检索结果-内蒙古大学图书馆

International Conference on Electrical Machines and Systems (ICEMS)

作者： Yi Zhang Donglai Zhang Yunhan Fan Qian Wan Qing Liu Shaolin Wang Power Electronics and Motion Control Research Center Harbin Institute of Technology (Shenzhen) Shenzhen China Unit 61655 the People’s Liberation Army Chongqing China Department of Aerospace Power Shenzhen Aerospace New Power Technology Co. Ltd Shenzhen China Beijing institute of Spacecraft System Engineering China Academy of Space Technology Beijing China

With the increase of power utilization rate of renewable energy systems and the profound studies of DC microgrids, DC distribution systems are getting more attention. To improve the quality of DC bus, it is necessary to consider the voltage fluctuations caused by loop switching such as battery management and maximum power output in the system. An optimization method is proposed to accelerate the switching process of multiple control loops, especially for multi-module expansion, which can improve the performance of dynamic response The proposed method just requires the addition of a few devices to the circuit structure and realizes nonlinear control, with which the conditional intervention only happens during transient processes without affecting the steady-state loop design. Compared with traditional methods, this method can achieve power expansion of the system as well as a quick response under load step or bus voltage overshoot.

关键词：

来源：评论

学校读者我要写书评

暂无评论

research on Fault Diagnosis Method Based on FMEA/FTA and Bayesian Network

Research on Fault Diagnosis Method Based on FMEA/FTA and Bay...

引用

International Conference on Sensing, Diagnostics, Prognostics, and control (SDPC)

作者： Chengbing He Runze Wang Li Ma Xiaobo Li Xiaofeng Jiao Lei Song School of Energy Power and Mechanical Engineering North China Electric Power University Beijing China Inner Mongolia Electric Power Science & Research Institute Inner Mongolia Hohhot China Technology and Engineering Center for Space Utilization line Chinese Academy of Sciences Beijing China

ISBN: (数字)9781728101996

ISBN: (纸本)9781728102009

The construction of Bayesian network (BN) model is a bottleneck problem that needs to be solved urgently in the field of fault diagnosis. Combining failure mode and effect analysis(FMEA) and fault tree analysis(FTA) can solve this problem well. In this paper, a BN model based on FMEA/FTA is proposed. The transformation methods of FMEA to BN and FTA to BN are analyzed. The structural matrix is used to realize the information transformation. The noisy-max model is used to determine the BN parameters. Taking the rub-impact fault between the high pressure rotor and the front shaft seal of a 600 MW turbogenerator unit as an example, the application of the BN model based on FMEA/FTA in fault diagnosis is realized from three aspects which are BN model construction, prior probability and conditional probability assignment, and diagnosis reasoning, respectively.

关键词： Shafts Seals Fault diagnosis power systems Fault trees Noise measurement Rotors

来源：评论

学校读者我要写书评

暂无评论

Condition Evaluation Method of Wind Turbine Based on Real-time Reliability

Condition Evaluation Method of Wind Turbine Based on Real-ti...

引用

International Conference on Sensing, Diagnostics, Prognostics, and control (SDPC)

作者： Chengbing He Li Ma Runze Wang Xiaobo Li Xiaofeng Jiao Lei Song School of Energy Power and Mechanical Engineering North China Electric Power University Beijing China Inner Mongolia Electric Power Science & Research Institute Inner Mongolia Hohhot China Technology and Engineering Center for Space Utilization line Chinese Academy of Sciences Beijing China

ISBN: (数字)9781728101996

ISBN: (纸本)9781728102009

With the rapid development of wind power generation worldwide, the condition evaluation of wind turbine has received more and more attention. In this paper, wind turbine is divided into three levels: component level, device level, and subsystem level, and the system of condition evaluation is constructed. The real-time reliability analysis model of wind turbine is proposed. The real-time reliability reduction is calculated from component level, equipment level and subsystem level in turn by using variable weight synthesis method. Finally, the condition evaluation of wind turbine is realized. The validity of this method is verified by a case analysis. The research results in this paper can provide decision-making assistance for the management of daily operation and maintenance of wind turbines and improve the operational efficiency of wind farms.

