Stator flux oriented sensorless DTFC for IPMSMs using pseudo‑random HF signal injection

Junlei Chen,Xiang Wu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.12

In this article, a stator flux oriented sensorless control method is proposed for interior permanent magnet synchronous motor (IPMSM) drives based on the direct torque and flux control (DTFC) and pseudo-random high-frequency signal injection (PR-HFSI) in the zero-low speed range. The DTFC for IPMSMs is introduced briefly and the conventional high-frequency signal injection (HFSI) method, which requires an additional transformation, is also introduced. Then the stator flux oriented PR-HFSI is proposed comprising injection mode and rotor observation, with the aim of noise reduction and easy implementation. Furthermore, the high-frequency noise in HFSI and the mechanisms of noise suppression in PR-HFSI are analyzed based on current spectrums. Meanwhile, the optimal noise reduction frequency combination of n kinds frequency injections is also analyzed. Finally, the performance of the proposed stator flux oriented PR-HFSI method is confirmed with experiments on a 60 kW IPMSM test bench.

Aerodynamic Numerical Analysis of the Low Reynolds Number Diamond Joined-Wing Configuration Unmanned Aerial Vehicle

Junlei Sun,Heping Wang,Zhou Zhou,Shan Lei 한국항공우주학회 2018 International Journal of Aeronautical and Space Sc Vol.19 No.3

Aerodynamic numerical simulation of low Reynolds number long-endurance Diamond Joined-Wing configuration unmanned aerial vehicle was performed. First, low Reynolds number aerodynamic characteristics of a typical wing are numerically simulated by solving the Reynolds averaged Navier–Stokes (RANS) equations based on the structural grid technology and the k–kL–ω transition model. To prove the accuracy of this method, experimental data and numerical simulation results were compared. Second, the performance of low Reynolds number Diamond Joined-Wing configuration UAV (unmanned aerial vehicle) aerodynamic characteristics and control surfaces was studied by numerical simulation and theoretical analysis. The analysis of the interference between the Frt-wing (front wing) and the Aft-wing (after wing) of the Diamond Joined-Wing configuration UAV and the reason for the change in the pitching moment in the lateral-directional motion is carried out. The results show that the Diamond Joined-Wing configuration UAV has a typical low Reynolds number surface flow characteristics, Frt-wing and Aft-wing flow interference are relatively minor at a small angle of attack, which has a high basic aerodynamic performance in addition to good stall characteristics, with longitudinal and lateral-directional static stability. The performance of control surfaces and flaps is higher to meet the design requirements. Finally, the accuracy of the numerical simulation results was verified by vehicle aerodynamic testing.

Design and Implementation of Wind Load Resistance Performance Data Acquisition System of Building Curtain Wall

Zhigang Feng,Junlei Feng 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.2

With the development of the curtain wall industry and expiration of the curtain wall structures which designed and built in the early life, the testing for building curtain walls will be increasingly focused on. In this paper, a Client/Server structure acquisition system of the curtain wall wind pressure resistance characteristics data, which is based on the Advantech data acquisition card PCI-1747U, has been designed and implemented for the GB/T 15227-2007 (Test method of air permeability, watertightness, wind load resistance performance for curtain walls). The hardware of the data acquisition system contain three major components: The sensor part; The signal conditioning circuits part, which consists of sensor supply circuit, I-V conversion circuit and filter circuit; data acquisition part consists of Advantech card PCI-1747U and Advantech industrial computer 610L. The software of the system contain the data acquisition Server and data processing client. They communicate through TCP/IP protocol and complete the sensor calibration, static test and dynamic test of the wind load performance data, query and output historical data and other functions. Microsoft SQL Server 2000 database was used to management the test data. After running and debugging, the system’s sample time and accuracy reached the requirement of wind load resistance performance test.

Tracking Object by Logic Reasoning

Huibin Wang,Junlei Shen,Jie Shen,Zhe Chen 보안공학연구지원센터 2012 International Journal of Hybrid Information Techno Vol.5 No.2

The Top-K QoS-aware Paths Discovery for Source Routing in SDN

( Xi Chen ),( Junlei Wu ),( Tao Wu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.6

Source routing is the routing scheme that arranges the whole path from source to target at the origin node that may suit the requirements from the upper layer applications’ perspective. The centralized control in SDN (Software-Defined Networking) networks enables the awareness of the global topology at the controller. Therefore, augmented source routing schemes can be designed to achieve various purposes. This paper proposes a source routing scheme that conducts the top-K QoS-aware paths discovery in SDN. First, the novel non-invasive QoS over LLDP scheme is designed to collect QoS information based on LLDP in a piggyback fashion. Then, variations of the KSP (K Shortest Paths) algorithm are derived to find the unconstrained/constrained top-K ranked paths with regard to individual/overall path costs, reflecting the Quality of Service. The experiment results show that the proposed scheme can efficiently collect the QoS information and find the top-K paths. Also, the performance of our scheme is applicable in QoS-sensitive application scenarios compared with previous works.

