A Novel Battery State of Health Estimation Method Based on Outlier Detection Algorithm

Chang-hao Piao,Zi-hao Hu,Ling Su,Jian-fei Zhao 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

A novel battery SOH estimation algorithm based on outlier detection has been presented. The Battery state of health (SOH) is one of the most important parameters that describes the usability state of the power battery system. Firstly, a battery system model with lifetime fading characteristic was established, and the battery characteristic parameters were acquired from the lifetime fading process. Then, the outlier detection method based on angular distribution was used to identify the outliers among the battery behaviors. Lastly, the functional relationship between battery SOH and the outlier distribution was obtained by polynomial fitting method. The experimental results show that the algorithm can identify the outliers accurately, and the absolute error between the SOH estimation value and true value is less than 3%.

Improved Global Maximum Power Point Tracking for Photovoltaic System via Cuckoo Search under Partial Shaded Conditions

Shi, Ji-Ying,Xue, Fei,Qin, Zi-Jian,Zhang, Wen,Ling, Le-Tao,Yang, Ting The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Conventional maximum power point tracking (MPPT) methods are ineffective under partially shaded conditions because multiple local maximum can be exhibited on power-voltage characteristic curve. This study proposes an improved cuckoo search (ICS) MPPT method after investigating the cuckoo search (CS) algorithm applied in solving multiple MPPT. The algorithm eliminates the random step in the original CS algorithm, and the conception of low-power, high-power, normal and marked zones are introduced. The adaptive step adjustment is also realized according to the different stages of the nest position. This algorithm adopts the large step in low-power and marked zones to reduce search time, and a small step in high-power zone is used to improve search accuracy. Finally, simulation and experiment results indicate that the promoted ICS algorithm can immediately and accurately track the global maximum under partially shaded conditions, and the array output efficiency can be improved.

Improved Global Maximum Power Point Tracking for Photovoltaic System via Cuckoo Search under Partial Shaded Conditions

Ji-Ying Shi,Fei Xue,Zi-Jian Qin,Wen Zhang,Le-Tao Ling,Ting Yang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Conventional maximum power point tracking (MPPT) methods are ineffective under partially shaded conditions because multiple local maximum can be exhibited on power–voltage characteristic curve. This study proposes an improved cuckoo search (ICS) MPPT method after investigating the cuckoo search (CS) algorithm applied in solving multiple MPPT. The algorithm eliminates the random step in the original CS algorithm, and the conception of low-power, high-power, normal and marked zones are introduced. The adaptive step adjustment is also realized according to the different stages of the nest position. This algorithm adopts the large step in low-power and marked zones to reduce search time, and a small step in high-power zone is used to improve search accuracy. Finally, simulation and experiment results indicate that the promoted ICS algorithm can immediately and accurately track the global maximum under partially shaded conditions, and the array output efficiency can be improved.

Failure analysis of prestressed concrete containment vessels under internal pressure considering thermomechanical coupling

Wu Yu-Xiao,Fei Zi-Jian,Feng De-Cheng,Song Meng-Yan 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.12

After a loss of coolant accident (LOCA) in the prestressed concrete containment vessels (PCCVs) of nuclear power plants, the coupling of temperature and pressure can significantly affect the mechanical properties of the PCCVs. However, there is no consensus on how this coupling affects the failure mechanism of PCCVs. In this paper, a simplified finite element modeling method is proposed to study the effect of temperature and pressure coupling on PCCVs. The experiment results of a 1:4 scale PCCV model tested at Sandia National Laboratory (SNL) are compared with the results obtained from the proposed modeling approach. Seven working conditions are set up by varying the internal and external temperatures to investigate the failure mechanism of the PCCV model under the coupling effect of temperature and pressure. The results of this paper demonstrate that the finite element model established by the simplified finite element method proposed in this paper is highly consistent with the experimental results. Furthermore, the stress-displacement curve of the PCCV during loading can be divided into four stages, each of which corresponds to the damage to the concrete, steel liner, steel rebar, and prestressing tendon. Finally, the failure mechanism of the PCCV is significantly affected by temperature.

