Photovoltaic Modified β-Parameter-based MPPT Method with Fast Tracking

Li, Xingshuo,Wen, Huiqing,Jiang, Lin,Lim, Eng Gee,Du, Yang,Zhao, Chenhao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Maximum power point tracking (MPPT) is necessary for photovoltaic (PV) power system application to extract the maximum possible power under changing irradiation and temperature conditions. The β-parameter-based method has many advantages over conventional MPPT methods; such advantages include fast tracking speed in the transient stage, small oscillations in the steady state, and moderate implementation complexity. However, a problem in the implementation of the conventional beta method is the choice of an appropriate scaling factor N, which greatly affects both the steady-state and transient performance. Therefore, this paper proposes a modified β-parameter-based method, and the determination of the N is discussed in detail. The study shows that the choice of the scaling factor N is determined by the changes of the value of β during changes in irradiation or temperature. The proposed method can respond accurately and quickly during changes in irradiation or temperature. To verify the proposed method, a photovoltaic power system with MPPT function was built in Matlab/Simulink, and an experimental prototype was constructed with a solar array emulator and dSPACE. Simulation and experimental results are illustrated to show the advantages of the improved β-parameter-based method with the optimized scaling factor.

Improved Beta parameter based MPPT method in Photovoltaic system

Xingshuo Li,Huiqing Wen,Chenhao Zhao 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

Maximum power point tracking(MPPT) is very important in relation to solar energy development. Currently, there are two problems facing the existing MPPT methods namely the tradeoff between the steady-state oscillations and dynamic behavior, and then the tradeoff between high computational load and accuracy. The Beta method can address these two problems since it shows a fast tracking speed in the transient stage, smaller oscillations in the steady-state and medium complexity of implementation. However, for optimal performance, it is essential to identify the configuration of the parameters with regard to the Beta method. Therefore, paper will examine the different performance level with the different values of the parameters, and then will provide an optimum example. In order to verify this procedure, a boost converter was proposed in MatLab/Simulink for simulation. Finally, an experimental prototype was constructed with a solar array emulator and DSPACE.

Photovoltaic Modified β-Parameter-based MPPT Method with Fast Tracking

Xingshuo Li,Huiqing Wen,Lin Jiang,Eng Gee Lim,Yang Du,Chenhao Zhao 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Maximum power point tracking (MPPT) is necessary for photovoltaic (PV) power system application to extract the maximum possible power under changing irradiation and temperature conditions. The β-parameter-based method has many advantages over conventional MPPT methods; such advantages include fast tracking speed in the transient stage, small oscillations in the steady state, and moderate implementation complexity. However, a problem in the implementation of the conventional beta method is the choice of an appropriate scaling factor N, which greatly affects both the steady-state and transient performance. Therefore, this paper proposes a modified β-parameter-based method, and the determination of the N is discussed in detail. The study shows that the choice of the scaling factor N is determined by the changes of the value of β during changes in irradiation or temperature. The proposed method can respond accurately and quickly during changes in irradiation or temperature. To verify the proposed method, a photovoltaic power system with MPPT function was built in Matlab/Simulink, and an experimental prototype was constructed with a solar array emulator and dSPACE. Simulation and experimental results are illustrated to show the advantages of the improved β-parameter-based method with the optimized scaling factor.

Room-temperature power factor of CuAlO2 composite tablets enhanced by MWCNTs

Ma Lingxiao,Dong Chenhao,Li Wenquan,Su Qing,Zhou Jinyuan,Xie Erqing,Lan Wei 한국물리학회 2022 Current Applied Physics Vol.33 No.-

CuAlO2 with high theoretical thermoelectric performance has potential applications in thermal energy conversion. Herein, multi-wall carbon nanotubes (MWCNTs)/CuAlO2 composite tablets are prepared by using different amounts of MWCNTs and solid paraffin binder, where MWCNTs served as a conductive agent and rendered three orders of magnitude increase in electrical conductivity. Seebeck coefficient of the composites was reduced with increasing MWCNTs content. Consequently, an optimal room-temperature thermoelectric power factor (PF) of 1.31 μW m 1K 2 has been rendered by MWCNTs/CuAlO2 composite tablet with 1 wt % MWCNTs. Moreover, PF value increased with increasing temperature after a slight decrease at 333 K, which can be ascribed to the modulation of electrical conductivity. Current work provides an effective strategy to improve thermoelectric performance of CuAlO2 materials.

Sulforaphane Ameliorates Diabetes-Induced Renal Fibrosis through Epigenetic Up-Regulation of BMP-7

Lili Kong,Hongyue Wang,Chenhao Li,Huiyan Cheng,Yan Cui,Li Liu,Ying Zhao 대한당뇨병학회 2021 Diabetes and Metabolism Journal Vol.45 No.6

