Neutral-point Voltage Balancing Strategy for Three-level Converter based on Disassembly of Zero Level

Wang, Chenchen,Li, Zhitong,Xin, Hongliang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

The neutral-point (NP) voltage of three-phase three-level NP-clamped converters is needed for balance. To maintain NP potential and suppress ripple, a novel NP voltage balancing strategy is proposed in this work. The mechanism of NP voltage variation is studied first. Then, the relationship between the disassembly of zero level (O level) and NP current is studied comprehensively. On these bases, two methods for selecting one of three output phases for the disassembly of its O level are presented. Finally, simulation and experimental results verify the validity and practicability of the proposed algorithms.

DC-link voltage balance control method considering the wide regulation range in SOR for single-phase cascaded H-bridge rectifier

Wang, Xin,Wang, Chenchen,Gu, Changbin The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.1

In this paper, a DC-link voltage balance control method that considers the wide regulation range in the steady-state operating region is proposed for a single-phase cascaded H-bridge rectifier. A mathematical model of the DC-link voltage is also established while considering the imbalance caused by the inconsistency of the active power absorbed and consumed by the cell. On the basis of the steady-state operating region of the cascaded H-bridge rectifier, the operating loci of different balance methods are analyzed and a novel balance method is proposed. The DC-link voltage regulation range of the proposed method is then compared with that of two other commonly used methods based on the operating locus in the steady-state operating region. The comparison results show that the proposed method has the widest regulation range in the steady-state operating region wherever the cascaded H-bridge rectifier is operated. The experimental results also verify the effectiveness and superiority of the proposed method.

Neutral-point Voltage Balancing Strategy for Three-level Converter based on Disassembly of Zero Level

Chenchen Wang,Zhitong Li,Hongliang Xin 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

The neutral-point (NP) voltage of three-phase three-level NP-clamped converters is needed for balance. To maintain NPpotential and suppress ripple, a novel NP voltage balancing strategy is proposed in this work. The mechanism of NP voltagevariation is studied first. Then, the relationship between the disassembly of zero level (O level) and NP current is studiedcomprehensively. On these bases, two methods for selecting one of three output phases for the disassembly of its O level arepresented. Finally, simulation and experimental results verify the validity and practicability of the proposed algorithms.

An Equivalent Carrier-based Implementation of a Modified 24-Sector SVPWM Strategy for Asymmetrical Dual Stator Induction Machines

Wang, Kun,You, Xiaojie,Wang, Chenchen The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

A modified space vector pulse width modulation (SVPWM) strategy based on vector space decomposition and its equivalent carrier-based PWM realization are proposed in this paper, which is suitable for six-phase asymmetrical dual stator induction machines (DSIMs). A DSIM is composed of two sets of symmetrical three-phase stator windings spatially shifted by 30 electrical degrees and a squirrel-cage type rotor. The proposed SVPWM technique can reduce torque ripples and suppress the harmonic currents flowing in the stator windings. Above all, the equivalent relationship between the proposed SVPWM technique and the carrier-based PWM technique has been demonstrated, which allows for easy implementation by a digital signal processor (DSP). Simulation and experimental results, carried out separately on a simulation system and a 3.0 kW DSIM prototype test bench, are presented and discussed.

Effect of Lonicera edulis polysaccharide on reducing oral dyeing of lonicera edulis juice

Wang Xin,Luo Yu,Ma Rui,Wang Zhili,Yu Shiyou,Li Chenchen,Han Chunran 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.3

