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On-line implementation of model free controller for oxygen stoichiometry and pressure difference control of polymer electrolyte fuel cell

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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 2022年第90期47卷 38311-38326页

作者： Ziane, M. Ait Pera, M. C. Join, C. Benne, M. Chabriat, J. P. Steiner, N. Yousfi Damour, C. Univ La Reunion ENERGY Lab Rue Cassin F-97715 St Denis France Univ Bourgogne Franche Comte FCLAB CNRS FEMTO ST inst Rue Thierry Mieg F-90010 Belfort France Univ Lorraine CRAN CNRS UMR 7039 BP 239 F-54506 Vandoeuvre les Nancy France

This paper proposes and validates a model free controller to improve the real time oper-ating conditions of Proton Exchange Membrane Fuel Cells (PEMFC). This approach is based on an ultra-local model that does not depend on a precise knowledge of the system. It is perfectly adapted to a complex system such as the fuel cell, while benefiting from the ease of online implementation and low computational cost. The designed controller is used to regulate both the oxygen stoichiometry and the membrane inlet pressure, which are crucial operating conditions for the fuel cell's lifetime. The objectives of the proposed control strategy are twofold: preventing the starvation failure, and limiting the potential for mechanical degradation of the membrane during a large pressure difference. The performance of the proposed control strategy is initially evaluated by a simulation envi-ronment for both oxygen stoichiometry and inlet pressure difference control of fuel cell stack. An online validation on 1.2 KW fuel cell stack is conducted to control the membrane pressure drop. Two case studies are comprehensively investigated in relation to stoichi-ometry control: set point tracking and rejection of unmeasured disturbances caused by current variations. Simulations and experimental results reveal that the proposed

关键词： Proton exchange membrane fuel cell (PEMFC) Intelligent proportional controller On-line control Oxygen stoichiometry pressure difference control

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Simulation model for pressure difference control to prevent cross-infection in hospitals treating normal and epidemic patients

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ENERGY AND BUILDINGS 2024年 319卷

作者： Feng, Yanbo Zhu, Han Feng, Xiwen Chen, Qianru Sun, Xiangyu Li, Zhengrong Tongji Univ Sch Mech Engn Shanghai Peoples R China Tongji Architectural Design Grp Co Ltd Shanghai Peoples R China

Effective ventilation systems are crucial for preventing the spread of respiratory infectious diseases in hospitals for both normal and epidemic (HFNE) treatments. pressure differences between rooms are used to ensure that air flows from clean spaces into contaminated areas only. This paper established a pressure difference control simulation model and investigated China's HFNE facilities during the COVID-19 pandemic. The proposed model was developed using Simulink software and validated against a multizone model developed by CONTAM software. The Simulink model helped identify aspects of room and ventilation design requiring particular focus. The factors influencing pressure difference control in HFNEs were analyzed using a hybrid control strategy. A fuzzy proportional-integral-derivative controller was used for control optimization under the influence of opening and closing doors and other dynamic disturbances. The pressure difference control system established in this paper exhibits superior performance and provides a reference for the design and construction of HFNEs in the future.

关键词： pressure difference control Ventilation systems Hospital design Fuzzy proportional-integral-derivative controller

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Simulation analysis and experimental research on static performance of water-hydraulic pressure difference control valve

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FLOW MEASUREMENT AND INSTRUMENTATION 2024年 100卷

作者： Yang, Yong Zhang, Zengmeng Jia, Yunrui Geng, Tingyu Xu, Weiling Zhang, Kang Dalian Maritime Univ Coll Naval Architecture & Ocean Engn Dalian Peoples R China Dalian Maritime Univ Liaoning Prov Key Lab Rescue & Salvage Engn Dalian Peoples R China Dalian Maritime Univ Int Joint Res Ctr Subsea Engn Technol & Equipment Dalian Peoples R China

