An analysis on the circuit breaking phenomenon of High-temperature Superconductor Circuit Breaker (HTSCB)
Development of High-Temperature Superconductor (HTS) materials in recent years has raised interest in carrying out novel research work of HTS application in power technology. Despite HTS solutions are said to provide better power system stability benefits, the integrity and operation of HTSCB yet need to be well investigated and validated by means of its appropriate modelling in power system distribution network. In this research, the technical characteristics of HTSCB is determined by one of the basic arc model theories. The further experiments are designated to analyze the performance of future HTSCB.
The performance of HTSCB is designed by developing an HTS arc model. This is the most complex, challenging and important aspect of this research. The parameters of arc model should precisely be set before any effort is carried out to analyze its behaviour in a distribution network under a variety of fault circumstances. Simulation studies are conducted to show the electrical arc characteristics of HTSCB under the high current condition. The arc model can then be inserted in different network models and analyzed for numerous system loading with over current situations and for different HTS applications. The modelling is executed on a single-phase distribution network model. The limitations of the conventional arc models for HTS application are briefly discussed in this study from the simulation study. The scope of further development of HTS arc model is also identified.
The developed arc model is later used to mitigate the residual flux problem of HTS Transformer. The inrush current of an HTS transformer can rise ten times higher than the rated current. The inrush current also exist a longer period of time comparing to short-circuit current. The repeated switching of HTS transformer is a big concern for its superconductivity. HTS arc model with HTS transformer is investigated for different fault interruption methods. During the process, the residual flux of HTS transformer is mitigated at the minimum operating time.
Finally, the design and experimental validation of arcing phenomenon in cryogenic arc chamber is investigated. A comprehensive analysis of flow field and numerical solution in cryogenic arc chamber is analyzed to observe the magnetic field in cryogenic arc chamber. The results of HTSCB and its arc model promises a novel circuit breaking phenomenon. The simulation results show the benefits of less pre-striking effect to use in HTS machines in Alternative Current (AC) applications and experimental result validate the result of arc model. The overall investigations show that the significant geometrical parameters of arc chamber and breaker contacts need to be optimized to improve the performance of HTSCB. The detailed analysis of flow separation, losses, its origin and minimized electrical field strength in short circuit condition help the design to improve its flow field and efficiency.