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Cheng H.,Lanzhou Polytechnic College | Cao W.-S.,Xi'an Jiaotong University | Zhou M.-X.,Lanzhou University of Technology
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2012

According to the performance analysis of the mathematical model of the three-phase grid-connected inverter (GCI) and the fluctuation mechanism on DC voltage of directly-driven wind turbine with permanent magnet synchronous generator (D-PMSG) under unbalanced network voltage conditions, a dual current-loop control strategy (DCC) which oriented on positive and negative voltage and current respectively is proposed to inhibit the DC voltage fluctuation, meanwhile the notch filter is introduced to conventional control strategy of phase-locked loop, so as to complete the wind generator un-off-line operation on grid faults. A 1.5 MW D-PMSG with back-to-back IGBT frequency converter is simulated in the PSCAD/EMTDC environment, and simulation results show that the maximum wind energy tracking is achieved in this system and the proposed DCC strategy can prohibit the rise of DC voltage successfully and enhance the ride-through capability of D-PMSG wind generation system under unbalanced network voltage conditions.


He L.,Lanzhou Polytechnic College
ICEIT 2010 - 2010 International Conference on Educational and Information Technology, Proceedings | Year: 2010

In this paper; Chinese University of existing physical education model analyzes the construction with Chinese universities as the center of leisure sport "club" type of recreational sport education model. Research shows that education is an adaptive recreational sports leisure times through body movement, seeking to set individual mental and physical development of competitive, exhibition, entertainment and educational activities for the whole of modern education. In recreational sports as the center of the "Club" model PE teaching, it is focusing on student life of leisure sports sense and the student movement habits, taking into account the student's interest and expertise, which is an ideal mode of Physical Education. © 2010 IEEE.


Zhao S.-P.,Lanzhou Polytechnic College
IASP 10 - 2010 International Conference on Image Analysis and Signal Processing | Year: 2010

This paper presents a combined denoising method based on an adaptive Wiener filtering in the wavelet domain and an adaptive Wiener filter in the spatial domain. First a pre-denoised image is obtained with the thresholding denoising in the wavelet domain and the residual noise variance of that is re-estimated. Then an adaptive Wiener filtering in spatial domain is applied to the reconstructed image to improve the accuracy. Computer simulation results show that, compared with a separate wavelet and spatial domain Wiener filtering, the mean squared error of the proposed method is the smallest and it obtains better denoising results. ©2010 IEEE.


Zhang L.,Lanzhou Polytechnic College | Han G.-C.,Lanzhou Polytechnic College
2011 2nd International Conference on Mechanic Automation and Control Engineering, MACE 2011 - Proceedings | Year: 2011

The study was conducted in a typical coal-mining industrial area in Gansu Province in Northwest China of Loess highland at Cold and Arid Regions. Gangue samples were collected from several mines and soil samples were collected nearly gangue pile from different coal mining region with a variety of mining history. According to the character of geology and topography at Cold and Arid Regions, gangue samples were incinerated, soil samples were treated with HCl-HNO3-HClO4, then the contents of Cd, Co, Cr, Cu, Mn, Pb and Zn were determined by atomic absorption spectrophotometry and the dates were handed by SPSS 12.0 For Windows. From the total analysis, Single pollution index analysis and integrated pollution index analysis, several important conclusions can be obtained from this study. The results show that coal-mining soil has been contaminated from human activity of mining and heavy metals were accumulated in a way. Therefore, it is necessary that the mobility and environmental impact of element should be taken in account and further investigated in Cold and Arid Regions. © 2011 IEEE.


Zhang G.,Lanzhou Polytechnic College
Proceedings - 4th International Conference on Intelligent Computation Technology and Automation, ICICTA 2011 | Year: 2011

In this paper, according to the generalized inverse theory, we give the algebraic structures of stabilizing feedback controllers to discrete-time linear systems. Necessary and sufficient conditions for stability of the systems are given. A class of stable state feedback controller is designed. Stabilizing analysis for the discrete-time linear system provides a theoretical guidance to the new method, and explains this method in practical engineering control system design possibility. As an application, a new result for stochastic constant system is given. The paper gives the corresponding numerical example. © 2011 IEEE.


He S.,Lanzhou Polytechnic College
ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering | Year: 2010

It has been found that the psychological health education and physical exercises are equally important in physical education teaching. Because the secondary school students are in the stage of grow and learn knowledge, sports teachers should actively study psychology teaching theory and apply to physical education teaching in order to truly train constructors who have a strong physique, a healthy psychological quality and sound personality. © 2010 IEEE.


He S.,Lanzhou Polytechnic College
ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering | Year: 2010

Advanced the concepts of Popularize education and lifelong education require strengthen research to the e-education. At present, educational concept advocates universal education lifelong education and quality education. Asynchronous teaching and self-study are peculiar to e-education and that characteristics will undoubtedly conform to the current trend of educational development. For develop e-education in the school teaching is the higher requirement of the modern educational concept of new era to physical education which has decisive significance for realize popularize and lifelong physical education aim. © 2010 IEEE.


He S.,Lanzhou Polytechnic College
Advances in Intelligent and Soft Computing | Year: 2012

The provisions of artistic gymnastics class action is the basis on the development of rhythmic gymnastics, and it sets the action choreography that is based on the level of lay movements, rhythmic gymnastics being a measure of the level of signs. Complete action on the arrangement of rhythmic gymnastics has been studied, which is mainly on 1986 edition and 2002 edition of the project schedule, the body movement is difficult and musical arrangements that were compared to analyze the similarities and differences between artistic gymnastics movement in the advantages and disadvantages of the 1986. Rhythmic Gymnastics Level is the difficulty of movement in the provisions of the general body movements that are not balanced, the difficult level and number are suitable, but the lack of tough action is the most difficult jump class body. The swivel type and flexibility / body wave class were less difficult. 2002 Rhythmic Gymnastics class action provides the body movement difficulties and quantity in the difficulty level being rising, but some routine difficulty level is too high in the body. There has been difficult levels for C and E difficulty of body movement difficulties, we can highlight the class action provisions in the competitive nature, and it also represents the class action provisions of the development. Research requirements are for the level of Artistic Gymnastics Movements development direction. © 2012 Springer Science+Business Media Dordrecht.


Ma S.C.,Lanzhou Polytechnic College
Advanced Materials Research | Year: 2013

This paper deeply analyzes the urban civil system, energy-saving decision-making mechanism, the system components and the related energy-saving anti-adjustment mechanism based on the proposed energy-saving urban civil system's basis. It also presents the classification decision-making and decision-making process for the civil on various components on building systems in decision-making energy-saving features on the system proposed civil heat, urban heating network and the energy saving civil monomer decision making. It also builds the decision support for the city civil agent-based energy-saving system, realizing the basic institutions of the agent to propose the energy-saving urban civil decision. © (2013) Trans Tech Publications, Switzerland.


Zhang G.,Lanzhou Polytechnic College
Proceedings 2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011 | Year: 2011

By using the Moore-Penrose inverse and the singular value decomposition theory, in this paper, the author designed controllers make the eigenvalues of the closed-loop system located in a ring of the unit circle, and the variance of each steady state compose to the given constraint. And author derives the existing sufficient and necessary conditions and the expression of solution by a modified algebraic Lyapunov matrix equation. The corresponding numerical example explains this method designed in practical engineering control system possible. © 2011 IEEE.

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