关键词： Wind turbines Reliability Real-time systems Gears Hidden Markov models Analytical models Mathematical model

来源：评论

学校读者我要写书评

暂无评论

Quasi-Parallel Resonant Switched Capacitor DC-DC Converter with Continuous Voltage Regulation Capability

Quasi-Parallel Resonant Switched Capacitor DC-DC Converter w...

引用

IEEE Energy conversion Congress and Exposition, ECCE

作者： Jingjing Qi Xuezhi Wu Wenzheng Xu Kai Sun Department of Electrical Engineering State Key Laboratory of Power System Operation and Control Tsinghua University Beijing China National Active Distribution Network Technology Research Center Beijing Jiaotong University Beijing China

ISBN: (数字)9798350376067

ISBN: (纸本)9798350376074

Resonant switched capacitor converters have the advantages of small size, light weight and high efficiency, but have poor voltage regulation ability. To overcome this problem, a quasi-parallel resonant switched capacitor DC-DC converter is proposed in this paper, which mainly incorporates a resonant switched capacitor converter with soft-switching and variable voltage ratio and a Buck converter. Most of the power can be transmitted by the resonant switched capacitor converter, while the Buck converter is responsible for output voltage regulation. In addition, the voltage ratio of the resonant switched capacitor converter can be flexibly changed base on the input voltage, which is beneficial for Buck converter to always handle a small portion of power. Furthermore, input voltage feedforward control is incorporated to suppress the input voltage disturbance. The proposed converter can not only continuously regulate the voltage over a wide range, but also perform high efficiency and achieve rapid dynamic response. The operating principle of the converter is introduced, the circuit characteristic is analyzed, and the correctness of the theoretical analysis is verified by experiments.

关键词： Dynamic response Buck converters Voltage fluctuations Fluctuations Capacitors Soft switching Switches Regulation Voltage control Zero current switching

来源：评论

学校读者我要写书评

暂无评论

DC component suppression strategy for single-phase grid-connected inverter

引用

Dianli Zidonghua Shebei/Electric power Automation Equipment 2015年第4期35卷 145-150页

作者： Yang, Liang Su, Jian Liu, Haitao LÜ, Zhipeng Wang, Yichao He, Jiabei Wang, Cong China University of Mining and Technology Beijing100083 China China Electric Power Research Institute Beijing100192 China National Electric Power Conversion and Control Engineering Technology Research Center Hunan University Changsha410082 China

Aiming at the DC injection of grid-connected inverter, the grid-connected inverter with LCL filter is studied and a strategy of current tracking control is presented to suppress its DC component, which adopts the dual closed loop technique to directly control the grid-connecting current. A DC component suppression branch consisting of an integral controller is added to the conventional fundamental current control branch in the outer current-loop, which increases the DC output impedance of inverter to suppress its DC component, without affecting the fundamental current tracking control. The implementation of the proposed strategy is simple because, without DC component detection, only the virtual impedance is connected in series to the output port of inverter, which is infinite to DC component while small to AC frequency. A model is built and the frequency domain analysis proves its DC inhibition performance. The simulative and experimental results show that, the fundamental reference tracking with zero steady-state error is realized and the DC component is well suppressed. Electric power Automation Equipment Press

关键词： Electric inverters

来源：评论

学校读者我要写书评

暂无评论

Enhancing Aerosol Emission Reduction in an Ammonia-Based Wfgd System with Tray Implementation

SSRN

引用

SSRN 2023年

作者： Huang, Rongting Tao, Yichun Chen, Wanyi Lei, Lin Li, Shihang Yang, Linjun Zhou, Fubao Jiangsu Engineering Research Center of Dust Control and Occupational Protection School of Safety Engineering China University of Mining and Technology Xuzhou221116 China Key Laboratory of Energy Thermal Conversion and Control Ministry of Education Southeast University Nanjing China China Academy of Safety Science and Technology Beijing116016 China