Many hydraulic tools, like hydraulic cylinders and hydraulic artificial muscle joints are operated by adjusting pressure differences between different zones. Typically, the method employed to change the pressure difference is establishing hydraulic bridges and adjusting liquid resistance. While effective, this method's drawback is complex structures. To address this issue, a water-hydraulic pressure difference control valve, integrating two hydraulic bridges, was designed. The static performances including the output pressure difference, the flow rate and the force acting on the valve core were analyzed using AMESim and computational fluid dynamics simulations. Based on the simulation results, a prototype of voice coil motor direct drive pressure difference control valve was manufactured and the corresponding experiments were carried out. The computational fluid dynamics simulation results show that the internal leakage and the through-flow capacity difference between throttling grooves affect the flow field characteristics of the valve. When the pump pressure is 3 MPa and the valve opening is at the middle position, the internal leakage increases the flow rate from 2.25 L/min to 2.38 L/min, and the through-flow capacity difference reduces the control port pressure from the theoretical analysis of 1.5 MPa-1.41 MPa. Furthermore, combined with the analysis of the external liquid resistance, the AMESim model of the pressure difference control valve is modified. When the pump pressure is 3 MPa, the pressure difference and flow rate average deviations between the modified AMESim model and the experiment are 0.021 MPa and 0.048 L/ min. Finally, a rotational angle experiment for a water hydraulic artificial muscle joints showed satisfactory control effects, suggesting the valve's application in controlling hydraulic tools and actuators.

关键词： pressure difference control Water-hydraulic system control valve CFD Experimental research

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Multizone modeling of pressure difference control analyses for an infectious disease hospital

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BUILDING AND ENVIRONMENT 2021年 206卷 108341-108341页

作者： Guo, Jiamin Liu, Junjie Tu, Daixin Zhang, Jinxian Xu, Jing Xue, Peng Tianjin Univ Sch Environm Sci & Engn Tianjin Key Lab Indoor Air Environm Qual Control Weijin Rd 92 Tianjin Peoples R China Tianjin Univ Res Inst Architectural Design & Urban Planning Tianjin Peoples R China Tianjin Zhongtian Environm Technol Co Ltd Tianjin Peoples R China Beijing Univ Technol Beijing Key Lab Green Built Environm & Energy Eff Beijing Peoples R China

Infectious disease hospitals must maintain pressure differences among rooms to direct the airflow toward the negative pressure isolation ward (NPIW) to prevent the spread of airborne pathogens. However, their values cannot be maintained easily in dynamic situations, especially when the door to the isolation room is open. There is a lack of guidelines for how to cope with this situation. A variable air volume (VAV) damper is set in the exhaust duct of the NPIW attempts to achieve active control by VAV but is often set to deliver constant air volume (CAV) because of a lack of confidence in its controllability. In this study, models based on a real infectious disease hospital are built and verified by the multizone model on Modelica. An appropriate active pressure difference control strategy for VAVs in NPIW is explored and it is applied in a floor of hospital model to analyze the influence of pressure differences among multiple rooms by VAV operation. The results show that the pressure difference deviations can be reduced by 9.98%-25.73% for different leakage paths of the isolation room with this control strategy. The pressure differences among hospital are stable during the VAV operation in the usual dynamic scenario. The airtightness of the door at zones junctions and external windows needs to be reduced to strengthen their anti-interference ability of pressure difference. This study fills the gap of guidelines and provides a reference for the application of VAVs for active pressure difference control in infectious disease hospitals.

关键词： Infectious disease hospital pressure difference control Multizone model Simulation Modelica Variable air volume

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Minimization of Particle Deposition on Wafers Caused by the pressure Change in the Vacuum Chamber Through a pressure control Regulation Process

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IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING 2024年第3期37卷 340-344页

作者： Ku, Ching-Ming Yea Jang, Wen Cheng, Stone Natl Yang Ming Chiao Tung Univ Dept Mech Engn Hsinchu 30010 Taiwan

In wafer etching, regular cleaning and maintenance of process chambers are necessary to reduce particle contamination of etched wafers during the wafer transfer process. Investigating alternative cleaning and maintenance is imperative. This study analyzed the number of particles falling onto a silicon wafer when the pressure difference within the process chamber was manipulated. We observed that rapid opening of the pressure control valve, which regulates the chamber's pressure, caused contamination during wafer transport. This was particularly true when the change in the pressure ratio was considerable. The by-products near the side of the chamber's pressure control valve were activated and transported. We verified this finding by adjusting the opening ratio of the pressure control valve (i.e., its degree of opening). We proposed that during the transition step of the etching process, this opening ratio can be controlled by regulating the process pressure through gas flow settings. This method could suppress the deposition of reflected particles originating from the turbomolecular pump's pumping line on wafers, thereby minimizing the contamination of wafers.

关键词： pressure difference control vacuum technology wafer transport pressure difference control vacuum technology wafer transport

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Research on Closed-loop control of Engine Propellant Supply System 41

Research on Closed-loop Control of Engine Propellant Supply ...