Flux control of consequent‑pole hybrid excitation motors in constant power region to achieve both high efficiency and fast convergence speed

Xingchi Lu,Ying Fan,Junlei Chen,Yutong Lei 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.1

This paper proposes a new flux control strategy for consequent-pole brushless hybrid excitation (CPBHE) machines to achieve a high efficiency and a fast convergence. Based on an analysis of the mathematical model of a CPBHE machine, a loss model of the CPBHE machine is derived, which demonstrates the feasibility of adopting d-axis flux to search for the optimal efficiency point. Furthermore, to improve the convergence speed of the online search algorithm and to make it suitable for the frequently varying operating conditions of electric vehicles (EVs), an adaptive step search algorithm based on the margin of the voltage limit combined with the offline table lookup method is proposed. Experimental results show that the proposed algorithm can optimize the efficiency of a motor system in the flux-weakening region and that it features a fast optimization process that makes it suitable for EV drives.

Expression Profiles of the Insulin-like Growth Factor System Components in Liver Tissue during Embryonic and Postnatal Growth of Erhualian and Yorkshire Reciprocal Cross F₁ Pigs

Pan, Zengxiang,Zhang, Junlei,Zhang, Jinbi,Zhou, Bo,Chen, Jie,Jiang, Zhihua,Liu, Honglin Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.7

In Erhualian and Yorkshire reciprocal cross $F_1$ pig populations, we examined the mRNA expression characteristic of liver-derived IGF-1, IGF-1R, IGF-2, IGF-2R and IGFBP-3 during the embryonic and postnatal developmental periods (E50, E70, E90, D1, D20, D70, D120 and D180). Our results demonstrated that the IGF-system genes mRNA levels exhibited an ontogenetic expression pattern, which was potentially associated with the porcine embryonic development, postnatal growth, organogenesis and even the initiation and acceleration of puberty. The expression pattern of IGF-system genes showed variation in the reciprocal cross ($F_1$ YE and EY pigs). This study also involved the expression features of imprinted genes IGF-2 and IGF-2R. The parent-of-origin effect of imprinted genes was reflected by their differential expression between the reciprocal crosses populations. The correlation analysis also indicated that the regulatory network and mechanisms involved in the IGF system were a complex issue that needs to be more fully explored. A better understanding of IGF system components and their interactive mechanisms will enable researchers to gain insights not only into animal organogenesis but also into somatic growth development and even reproduction.

Endoplasmic Reticulum Mediated Necrosis-like Apoptosis of HeLa Cells Induced by Ca²⁺ Oscillation

Hu, Qingliu,Chang, Junlei,Tao, Litao,Yan, Guoliang,Xie, Mingchao,Wang, Zhao Korean Society for Biochemistry and Molecular Biol 2005 Journal of biochemistry and molecular biology Vol.38 No.6

Apoptosis and necrosis are distinguished by modality primarily. Here we show an apoptosis occurred instantly, induced by $300\;{\mu}M$ W-7 ((N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride), inhibitor of calmodulin), which demonstrated necrotic modality. As early as 30 min after W-7 addition, apoptotic (sub-diploid) peak could be detected by fluorescence-activated cell sorter (FACS), “DNA ladders” began to emerge also at this time point, activity of caspase-3 elevated obviously within this period. Absence of mitochondrial membrane potential (MMP) reduction and cytochrome c, AIF (apoptosis inducing factor) release, verified that this rapid apoptosis did not proceed through mitochondria pathway. Activation of caspase-12 and changes of other endoplasmic reticulum (ER) located proteins ascertained that ER pathway mediated this necrosis-like apoptosis. Our findings suggest that it is not credible to judge apoptosis by modality. Elucidation of ER pathway is helpful to comprehend the pathology of diseases associated with ER stress, and may offer a new approach to the therapy of cancer and neurodegenerative diseases.

Self-nitrogen-doped carbon materials derived from the petioles and blades of apricot leaves as metal-free catalysts for selective oxidation of aromatic alkanes

Sun Yongbin,Hao Junlei,Zhu Xuesai,Zhang Baobin,Yin Hao,Xu Shanguang,Hou Chao,Liu Kun 한국탄소학회 2020 Carbon Letters Vol.30 No.2

Carbon materials with tailorable structures and superior properties have great potential applications in environmental protec�tion, energy conversion, and catalysis. Plant biomass as abundant and green non-toxic raw materials has been considered as good precursors for synthesizing heteroatom-doped carbon materials. However, few studies have been reported on the dif�ferent natures of carbon materials derived from diferent parts of the same plant biomass. In this study, we prepared carbon materials from the petioles and blades of apricot leaves by direct pyrolysis without additives. Detailed characterizations indicate that these two carbon materials are similar in element composition and graphitization degree, but difer greatly in surface area and pore volume. These diferences can be attributed to the diferent contents of inorganic salts, vascular bundles, and proteins in petioles and blades. When used as catalysts for the oxidation of ethylbenzene, the petiole-derived carbon shows better catalytic performance than the blades derived carbon due to its high surface area, large average pore size, and doped nitrogen atoms. Furthermore, the carbon catalysts derived from the petioles and blades of poplar leaves and parasol tree leaves show the same diference in catalytic reaction, implying that the above-mentioned conclusion is rather universal, which can provide reference for the synthesis of carbon materials from leaves.

Endoplasmic Reticulum Mediated Necrosis-like Apoptosis ofHeLa Cells Induced by Ca2+ Oscillation

Qingliu Hu,Guoliang Yan,Junlei Chang,Litao Tao,Mingchao Xie,Zhao Wang 한국생화학분자생물학회 2005 BMB Reports Vol.38 No.6