Background: The dietary agent sulforaphane (SFN) has been reported to reduce diabetes-induced renal fibrosis, as well as inhibit histone deacetylase (HDAC) activity. Bone morphologic protein 7 (BMP-7) has been shown to reduce renal fibrosis induced by transforming growth factor-beta1. The aim of this study was to investigate the epigenetic effect of SFN on BMP-7 expression in diabetes-induced renal fibrosis.Methods: Streptozotocin (STZ)-induced diabetic mice and age-matched controls were subcutaneously injected with SFN or vehicle for 4 months to measure the in vivo effects of SFN on the kidneys. The human renal proximal tubular (HK11) cell line was used to mimic diabetic conditions in vitro. HK11 cells were transfected to over-express HDAC2 and treated with high glucose/palmitate (HG/Pal) to explore the epigenetic modulation of BMP-7 in SFN-mediated protection against HG/Pal-induced renal fibrosis.Results: SFN significantly attenuated diabetes-induced renal fibrosis in vivo. Among all of the HDACs we detected, HDAC2 activity was markedly elevated in the STZ-induced diabetic kidneys and HG/Pal-treated HK11 cells. SFN inhibited the diabetes-induced increase in HDAC2 activity which was associated with histone acetylation and transcriptional activation of the BMP-7 promoter. HDAC2 over-expression reduced BMP-7 expression and abolished the SFN-mediated protection against HG/Pal-induced fibrosis in vitro.Conclusion: Our study demonstrates that the HDAC inhibitor SFN protects against diabetes-induced renal fibrosis through epigenetic up-regulation of BMP-7.

SIRT3-mediated mitochondrial unfolded protein response weakens breast cancer sensitivity to cisplatin

Chen Hao,Zhang Dong-Ming,Zhang Zhi-Ping,Li Ming-Zhang,Wu Hai-Feng 한국유전학회 2021 Genes & Genomics Vol.43 No.12

Background Mitochondrial unfolded protein response plays an important role in the occurrence and development of breast cancer. However, the role of mitochondrial unfolded protein response (UPRmt) in the sensitivity of breast cancer to cisplatin chemotherapy has not yet been cleared. Objectives The purpose of this study is to explore the role of mitochondrial unfolded protein response in breast cancer sensitivity to cisplatin. Methods In this study, qRT-PCR, Western blotting, Immunofuorescence, CCK-8, Colony formation, Transwell assay and TUNEL staining assay were used to confrm the role of UPRmt in breast cancer cells treated with cisplatin. Results Cisplatin increased the levels of UPRmt including CLPP, HSP60, LONP1 in MCF7 and MDA-MB-231 cells. UPRmt inducer Nicotinamide ribose (NR) could promote the proliferation and invasion of breast cancer cells treated with cisplatin. Importantly, SIRT3 was discovered to increase UPRmt in breast cancer cells and silencing of SIRT3 could inhibit the efect of NR in breast cancer. Conclusions UPRmt regulated by SIRT3 could protect breast cancer cell from cisplatin. Controlling SIRT3-induced UPR may be a potential therapeutic target to increase the sensitivity of breast cancer chemotherapy.

China Consensus Document on Allergy Diagnostics

Chen Hao,Li Jing,Cheng Lei,Gao Zhongshan,Lin Xiaoping,Zhu Rongfei,Yang Lin,Tao Ailin,Hong Haiyu,Tang Wei,Guo Yinshi,Huang Huaiqiu,Sun Jinlyu,Lai He,Lei Cheng,Liu Guanghui,Xiang Li,Chen Zhuanggui,Ma Ha 대한천식알레르기학회 2021 Allergy, Asthma & Immunology Research Vol.13 No.2

The prevalence of allergic diseases has increased dramatically in recent years in China, affecting the quality of life in 40% of the population. The identification of allergens is the key to the diagnosis of allergic diseases. Presently, several methods of allergy diagnostics are available in China, but they have not been standardized. Additionally, cross-sensitization and co-sensitization make allergy diagnostics even more complicated. Based on 4 aspects of allergic disease (mechanism, diagnosis procedures, allergen detection in vivo and in vitro as well as the distribution map of the most important airborne allergens in China) and by referring to the consensus of the European Society of Allergy and Clinical Immunology, the World Allergy Organization, and the important literature on allergy diagnostics in China in recent years, we drafted this consensus of allergy diagnostics with Chinese characteristics. It aims to standardize the diagnostic methods of allergens and provides a reference for health care givers. The current document was prepared by a panel of experts from the main stream of professional allergy associations in China.

EA-D p45-IgG as a Potential Biomarker for Nasopharyngeal Carcinoma Diagnosis

Chen, Hao,Luo, Yao-Ling,Zhang, Lin,Tian, Li-Zhen,Feng, Zhi-Ting,Liu, Wan-Li Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Aim: To identify new biomarkers for NPC diagnosis with an anti-EBV Western blot test kit. Methods: Serum samples from 64 NPC patients and healthy subjects with four specific VCA-IgA/EA-IgA profiles were tested with an anti-EBV Western blot test kit from EUROIMMUN AG. Proteins were quantified with scores of intensity visually assigned to the protein bands. The markers which showed statistical differences between the NPC and non-NPC subjects were further evaluated in another 32 NPC patients and 32 controls in comparison with established biomarkers including VCA-IgA, EA-IgA, EBV-related protein IgG, and EBV DNA. Results: Among the markers screened, EA-D p45-IgG showed a statistically significant difference (p < 0.05) between NPC and non-NPC subjects with VCA-IgA positivy. In 32 VCA-IgA positive NPC patients and 32 control subjects, the diagnostic accuracy of EA-D p45-IgG was 78.1% with a positive predictive value of 77.8% and a negative predictive value of 78.6%. In the verification experiment, the specificity and sensitivity of EA-D p45-IgG were 75.0% and 90.6 %, respectively. Conclusions: EA-D p45-IgG might be a potential biomarker for NPC diagnosis, especially among VCA-IgA positive subjects.