A Novel Energy Storage System based on Flywheel for Improving Power System Stability

Wu, Jinbo,Wen, Jinyu,Sun, Haishun,Cheng, Shijie The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

In this paper, a novel flywheel energy storage device, called the flexible power conditioner, which integrates both the characteristics of the flywheel energy storage and the doubly-fed induction machine, is proposed to improve power system stability. A prototype is developed and its principle, composition, and design are described in detail. The control system is investigated and the operating characteristics are analyzed. The test results based on the prototype are presented and evaluated. The test results illustrate that the prototype meets the design requirement on power regulation and starting, and provides a cost-effective and effective means to improve power system stability.

A Novel Energy Storage System based on Flywheel for Improving Power System Stability

Jinbo Wu,Jinyu Wen,Haishun Sun,Shijie Cheng 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.4

In this paper, a novel flywheel energy storage device, called the flexible power conditioner, which integrates both the characteristics of the flywheel energy storage and the doubly-fed induction machine, is proposed to improve power system stability. A prototype is developed and its principle, composition, and design are described in detail. The control system is investigated and the operating characteristics are analyzed. The test results based on the prototype are presented and evaluated. The test results illustrate that the prototype meets the design requirement on power regulation and starting, and provides a cost-effective and effective means to improve power system stability.

Indirect Adaptive Robust Control Design for Course Tracking of Ships Subject to Unknown Control Coefficient and Disturbances

Jinbo Wu,Chenghao Zeng,Yifei Hu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.6

For course control of ships with unknown control coefficient and model parameters, an indirect adaptive robust controller, in which the parameter estimation law and the control law are designed separately, is proposed. This design method can achieve not only excellent course control performance but also accurate parameter estimates for secondary purposes such as assisting in ship maneuvering decision. Firstly, a Nussbaum function is combined with the adaptive dynamic surface control method to design a strong robust controller which can ensure the stabilityof the closed-loop ship course control system in spite of parameter uncertainties, unknown control coefficient and disturbances. Secondly, the nonlinear model for ship steering is converted into linear form by using the X-swapping technique. And a modified least-squares identification algorithm is then proposed to estimate the unknown model parameters. The global uniform ultimate boundedness of all signals of the resulting closed-loop system is guaranteed via Lyapunov stability theory. Lastly, simulation results are executed to demonstrate the effectiveness of theproposed design method.

An accurate and robust adaptive notch filter-based phase-locked loop

Li, Jinbo,Wang, Qin,Xiao, Lan,Liu, Zehao,Wu, Qunfang The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

The use of an adaptive notch filter (ANF) is one of the most popular methods to block harmonics in a phase-locked loop (PLL). Existing ANFs suffer from drawbacks such as a low harmonic rejection capability, complex structure or instability. To improve the performance of ANF-based PLLs, an enhanced ANF (EANF) is proposed in this paper. Its structure, filtering characteristics and frequency-adaptive method are analyzed. Multiple EANFs can be easily cascaded and achieve adaptation through a common frequency feedback loop (FFL). A small signal model is provided, and its control parameters are tuned through the symmetrical optimum method. The harmonic rejection capability and stability of the proposed method are confirmed through simulation and experimental results.

Immunomodulatory effects of Clostridium butyricum on human enterocyte-like HT-29 cells

Gao Quanxin,Wang Jinbo,Qi Lili,Wu Tianxing,Xia Tingting 한국통합생물학회 2013 Animal cells and systems Vol.17 No.2

Oral administration of Clostridium butyricum as probiotics is increasingly gaining importance in the treatment of intestinal inflammations and improvement of animal performance. The mechanisms of host cell receptor recognition of C. butyricum and downstream immune signaling pathways leading to this beneficial event, however, remain unclear. In this study, C. butyricum was investigated for its capability to influence the innate immune response of HT-29 cells to explore its mechanism of action. Our data showed that C. butyricum was able to stimulate toll-like receptor 2 (TLR2) production at mRNA level; however, TLR4, TLR5, TLR9, and myeloid differentiation primary response protein 88 (MyD88) transcription levels remain unaltered. The nuclear factor kB (NF-kB), interleukin-8 (IL-8), and tumor necrosis factor alpha (TNF-a) levels in response to C. butyricum were significantly increased, indicating that HT-29 cells were sensitised by C. butyricum. It is the first time that our findings have showed the specific signaling pathways in HT-29 cells stimulated by C. butyricum, which, at least in part, can help to explain the beneficial properties of C. butyricum.

