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IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Echang Li Xiaodong Chu Minghui Yang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan P. R. China Dispatching Center of Shandong Electric Power Corporation Jinan P. R. China

ISBN: (纸本)9781509054190

Stability issues will arise with multiple HVDC links feeding an AC power network, among which voltage stability is of great significance. In this paper, the quantitative relationship is obtained between static voltage stability and the associated factors by using the multivariate regression analysis. The information aggregation approach is employed to derive independent variables for constructing a multivariate regression model. Simulation results on a five-infeed HVDC system verify the effectiveness of the method.

关键词： Couplings Stability criteria Eigenvalues and eigenfunctions Indexes Zinc Regression analysis

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Research on the Performance of Hydraulic Excavator with Pump and Valve Combined Separate Meter In and Meter Out Circuits

Research on the Performance of Hydraulic Excavator with Pump...

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2015 International Conference on Fluid Power and Mechatronics

作者： Lei Ge Zhixin Dong Weinan Huang Long Quan Jing Yang Wenyong Li Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education

Conventional hydraulic actuator is controlled by mechanically connected orifices valve. The controllability of this method is poor and the energy consumption is huge especially under the over-running condition. So a novel system configuration of the hydraulic excavator is presented to improve the problem mentioned above, in which boom cylinder, stick cylinder and swing motor are controlled with separate meter in and meter out technology, bucket cylinder and travel motors are controlled with conventional valves. Firstly, the paper provides a comprehensive review on the development of the separate meter in and meter out technology. Then the principles of load sensing system and SMISMO system applied on the excavator are illustrated though two diagram to show the difference of the two systems. And then a virtual prototype based on the real physical structures is established, which consists of the hydraulic excavator mechanical structure with multi-body dynamics and electro-hydraulic system. The model is verified by the statics and dynamics experiments. Then the dynamic, static performances as well as the energy consumption characteristics of the boom, arm and swing actuators are investigated under the condition of load sensing hydraulic system and the proposed system using the virtual prototype. The control strategy of the actuators is formulated according to their load condition and operation characteristics also based on the detailed analysis. After that, the physical prototype based on the proposed configuration system is established and its performance is tested. The experimental results show that the accuracy of the virtual prototype is validated;the proposed configuration system can significantly decreases the pressure losses through the valve and improve the energy efficiency of the machine;the pressure shocks within hydraulic actuators is decreased as well, thus the stationarity of the whole machine is improved accordingly.

关键词： flow matching separate meter in and meter out pressure and flow combined control pump and valve hybrid control

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Coordinated voltage control using tiered weight coefficients of optimization targets

Coordinated voltage control using tiered weight coefficients...

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China International Conference on Electricity Distribution, CICED

作者： Yan Zhang Yongzhi Su Hengxu Zhang Wen Zhang Xin Wang State Grid Shandong Electric Power Research Institute Jinan China State Grid Shandong Electric Power Company Jinan China Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong University Jinan China

ISBN: (纸本)9781467390712

Considering the locality feature of voltage control problems, This paper proposes a coordinated voltage control method with tiered weight coefficients of optimization targets, the optimization problem is formulated and solved based on the model predictive control method. At the initial control time, the correlation degree between buses is obtained based on the dynamic voltage response feature and fuzzy clustering method and the weak buses are identified according to the predicted system trajectory. In the optimization objective function, the higher correlation degree between the controlled buses and the weak buses leads to lager weight coefficients of the corresponding voltage deviation terms. In a fault scenario, the weight coefficients of the optimization targets are tiered-distributed, and the simulation results of the Nordic32 52-bus test system shows that the proposed method remarkably reduces optimization scale under the premise of a global control performance.

关键词： Voltage control Optimization Trajectory Sensitivity Computational modeling Predictive models Threshold voltage

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Architectural distortion recognition based on a subclass technique and the sparse representation classifier

Architectural distortion recognition based on a subclass tec...

