A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Wang, Ping,Zhao, Chendong,Zhang, Yun,Li, Jing,Gao, Yongping The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

Convergence properties for the partial sums of widely orthant dependent random variables under some integrable assumptions and their applications

Yongping He,Xuejun Wang,Chi Yao 대한수학회 2020 대한수학회보 Vol.57 No.6

Widely orthant dependence (WOD, in short) is a special dependence structure. In this paper, by using the probability inequalities and moment inequalities for WOD random variables, we study the $L_p$ convergence and complete convergence for the partial sums respectively under the conditions of RCI$(\alpha)$, SRCI$(\alpha)$ and $R$-$h$-integrability. We also give an application to nonparametric regression models based on WOD errors by using the $L_p$ convergence that we obtained. Finally we carry out some simulations to verify the validity of our theoretical results.

Stable and Active Oxidation Catalysis by Cooperative Lattice Oxygen Redox on SmMn₂O₅ Mullite Surface

Zheng, Yongping,Thampy, Sampreetha,Ashburn, Nickolas,Dillon, Sean,Wang, Luhua,Jangjou, Yasser,Tan, Kui,Kong, Fantai,Nie, Yifan,Kim, Moon J.,Epling, William S.,Chabal, Yves J.,Hsu, Julia W. P.,Cho, Kye American Chemical Society 2019 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.141 No.27

<P>The correlation between lattice oxygen (O) binding energy and O oxidation activity imposes a fundamental limit in developing oxide catalysts, simultaneously meeting the stringent thermal stability and catalytic activity standards for complete oxidation reactions under harsh conditions. Typically, strong O binding indicates a stable surface structure, but low O oxidation activity, and <I>vice</I><I>versa</I>. Using nitric oxide (NO) catalytic oxidation as a model reaction, we demonstrate that this conflicting correlation can be avoided by cooperative lattice oxygen redox on SmMn<SUB>2</SUB>O<SUB>5</SUB> mullite oxides, leading to stable and active oxide surface structures. The strongly bound neighboring lattice oxygen pair cooperates in NO oxidation to form bridging nitrate (NO<SUB>3</SUB><SUP>-</SUP>) intermediates, which can facilely transform into monodentate NO<SUB>3</SUB><SUP>-</SUP> by a concerted rotation with simultaneous O<SUB>2</SUB> adsorption onto the resulting oxygen vacancy. Subsequently, monodentate NO<SUB>3</SUB><SUP>-</SUP> species decompose to NO<SUB>2</SUB> to restore one of the lattice oxygen atoms that act as a reversible redox center, and the vacancy can easily activate O<SUB>2</SUB> to replenish the consumed one. This discovery not only provides insights into the cooperative reaction mechanism but also aids the design of oxidation catalysts with the strong O binding region, offering strong activation of O<SUB>2</SUB>, high O activity, and high thermal stability in harsh conditions.</P> [FIG OMISSION]</BR>

Parameters Estimation of Automotive Ignition Coils Based on Support Vector Regression

Qisong Wang,Song Li,Yongping Zhao 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

Ignition coils is an important part of automotive ignition system, which directly influences the vehicle’s power performance, energy consumption and environmental protection property. In this paper, a MIMO model based on support vector regression (SVR) is proposed aiming at estimating technological parameters of automotive ignition coils. With the performance parameters, such as spark current and ignition energy as inputs, the model can reach the goal to estimate the technological parameters such as windings and wire diameters of primary coils and secondary coils by choosing appropriate SVR parameters, kernel functions and training algorithm. Furthermore, experimental samples of ignition coils are specially designed, manufactured and measured to obtain training data. Simulated results prove the rationality and accuracy of the model, which shows that the model can provide guidance for the design of ignition coils.

Combination of Attractants with Entomopathogenic Fungus for Controlling Pine Sawyer Beetle, Monochamus alternatus Hope

Sibao Wang,Jiawei Du,yongping Huang 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

A Bidirectional Three-level DC-DC Converter with a Wide Voltage Conversion Range for Hybrid Energy Source Electric Vehicles

Ping Wang,Chendong Zhao,Yun Zhang,Jing Li,Yongping Gao 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

In order to meet the increasing needs of the hybrid energy source system for electric vehicles, which demand bidirectional power flow capability with a wide-voltage-conversion range, a bidirectional three-level DC-DC converter and some control strategies for hybrid energy source electric vehicles are proposed. The proposed topology is synthesized from Buck and Boost three-level DC-DC topologies with a high voltage-gain and non-extreme duty cycles, and the bidirectional operation principle is analyzed. In addition, the inductor current ripple can be effectively reduced within the permitted duty cycle range by the coordinated control between the current fluctuation reduction and the non-extreme duty cycles. Furthermore, benefitting from duty cycle disturbance control, series-connected capacitor voltages can also be well balanced, even with the discrepant rise and fall time of power switches and the somewhat unequal capacitances of series-connected capacitors. Finally, experiment results of the bidirectional operations are given to verify the validity and feasibility of the proposed converter and control strategies. It is shown to be suitable for hybrid energy source electric vehicles.