Enhancement of NO absorption in ammonium-based solution using heterogeneous Fenton reaction at low H2O2 consumption

Yuanquan Xiong,Bo Wu,Jinbo Ru,Hao Feng 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.12

A novel NO removal system is designed, where NO is initially oxidized by •OH radicals from the decomposition of hydrogen peroxide (H2O2) over hematite and then absorbed by ammonium-based solution. According to the high performance liquid chromatography (HPLC) profile and the isopropanol injection experiments, the •OH radicals are proved to play a critical role in NO removal. The NO removal efficiency primarily depends on H2O2 concentration, gas hourly space velocity (GHSV), H2O2 feeding rate and reaction temperature, while the flue gas temperature slightly affects the NO removal efficiency. The low H2O2 consumption makes this system a promising technique in NO removal process using wet-method. The evolution of catalyst in reaction is analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The nitrite ion and nitrate ion in aqueous solution are detected by the continuous phase flow analyzer. Finally, the macrokinetic parameters of the NO oxidation are obtained by using the initial rate method.

Capacitor voltage balancing method for hybrid modular multilevel converters based on second‑harmonic voltage injection

Hongxu Li,Qin Wang,Qunfang Wu,Lan Xiao,Jinbo Li 전력전자학회 2024 JOURNAL OF POWER ELECTRONICS Vol.24 No.4

Due to different output voltages, capacitor voltage imbalance occurs between half-bridge sub-modules (HBSM) and fullbridge sub-modules (FBSM) in hybrid modular multilevel converters (MMCs) under a boosted modulation index (m). To address this issue, a capacitor voltage balancing method based on second-harmonic voltage injection is proposed in this paper. The mechanism of the proposed method is to eliminate the DC component in the charging power of sub-modules under the restriction that the HBSM cannot output negative voltage. The proposed method is divided into two cases according to m. Case 1 is used when m ≤ 1.4, while Case 2 is implemented when m > 1.4. When compared with similar capacitor voltage balancing methods, the proposed SVI method has a simpler structure that can greatly reduce the number of computations. Simulation and experimental results verify the effectiveness of the proposed capacitor voltage balancing method.

Laparoscopic surgery contributes to a decrease in short-term complications in surgical ulcerative colitis patients during 2008–2017: a multicenter retrospective study in China

Zerong Cai,Xiaosheng He,Jianfeng Gong,Peng Du,Wenjian Meng,Wei Zhou,Jinbo Jiang,Bin Wu,Weitang Yuan,Qi Xue,Lianwen Yuan,Jinhai Wang,Jiandong Tai,Jie Liang,Weiming Zhu,Ping Lan,Xiaojian Wu 대한장연구학회 2023 Intestinal Research Vol.21 No.2

Background/Aims: The aim of this study was to analyze the chronological changes in postoperative complications in surgical ulcerative colitis patients over the past decade in China and to investigate the potential parameters that contributed to the changes. Methods: Ulcerative colitis patients who underwent surgery during 2008–2017 were retrospectively enrolled from 13 hospitals in China. Postoperative complications were compared among different operation years. Risk factors for complications were identified by logistic regression analysis. Results: A total of 446 surgical ulcerative colitis patients were analyzed. Fewer short-term complications (24.8% vs. 41.0%, P=0.001) and more laparoscopic surgeries (66.4% vs. 25.0%, P<0.001) were found among patients who received surgery during 2014–2017 than 2008–2013. Logistic regression suggested that independent protective factors against short-term complications were a higher preoperative body mass index (odds ratio [OR], 0.870; 95% confidence interval [CI], 0.785–0.964; P=0.008), laparoscopic surgery (OR, 0.391; 95% CI, 0.217–0.705; P=0.002) and elective surgery (OR, 0.213; 95% CI, 0.067–0.675; P=0.009). The chronological decrease in short-term complications was associated with an increase in laparoscopic surgery. Conclusions: Our data revealed a downward trend of short-term postoperative complications among surgical ulcerative colitis patients in China during the past decade, which may be due to the promotion of minimally invasive techniques among Chinese surgeons.