Fluorescence spectroscopy, particle size determination, and potential analysis were exploited to elucidate the effect of Lonicera edulis polysaccharide on polyphenol protein. The results revealed that Lonicera edulis polysaccharides mediated the binding of polyphenols and proteins through competition and formation of ternary complexes and were also able to enhance the stability of the polyphenol-protein complex solution system. A certain electrostatic effect was also present in the process simultaneously. As confirmed by the dyeing test, to improve oral dyeing, the optimum conditions of adding polysaccharide, pectin, and casein were as follows: the dosage of the polysaccharide group was 1.2 mg/mL, coloring time was 100 min, pH value was 4.0. Pectin group added 0.8 mg/mL with coloring time 80 min, pH 5.0. The addition of casein was 1.2 mg/mL; the coloring time was 100 min with pH 5.0. The sample juice substantiated a significant improvement in the dyeing of porcine tongue mucosa. Under the optimal conditions, microscopic observation validates that the mucosal color of the porcine tongue epidermis was closer to that of unstained porcine tongue epidermis, which significantly improved astringency and oral staining. Fluorescence spectroscopy, particle size determination, and potential analysis were exploited to elucidate the effect of Lonicera edulis polysaccharide on polyphenol protein. The results revealed that Lonicera edulis polysaccharides mediated the binding of polyphenols and proteins through competition and formation of ternary complexes and were also able to enhance the stability of the polyphenol-protein complex solution system. A certain electrostatic effect was also present in the process simultaneously. As confirmed by the dyeing test, to improve oral dyeing, the optimum conditions of adding polysaccharide, pectin, and casein were as follows: the dosage of the polysaccharide group was 1.2 mg/mL, coloring time was 100 min, pH value was 4.0. Pectin group added 0.8 mg/mL with coloring time 80 min, pH 5.0. The addition of casein was 1.2 mg/mL; the coloring time was 100 min with pH 5.0. The sample juice substantiated a significant improvement in the dyeing of porcine tongue mucosa. Under the optimal conditions, microscopic observation validates that the mucosal color of the porcine tongue epidermis was closer to that of unstained porcine tongue epidermis, which significantly improved astringency and oral staining.

Measurement of the feedback coefficient by monitoring the power difference at power jump point in self-mixing vibration signal

Chenchen Wang,Junfeng Zhou,Yunkun Zhao,Youze Chen,Benli Yu,Liang Lu 한국물리학회 2019 Current Applied Physics Vol.19 No.4

This paper proposed a new method for measuring the feedback coefficient in the self-mixing interference. In experiment, the value of feedback coefficient is obtained by measuring the power difference at power jump point that based on the self-mixing vibration sensing system. It realized the measurement of feedback coefficient in range of 1–7.8 and shows a good agreement with the theoretical derivation and the corresponding simulation. Meanwhile, there is a good fitting result with the determination coefficient of 0.98 and line-width broadening factor of 3.245 respectively, which also realized measurement of feedback coefficient and line-width broadening factor at the same time.

An Equivalent Carrier-based Implementation of a Modified 24-Sector SVPWM Strategy for Asymmetrical Dual Stator Induction Machines

Kun Wang,Xiaojie You,Chenchen Wang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

A modified space vector pulse width modulation (SVPWM) strategy based on vector space decomposition and its equivalent carrier-based PWM realization are proposed in this paper, which is suitable for six-phase asymmetrical dual stator induction machines (DSIMs). A DSIM is composed of two sets of symmetrical three-phase stator windings spatially shifted by 30 electrical degrees and a squirrel-cage type rotor. The proposed SVPWM technique can reduce torque ripples and suppress the harmonic currents flowing in the stator windings. Above all, the equivalent relationship between the proposed SVPWM technique and the carrier-based PWM technique has been demonstrated, which allows for easy implementation by a digital signal processor (DSP). Simulation and experimental results, carried out separately on a simulation system and a 3.0 kW DSIM prototype test bench, are presented and discussed.

Cardiac-targeted delivery of nuclear receptor RORα via ultrasound targeted microbubble destruction optimizes the benefits of regular dose of melatonin on sepsis-induced cardiomyopathy

