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A Novel Synchronous Switch Method Based on Kalman Filter
Zheng Guilin,Chen Xi 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2
In order to create the idea of AC switch without electric arc and inrush voltage to the power system, the study of accurately catches AC zero crossing of a mechanical relay is put forward in this paper. It is the key to make the switch act at the right predicted time which realizes switch on or off exactly at the AC zero crossing point. However, the action time of a mechanical switch is affect by many factors such as driving voltage, ambient temperature, age of the mechanic structure. Aim at the discrete measurements of latching relay action time, the Kalman filter mathematic model is introduced in this paper to eliminate the dynamic noise and measurement noise which affects the bias time drift from the zero voltage or zero current point. Simulation result by matlab and group data get from experiments of a realized multichannel switch indicate that Kalman filter algorithm can overcome the discreteness of latching relay action time measurements. Also confirmed by statistical experiments that synchronous switch action precisely and reliably at AC zero point which can ensure the ability of suppress electric arc and high frequency inrush current.
Influence of CeO2 morphology on the catalytic oxidation of ethanol in air
Guilin Zhou,Baoguo Gui,Hongmei Xie,Fang Yang,Yong Chen,Shengming Chen,Xuxu Zheng 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.1
Nano-CeO2 catalysts of different shapes were synthesized at different hydrothermal crystallizationtemperatures from an alkaline aqueous solution. X-ray diffraction (XRD), transmission electronmicroscope (TEM), and H2 temperature-programmed reduction (H2-TPR) were used to study thesynthesized nano-CeO2 catalyst samples. The catalytic properties of the prepared nano-CeO2 catalystsfor the catalytic oxidation of ethanol in air were also investigated. TEM analysis showed that CeO2nanorod and nanocube catalysts have been synthesized at hydrothermal crystallization temperatures of373 K and 453 K, respectively. XRD results showed that the synthesized nano-CeO2 catalysts have similarcubic fluorite structures. H2-TPR results indicated that CeO2 nanorod and nanocube catalysts exhibitdifferent reduction behaviors for H2 and that the nanorod catalyst has better low-temperature reductionperformance than the nanocube catalyst. Ethanol catalytic oxidation results indicated that oxidation andcondensation products (including acetaldehyde, acetic acid, CO2, and ethyl acetate) have been producedfrom the prepared catalysts. The ethyl acetate and acetic acid can be ignited by ethanol at lowtemperature on the CeO2(R) catalyst to give low catalytic combustion temperature for ethyl acetate andacetic acid molecules. CeO2 nanorods gave ethanol oxidation conversion rates above 99.2% at 443 K andCO2 selectivity exceeding 99.6% at 483 K, while CeO2 nanocubes gave ethanol oxidation conversion ratesof about 95.1% until 508 K and CO2 selectivity of only 93.86% at 543 K. CeO2 nanorod is a potential lowcostand effective catalyst for removing trace amounts of ethanol to purify air.