With the prevailing power scenario, every watt-second of electrical energy has its own merit in satisfying the consumer demand. At the state of such a stringent energy demanding era, failure of a power generation equi...With the prevailing power scenario, every watt-second of electrical energy has its own merit in satisfying the consumer demand. At the state of such a stringent energy demanding era, failure of a power generation equipment compounds the energy constraints which will not only result in a huge loss of generation but also have an impact on capital revenue. The unexpected failure of generator step-up （GSU） transformer is espe- cially a major disturbance in the power system operation and leads to unscheduled outages with power delivery problems. The time lag in bringing back the equipment in service after rectification or replacement may increase the criticality as the process involves mobilization of spares and maintenance professionals. Hot atmosphere existing in the vicinity of thermal power stations running round-the- clock with more than 100% plant load factor （PLF） increases the thermal stress of the electrical insulation which leads to premature failure of windings, bushings, core laminations, etc. The healthy state of the GSU transformer has to be ensured to minimize the loss of power generation. As the predication related to failure of a GSU transformer is associated with some uncertainties, a fuzzy approach is employed in this paper along with actual field data and case studies for the well-being analysis of GSU transformer.展开更多
This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying. The model solves the coupled shallow water and Exner e...This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying. The model solves the coupled shallow water and Exner equations, with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact （HLLC） approximate Riemann solver. Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach. The new model is validated against several theoretical benchmark tests and promising results are obtained.展开更多
文摘With the prevailing power scenario, every watt-second of electrical energy has its own merit in satisfying the consumer demand. At the state of such a stringent energy demanding era, failure of a power generation equipment compounds the energy constraints which will not only result in a huge loss of generation but also have an impact on capital revenue. The unexpected failure of generator step-up （GSU） transformer is espe- cially a major disturbance in the power system operation and leads to unscheduled outages with power delivery problems. The time lag in bringing back the equipment in service after rectification or replacement may increase the criticality as the process involves mobilization of spares and maintenance professionals. Hot atmosphere existing in the vicinity of thermal power stations running round-the- clock with more than 100% plant load factor （PLF） increases the thermal stress of the electrical insulation which leads to premature failure of windings, bushings, core laminations, etc. The healthy state of the GSU transformer has to be ensured to minimize the loss of power generation. As the predication related to failure of a GSU transformer is associated with some uncertainties, a fuzzy approach is employed in this paper along with actual field data and case studies for the well-being analysis of GSU transformer.
基金supported by the UK Engineering and Physical Sciences Research Council(Grant No.EP/F030177/1)
文摘This work presents a new finite volume Godunov-type model for predicting morphological changes under the rapidly varying flood conditions with wetting and drying. The model solves the coupled shallow water and Exner equations, with the interface fluxes evaluated by an Harten-Lax-van Leer-Contact （HLLC） approximate Riemann solver. Well-balanced solution is achieved using the surface gradient method and wetting and drying are handled by a non-negative reconstruction approach. The new model is validated against several theoretical benchmark tests and promising results are obtained.