Shanjie Wang,Kegong Chen,Ye Wang,Zeng Wang,Zhaoying Li,JunChen Guo,Jianfeng Chen,Wenhua Liu,Xiaohui Guo,Guangcan Yan,Chenchen Liang,Huai Yu,Shaohong Fang,Bo Yu 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Large-dose melatonin treatment in animal experiments was hardly translated into humans, which may explain the dilemma that the protective effects against myocardial injury in animal have been challenged by clinical trials. Ultrasound-targeted microbubble destruction (UTMD) has been considered a promising drug and gene delivery system to the target tissue. We aim to investigate whether cardiac gene delivery of melatonin receptor mediated by UTMD technology optimizes the efficacy of clinically equivalent dose of melatonin in sepsis-induced cardiomyopathy. Methods Melatonin and cardiac melatonin receptors in patients and rat models with lipopolysaccharide (LPS)- or cecal ligation and puncture (CLP)-induced sepsis were assessed. Rats received UTMD-mediated cardiac delivery of RORα/cationic microbubbles (CMBs) at 1, 3 and 5 days before CLP surgery. Echocardiography, histopathology and oxylipin metabolomics were assessed at 16–20 h after inducing fatal sepsis. Results We observed that patients with sepsis have lower serum melatonin than healthy controls, which was observed in the blood and hearts of Sprague–Dawley rat models with LPS- or CLP-induced sepsis. Notably, a mild dose (2.5 mg/kg) of intravenous melatonin did not substantially improve septic cardiomyopathy. We found decreased nuclear receptors RORα, not melatonin receptors MT1/2, under lethal sepsis that may weaken the potential benefits of a mild dose of melatonin treatment. In vivo, repeated UTMD-mediated cardiac delivery of RORα/CMBs exhibited favorable biosafety, efficiency and specificity, significantly strengthening the effects of a safe dose of melatonin on heart dysfunction and myocardial injury in septic rats. The cardiac delivery of RORα by UTMD technology and melatonin treatment improved mitochondrial dysfunction and oxylipin profiles, although there was no significant influence on systemic inflammation. Conclusions These findings provide new insights to explain the suboptimal effect of melatonin use in clinic and potential solutions to overcome the challenges. UTMD technology may be a promisingly interdisciplinary pattern against sepsis-induced cardiomyopathy.

Load of Ag3PO4 Particles on Sulfonated Polyphenylene Sulfide Superfine Fibre with High Visible-light Photocatalytic Activity

Pei Wang,Chenchen He,Lingquan Hu,Shaohua Chen,Xianze Yin,Jing Xu,Luoxin Wang,Hua Wang 한국섬유공학회 2018 Fibers and polymers Vol.19 No.7

Ag3PO4 was loaded on sulfonated polyphenylene sulfide (SPPS) superfine fibre by a facile precipitation method. Both the structure and properties of the as-synthesized Ag3PO4/SPPS composites were characterized via XRD, SEM, EDS, XPS, FTIR, and UV-vis. The photocatalytic performance of Ag3PO4/SPPS composites was investigated via degradation of Methylene blue(MB) solution under visible light irradiation. The degradation results revealed that the photocatalytic activity of Ag3PO4/SPPS composites was greatly enhanced by the incorporation of Ag3PO4 with SPPS superfine fibre. For concentrations of AgNO3 and Na2HPO4 solutions of 0.3 M and 0.06 M in the preparation process, the Ag3PO4/SPPS composite showed higher photocatalytic activity under visible light irradiation.

Identification of putative ingestion‑related olfactory receptor genes in the Chinese mitten crab (Eriocheir japonica sinensis)

Chenchen Shen,Dan Tang,Yiping Zhang,Lv Wu,Yaqi Luo,Boping Tang,Zhengfei Wang 한국유전학회 2021 Genes & Genomics Vol.43 No.5

Background Olfaction plays a central role in mating, spawning, obtaining food and escaping predators, which is essential for survival and reproduction of animals. The nature of the olfactory perception in crabs, which is a major group of crustaceans, has remained elusive. Objective This project aims to explore the molecular mechanism of olfaction in crabs and further improve our understanding of olfactory perception in crustaceans. Methods The olfactory receptors and ingestion-related gene expression in Eriocheir japonica sinensis were studied by transcriptomic techniques. The de novo assembly, annotation and functional evaluation were performed with bioinformatics tools. Results A series of chemosensory receptors associated with olfaction were identifed including 33 EsIRs, 24 EsIGluRs, 58 EsVIGluRs, 1 EsOR and 1 EsGC-D. We found IRs were key odorant receptors demonstrating a specifc species evolutionary trend in crustaceans. Furthermore, we identifed ORs in E. j. sinensis and Litopenaeus vannamei. The incomplete EsOR and LvOR1 structures implied that ORs exist in crustaceans, and may have been degenerated or even lost in the olfactory evolutionary process. In addition, comparative transcriptome analysises demonstrated two possible olfactory transduction pathways of E. j. sinensis: the cGMP-mediated olfactory pathway related to vegetable odor molecules and the cAMP-mediated olfactory pathway related to meat odor molecules. The above results were consistent with its omnivorous ingestion of E. j. sinensis. Conclusions Our study revealed the unique olfactory molecular mechanism of omnivorous crabs and provided valuable information for further functional research on the chemoreception mechanisms in crustaceans.