Operating parameter optimization is a viable strategy to reduce aerosol emissions from an ammonia-based wet flue gas desulfurization (ammonia WFGD) system. But the optimization techniques typically cause SO2 removal efficiency reduction. Multi-hole trays can be installed in the scrubber to balance the aerosol emission control and the desulfurization efficiency. The experimental results show that the tray installation alone can barely enhance aerosol emission control. However, the tray installation can improve the SO2 removal efficiency to spare more space for operating parameter optimization. The smaller hole size favors the SO2 removal with a particular hole ratio. Optimizing the liquid-to-gas ratio (L/G) works well with tray installation to realize aerosol emission reduction, with the aerosol reduction rate over 50%. The improvement brought about by the tray installation only works within a specific L/G range, beyond which the tray cannot make up for the desulfurization efficiency reduction caused by L/G optimization. The best aerosol emission reduction rate was achieved at L/G = 8 L/m3 with the tray installation of 35% hole ratio and 10 mm diameter, with the desulfurization efficiency maintained above 90%. The tray with 35% hole ratio and 20 mm diameter can be employed at L/G = 8 L/m3 for better aerosol emission if the SO2 removal efficiency below 90% is acceptable. The choice is due to desulfurization efficiency and aerosol emission control demand. © 2023, The Authors. All rights reserved.

关键词： Emission control

来源：评论

学校读者我要写书评

暂无评论

High Direction-changing Frequency Bidirectional DC-DC Converter for Charging/Discharging Applications

High Direction-changing Frequency Bidirectional DC-DC Conver...

引用

Annual Conference of the IEEE Industrial Electronics Society

作者： Ming Fu Tiecai Li Donglai Zhang Yalin Li China Shenzhen Academy of Aerospace Technology Power Electronic and Motion Control Research Center Harbin Institute of Technology Shenzhen Graduate School Shenzhen Shenzhen China School of Electrical Engineering and Automation Harbin Institute of Technology Harbin China Electrical System Engineering Department Institute of Telecommunication Satellite China Academy of Space Technology Beijing China

Based on the battery charging and discharging regulator (BCDR) in spacecraft power conditioning unit application, a bidirectional DC-DC converter BCDR with high direction-changing frequency is proposed in this paper, including the Weinberg-buck bidirectional DC-DC topology and the corresponding bidirectional control. Additionally, the test on the BCDR prototype shows that BCDR parallel modules could achieve the quick switching between charging and discharging with the direction-changing frequency meeting the requirement of 1 kHz, the regulated power bus of small voltage ripple, and high charging and discharging efficiency, in agreement with the expected design.

关键词： Integrated circuits Partial discharges Switches Batteries power conditioning DC-DC power converters Regulators

来源：评论

学校读者我要写书评

暂无评论

An Early Fault Detection Method of the Induced Draft Fan Based on Long-Short Term Memory Network and Double Warning Thresholds

An Early Fault Detection Method of the Induced Draft Fan Bas...

引用

Chinese control and Decision Conference, CCDC

作者： Wei Wei You Lv Yizhuo Liu Qing Li Shisen Xu Jun Li School of Control and Computer Engineering North China Electric Power University Beijing P. R. China Key Laboratory of Power Station Energy Transfer Conversion and System North China Electric Power University Beijing P. R. China Beijing Key Laboratory of New Technology and System on Measuring and Control for Industrial Process North China Electric Power University Beijing P. R. China Huaneng Technology Innovation Center Beijing P. R. China Xian Thermal Power Research Institute Company Limited Xian P. R. China

ISBN: (纸本)9781665478977

The induced draft (ID) fan is a significant piece of auxiliary equipment in thermal power plants. An early detection of possible faults in the ID fan may be used for effective predictive maintenance, thereby reducing the overall maintenance cost and improving the reliability and availability of thermal power plants. This paper proposed a genetic algorithm and long-short term memory network (GA-LSTM)-based condition monitoring approach using normal operation data of the ID fan. Furthermore, the LSTM network and the sliding window technique were introduced to construct double thresholds, which contains a dynamic threshold and a static threshold. The GA-LSTM-double thresholds method was applied to a coal-fired power plant to achieve early fault detection and diagnosis. The results demonstrates that the proposed method is capable of detecting minor anomalies in advance.

