Fast FCS-MPC-Based SVPWM Method to Reduce Switching States of Multilevel Cascaded H-Bridge STATCOMs

Wang, Xiuqin,Zhao, Jiwen,Wang, Qunjing,Li, Guoli,Zhang, Maosong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Finite control set model-predictive control (FCS-MPC) has received increasing attentions due to its outstanding dynamic performance. It is being widely used in power converters and multilevel inverters. However, FCS-MPC requires a lot of calculations, especially for multilevel-cascaded H-bridge (CHB) static synchronous compensators (STATCOMs), since it has to take account of all the feasible voltage vectors of inverters. Hence, an improved five-segment space vector pulse width modulation (SVPWM) method based on the non-orthogonal static reference frames is proposed. The proposed SVPWM method has a lower number of switching states and requires fewer computations than the conventional method. As a result, it makes FCS-MPC more efficient for multilevel cascaded H-bridge STATCOMs. The partial cost function is adopted to sequentially solve for the reference current and capacitor voltage. The proposed FCS-MPC method can reduce the calculation burden of the FCS-MPC strategy, and reduce both the switching frequency and power losses. Simulation and experimental results validate the excellent performance of the proposed method when compared with the conventional approach.

Fast FCS-MPC-Based SVPWM Method to Reduce Switching States of Multilevel Cascaded H-Bridge STATCOMs

Xiuqin Wang,Jiwen Zhao,Qunjing Wang,Guoli Li,Maosong Zhang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.1

Finite control set model-predictive control (FCS-MPC) has received increasing attentions due to its outstanding dynamicperformance. It is being widely used in power converters and multilevel inverters. However, FCS-MPC requires a lot ofcalculations, especially for multilevel-cascaded H-bridge (CHB) static synchronous compensators (STATCOMs), since it has totake account of all the feasible voltage vectors of inverters. Hence, an improved five-segment space vector pulse widthmodulation (SVPWM) method based on the non-orthogonal static reference frames is proposed. The proposed SVPWM methodhas a lower number of switching states and requires fewer computations than the conventional method. As a result, it makesFCS-MPC more efficient for multilevel cascaded H-bridge STATCOMs. The partial cost function is adopted to sequentiallysolve for the reference current and capacitor voltage. The proposed FCS-MPC method can reduce the calculation burden of theFCS-MPC strategy, and reduce both the switching frequency and power losses. Simulation and experimental results validate theexcellent performance of the proposed method when compared with the conventional approach.

Transcriptome reveals genes involving in black skin color formation of ducks

Lei Wang,Hehe Liu,Bo Hu,Jiwei Hu,Hengyong Xu,Hua He,Chunchun Han,Bo Kang,Lili Bai,Rongping Zhang,Jiwen Wang,Shengqiang Hu,Liang Li 한국유전학회 2021 Genes & Genomics Vol.43 No.2

Background Skin color is colorful for birds, which has been reported to be associated with multi-biological functions, such as crypsis, camoufage, social signaling and mate choice, but little is known about its underlying molecular mechanism. Objective Studies on the major genes afecting the black skin color of ducks. Methods For this purpose, Silver ammonia staining and RNA-seq analysis were carried out to identify the diferences in tissue morphology and gene expressions between black and yellow skin ducks. Results The silver ammonia dyes slice results showed that in the development of black duck, the content of melanin in black skin gradually increased and then decreased, and the content of melanin in yellow and black skin was signifcantly diferent. Through transcriptome, a total of 102 and 84 diferentially expressed genes (DEGs) were identifed in beak skin and web skin, respectively. These DEGs were enriched in melanin biosynthesis and play a critical role in melanogenesis pathway. Co-expression analysis showed that EDNRB2 was the only gene associated with black skin color in DEGs, which was also consistent with qRT-PCR. Conclusions The melanin synthesis pathway dominated by EDNRB2 up-regulated the amount of melanin synthesis, leading to the formation of black skin in ducks.

A Rock Mass Strength Prediction Method Integrating Wave Velocity and Operational Parameters based on the Bayesian Optimization Catboost Algorithm

Yaxu Wang,Ruirui Wang,Jiwen Wang,Ningbo Li,Hongyi Cao 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7

Tunnel Boring Machines (TBMs) have been the main equipment for tunneling and underground construction due to their high safety performance and tunneling efficiency. However, the unknown and changing geological conditions during construction pose a challenge to TBM construction. As one of the essential parameters of rock properties, accurate acquisition of uniaxial compressive strength (UCS) is crucial for TBMs to adapt to changing ground conditionsin a timely manner. Therefore, this study proposes a Catboost intelligent model based on Bayesian Optimization to predict UCS. Rock mass are velocity information and key TBM operational parameters are used as model input variables. The Gaussian data augmentation method is used to compensate for the difficulty of obtaining field data in large quantities. The Zhujiang Delta Water Resources Allocation Engineering field data are used in the model, and the obtained evaluation indicators MAPE, RMSE, VAF and a20-index are obtained as 9.91%, 499.38 MPa, 90.7% and 0.95, respectively. In addition, another project is selected to verify the applicability of the model. The validation results also confirm that the model is valid and reliable when applied to practical engineering.