Glucose and Insulin Stimulate Lipogenesis in Porcine Adipocytes: Dissimilar and Identical Regulation Pathway for Key Transcription Factors

Zhang, Guo Hua,Lu, Jian Xiong,Chen, Yan,Dai, Hong Wei,ZhaXi, YingPai,Zhao, Yong Qing,Qiao, Zi Lin,Feng, Ruo Fei,Wang, Ya Ling,Ma, Zhong Ren Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.11

Lipogenesis is under the concerted action of ChREBP, SREBP-1c and other transcription factors in response to glucose and insulin. The isolated porcine preadipocytes were differentiated into mature adipocytes to investigate the roles and interrelation of these transcription factors in the context of glucose- and insulin-induced lipogenesis in pigs. In ChREBP-silenced adipocytes, glucose-induced lipogenesis decreased by ~70%, however insulin-induced lipogenesis was unaffected. Moreover, insulin had no effect on ChREBP expression of unperturbed adipocytes irrespective of glucose concentration, suggesting ChREBP mediate glucose-induced lipogenesis. Insulin stimulated SREBP-1c expression and when SREBP-1c activation was blocked, and the insulin-induced lipogenesis decreased by ~55%, suggesting SREBP-1c is a key transcription factor mediating insulin-induced lipogenesis. $LXR{\alpha}$ activation promoted lipogenesis and lipogenic genes expression. In ChREBP-silenced or SREBP-1c activation blocked adipocytes, $LXR{\alpha}$ activation facilitated lipogenesis and SREBP-1c expression, but had no effect on ChREBP expression. Therefore, $LXR{\alpha}$ might mediate lipogenesis via SREBP-1c rather than ChREBP. When ChREBP expression was silenced and SREBP-1c activation blocked simultaneously, glucose and insulin were still able to stimulated lipogenesis and lipogenic genes expression, and $LXR{\alpha}$ activation enhanced these effects, suggesting $LXR{\alpha}$ mediated directly glucose- and insulin-induced lipogenesis. In summary, glucose and insulin stimulated lipogenesis through both dissimilar and identical regulation pathway in porcine adipocytes.

Combining Model-based and Heuristic Techniques for Fast Tracking the Global Maximum Power Point of a Photovoltaic String

Shi, Ji-Ying,Xue, Fei,Ling, Le-Tao,Li, Xiao-Fei,Qin, Zi-Jian,Li, Ya-Jing,Yang, Ting The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Under partial shading conditions (PSCs), multiple maximums may be exhibited on the P-U curve of string inverter photovoltaic (PV) systems. Under such conditions, heuristic methods are invalid for extracting a global maximum power point (GMPP); intelligent algorithms are time-consuming; and model-based methods are complex and costly. To overcome these shortcomings, a novel hybrid MPPT (MPF-IP&O) based on a model-based peak forecasting (MPF) method and an improved perturbation and observation (IP&O) method is proposed. The MPF considers the influence of temperature and does not require solar radiation measurements. In addition, it can forecast all of the peak values of the PV string without complex computation under PSCs, and it can determine the candidate GMPP after a comparison. Hence, the MPF narrows the searching range tremendously and accelerates the convergence to the GMPP. Additionally, the IP&O with a successive approximation strategy searches for the real GMPP in the neighborhood of the candidate one, which can significantly enhance the tracking efficiency. Finally, simulation and experiment results show that the proposed method has a higher tracking speed and accuracy than the perturbation and observation (P&O) and particle swarm optimization (PSO) methods under PSCs.

A Novel Battery State of Health Estimation Method Based on Outlier Detection Algorithm

Piao, Chang-hao,Hu, Zi-hao,Su, Ling,Zhao, Jian-fei The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.6

A novel battery SOH estimation algorithm based on outlier detection has been presented. The Battery state of health (SOH) is one of the most important parameters that describes the usability state of the power battery system. Firstly, a battery system model with lifetime fading characteristic was established, and the battery characteristic parameters were acquired from the lifetime fading process. Then, the outlier detection method based on angular distribution was used to identify the outliers among the battery behaviors. Lastly, the functional relationship between battery SOH and the outlier distribution was obtained by polynomial fitting method. The experimental results show that the algorithm can identify the outliers accurately, and the absolute error between the SOH estimation value and true value is less than 3%.

