Advanced Materials Research Vols. 516-517

Abstract: This paper reviews the harmonic current detection algorithm of APF&SVG. And the new different research of each detection method is introduced. The advantage and disadvantage of each methods is also analyzed. It has provided some references to the electric current detection algorithm choice for the design of the APF and SVG.

Abstract: Monodispersed anamorphic cubic NiO materials have been synthesized by a simple method. SEM, TEM and XRD have been employed for the morphology and structure characterization. The calcination conditions have been carefully studied about their effects on supercapacitor properties. Electrochemical data prove that the monodispersed nano anamorphic cubic NiO materials contain a good specific capacitance and excellent specific capacitance retention after 2000 continuous charge-discharge cycles. These results suggest that both the morphology and structure have important effects on the high performance supercapacitors.

Abstract: To support the demand response function for smart grid, an intelligent power meter with hybrid communication module has been proposed in this paper. The circuit module consisting of VI measurement, power calculation chip, microprocessor and PLC/ZigBee/RS-485 communication is designed to support load control to achieve load reduction after receiving the demand response command of via two way communication. The load control function can also be activated by the real time pricing information, which has been downloaded from utility control center. The embedded power management system is developed to perform the management of intelligent power meters to monitor and control electrical appliances. Based on the field test, the intelligent power meter can be used for load shedding or power due to achieve energy conservation and enhance system stability for smart grid application.

Abstract: To improve the multi-target detection performance of sensor arrays at low signal-to-noise ratios, a new method called DTAE（Detection Technique based on Approximate Eigenvectors）is proposed. In the proposed method, the approximate eigenvectors of the signal subspace corresponding to the estimate of the source cluster centroid are computed first, then the array output data are weighted by the approximate eigenvectors, finally the estimate of the number of signals is acquired by a certain criterion using the information of the peak-to-average power ratio of the weighted data in frequency domain. Simulations show DTAE demonstrates better detection performance than traditional methods such as EDT(Eigenvector Detection Technique) and AIC（Akaike Information Criterion）etc. at low SNR.

Abstract: Tin thin films on Cu foil substrates as the anodes of lithium ion battery were prepared by direct current (DC) and radio frequency (RF) magnetron sputtering (MS), respectively. The surface morphology and cyclic performance of the films were characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), inductively coupled plasma atomic emission spectrometry (ICP) and galvanostatic charge/discharge (GC) measurements. It is found that the cyclic performance of Sn film prepared by RFMS as anode of lithium ion battery is far better than that prepared DCMS. The discharge capacity of the film prepared by DCMS changes from 748 mAh/g of 1st cycle to 99 mAh/g of 30th cycle. Nevertheless, the discharge capacity of the film prepared by RFMS changes from 653 mAh/g of 1st cycle to 454 mAh/g of 30th cycle. The better performance of the film prepared by RFMS is ascribed to the retardation of the bulk tin cracking from volume change during lithium intercalation and de-intercalation, which avoids the pulverization of tin.

Abstract: New complex inorganic ion exchanger Mg_2.5Ti(PO₄)₃ is synthesized. Chemical composition, structure and some related properties and complex mechanism of this ion exchanger are investigated by electron microscopic, X-ray diffraction and chemical methods. Results of column test indicated, that the exchange capacity obtained from tests for Li⁺ in 0.1mol /L HNO₃ solution is 9.0mmol/g.

Abstract: Amperometric NOx sensors have been developed for the applications of on-board vehicle exhaust sensing for diesel powertrains to meet the strict government emission regulations in North America and Europe. The sensing mechanism of these sensors to NO_x was studied along with several noise factors that affect the NO_x output. It was found that cross sensitivity to oxygen may result in an increased offset. The results from this study indicate that polarization of one or more of the electrodes is a major factor affecting the magnitude of the offset.

Abstract: Nowadays Static Synchronous Compensator (STATCOM) has gradually become one of the representative techniques in the field of dynamic reactive power compensation in the power distribution system. This paper analyzed the topology and the voltage imbalance problem of the up and down capacitors on DC side of the three-phase four-wire STATCOM. In allusion to the imbalance problem of neutral point, a novel control strategy based on the control of zero-sequence current was proposed. By the triple close-loop control strategy, the STATCOM can achieve great control accuracy and dynamic performance. Simulation result proves that the proposed control method is effective.

Abstract: A PLC (Programmable Logic Controller) based real time simulation and test strategy for the industrial process control has been proposed. Different stages of system design and test are achieved to fulfill requirements of the industrial process control. The on-line and real time simulation system provides a platform for verifying accuracy and reliability of user control codes. It is not only for normal operations, but also for abnormal sequence inspections. According to the experience of a real industrial project, it is proved to shorten a large amount of commissioning and debugging time for implementing a control system. By the flexibility and operability of a HMI console, training measures can be put into practice in the dedicated simulation environment instead. Risks are considerably diminished and the efficiency of project development is improved as well.

Abstract: Wireless power transfer brings the possibility of connector-free for electric devices. Because there is no electric connection between power source and load, the system employs wireless power transfer based on magnetic resonance becomes safer, more convenient and more reliable. The wireless power transfer system of four-coils based on magnetic resonances is analyzed, including phenomenon of frequency splitting, effect of the angle between the source coil and the device coil, and effect of external objects. Simulation results are presented in this paper.