摘要：This paper presented a control design methodology for a proton exchange membrane fuel cell (PEMFC) generation system for residential applications. The dynamic behavior of the generation system is complex in such applications. A comprehensive control design is very important for achieving a steady system operation and efficiency. The control strategy for a 60 kW generation system was proposed and tested based on the system dynamic model. A two-variable single neuron proportional-integral (PI) decoupling controller was developed for anode pressure and humidity by adjusting the hydrogen flow and water injection. A similar controller was developed for cathode pressure and humidity by adjusting the exhaust flow and water injection. The desired oxygen excess ratio was kept by a feedback controller based on the load current. An optimal seeking controller was used to trace the unique optimal power point. Two negative feedback controllers were used to provide AC power and a suitable voltage for residential loads by a power conditioning unit. control simulation tests showed that 60 kW PEMFC generation system responded well for computer-simulated step changes in the load power demand. This control methodology for a 60 kW PEMFC generation system would be a competitive solution for system level designs such as parameter design, performance analysis, and online optimization.

摘要：近年来,队列智能方法逐步演变为一种基于人工智能的优化方法。本文首次采用队列智能方法对分数阶PID控制器的参数进行优化。验证了队列智能方法在分数阶PID控制器设计中的性能,并与其他方法如粒子群优化方法、遗传算法和改进的电磁算法等的性能进行比较。结果表明,与其它3种算法相比,队列智能方法在代价函数、计算时间和函数评估方面表现出更好性能。此外,队列智能方法对应的标准差表明,提出的方法在解决控制问题时具有鲁棒性。

摘要：Recently, the use of ubiquitous sensor network technology has spread vastly. The ubiquitous sensor networks are widely de- ployed in factory auttxnation as they provide effective measuring solution for instruments. The wired/wireless network module, which provides the interface to connect to the u-sensor network, is needed but there is no perfect standardization about the interface. In this situation, the interface compatibility between measuring instrument can be maintained using the IEEEI451 international standard. In this paper, the Wireless Transducer Interface Mcduie （WTIM） based on IEEE1451.5 was designed. It coxnects to the measuring instnmnt, like the muiti-meter, power meter, and etc., to support the RS232 interface. As these devices cannot connect to network without a mod- ule, we use the WTIM to help these devices connect to network sys- ton. Its ftmction was verified through the ubiquitous network connection and data transfer between monitoring PC and measuring instrument. This technology is expected to reduce cost in order to construct the wireless industry automation system using existing devices.

摘要：In order to enhance the glutathione peroxidase（GPX） catalytic activity of the selenium-containing single-chain variable fragments（Se-scFv）, a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional（3D） model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b（＋）, then the scFv protein was expressed in soluble form in Escherichia coli BL21（DE3） and purified by Ni2＋-immobilized metal affinity chromatography（IMAC）. The serine residue of scFv in the active site was converted into selenocysteine（Sec） with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.

摘要：In this paper, the nonlinear state feedback controller has been developed to control the pressures of the oxygen and the hydrogen in the PEM(Proton Exchange Membrane) fuel cell system. Nonlinear model of the PEM fuel cell system was introduced to study the design problems of the state observer and model based controller. A cascade observer using the filtering technique was used to estimate the pressure derivatives of the cathode and the anode in the system. In order to estimate the pressures of the cathode and the anode, the sliding mode observer was designed by using these pressure derivatives. To estimate the oxygen pressure and the hydrogen pressure in the system, the nonlinear state observer was designed by using the cathode pressure estimates and the anode it. These results will be very useful to design the state feedback controller. The validity of the proposed observers and the controller has been investigated by using a Lyapunov’s stability analysis strategy.