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International Congress on Image and Signal Processing, BioMedical Engineering and Informatics (CISP-BMEI)

作者： Xiaoming Liu Leilei Zhai Ting Zhu Zhou Yang School of Automation Huazhong University of Science and Technology Wuhan China Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System Wuhan China Key Laboratory of Image Processing and Intelligent Control of Education Ministry of China Wuhan China College of Computer Science and Technology Wuhan University of Science and Technology Wuhan China

ISBN: (纸本)9781509037117

Architectural distortion is the third most common sign of breast cancer in mammograms. The accurate recognition is important for computer aided diagnosis of breast cancer. However, due to the subtle symptom and complex structures in the mammogram images, it is difficult to recognize whether a region of interest (ROI) is truly an architectural distortion. In this paper, we proposed a new method for architectural distortion recognition. In the proposed method, several texture features are extracted for each region of interest, including features from GLCM matrix, spiculated related features, entropy features, etc. Feature selection is obtained by a sub-classes clustering based multi-task learning method (SMTL), which can utilize the discriminative label information and reflect the multi-clustering characteristic of the data samples. Finally, the powerful sparse representation based classifier is used for the classification of AD or non-AD. The proposed method has been tested on DDSM dataset and compared with several other methods, the experimental results showed the effectiveness of the proposed method.

关键词： Feature extraction Distortion Entropy Training Mammography Delta-sigma modulation Breast cancer

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A multi-agent coordinated planning approach for deadline required emergency response tasks

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IET control Theory and Applications 2015年第3期9卷 447-455页

作者： Zhou, Chao Wang, Hongwei Zhuo, Hankz Hankui Key Laboratory of Image Processing and Intelligent Control of Education Ministry Institute of Systems Engineering Huazhong University of Science and Technology Wuhan430074 China School of Advanced Computing SunYat-sen University Guangzhou510006 China

This study investigates the emergency decision-making problem in a multi-agent system. Departments are modeled as agents to perform coordinated planning to obtain a global action plan with a short execution time constrained by a prescribed deadline. A novel multi-agent planning approach is proposed to coordinate for the solution among agents in the system. The approach consists of two stages. For the first stage, a coordinated planning and scheduling method is designed to generate a candidate global action plan. In this plan, durative actions are assigned to proper time intervals with the consideration of temporal relationships among agents. For the second stage, a coordination mechanism based on local heuristics is proposed to reduce the global time cost of the candidate plan to satisfy the deadline. An experimental study of emergency evacuation problem is conducted to demonstrate the effectiveness and efficiency of the proposed approach. © 2015 The Institution of Engineering and Technology.

关键词： Multi agent systems

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Dynamic hazard of belt transport tracking and discerning method based on mean shift

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International Journal of Mining and Mineral Engineering 2015年第4期6卷 309-320页

作者： Qiao, Tiezhu Duan, Yanfei Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan030024 China

For the conveyer belt in coal mine often damaged by hazards such as stones or metals in transit which can cause a longitudinal tear, and the feature of hazards' status changed when transportation belt being torn, a Mean shift tracking and monitoring method was approached. Infrared spectrum imaging model was established for hazard, and extracted hazard grey value according to reflected background radiation differences between hazard and coal in the best wavelength range. Hazard model is established using grey space joint histogram, Mean shift vector is established with bandwidth matrix and recursive equations are given in EM like manner. Experiments show that when hazards tearing the tape, the algorithm can be real-time tracking and monitoring the state of hazards to determine the tape tear. © 2015 Inderscience Enterprises Ltd.

关键词： Image processing

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Characteristics of a Piloted Digital Flow Valve Based on Flow Amplifier

Characteristics of a Piloted Digital Flow Valve Based on Flo...

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2015 International Conference on Fluid Power and Mechatronics

作者： Taotao Li Jiahai Huang Yanhong Bai Long Quan Shengguo Wang Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of Technology

Hydraulic switching techniques which have less throttling losses, good repeatability and can be controlled intelligently have been largely developed. The biggest challenge is the hydraulic fluctuation. It is generated in the process of opening and closing the valve. A two-stage digital flow valve operated by Pulse Width Modulation(PWM) signal is studied in this paper. The main stage is cartridge valve based on flow amplifying principle;the pilot stage is high-speed on/off valve. The fluctuation characteristic of the digital flow valve is investigated using theoretical derivation and simulation analysis. The results show that the outlet flow fluctuation is influenced by many parameters such as the frequency and duty ratio of PWM signal, the volume of control chamber, etc. It can be weakened through the proper design of these parameters. Although the fluctuation exists, the mean outlet flow can be proportionally controlled by adjustment of the duty ratio of the control signal.

关键词： Flow valve,High-speed on/off valve,PWM,cartridge valve

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Probabilistic forecasting for the ampacity of overhead transmission lines using quantile regression method

Probabilistic forecasting for the ampacity of overhead trans...