Combining Model-based and Heuristic Techniques for Fast Tracking the Global Maximum Power Point of a Photovoltaic String

Ji-Ying Shi,Fei Xue,Le-Tao Ling,Xiao-Fei Li,Zi-Jian Qin,Ya-Jing Li,Ting Yang 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Under partial shading conditions (PSCs), multiple maximums may be exhibited on the P-U curve of string inverter photovoltaic (PV) systems. Under such conditions, heuristic methods are invalid for extracting a global maximum power point (GMPP); intelligent algorithms are time-consuming; and model-based methods are complex and costly. To overcome these shortcomings, a novel hybrid MPPT (MPF-IP&O) based on a model-based peak forecasting (MPF) method and an improved perturbation and observation (IP&O) method is proposed. The MPF considers the influence of temperature and does not require solar radiation measurements. In addition, it can forecast all of the peak values of the PV string without complex computation under PSCs, and it can determine the candidate GMPP after a comparison. Hence, the MPF narrows the searching range tremendously and accelerates the convergence to the GMPP. Additionally, the IP&O with a successive approximation strategy searches for the real GMPP in the neighborhood of the candidate one, which can significantly enhance the tracking efficiency. Finally, simulation and experiment results show that the proposed method has a higher tracking speed and accuracy than the perturbation and observation (P&O) and particle swarm optimization (PSO) methods under PSCs.

Use of antibiotics and other treatments in Chinese adults with acute cough: An online survey

Xiao-yang Hu,Ru-yu Xia,Michael Moore,Beth Stuart,Wen Ling-Zi,Bertrand Graz,Lai Lily,Liu Jian-Ping,Yu-tong Fei,Merlin Willcox 한국한의학연구원 2023 Integrative Medicine Research Vol.12 No.1

Background: Acute respiratory tract infections are common worldwide and there has been a rapid in- crease in antibiotic consumption. This study aimed to identify use of various treatments and their as- sociation with the use of antibiotics and patient reported clinical recovery in Chinese adults with acute cough. Methods: An online survey recruiting people who had recently experienced cough was conducted. Their sociodemographic, clinical characteristics, treatments received and their perceived changes in symptoms were collected. Factors influencing avoidance of antibiotics and improvement in symptoms were explored. Results: A total of 22,787 adults with recent acute cough completed the questionnaire, covering all 34 province-level administrative units in China. Most respondents were male (68.0%), young (89.4%, aged 18–45), educated to university/degree or postgraduate level (44.6%), with a median cough severity of 6/10 on a numerical rating scale. Nearly half of the participants (46.4%) reported using antibiotics, among which 93.1% were for presumed upper respiratory tract infections (URTIs). Pharmacies (48.8%) were the most common source of antibiotics. Fewer patients took antibiotics after taking CHM (14.9%), compared to those who started with home remedies (18.0%), or allopathic non-antibiotic medication (25.0%). An- tibiotics, allopathic non-antibiotic medications, CHM and home remedies were all perceived beneficial in relieving cough. Conclusions: Chinese adult responders report use of a considerable variety of treatments alone or in combination for acute cough. Patient-reported clinical recovery was similar regardless of treatment. There is likely a high proportion of inappropriate use of antibiotics for treatment of simple acute cough. As the majority of respondents did not use antibiotics as a first-line, and use of CHM was associated with relief of cough symptoms and reduction in the use of antibiotics, this presents an important opportunity for prudent antibiotic stewardship in China.

Dual-Algorithm Maximum Power Point Tracking Control Method for Photovoltaic Systems based on Grey Wolf Optimization and Golden-Section Optimization

Shi, Ji-Ying,Zhang, Deng-Yu,Ling, Le-Tao,Xue, Fei,Li, Ya-Jing,Qin, Zi-Jian,Yang, Ting The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

This paper presents a dual-algorithm search method (GWO-GSO) combining grey wolf optimization (GWO) and golden-section optimization (GSO) to realize maximum power point tracking (MPPT) for photovoltaic (PV) systems. First, a modified grey wolf optimization (MGWO) is activated for the global search. In conventional GWO, wolf leaders possess the same impact on decision-making. In this paper, the decision weights of wolf leaders are automatically adjusted with hunting progression, which is conducive to accelerating hunting. At the later stage, the algorithm is switched to GSO for the local search, which play a critical role in avoiding unnecessary search and reducing the tracking time. Additionally, a novel restart judgment based on the quasi-slope of the power-voltage curve is introduced to enhance the reliability of MPPT systems. Simulation and experiment results demonstrate that the proposed algorithm can track the global maximum power point (MPP) swiftly and reliably with higher accuracy under various conditions.