关键词： Fans Fault detection Neurons Predictive models Indexes Reliability State estimation

来源：评论

学校读者我要写书评

暂无评论

State-space model of an inverter-based micro-grid

State-space model of an inverter-based micro-grid

引用

International Conference on Intelligent Green Building and Smart Grid (IGBSG)

作者： Changbin Hu Yang Wang Shanna Luo Fudong Zhang College of Electrical and Control Engineering North China University of Technology Beijing China Collaborative Innovation Center of Key Energy Saving Technologies in Beijing Beijing China State Grid Hebei Electric Power Research Institute Registration Hebei China

In order to describe the micro-grid and its dynamic performance more accurately, the state space models for the micro-grid components and systems have been developed in this paper. Considering about the interaction between inverters and effectiveness of dynamic networks, the state-space model of micro-grid including parallel voltage-controlled inverters has been proposed. Droop control has been adopted in micro-grid to automatically share power and regulate output voltage of parallel voltage-controlled inverters (VCIs) in micro-grids. The dynamic characteristics of the sources, distribution lines and control have been integrated in the developed state space model. The model focus on the detail of the control loops of the inverter but not the switching actions. The state-space model of micro-grid has been verified using Matlab/Simulink simulations.

关键词： Inverters Voltage control State-space methods Current control Mathematical model Load modeling Active filters

来源：评论

学校读者我要写书评

暂无评论

Analysis of a hybrid system combining solar-assisted methanol reforming and fuel cell power generation

引用

Energy conversion and Management 2023年 297卷

作者： Zhao, Ke Kong, Hui Tan, Sicong Yang, Xiao-Guang Zheng, Hongfei Yang, Tao Wang, Hongsheng School of Mechanical Engineering Beijing Institute of Technology Beijing100081 China State Key Laboratory of Power System Operation and Control Department of Thermal Engineering Tsinghua-BP Clean Energy Center Tsinghua University Beijing100084 China Shenzhen Automotive Research Institute Beijing Institute of Technology Guangdong Shenzhen518118 China & Department of Materials Science and Engineering City University of Hong Kong Hong Kong SAR Kowloon China

The proton exchange membrane fuel cell (PEMFC) is an efficient and clean power unit that has become a research hotspot for scholars around the world, but the hydrothermal management of the PEMFC limits the cell performance and hinders its large-scale application. In the paper, a hybrid system combining solar-assisted reforming of methanol and fuel cell power generation is proposed, in which methanol is used as a coolant in the hydrothermal management of the PEMFC subsystem to take away the waste heat, and further reformed for hydrogen production with the assistance of the solar energy subsystem to improve the hybrid system efficiency. The study is carried out at both the single cell level and system level to investigate the effect of solar energy on the performance of the hybrid system by simulation results, which are obtained from the finite element software, such as the performance of the PEMFC. The results show that the novel hydrothermal management method using methanol and water in the single cell can control the temperature at 60–80 °C. The highest power density of the single cell reaches 0.595 W/cm2 at a water-to-alcohol ratio of 1:1 and a coolant flow rate of 2.846 mol/s. In addition, the exergy of this hybrid system improves by 76.36% compared to the exergy of the solar thermochemical methanol reforming system at a reaction temperature of 200 °C when the methanol reforming reaction is more complete. The system efficiency can reach up to 59.15%, compared to the solar thermochemical methanol reforming system and the methanol reforming system heated by combustion of methanol, which can only reach 51.10% and 43.18%, respectively. This study provides a novel method for addressing the hydrothermal management issue of PEMFC and a new idea for the efficient utilization of solar energy. © 2023 Elsevier Ltd

关键词： Solar energy

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：