High Ratio Bidirectional DC-DC Converter with a Synchronous Rectification H-Bridge for Hybrid Energy Sources Electric Vehicles

Yun Zhang,Yongping Gao,Jing Li,Mark Sumner,Ping Wang,Lei Zhou 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6

In order to match the voltages between high voltage battery stacks and low voltage super-capacitors with a high conversion efficiency in hybrid energy sources electric vehicles (HESEVs), a high ratio bidirectional DC-DC converter with a synchronous rectification H-Bridge is proposed in this paper. The principles of high ratio step-down and step-up operations are analyzed. In terms of the bidirectional characteristic of the H-Bridge, the bidirectional synchronous rectification (SR) operation is presented without any extra hardware. Then the SR power switches can achieve zero voltage switching (ZVS) turn-on and turn-off during dead time, and the power conversion efficiency is improved compared to that of the diode rectification (DR) operation, as well as the utilization of power switches. Experimental results show that the proposed converter can operate bidirectionally in the wide ratio range of 3~10, when the low voltage continuously varies between 15V and 50V. The maximum efficiencies are 94.1% in the Buck mode, and 93.6% in the Boost mode. In addition, the corresponding largest efficiency variations between SR and DR operations are 4.8% and 3.4%. This converter is suitable for use as a power interface between the battery stacks and super-capacitors in HESEVs.

The Confucian Viewpoint on Rightneous and Personai Interests and The Hypothesis of Rational-economic Man

( Hanming Shao ),( Yongping Wang ) 성균관대학교 유교문화연구소 2006 儒敎文化硏究(中文版) Vol.6 No.-

長期以來, 有一種頗爲流行的觀点認爲, 儒家重義輕利, 幷把這種“重義輕利”的傳統看作是向現代化邁進的歷史包袱。本文考察了先秦儒家原典, 認爲先秦儒家的代表人物都不排斥“利”, 相反, 對個人正當的物質利益追求给予了充分肯定。儒家講“以義節利”, 不是要以“義”排斥和否定“利”, 而是防止個人自私自利之心的惡性膨脹, 導致人與人之間的爭斗, 造成社會的動亂, 最終導致全體社會成員皆不利的局面。先秦儒家幷不認爲“義”與“利”是完全沖突的, 逐利就一定不顧仁義, 講仁義就一定要放棄逐利, 二者不可兼得。而是認爲“利”和“義”是可以統一的。統一的前提條件就是“先義后利”。先秦儒家義利幷重, 先義后利的思想, 正是我們建設有中國特色的社會主義市場經濟可資利用的本土文化資源之一。 It has been very popular for a long time that some people thought that Confucian philosophy attached too much importance to personal loyalty and fought against or even opposed to one’s material benefit, and meanwhile considered the tendency that Confucian philosophy weighed higher personal loyalty than material benefit as a historical obstacle to the process of modernization. In this article, the author investigated the originality of Confucian philosophy and thought that none of the Confucian thinkers repulsed material benefit. On the contrary, Confucian philosophers thought much of personal pursuit of material benefit. The Confucian idea about “much loyalty, less benefit” does not mean denying the pursuit of personal benefit. In fact, they insisted the harmony instead of the total collision between the pursuit of personal loyalty and material benefit. The prerequisite for their unification was “personal loyalty prior to material pursuit”. This kind of Confucian standpoint on “one’s pursuit of personal loyalty superior to material benefit” is one of the native cultural resources that should be taken full advantage of in our construction of the socialist market economy. [Article in Chinese]

Protective efficacy of a novel multivalent vaccine in the prevention of diarrhea induced by enterotoxigenic Escherichia coli in a murine model

Hong Zhao,Yongping Xu,Gen Li,Xin Liu,Xiaoyu Li,Lili Wang 대한수의학회 2022 Journal of Veterinary Science Vol.23 No.1

Background: Enterotoxigenic Escherichia coli (ETEC) infection is a primary cause of livestock diarrhea. Therefore, effective vaccines are needed to reduce the incidence of ETEC infection. Objectives: Our study aimed to develop a multivalent ETEC vaccine targeting major virulence factors of ETEC, including enterotoxins and fimbriae. Methods: SLS (STa-LTB-STb) recombinant enterotoxin and fimbriae proteins (F4, F5, F6, F18, and F41) were prepared to develop a multivalent vaccine. A total of 65 mice were immunized subcutaneously by vaccines and phosphate-buffered saline (PBS). The levels of specific immunoglobulin G (IgG) and pro-inflammatory cytokines were determined at 0, 7, 14 and 21 days post-vaccination (dpv). A challenge test with a lethal dose of ETEC was performed, and the survival rate of the mice in each group was recorded. Feces and intestine washes were collected to measure the concentrations of secretory immunoglobulin A (sIgA). Results: Anti-SLS and anti-fimbriae-specific IgG in serums of antigen-vaccinated mice were significantly higher than those of the control group. Immunization with the SLS enterotoxin and multivalent vaccine increased interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations. Compared to diarrheal symptoms and 100% death of mice in the control group, mice inoculated with the multivalent vaccine showed an 80% survival rate without any symptom of diarrhea, while SLS and fimbriae vaccinated groups showed 60 and 70% survival rates, respectively. Conclusions: Both SLS and fimbriae proteins can serve as vaccine antigens, and the combination of these two antigens can elicit stronger immune responses. The results suggest that the multivalent vaccine can be successfully used for preventing ETEC in important livestock.

Comparing Water and Nitrogen Use Efficiencies under Different Cropping Systems in the North China Plain Based on Model Approach

Kelin Hu,Huanyuan Wang,Yongping Wei,Baoguo Li,Liang Jin,Karl Stahr 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6