The reliable and economical operation on electrical power distribution system (EPDS) becomes more and more significant under the normal situation and emergency. An intelligent control for EPDS is presented in this pap...
详细信息
The reliable and economical operation on electrical power distribution system (EPDS) becomes more and more significant under the normal situation and emergency. An intelligent control for EPDS is presented in this paper in which expert control and decision control are involved. Several inference mechanisms are proposed and applied in expert control for EPDS. The expert's knowledge is represented in the rule form. State observation, optimization principle and the queueing method for decision control schemes are adopted in multiobjective decision control so that a decision control scheme corresponding to a distinct state can be confirmed quickly. Intelligent control is realized by a hierarchical distributed microcomputer control system.
In this paper, an applied software package for identifying MIMO system is introduce. It is suitable for implementation on microcomputers. The package contains six algorithms of parameter estimation and five methods of...
详细信息
In this paper, an applied software package for identifying MIMO system is introduce. It is suitable for implementation on microcomputers. The package contains six algorithms of parameter estimation and five methods of determining model structure. A new model structure test method viz. model response comparison method and several transformation algorithms in recusive form from input-output difference equation into other model forms are included in the package. The modelling procedure involves two steps: (1), looking for a middle model with high order the dynamics of which is approximate to true object;(2), reducing model order to obtain a suitable parameteric model. The package is equipped for a special microcomputer to identify the dynamics. The identification experiments for a 350 MW boiler-turbine-generator (BTG) set by using the special microcomputer have been carried out, and the data are processed off-line by the package. Then the more overall mathematical models of the BTG set are obtained in the form of transfer functions.
This paper presents a model and computer simulation results of the distributed collectors field of a solar power plant. This plant is located in Tabernas (Almeria - Spain). The dynamic behaviour of the distributed col...
详细信息
This paper presents a model and computer simulation results of the distributed collectors field of a solar power plant. This plant is located in Tabernas (Almeria - Spain). The dynamic behaviour of the distributed collectors field is simulated by 100 lumpe parameter submodels. Temperatures of the oil and the tube walls are modelled separately. The model also takes into account sun position, field geometry, mirrors reflectivity, solar radiation, and the inlet field oil temperature.
The paper discusses the application of multivariable AR, ARMA modelling and the associated structure and parameter estimation methods in spectral analysis of nuclear noise processes. The methods selected for identific...
详细信息
The paper discusses the application of multivariable AR, ARMA modelling and the associated structure and parameter estimation methods in spectral analysis of nuclear noise processes. The methods selected for identification are off-line least-squares (LS) and Levinson-type 'recursive in structure' procedures extended by the use of information criteria AIC, BIC, φ. Based on an identified four variable ARMA model, a simulational study is presented to investigate the effect of choosing a particular LS method and the effect of changes in structure estimation on the shape of spectral estimates.
The presently used TBC and FFC methods have satisfactorily maintained power system frequency within a prescribed tolerance. With steady increase in power system capacity, however, undue fluctuations in tie-line power ...
详细信息
The presently used TBC and FFC methods have satisfactorily maintained power system frequency within a prescribed tolerance. With steady increase in power system capacity, however, undue fluctuations in tie-line power flow has become prominent. This fact suggests the shear necessity of establishing a more sophisticated LFC system. Intensive research efforts have been concentrated on applications of modern control theory, above all linear optimal control (LOC) using the state regulator theory. This paper presents a decentralized suboptimal LFC method which makes use of the frequencies of adjacent areas in addition to local information to calculate the control variables of each area. This artifice has made it possible to realize a practical yet almost optimal control scheme. Simulation studies on a 4 area system have demonstrated the effectiveness of the proposed method.
To motivate understanding and applications of adaptive control and to provide access for non expert users in modelling techniques, an Expert Supervisor System was developed. Methodologies from Knowledge Engineering ar...