Fuzzy Adaptive Sliding Mode Control for the Precision Position of Piezo-Actuated Nano Positioning Stage

Jiwen Fang,Lufan Zhang,Zhili Long,Michael Yu Wang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.10

This paper concerns hysteresis and creep of a piezo-actuated nano positioning stage. The hysteresis and creep, considered as bounded disturbance or uncertainty, are suppressed without a nonlinear model. An improved Fuzzy Adaptive Sliding Mode Control (FASMC) with a Proportional-Integral-Derivative sliding surface is designed to cancel both hysteresis and creep. However, the constant slopes of the sliding function may increase oscillations. Some variable gains with adaptive rules are introduced to overcome this drawback by changing the sliding function values online. Fuzzy control is applied to tune the switching control part to improve performance. Furthermore, an adaptation law is used to approximate the optimal value of the switching control. The stability of the sliding mode control law is proved in the sense of Lyapunov stability theorem. To eliminate chattering and obtain a smooth signal, the switching control is modified and a smooth function is introduced to substitute the signum function. An anti-saturation control is introduced to keep the input voltage within safety scope. Experimental results show that FASMC can achieve faster response for step input and sinusoid signal. Both hysteresis and creep of the piezoelectric actuator are suppressed by the proposed FASMC. Therefore, the FASMC can reduce the tracking errors of the piezo-actuated stage.

Research on the Method of Fault Diagnosis Based on Multiple Classifiers Fusion

Yan Wen,Jiwen Tan,Hong Zhan,Hao Wang 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.2

In traditional fault diagnosis method, a large number of experiments are needed to get the optimal performance classifier which diagnoses type of fault. Because of classifier algorithm limit, there is no one classifier can be applied to all kinds of fault diagnosis. In order to avoid the disadvantages caused by single classifier approach, decision level fusion method based on multiple classifiers fusion is introduced in the field of fault diagnosis. The fusion method with fuzzy comprehensive evaluation is put forward and the basic evaluation model is set up. The reasonable distribution of classifiers weight that affects diagnosis result directly is vital. Firstly, the evaluation function which measures member classifier’s diagnostic accuracy and correctness is constructed based on the theory of information entropy. Then, weights are distributed to each classifier with entropy coefficient according to the value of evaluation function. Experiments are carried out to demonstrate the effectiveness of the proposed method and results show that fault recognition rate after fusion is higher compared with the single classifier method.

Effect of Overfeeding on Plasma Parameters and mRNA Expression of Genes Associated with Hepatic Lipogenesis in Geese

Han, Chunchun,Wang, Jiwen,Xu, Hengyong,Li, Liang,Ye, Jianqiang,Li, Jiang,Zhuo, Weihua Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.4

The aim of our study was to research the effect of overfeeding on plasma parameters and mRNA expression of genes associated with hepatic lipogenesis in the Sichuan white goose and Landes goose. Fifty-four male Landes geese and 57 male Sichuan white geese were hatched on the same day under the same feeding conditions. After overfeeding for 14 days, (1) extrahepatic adipose tissues grew greatly in the Sichuan white geese, while more lipid accumulated in liver tissue in the Landes geese. (2) Sichuan white geese had a higher plasma concentration of triacylglycerols (TG), lipoproteins and insulin than the Landes geese. However, the Landes geese exhibited higher increase of plasma concentrations of TG, lipoproteins and insulin, with greater decrease of the diacylglycerol acyltransferase 2 (DGAT2) activity and DGAT2 mRNA level and a smller decrease of plasma glucose concentration. In addition, the mRNA level of MTP and LPL in liver was down- and up- regulated by overfeeding, respectively. (3) The correlations between the activity of LPL and the proportions of subcutaneous adipose tissue, abdominal adipose tissue, and liver weight, and the plasma concentration of VLDL were different in the two breeds. (4) The proportion of fatty liver weight was positively correlated to plasma concentrations of VLDL and TG in the overfed Sichuan white geese. Such a relationship did not exist in the Landes geese. (5) The activity of DGAT2 and its mRNA abundance in liver had significant negative correlations with the TG content in liver lipid and plasma insulin level in the Landes geese, while in the Sichuan white geese they had negative correlation (p>0.05) with TG concentration in liver lipid and had significant positive correlation with VLDL and TG concentrations in plasma.

