This study is concerned with 12-MW capacity turbochargers on diesel power generators. These are generators equipped with 18 cylinders. Our previous studies [1] showed that the processing of vibration signature collect...This study is concerned with 12-MW capacity turbochargers on diesel power generators. These are generators equipped with 18 cylinders. Our previous studies [1] showed that the processing of vibration signature collected from a power generator is very complex, insomuch the dominant vibration remains the one originating from explosion frequency in the diesel generator cylinders, with a fairly high number of cylinders. This vibration drowns out all other possible vibrations, which can expose defects. The study at hand is focused on turbochargers with 20,940 rpm, while the rotation speed in the diesel engine is 600 rpm only. With the turbocharger rotating at very high speed, it results in severe mechanical constraints on the rotor shaft in the turbocharger and its related organs (turbine blades). The wear of turbine blades can result in breakdowns in the turbocharger. This article is an attempt to early detect defaults in turbine blades based on vibration signature that can be experimentally determined. We noted in our investigations that a diesel engine and its turbochargers do not bear the same mechanic loads. While the diesel engine is the seat of violent shocks brought about by explosions in cylinders, the turbochargers are driven by the action of exhaust gas from explosions, without being affected by explosion shocks. The study found that explosion frequency in the diesel engine cylinders, which disrupted the vibration signals in the diesel engine and alternator, did not impact on the vibration signals in the turbocharger. We experimentally determined, following several campaigns of measurements, a vibration signature on the turbochargers under study, which corresponds to a defect in turbine blades.展开更多
This first quarter of the 21st century is increasingly marked by population growth,digital and industrial developments,a growing need for electricity supply,and climate change.All these,to name just a few,have made th...This first quarter of the 21st century is increasingly marked by population growth,digital and industrial developments,a growing need for electricity supply,and climate change.All these,to name just a few,have made the establishment of a stable,flexible,controlled,well-designed,extensive,and clean power system a necessity.Consequently,distributed microgrid generation based on alternative/renewable energies and/or low-carbon technologies has emerged.In this paper,we study the modeling,the control,and the power management strategy of a grid-connected hybrid alternating/direct current(AC/DC)microgrid based on a wind turbine generation system using a doubly fed induction generator,a photovoltaic generation system,and storage elements including hydrogen storage system and batteries.Adequate modeling is described,and the overall system monitoring is presented and applied to manage appropri-ate power sharing and to control active and reactive powers,in order to match load and weather fluctuation behavior.Simulations are carried out using a MATLAB/Simulink simulation tool.Simulations reveal convenient results in terms of the bidirectional interlinking converter capabilities regarding power balance establishment between the two subgrids,reactive power compensation to ensure a unity power factor,and DC-bus voltage regulation at 1200 V.In addition,the primary and secondary controls are approved for each distributed generation of the studied system to attain the assigned power references,regardless of whether the subgrid is heavily or lightly loaded throughout the four considered case studies,showing satisfactory tracking and interacting performances,and thus stimulating a stable system implementation.展开更多
文摘This study is concerned with 12-MW capacity turbochargers on diesel power generators. These are generators equipped with 18 cylinders. Our previous studies [1] showed that the processing of vibration signature collected from a power generator is very complex, insomuch the dominant vibration remains the one originating from explosion frequency in the diesel generator cylinders, with a fairly high number of cylinders. This vibration drowns out all other possible vibrations, which can expose defects. The study at hand is focused on turbochargers with 20,940 rpm, while the rotation speed in the diesel engine is 600 rpm only. With the turbocharger rotating at very high speed, it results in severe mechanical constraints on the rotor shaft in the turbocharger and its related organs (turbine blades). The wear of turbine blades can result in breakdowns in the turbocharger. This article is an attempt to early detect defaults in turbine blades based on vibration signature that can be experimentally determined. We noted in our investigations that a diesel engine and its turbochargers do not bear the same mechanic loads. While the diesel engine is the seat of violent shocks brought about by explosions in cylinders, the turbochargers are driven by the action of exhaust gas from explosions, without being affected by explosion shocks. The study found that explosion frequency in the diesel engine cylinders, which disrupted the vibration signals in the diesel engine and alternator, did not impact on the vibration signals in the turbocharger. We experimentally determined, following several campaigns of measurements, a vibration signature on the turbochargers under study, which corresponds to a defect in turbine blades.
文摘This first quarter of the 21st century is increasingly marked by population growth,digital and industrial developments,a growing need for electricity supply,and climate change.All these,to name just a few,have made the establishment of a stable,flexible,controlled,well-designed,extensive,and clean power system a necessity.Consequently,distributed microgrid generation based on alternative/renewable energies and/or low-carbon technologies has emerged.In this paper,we study the modeling,the control,and the power management strategy of a grid-connected hybrid alternating/direct current(AC/DC)microgrid based on a wind turbine generation system using a doubly fed induction generator,a photovoltaic generation system,and storage elements including hydrogen storage system and batteries.Adequate modeling is described,and the overall system monitoring is presented and applied to manage appropri-ate power sharing and to control active and reactive powers,in order to match load and weather fluctuation behavior.Simulations are carried out using a MATLAB/Simulink simulation tool.Simulations reveal convenient results in terms of the bidirectional interlinking converter capabilities regarding power balance establishment between the two subgrids,reactive power compensation to ensure a unity power factor,and DC-bus voltage regulation at 1200 V.In addition,the primary and secondary controls are approved for each distributed generation of the studied system to attain the assigned power references,regardless of whether the subgrid is heavily or lightly loaded throughout the four considered case studies,showing satisfactory tracking and interacting performances,and thus stimulating a stable system implementation.
