共查询到20条相似文献，搜索用时 15 毫秒
1.
Ran Li Ren Zhen Jiang Zejia 《保鲜与加工》1988,(6)
An optimal active power adjustment model is deve in this paper for hybrid AC/DC systems after outage contingencies. The objective of the model is to minimize the rejection of load when some elements are out of service, with adjustment strategy approaching practical system operation. A large number of outage contingencies are simulated when the Monte-Carlo Method is emyloyed to evaluate the system reliability, requiring fast calculation of each simulation. The model and computer method proposed in this paper satisfy such a requirment because of the application of concentric relaxation, recursive branch constraint treatment in linear programming and a direct method for B-1 matrix modification. This paper is concerned with the simplified steady state conditions of the system based on DC load-flow, which implies the reliability indices calculated are the measures about static loss of load. The results for a 14-bus hybrid AC/DC system are given. 相似文献
2.
As a single system of evaluation, both neural network (NN) and traditional expert system (ES) have many limitations. Developing evaluation system integrating NN with ES is an available way to offset their weakness. With black-box module, a new frame of evaluation system is developed in relative independent method. Then, a way of programming and realizing evaluation system, which is more close to human thinking, is put forward. 相似文献
3.
Wang Tingkai Wang Lichun 《保鲜与加工》1990,(4):57-65
This paper combines model reduction with system identification by means of time-domain function approximation, and presents a new time domain method of direct identification of linear reduced model and model reduction, and demonstrates existence theorem of its solution and criterion of order determination. Simulation tests show that the method is simple, accurate with few data requirement. 相似文献
4.
Liu Haijun Deng Renming 《保鲜与加工》1992,(5):51-56
This paper presents a new hierarchical and coordinative control method for reactive power optimization in large-scale interconnected power systems. It combines the interconnection forecast method for hierarchical control in large-scale steady state industrial systems with the incremental linear programming method for reactive power optimization in real time. The results of applying the method to power system examples show that the method not only solves the problem of high dimension in order, but also keeps the advantages of the incremental linear programming method. The proposed method is also suitable for the security analysis of reactive power correction in large-scale interconnected power systems. 相似文献
5.
In China, the county development is very important in promoting the national economy, coordinating the relationship between the city and rural area and achieving sustainable development of the country. The norm of county planning is a document directing the development of the total county area. Therefore, based on the theory of man-land system, this paper discusses the key in drawing up a county planning, such as regulating the economic structure, arranging the town system and protecting the eco-system. Finally, a draft norm of county planning was put forward. 相似文献
6.
Liang Xinhua Qin Yihong 《保鲜与加工》1988,(2)
The eigenvalue sensitivity methods is very useful not only in analysis of electric power system stability but also in design of the controllers. In this paper a new optimal method is proposed to design the parameters of PSS. Using this method the PSS is designed for a single machine-infinite bus system, and the results of digital simulation show that this method is very effective and useful. 相似文献
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8.
This paper presents a reactive power optimization method which combines thelinear programming model with secure correction. In correction. this mOdel presents a new idea inwhich the feasible control region of con trol variables is resolved by over constrained state varlables. This method is quick and reliable and overcomes oscillation of a general linear programming model. 相似文献
9.
The orientation of Chinese characters is very importantin the interface programming design of Auto CAD DXF documents.Beca-use some parameters are automatically computed by the Auto CADsystem,it is very difficult for Chinese characters to be oriented in DXFinterface programmings.This paper reports the calculating method of ori-ented parameters and the orientation method of Chinese characters in theinterface programming of DXF documents,and gives a general Fortran 77subroutine for the orientation of Chinese characters.The method solves thedifficulty of the orientation of Chinese characters in the interface program-mings of DXF documents,and makes it convenient for various CAD pic-tures to be oriented in Chinese Characters. 相似文献
10.
Optimization design of correction of the control systemby a passive network is studied in this paper.The design method guan-rantees collocation of a closed loop pole in a desired position,but alsominimizes the gain of the system amplifier,thus making the technicalrealization of the system easier.The design method is proved in thepaper. 相似文献
11.
FENG Wei-min~ 《保鲜与加工》2004,(6):103-108
The society-economy-environment appraisal for construction project can help our government to control macro-economy, make correlation policy and formulate laws and draw up city plan.It has great influence on the sustainable development of our society and it is the demand of the law for the environment evaluation in China.This paper introduced the basic structure of society-economy-environment appraisal system for construction project and the thought of elements transaction.Using the method of AHP, the model of project analyzing and optimizing selection is designed.For the more, the methods of the optimizing models on the selected schemes are put forward.Finally, the integrative analysis has been made on the system design and appliance of this appraisal system. 相似文献
12.
