Investigating the corona mechanism plays a key role in enhancing the performance of electrical insulation systems. Numerical simulation offers a better understanding of the physical characteristics of air corona disch...Investigating the corona mechanism plays a key role in enhancing the performance of electrical insulation systems. Numerical simulation offers a better understanding of the physical characteristics of air corona discharges. Using a two-dimensional axisymmetrical kinetics model, into which the photoionization effect is incorporated, the DC air corona discharge at atmosphere pressure is studied. The plasma model is based on a self-consistent, multi-component, and con- tinuum description of the air discharge, which is comprised of 12 species and 22 reactions. The discharge voltage-current characteristic predicted by the model is found to be in quite good agree- ment with experimental measurements. The behavior of the electronic avalanche progress is Mso described. 0＋ and N＋ are the dominant positive ions, and the values of 0- and 02 densities are much smaller than that of the electron. The electron and positive ion have a low-density thin layer near the anode, which is a result of the surface reaction and absorption effect of the electrode. As time progresses, the electric field increases and extends along the cathode surface, whereas the cathode fall shrinks after the corona discharge hits the cathode; thus, in the cathode sheath, the electron temperature increases and the position of its peak approaches to the cathode. The present computational model contributes to the understanding of this physical mechanism, and suggests ways to improve the electrical insulation system.展开更多
为了提高燃料电池装置的供电可靠性,本文基于质子交换膜燃料电池电堆,采用高性能、低成本、低功耗的STM32作为控制芯片,模拟了采样电路,设计了一个嵌入式控制方案。该设计采用结构化方案,分为主控器模块和功能子模块两部分,每个模块之...为了提高燃料电池装置的供电可靠性,本文基于质子交换膜燃料电池电堆,采用高性能、低成本、低功耗的STM32作为控制芯片,模拟了采样电路,设计了一个嵌入式控制方案。该设计采用结构化方案,分为主控器模块和功能子模块两部分,每个模块之间的通信运用控制器区域网络(controller area network,CAN)总线协议,基于labVIEW的设计应用平台,实现了燃料电池的氧气和氢气供应系统以及风冷系统的控制和监测,并以图形化的方式动态显示燃料电池系统的工作状态。实验结果表明,该控制方案提高了质子交换膜燃料电池的供电可靠性,具有可实现性和良好性。该研究具有一定的应用价值。展开更多
基金supported by the Major State Basic Research Development Program of China(973 Program)(No.2011CB20941)Scientific Research Foundation of State Key Lab. of Power Transmission Equipment and System Security of China(No.2007DA10512709102)+1 种基金National Natural Science Foundation of China(No.51007096)the Fundamental Research Funds for the Central Universities of China(No.CDJZR10150001)
文摘Investigating the corona mechanism plays a key role in enhancing the performance of electrical insulation systems. Numerical simulation offers a better understanding of the physical characteristics of air corona discharges. Using a two-dimensional axisymmetrical kinetics model, into which the photoionization effect is incorporated, the DC air corona discharge at atmosphere pressure is studied. The plasma model is based on a self-consistent, multi-component, and con- tinuum description of the air discharge, which is comprised of 12 species and 22 reactions. The discharge voltage-current characteristic predicted by the model is found to be in quite good agree- ment with experimental measurements. The behavior of the electronic avalanche progress is Mso described. 0＋ and N＋ are the dominant positive ions, and the values of 0- and 02 densities are much smaller than that of the electron. The electron and positive ion have a low-density thin layer near the anode, which is a result of the surface reaction and absorption effect of the electrode. As time progresses, the electric field increases and extends along the cathode surface, whereas the cathode fall shrinks after the corona discharge hits the cathode; thus, in the cathode sheath, the electron temperature increases and the position of its peak approaches to the cathode. The present computational model contributes to the understanding of this physical mechanism, and suggests ways to improve the electrical insulation system.
文摘为了提高燃料电池装置的供电可靠性,本文基于质子交换膜燃料电池电堆,采用高性能、低成本、低功耗的STM32作为控制芯片,模拟了采样电路,设计了一个嵌入式控制方案。该设计采用结构化方案,分为主控器模块和功能子模块两部分,每个模块之间的通信运用控制器区域网络(controller area network,CAN)总线协议,基于labVIEW的设计应用平台,实现了燃料电池的氧气和氢气供应系统以及风冷系统的控制和监测,并以图形化的方式动态显示燃料电池系统的工作状态。实验结果表明,该控制方案提高了质子交换膜燃料电池的供电可靠性,具有可实现性和良好性。该研究具有一定的应用价值。