Estimation of Lipoprotein-lipase Activity (LPL) and Other Biochemical Changes in Two Breeds of Overfeeding Geese

Xu, Hengyong,Wang, Yan,Han, Chunchun,Jiang, Li,Zhuo, Weihua,Ye, Jianqiang,Wang, Jiwen Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.9

This study aimed to examine the effect of overfeeding on biochemical parameters and lipoprotein-lipase (LPL) mRNA expression in different tissues associated with hepatic lipogenesis in Sichuan white and Landes geese. Fifty healthy male Sichuan white geese and fifty male Landes geese (Cygnus atratus) were hatched on the same day under the same feeding conditions and were selected as experimental animals. After overfeeding for 14 days (from 14 weeks to 16 weeks) and then slaughtering, the biochemical changes of hepatic lipogenesis were evaluated. Results showed that i) in Landes geese, the plasma concentration of glucose was higher (p<0.001), while plasma concentrations of insulin and VLDL were both lower (p<0.01); ii) the LPL mRNA level in pectoralis muscle and leg muscle of the overfed groups in both breeds was higher (p<0.05) than in the control groups; iii) in Sichuan white geese, the proportion of fatty liver weight was positively correlated with plasma triacylglycerols (TG)(p<0.05) and VLDL concentrations (p<0.05), while these correlations were not significant in Landes geese; and iv) the activity of LPL had significant positive correlation with the proportions of lipids in subcutaneous adipose tissue and abdominal adipose tissue in Sichuan white geese, while in Landes geese the correlation was negative (p<0.05) with proportions of lipids in the liver, LPL activity had a significant positive correlation with the proportions of lipids in subcutaneous adipose tissue. These results suggest that the Landes geese have a better ability to use the massive amount of ingested food and to store lipids preferentially in the liver, but the Sichuan white geese have a relatively lower ability to use energetic nutrients and lipid storage is more efficient in the adipose tissues.

The impact of diet on the composition and relative abundance of rumen microbes in goat

Kaizhen Liu,Qin Xu,Lizhi Wang,Jiwen Wang,Wei Guo,Meili Zhou 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.4

Objective: This experiment was conducted to explore the impact of diet on the ruminal microbial community in goats. Methods: Twelve goats were divided into two groups and fed complete feed (CF) or all forage (AF) diet. The total microbial DNAs in the rumen liquid were extracted. The V4 region of microbial 16S rRNA genes was amplified and sequenced using high-throughput. Information of sequences was mainly analyzed by QIIME 1.8.0. Results: The results showed that Bacteroidetes and Firmicutes were the most predominant microbial phyla in the rumen of all goats. At genus level, the abundance of fiber-digesting bacteria such as Ruminococcus and Lachnospiracea incertae sedis was significantly higher in AF than that in CF, while the levels of fat-degrading bacterium Anaerovibrio and protein-degrading bacterium Pseudomonas were opposite. The core shared genera, Prevotella and Butyrivibrio were widespread in the rumen of goats and no significant difference was observed in relative abundance between groups. Conclusion: We concluded that the richness of fiber-, protein-, and fat-digesting bacteria was affected by diet and tended to increase with the rise of their corresponding substrate contents in the ration; some bacteria shared by all goats maintained stable despite the difference in the ration, and they might be essential in maintaining the normal function of rumen.

Enrichment and verification of differentially expressed miRNAs in bursa of Fabricius in two breeds of duck

Jun Luo,Junying Liu,He-he Liu,Tao Zhang,Jiwen Wang,Hua He,Chunchun Han 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.7

Objective: The bursa of Fabricius (BF) is a central humoral immune organ belonging specifically to avians. Recent studies had suggested that miRNAs were active regulators involved in the immune processes. This study was to investigate the possible differences of the BF at miRNA level between two genetically disparate duck breeds. Methods: Using Illumina next-generation sequencing, the miRNAs libraries of ducks were established. Results: The results showed that there were 66 differentially expressed miRNAs and 28 novel miRNAs in bursa. A set of abundant miRNAs (i.e., let-7, miR-146a-5p, miR-21-5p, miR-17~92) which are involved in immunity and disease were detected and the predicted target genes of the novel miRNAs were associated with duck high anti-adversity ability. By gene ontology analysis and enriching KEGG pathway, the targets of differential expressed miRNAs were mainly involved in immunity and disease, supporting that there were differences in the BF immune functions between the two duck breeds. In addition, the metabolic pathway had the maximum enriched target genes and some enriched pathways that were related to cell cycle, protein synthesis, cell proliferation and apoptosis. It indicted that the difference of metabolism may be one of the reasons leading the immune difference between the BF of two duck breeds. Conclusion: This data lists the main differences in the BF at miRNAs level between two genetically disparate duck breeds and lays a foundation to carry out molecular assisted breeding of poultry in the future.