Cao Shugang Qi Qingjie 《保鲜与加工》1990,(4):97-103
The production-transportation system in a mine is analysed with the principle of system analysis in this paper and the working process of this system is simulated with the technology of random simulation in a computer. Finally, the optimal projects of designing and administering are put forward. 相似文献
13.
Zhao Youxin Li Wenyuan 《保鲜与加工》1991,(1):1-5
A method introducing fictious variables for resolving the linear model of reactive power and voltages control in power systems is presented. The method theoritically guarantees the resolvability and optimizition of linear programming model. This method has been proved successful by IEEE 6 -node test system and the several practical power systems such as 49-node, 155 -node systems. 相似文献
14.
The paper provides a detailed study of switching conditions of minimum-time control systems based on application in engineering. By analysis in theory and experiment, the authors deduce a set of switching conditions with state and control variabes inequality constraints, the variations of system parameters and the time-delay of computer in real time control. As an example, a DC motor speed control system is considered. By digital simulation and physical experiments,these conditions proved to be correct. The method in this paper is also suitable for other control systems using compound control algorithm. 相似文献
15.
Li Binhua Ren Yulong 《保鲜与加工》1990,(2)
The problem of transmission network planning is studied thoroughly by applying the mathmatical optimal tecqhniue in this paper. A novel approach is put forward for computer aided transmission network planning, which is quite different from what is based on D.C. load flow equations. A nonlinear transmission planning model is set up by regarding A.C. load flow equations as the system model. A practical model which can be solved more easily, and an united algorithm are obtained by applying the SUMT to the nonlinear model. The results of some practical examples indicate that this method can not only make the planning results more accurate, but also provide the voltage qualities and produce planning plans autometically and seek the plans optimally and fast. 相似文献
16.
Yi Shuping Wu Yuanyi Xu Xiangsui 《保鲜与加工》1990,(4):34-40
Based on Group Technology, a CAD/CAPP integrated system is developed. This paper mainly covers the research work of the CAPP subsystem. In this subsystem, geometric and manufacturing information is obtained from the CAD data base, modular block programming and full Chinese menu are adopted, process planning is produced with the semi-generative method, and process card involved the operation charts is yielded by printer.
The operation is simple and convenient, and the performance is quick. The ? CAPP subsystem is successfully integrated with the CAD subsystem. The subsystem is an advanced CAPP system. 相似文献
17.
In terms of the design of Traditional Embedded Real-time Operating System(ERTOS),the authors make use of the integration and big Kernel structure,which has the limitation in some aspects,such as the retractable,portable,supportable for hardware platform with new structure and open for interface standard and so on.Based on the analysis of RTOS,a sort of design model of embedded multitasking real-time operating system is proposed.First,the hardware(abstract) layer and operating system kernel are studied.Then,the highly scalable,real-time,transplantable and application programming preface design of ERTOS are presented.This design model takes use of the hardware Bard Support Package(BSP) to support the transplanting in sorts of OEM board or hardware system board,therefore solves the questions in traditional system,and last meets the current need for ERTOS. 相似文献
18.
The 3D urban planning information system has been the focus topic in urban palnning management. In this paper,the related development of 3D urban planning is reviewed and the development object,data acquisition, system application level and three important characters of 3D urban planning information system have been also discussed. Thus, a system framework iseatablished. Finally,several primary problems are put forward and thought to be resolved to improve the practicability of 3D urban planning information system over large scale. 相似文献
19.
In order to reduce the inconvenience of maintainability and reusability of web application system based on MVC, which is brought by the code of access security and coupling tightly with other modules, A web system development model based on access security MVC is put forward. The main framework and running process are provided and the key techniques of this model are researched. The model is applied to the practical development of the network distribution management system. 相似文献
20.
This thesis uses the theory and method of the system dynamics to analyze the characteristics of the urban land planning system and set up the urban land planning system dynamic model, The model could describe the influence and request of factors of the society. economy and environment to the urban planning by using the system, the quantitative and the dynamic methods. By adjusting the parameter and repeating model imitation, the model could provide the possibility of realizing the present land planning and provide the quantitative analysis method for the planning department to make or adjust the land planning, and assist the government department to make decisions. 相似文献