This paper overviews the benefits,challenges,research trends and potential solutions on the design and application of gallium nitride(GaN) technology in hard-switching power electronic converters from the device level...This paper overviews the benefits,challenges,research trends and potential solutions on the design and application of gallium nitride(GaN) technology in hard-switching power electronic converters from the device level up to converter level.展开更多
In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics ...In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonance-trigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.展开更多
针对无线传感器网络自身的可靠性和维护问题,提出了一种基于FPAA(field programmable analog arrays)的自修复智能无线传感器节点的实现方法。该方法以FPAA为核心构成传感器的主要信号调理电路,节点设计有硬件故障自诊断功能,在节点部...针对无线传感器网络自身的可靠性和维护问题,提出了一种基于FPAA(field programmable analog arrays)的自修复智能无线传感器节点的实现方法。该方法以FPAA为核心构成传感器的主要信号调理电路,节点设计有硬件故障自诊断功能,在节点部分硬件模块发生故障的情况下,可修复相应故障,确保节点在无人职守及野外应用时的可靠性,避免节点的直接丢弃。重点介绍了自修复节点的实现方法、软硬件研发并对节点进行了自修复实验研究,分析了自修复节点的功耗及可工作时间,节点能够在2节具有1 700 mAh的AA电池的供电下工作半年时间。展开更多
基金supported by the Engineering Research Center Program of the National Science Foundation and DOE under NSF Award Number EEC-1041877the Current Industry Partnership Program
文摘This paper overviews the benefits,challenges,research trends and potential solutions on the design and application of gallium nitride(GaN) technology in hard-switching power electronic converters from the device level up to converter level.
文摘In this paper the influence of different carrier waveforms upon the output characteristics of PWM inverter is described in detail. When a triangular carrier waveform is used in hard-switching PWM inverters, harmonics exist in the neighborhood of the output frequency of the inverter output voltage and current due to the dead time. The triangular carrier waveform used in soft-switching PWM inverter will cause difficulties in controlling resonance-trigger time, higher loss in the resonant circuit, and less utilization of the DC bus voltage. If a sawtooth carrier is used in hard-switching PWM inverter, there will be severe distortion in the current waveform. When sawtooth carriers with alternate positive and negative slopes are used in soft-switching PWM inverters, the resonance-trigger time is easy to control, and distortion in the output voltage and current caused by the dead time will not appear.