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IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC)

作者： Zhiqing Wei Mengxia Wang Xueshan Han Haicheng Zhang Qiang Zhang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education (Shandong University) Shandong Jinan China Binzhou Power Supply Company of State Grid Shandong Electric Power Company Shandong Binzhou China Shandong Electric Power Dispatching and Control Center Shandong Jinan China

ISBN: (纸本)9781509054190

Dynamic thermal rating (DTR) is an effective technique to improve the ampacity of overhead power transmission lines based on the monitoring of real-time environmental conditions. With DTR technology being introduced, the thermal rating of transmission line is no longer constant but time-dependent. To fully utilize the transfer capability of transmission lines, it is necessary to provide operators with probabilistic forecasting information of DTR to make dispatch decision. In this paper, a new probabilistic forecast method based on the quantile regression analysis theory is proposed to realize the probabilistic prediction of DTR. The weather parameters which have significant influence on the real-time ampacity and historical line ratings are embedded in the quantile regression prediction model. The proposed method can not only give the point prediction and interval prediction result, but also can provide the forecasting results of probability distribution function. Finally, the validity of the proposed method is illustrated by case studies.

关键词： Forecasting Conductors Wind forecasting Probabilistic logic Power transmission lines Probability distribution

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Research on the performance of hydraulic excavator with pump and valve combined separate meter in and meter out circuits

Research on the performance of hydraulic excavator with pump...

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International Conference on Fluid Power and Mechatronics (FPM)

作者： Lei Ge Zhixin Dong Weinan Huang Long Quan Jing Yang Wenyong Li Taiyuan University of Technology Key Lab of Advanced Transducers and Intelligent Control System of Ministry of Education Taiyuan China

ISBN: (纸本)9781479987719

Conventional hydraulic actuator is controlled by mechanically connected orifices valve. The controllability of this method is poor and the energy consumption is huge especially under the over-running condition. So a novel system configuration of the hydraulic excavator is presented to improve the problem mentioned above, in which boom cylinder, stick cylinder and swing motor are controlled with separate meter in and meter out technology, bucket cylinder and travel motors are controlled with conventional valves. Firstly, the paper provides a comprehensive review on the development of the separate meter in and meter out technology. Then the principles of load sensing system and SMISMO system applied on the excavator are illustrated though two diagram to show the difference of the two systems. And then a virtual prototype based on the real physical structures is established, which consists of the hydraulic excavator mechanical structure with multi-body dynamics and electro-hydraulic system. The model is verified by the statics and dynamics experiments. Then the dynamic, static performances as well as the energy consumption characteristics of the boom, arm and swing actuators are investigated under the condition of load sensing hydraulic system and the proposed system using the virtual prototype. The control strategy of the actuators is formulated according to their load condition and operation characteristics also based on the detailed analysis. After that, the physical prototype based on the proposed configuration system is established and its performance is tested. The experimental results show that the accuracy of the virtual prototype is validated; the proposed configuration system can significantly decreases the pressure losses through the valve and improve the energy efficiency of the machine; the pressure shocks within hydraulic actuators is decreased as well, thus the stationarity of the whole machine is improved accordingly.

关键词： Valves Actuators Prototypes Energy consumption Cavity resonators Load modeling

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Transient Flow Field Characteristic Analysis of Poppet Valve Based on Dynamic Mesh 6DOF Technique

Transient Flow Field Characteristic Analysis of Poppet Valve...

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2015 International Conference on Fluid Power and Mechatronics

作者： Guo Xiao-xia Huang Jia-hai Quan Long Wang Sheng-guo Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of Technology

In the fluid engineering, many projects involve movement and deformation of the boundary, but it is difficult to describe them by a simple algebraic expression because the movement of the boundary is determined by the force of hydraulic pressure, torque and other force which work together on the boundary. However, the previous numerical analyses are limited to the steady method or directly giving a speed to the spool which is difficult to actually simulate the movement of the spool. This paper developed a 6DOF model of a threedimensional poppet valve to stimulate the transient flow field in the opening process by means of computational fluid dynamics software—Fluent. The movement of the spool is decided by fluid force which exert on it and its gravity. By comparing numerical simulation results of the valve displacement, pressure of the control chamber and the inlet and outlet flow rate of poppet valve with the experimental results, the numerical results are the same as the experimental results. So the method that the paper proposed is feasible and more truly to simulate the flow state in the opening process of hydraulic valve. And on this basis, the pressure field, velocity field and flow regime are researched when poppet valve reaches steady state, which provides an important theoretical basis for further research on hydraulic valve performance.

关键词： poppet valve numerical calculation Dynamic Mesh Fluent

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