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第41届中国控制会议

作者： Jun Zhao Yufeng Gu Qianqian Zhang Wen Yan Shaohua Sun AVIC Computing Technique Research Institute Xi'an Science and Technology on Aircraft Control Laboratory

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

According to the requirements of high reliable control of engine propellant supply system,the paper proposed a digital controller implementation scheme with DSP and CPLD as the core controller,and designed interface circuits of BLDCM,pintle injector,solenoid valve and *** paper also proposed a variable parameter PI rotate speed closed-loop control method for BLDCM,and two-stage propellant closed-loop distribution control method for pressure difference at the outlet of a pintle *** the basis of simulation,the system experiment platform was built,and the no-load and loading experiments of the BLDCM were carried out,as well as the pressure difference control experiment of the injector outlet,which verified the effectiveness of the control strategy and the correctness of the system *** and experimental results show that the control system meets the requirements of technical indicators in the aspects of quick response,stability,reliability and high precision,and has good engineering reference value.

关键词： Propellant Supply System Variable Parameter PI Closed-loop control BLDCM pressure difference control

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Study on the Elman Neural Network Operation control Strategy of the Central Air Conditioning Chilled Water System

Study on the Elman Neural Network Operation Control Strategy...

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作者： Jianwei Li Qingchang Ren Hai Long Zengxi Feng School of Civil Engineering Xi'an University of Architecture & Technology China Nuclear Power Technology Research Institute School of Information & Control Engineering Xi'an University of Architecture & Technology China Nuclear Power Operations Co. Ltd.

The stable operation of the central air conditioning water system always is a major difficulty for the control profession. Paper focus on the water system with multi variable, strong coupling, nonlinear, large time delay characteristics, presented use feed forward coupling compensation method, to eliminate the coupling effect between temperature and pressure. In this paper, the Elman neural network controller is designed for the first time, and the simulation results show that the response time of Elman neural network controller is shorter, the system is more stable and the overshoot is small.

关键词： Feed Forward Coupling Compensation Central Air Conditioning Water System Always Temperature difference control pressure difference control Elman Neural Network

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Diversity of energy-saving control strategy for a parallel chilled water pump based on variable differential pressure control in an air-conditioning system

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ENERGY 2015年 88卷 718-733页

作者： Liu Xuefeng Liu Jinping Lu Zhitao Xing Kongzu Mai Yuebang S China Univ Technol Sch Elect Power Guangdong Prov Acad Bldg Res Guangzhou 510641 Guangdong Peoples R China

An analytical model of a parallel chilled water pump set was established in this study. The bypass-loop adjustment characteristic was found to be a key component of this model. A pump set consisting of four of the same type of pumps was the focus of this study, and the running characteristics for five types of control strategies were examined in detail: the control strategy of the power frequency pump quantity control, the hybrid control strategy of a single pump of variable frequency combined with power frequency pump quantity control, the control strategy of two pumps of synchronous variable frequencies, the control strategy of three pumps with synchronous variable frequencies, and the control strategy of four pumps with synchronous variable frequencies. These strategies were analyzed under different supply return water differential pressures. It was proposed that the hybrid control strategy of single pump variable frequency combined with power frequency pump quantity control is most suitable for variable flow to the chilled water system under a low flow ratio or a high supply-return water differential pressure. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Chilled water system pressure difference control Parallel operation Chilled water pump

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Research on Chilled Water pressure difference of the Model Reference Adaptive control

Research on Chilled Water Pressure Difference of the Model R...

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Chinese Intelligent Automation Conference (CIAC)

作者： Jiang, Hongmei Cai, Dongdong Nian, Yugui Ren, Qingchang Lanzhou Univ Technol Coll Elect & Informat Engn Lanzhou Gansu Peoples R China Luoyang Power Supply Co Luoyang Peoples R China Xian Univ Architecture & Technol Sch Civil Engn Xian Shaanxi Peoples R China

ISBN: (纸本)9783642385247;9783642385230

Air-conditioning system chilled water pressure difference is a time-varying complicated nonlinear system, using the conventional PID control loop is difficult to achieve good control quality. According to the actual control requirements, puts forward the RBF neural network model reference adaptive control strategy, design the chilled water pressure difference control system. It use the RBF neural network controller and DRNN network model identification parameter learning algorithm. The simulation results show that this control strategy has good effect, it can achieve control requirements better.

关键词： pressure difference control Neural network Model reference Adaptive Model identification

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