning test and overhaul. The monitoring of abnormal conditions of contacts in operation has not been realized yet. To early detect the hidden contact defects...
Temperature rise reduction is necessary to improve performance of high voltage products and in particular of gas insulated switchgear (GIS). A specific design of the conductor geometry is proposed to reduce temperature by improving heat transfer inside the GIS. The efficiency of this design is evaluated on experimental tests.
In this paper the authors introduce a physical picture of anomalous heat transfer in rigid conductor. The analysis shows that a fractional-order Fourier transport is obtained by the analysis of the heat transport in a functionally graded conductor. The order of the fractional-type operator obtained is related to the grading of the physical properties of the conductor.
Temperature increment in high voltage copper conductors is one of the important parameters that needs to be monitored continuously. This is due to significant temperature rise in the conductor may lead to thermal breakdown, which consequently causing power outage. One of the factors affecting temperature rise in conductors is the applied voltage waveform. In this work, simulation of temperature increment...
This paper presents the temperature rise analysis of a three phase busbar system. Busbar normally used to transmit and distribute current to distribution board in a building. Higher current capacity will naturally increase heat generation in the busduct system. The heat generation normally creates power losses or eddy current losses at the conductor. In this paper, a two dimensional finite element...
Superconducting applications like cables, current leads and high current power lines made with YBCO coated conductors (CC) require a protection of the CC against overheating in case of over currents. One possible protection of the CCs is the application of a highly conductive stabilization layer, such as electroplated Cu. The duration of over currents can vary between microseconds and several seconds...
Because of its high-capacity, low losses and no electromagnetic interference, the gas-insulated transmission line (GIL), which is a replacement of an overhead line in special environments, has been used for over 40 years, mainly as bus ducts of gas-insulated substations or underground connections in power plants. The insulated and cooling gas in GIL is mainly SF6 or its mixtures, which have high global...
Considering the ongoing increase of the amount of electronic components in vehicles the optimization of the power network is essential. To optimize the cable harness the ampacity, the voltage drop and the temperature of every cable have to be determined. In this paper stationary and transient ways of modeling cables are presented and compared. All simulation models are created in VHDL-AMS and validated...
In order to achieve the real-time calculation of cable core temperature, according to principles of heat transfer, proposed is the way of calculating cable core temperature based on the actual operating current and the cable surface temperature. This paper studies the dynamic response of cable core temperature based on the core temperature. Changes of actual running currents result in dynamic response...
SF6 gas has been widely used currently in electric power systems, such as GIS, GIL and GIT. However, because of the high global warming potential (GWP), SF6 was listed as one of the six restricted gases in "Kyoto Protocol" in 1997. Some fluorocarbon gases with low environmental effect and high dielectric performance are studied as the substitution candidates for SF6. This paper presents...
This paper describes the coupled magneto-thermal analysis technique to calculate the temperature rise in the gas insulated switchgear (GIS) bus bar. Harmonic eddy current analysis is carried out and the power losses are calculated in the conductor and shield tank. Two methods are presented to analyze the temperature distribution on the conductor and tank surface. The one is to solve the thermal conduction...
In this paper, a three-dimensional (3D) eddy current field model to calculate the eddy current losses in an isolated phase bus is proposed. The temperature rises of the conductors and enclosures in the isolated phase bus are evaluated using the proposed set of thermal equations. Good agreement between the computed and test results is a good validation of the proposed methodology.
The transient and steady-state thermal modelling of a power bus bar used in automobile power electrical architectures is presented in this paper. Using the developed model, the current carrying capacity, also called ampacity, of this kind of power cable can be accurately predicted. After brief information about bus bars for hybrid-electric vehicle (HEV) and electric vehicle (EV), the study then focuses...
Knowledge of the evolution of the resistance of a conductor during a short - circuit allows to measure the temperature of the conductor, and makes it possible to investigate new criteria that characterize short - circuit currents.
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