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Parameters optimization design for LCL-type STATCOMs under complex power grid
Wang, Xiangyu,Wang, Minglei,Wang, Liguo,Fu, Guangjie,Qiao, Jinxin The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.2
LCL filter parameters and control parameters are interdependent and inter-restricted. They can all affect the stability of a static synchronous compensator (STATCOM) under the effects of a complex power grid such as harmonic grid voltage and grid impedance variation. An advanced parameters optimization method integrated with LCL filter and control strategy is proposed. At first, the ABC-Pareto algorithm (Pareto multi-objective optimization of an artificial bee colony algorithm) is used to reasonably choose the LCL filter parameters. Under the premise of using capacitor current feedback active damping control and grid voltage feedforward control, the mathematical models of the STATCOM are derived. The constraints of control performances on the control parameters are obtained. According to these constraints, it is possible to construct a satisfactory 3D space. The control parameters can be chosen reasonably by finding the optimized space when the power grid is changed. Simulation and experimental results show the effectiveness and superiority of the proposed method.
Research on Peak-detection Algorithm for High-precision Demodulation System of Fiber Bragg Grating
Peng Wang,Xu Han,Simin Guan,Hong Zhao,Minglei Shao 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.6
In order to improve the detection accuracy of wavelength, the filtering and curve fitting technologies were applied in the FBG wavelength demodulation system based on tunable F-P filter. These methods could realize the accurate peak-location of output signals of the photo detector. According to the characteristics of noise, the FIR low-pass filter was designed to filter the obtained light power signals so as to provide the input signals with high SNR for the peak-detection algorithms. By analyzing and comparing several typical peak-searching algorithms, the algorithm of Gauss formula nonlinear curve fitting (L-M) was chosen to fit the digitized light power signals. The experimental results show that L-M fitting algorithm reduces the mean square error by 7.5% compared with the Gauss fitting algorithm. For the Gauss signal in the wavelength demodulation system designed in the paper, the L-M algorithm has lower mean square error than other peak-searching algorithms. This algorithm is suitable for FBG wavelength demodulation system based on tunable F-P filter. It can efficiently raise the accuracy of wavelength demodulation system.
Modeling and Performance Analysis of MAC Protocol for WBAN with Finite Buffer
( Minglei Shu ),( Dongfeng Yuan ),( Changfang Chen ),( Yinglong Wang ),( Chongqing Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.11
The IEEE 802.15.6 standard is introduced to satisfy all the requirements for monitoring systems operating in, on, or around the human body. In this paper, analytical models are developed for evaluating the performance of the IEEE 802.15.6 CSMA/CA-based medium access control protocol for wireless body area networks (WBAN) under unsaturation condition. We employ a three-dimensional Markov chain to model the backoff procedure, and an M/G/1/K queuing system to describe the packet queues in the buffer. The throughput and delay performances of WBAN operating in the beacon mode are analyzed in heterogeneous network comprised of different user priorities. Simulation results are included to demonstrate the accuracy of the proposed analytical model.
Wang, Ye,Tian, Minglei,Row, Kyung Ho Taylor Francis 2009 JOURNAL OF LIQUID CHROMATOGRAPHY AND RELATED TECHN Vol.33 No.2
<P> Linear solvation energy relationships are used to investigate the fundamental chemical interactions governing the retention of 9 aromatic solutes in 36 mobile phases in reversed phase liquid chromatography. The systems studied involve sodium dodecyl sulfate (0.03-0.09 M) and two kinds of ionic liquids (0.003-0.009 M), with 5 to 20% acetonitrile as mobile phase modifiers in water. The mechanism of retention in two kinds of additive were analyzed and compared. The results suggest that LSER formalism is able to reproduce adequately the experimental retention factors of the solutes studied in the different experimental conditions investigated.</P>
FPGA-Based Real-Time System for Demodulating FBG Wavelength
Peng Wang,Minglei Shao,Xu Han,Shanshan Li 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.6
In order to detect the wavelength drift of FBG (fiber Bragg grating) sensors, the real-time demodulating system based on tunable F-P filter (TFPF) was built. The optical parts of the demodulation system include broadband optical source, TFPF unit, reference grating model, sensing grating array, and couplers. The electronic parts of the demodulation system consist of AD converting unit, DA converting unit, field programmable gate array (FPGA) unit and human-computer interaction unit. With the high-speed data processing capacity, FPGA was utilized to realize digital logic circuits of the demodulation system. It includes resetting unit, phase locked loop (PLL) unit, driving TFPF unit, detecting keys unit, LCD displaying unit, FIR filtering unit and data calculating unit. The demodulating system has such features as high reliability and speed, instantaneity, and programmability. It can satisfy the requirements of wavelength demodulation of FBG sensors in practical engineering.
