A new SOI （Silicon On Insulator） high voltage device with Step Unmovable Surface Charges （SUSC） of buried oxide layer and its analytical breakdown model are proposed in the paper. The unmovable charges are impleme...A new SOI （Silicon On Insulator） high voltage device with Step Unmovable Surface Charges （SUSC） of buried oxide layer and its analytical breakdown model are proposed in the paper. The unmovable charges are implemented into the upper surface of buried oxide layer to increase the vertical electric field and uniform the lateral one. The 2-D Poisson＇s equation is solved to demonstrate the modulation effect of the immobile interface charges and analyze the electric field and breakdown voltage with the various geometric parameters and step numbers. A new RESURF （REduce SURface Field） condition of the SOl device considering the interface charges and buried oxide is derived to maximize breakdown voltage. The analytical results are in good agreement with the numerical analysis obtained by the 2-D semiconductor devices simulator MEDICI. As a result, an 1200V breakdown voltage is firstly obtained in 3pro-thick top Si layer, 2pro-thick buried oxide layer and 70pro-length drift region using a linear doping profile of unmovable buried oxide charges.展开更多
The results of the implementation of an actual microgrid in the Netherlands are presented. This microgrid has photovoltaic panels as microsources, energy storage, and a flexible AC distribution interfacing system that...The results of the implementation of an actual microgrid in the Netherlands are presented. This microgrid has photovoltaic panels as microsources, energy storage, and a flexible AC distribution interfacing system that can operate connected to the public grid or autonomously where it regulates the site＇s voltage and frequency. In this paper, the potential of the microgrid in improving power quality issues of the site, specifically harmonic distortions, is demonstrated. Results show that flexible AC distribution interfacing system devices were able to compensate voltage harmonics when the microgrid was operating connected to the public grid and when operating autonomously. Other tests such as short-circuit, synchronization and blackstart were also conducted. The improvement in power quality and positive results of the other tests demonstrate that a self-supporting, reliable and efficient operation of the microgrid can be achieved.展开更多
The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification...The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification and discharge at the interface under certain condition. It is of significant importance to take an insight into the phenomenon occurring at the interface. Through experiment, the pressboard is found as a porous material. The interface changes abruptly from bulk pressboard to the bulk oil as a result of the porous structure. A new model is proposed which divides the interface into bulk oil region, transition region, and bulk pressboard region. The width of the transition region is decided according to the microtome figure. The effective permittivity of the transition region is calculated using a new model based on fractal theory. The model is validated and compared with previous calculation model. The effect of the existence of transition region on the electric field distribution is discussed.展开更多
基金Supported by the National Natural Science Foundation of China (No.60276040).
文摘A new SOI （Silicon On Insulator） high voltage device with Step Unmovable Surface Charges （SUSC） of buried oxide layer and its analytical breakdown model are proposed in the paper. The unmovable charges are implemented into the upper surface of buried oxide layer to increase the vertical electric field and uniform the lateral one. The 2-D Poisson＇s equation is solved to demonstrate the modulation effect of the immobile interface charges and analyze the electric field and breakdown voltage with the various geometric parameters and step numbers. A new RESURF （REduce SURface Field） condition of the SOl device considering the interface charges and buried oxide is derived to maximize breakdown voltage. The analytical results are in good agreement with the numerical analysis obtained by the 2-D semiconductor devices simulator MEDICI. As a result, an 1200V breakdown voltage is firstly obtained in 3pro-thick top Si layer, 2pro-thick buried oxide layer and 70pro-length drift region using a linear doping profile of unmovable buried oxide charges.
文摘The results of the implementation of an actual microgrid in the Netherlands are presented. This microgrid has photovoltaic panels as microsources, energy storage, and a flexible AC distribution interfacing system that can operate connected to the public grid or autonomously where it regulates the site＇s voltage and frequency. In this paper, the potential of the microgrid in improving power quality issues of the site, specifically harmonic distortions, is demonstrated. Results show that flexible AC distribution interfacing system devices were able to compensate voltage harmonics when the microgrid was operating connected to the public grid and when operating autonomously. Other tests such as short-circuit, synchronization and blackstart were also conducted. The improvement in power quality and positive results of the other tests demonstrate that a self-supporting, reliable and efficient operation of the microgrid can be achieved.
基金Project(2009CB724504)supported by the National Basic Research Program of China
文摘The oil-pressboard insulation is a typical composite insulation system widely used in the design and manufactory of large power apparatus. The implement of oil-pressboard insulation may lead to surface electrification and discharge at the interface under certain condition. It is of significant importance to take an insight into the phenomenon occurring at the interface. Through experiment, the pressboard is found as a porous material. The interface changes abruptly from bulk pressboard to the bulk oil as a result of the porous structure. A new model is proposed which divides the interface into bulk oil region, transition region, and bulk pressboard region. The width of the transition region is decided according to the microtome figure. The effective permittivity of the transition region is calculated using a new model based on fractal theory. The model is validated and compared with previous calculation model. The effect of the existence of transition region on the electric field distribution is discussed.