详细信息
To motivate understanding and applications of adaptive control and to provide access for non expert users in modelling techniques, an Expert Supervisor System was developed. Methodologies from Knowledge Engineering area as well as those used to build Expert systems are used to implement the Expert Supervisor and to acquire the Knowledge of human experts. Production rules of the form IF THEN are used to configure the Knowledge Base. These rules were constructed to consider the following situations: Order Analysis, System Excitation Analysis, Convergence Detection, Nonstationary Detection, Correlation Analysis. When running the System, from the Knowledge Base and data obtained during the identification algorithm execution, the expert supervisor infers and detect the necessity to modify parameters such as model order, excitation level, etc. The identification algorithm used is an Adaptive Trace algorithm with a fault detection method.
Designing a complex system such as a control, automation or electronic system most engineering activities involve graphical representations for the different design and modelling stages. Starting the design cycle the ...
详细信息
Designing a complex system such as a control, automation or electronic system most engineering activities involve graphical representations for the different design and modelling stages. Starting the design cycle the structure and function of the system has to be specified. For ease of imagination and decision the difficult interrelations between system components and subfunctions are frequently depicted by graphical schematics and diagrams. In this paper we introduce the idea and basic functions of a general purpose Computer Aided Schematics (CAS) system that may assist efficiently all schematics-based processes ranging from interactive to completely automatic drawing including the interfaces to further data processing. We discuss the benefits of the CAS approach as rapid generation and updating of correct and consistent graphics and its impact on the whole design and documentation cycle. Furthermore, some of the intricate, mainly graph theoretical optimization problems inherent in the computer generated layout of schematic drawings are addressed. Finally, we outline the possible application of CAS techniques to different engineering disciplines, where graphical programming and documentation of programmable controllers (PC's) is believed to be a profitable domain. First encouraging experience in the automatic documentation of complex control programs is reported.
This paper describes a strategy for the incorporation of knowledge-based aids within the operation and the control of a power- and steam-generating plant. The primary aim of this project is to enhance, not replace, th...
详细信息
This paper describes a strategy for the incorporation of knowledge-based aids within the operation and the control of a power- and steam-generating plant. The primary aim of this project is to enhance, not replace, the existing control system(s) with the characteristic qualities of knowledge-based systems or expert systems. In real time, expert systems can improve the efficiency of an operator by acting as an intelligent monitor, reducing the amount of data that he has to cope with. They can point at the likely causes of disturbances and offer advise as to their possible consequences and as to what actions may be taken in order to return to normal operation. Process upsets and disturbances can be simulated and the expert system can use its knowledge about the behaviour and the limitations of system in order to arrive at a predictive alarming capability. In the long term, this may then lead to a form of predictive control of a plant. An architecture that deals with these topics is proposed and a possible implementation is discussed in detail. Finally, attention is given to the problems of knowledge elicitation, building up the knowledge base, and integrating the system into the existing control software of a plant.
The improvement to the performance of turbine controlsystems of large-sized PWR units has been studied. The simulation and analysis tool is briefly described: it is a new computer program known as 'STAG' inte...
详细信息
The improvement to the performance of turbine controlsystems of large-sized PWR units has been studied. The simulation and analysis tool is briefly described: it is a new computer program known as 'STAG' intended for the study of the dynamic behaviour of electrical power systems. This program is distinguished by its use of a continuously variable integration step which allows it to calculate with an equal accuracy both the fast electro-mechanical phenomena and the slow thermal phenomena encountered on generating units. It also has a simulation macro-language at its disposal which provides facilities for the easy representation of new process and controllers models. Improvements to the operating performance of turbine control system is sought through a fundamental modification to the governor's design. This is highlighted by the simulation of the sets' behaviour under network short-circuit conditions, taking into account the interactions with other sets nearby.
A digital voltage controller is presented, based on the optimal-aim control method, and able to enhance the dynamic and transient stability of single- and multi-machine power networks. The single- and multi-machine co...
详细信息
A digital voltage controller is presented, based on the optimal-aim control method, and able to enhance the dynamic and transient stability of single- and multi-machine power networks. The single- and multi-machine controllers are, thus, built upon the same theory, the multi-machine case being a generalization of the single-machine case. The theoretical basis are presented, as well as simulations results on some typical networks. The possibilities to minimize the amount of data transmission between the power plants are also studied and validated.
暂无评论