A Low-Cost Portable Real-Time EEG Signal Acquisition System Based on DSP
Peng Wang,Shanshan Li,Minglei Shao,Chao Liang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.2
EEG apparatus are expensive and bulky. Their real-time performance is weak, and EEG signals are easy to be distorted. In this paper, a low-cost portable EEG signal acquisition system based on DSP is developed. By a noninvasive method with bipolar leads, weak EEG signals are induced to the pre-processing circuits, where they will undergo multi-level amplifying and filtering. Then, the analog signals are converted into digital signals using ADS8320. These digitized signals are filtered in DSP (TMS320VC5509) so that the power interference and physiological artifacts are removed with LMS (Last Mean Square) algorithm and ICA (Independent Component Analysis) algorithm. Experimental results demonstrate that the system can acquire weak EEG signals in real time, display and save the processing results. The acquisition system has the advantages of usableness and portability, and helpful to the popularity of community-based and family-based EEG diagnostic equipments.
Ye Wang,Dandan Han,Minglei Tian,노경호 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.3
Linear solvation energy relationships (LSERs) are used to investigate the fundamental chemical interactions governing the retention of nine aromatic compounds on a C18 column. The mobile phases studied involve ionic liquids 1-Methyl-3-octylimidazolium tetrafluoroborate ([OMIm][BF4]) (0.003-0.009M), with 5 to 20% acetonitrile in water as mobile phase modifiers. The ability of the LSERs to account for the chemical interactions underlying solute retention is shown. A comparison of predicted and experimental retention factors suggests that LSER formalism is able to reproduce adequately the experimental retention factors of the solutes studied in the different experimental conditions investigated.
( Ruixia Liu ),( Yinglong Wang ),( Minglei Shu ),( Huiqi Zhao ),( Changfang Chen ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.11
The coexisting wireless body area networks (WBAN) is a very challenging issue because of strong inter-networks interference, which seriously affects energy consumption and spectrum utilization ratio. In this paper, we study a power control strategy with nearest neighbor nodes distribution for coexistingWBAN based on stochastic geometry. Using homogeneous Poisson point processes (PPP) model, the relationship between the transmission power and the networks distribution is analytically derived to reduce interference to other devices. The goal of this paper is to increase the transmission success probability and throughput through power control strategy. In addition, we evaluate the area spectral efficiency simultaneously active WBAN in the same channel. Finally, extensive simulations are conducted to evaluate the power control algorithm.
Peng Guo,Zhaojie Wang,Hongyu Chen,Shaohui Ge,Chen Chen,Haowei Wang,Jinbao Zhang,Minglei Hua,Shuxian Wei,Xiaoqing Lu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.15 No.01
The increasing energy crisis promotes the study on novel electrode materials with high performance for supercapacitive storage and energy conversion. Transition metal phosphates have been reported as a potential candidate due to the unique coordination and corresponding electronic structure. Herein, we adopted a facile method for preparing NaCoPO4@C derived from a metal organic framework (MOF) as a bifunctional electrode. ZIF-67 was synthesized before a refluxing process with Na2HPO4 to form a precursor, which is transformed into the final product via calcination in different atmospheres. Specifically, the resultant NaCoPO4@C exhibits a high specific capacitance of 1178.7 F g -1 at a current density of 1 A g -1 for a supercapacitor. An asymmetric supercapacitor (ASC) assembled with active carbon displays a high capacitance of 163.7 F g -1 at 1 A g -1. In addition, as an oxygen evolution reaction (OER) catalyst, the NaCoPO4@C electrode requires only 299 mV to drive a current density of 10 mA cm -2. These results suggest that the rational design of MOF-derived NaCoPO4@C provides a variety of practical applications in electrochemical energy conversion and storage.
Zhao, Yun,Qin, Minglei,Wang, Anjie,Kim, Dongpyo WILEY‐VCH Verlag 2013 ADVANCED MATERIALS Vol.25 No.33
<P><B>Various hydrophobic hairy carbonaceous fibers</B> are obtained by a low‐temperature CVD process on catalyst‐patterned surface patches which are selectively coated with silica to make the surface superhydrophobic and yet allow strong water adhesion for the “Salvinia effect”. The versatility of the functional hairy fiber surfaces is demonstrated with a liquid barrier grid for cell microarray, a gas retaining capability under water/liquid for a membrane‐free microfluidic chemical process, and functionalized papillae for cell immobilization with green algae.</P>