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In recent years, variable speed permanent frequency generation, as the main part of wind power generation, has been widely concerned by people. In this paper, choose direct-drive permanent magnet wind power system as the study system, based on the mathematical model of three-phase voltage type PWM inverter on the system grid, then make some improvements on the double-closed loop control strategy,...
In recent years, wind power which is an intermittent and random energy source affects the frequency stability of automatic generation control (AGC) system with the large-scale wind power integration. So, it is necessary to improve the conventional frequency control method and model. Firstly, a dynamic wind farm model is set up based on wind turbines clustering for the accuracy of data in this paper...
Wet air oxidation (WAO) technologies developed in the fifties of last century who treats the waste water with a high temperature and high pressure. In the late 50 years, it is widely used dispose the non-biodegradable organic waste water, the waste water with high concentration or refractory sludge. In according to large amount of oxygen generated by fossil energy power should be supplied for system...
This paper considers the stabilization problem of networked control systems concerned both bounded channel uncertainty and arbitrary packet loss. Based on a previous approach which considers packet loss only, this paper proposes a new model to describe the NCS with both packet loss and channel uncertainty in an unified framework. The stability conditions of networked control systems are given by a...
In order to determine whether the groundwater seepage has an impact on the ground heat exchanger in thermal efficiency, a three-dimensional coupling thermal seepage model of the vertical u-tube ground heat exchanger was established. The standard κ-ε turbulence model was used inside the pipe and the porous media model was used outside the pipe. The heat transfer process was simulated by the FLUENT...
The multi-objective control problem for discrete bilinear system with disturbances is studied and a multi-objective optimal control algorithm for solving discrete bilinear systems with sinusoidal disturbances is proposed. In the lower order of the algorithm, the auxiliary Lagrangian problem of bilinear -two quadratic form structure is solved by Dynamic Programming. The weighting vector in the auxiliary...
In this paper, the problem of H∞ filtering for a class of nonlinear systems based on prey-predator model is considered. Taking into account the nonlinearity of the prey-predator systems, the model of these systems is constructed. Then, via Lyapunov stability theory and linear matrix inequality technique, the method of H∞ filter design for nonlinear prey-predator systems with stage structure and external...
Proton Exchange Membrane Fuel cell has many perfect characters and becomes one of the most important research subjects among domestic and international fuel cell fields. Heat transfer management is one of the key technologies for PEM fuel cell. This paper built a temperature model of PEM fuel cell based on fuzzy technology, which divided the fuzzy space evenly by established rules, got the number...
The evaluation of the city public emergency capability is an important basis of the development of the city emergency capability. This paper made a evaluation to the eight sample cities based on the Fuzzy Set Theory. And the sample cities are choice by the three criteria such as disaster distribution, city type and geography location and so on. And they are Nanning, Harbin, Yinchuan, Shenyang, Jinan,...
The problem of reducing conservatism of observer design of discrete-time Takagi-Sugeno fuzzy systems is addressed via a new kind of fuzzy observer. The so-called multi-instant fuzzy observer is parameter-dependent on both past-time and current-time normalized fuzzy weighting functions. Since more information about the underlying fuzzy systems could be involved into observer design, the conservatism...
In this paper, a High Precise Optimization Algorithm for manipulating multi-layered feed-forward neural network is studied. Its basic principle is: defining neural network average error as objective function, weights and thresholds as design variables, through design variables rationally sorted, objective function is dynamically formed. Compared the new method with BP, the optimum step-length can...
The problem of actuator hard-nonlinear appears in many practical control systems especially the plant with serious nonlinearity and need run in large rang situations. If the controller is designed only with conventional linearly techniques, the presence of hard-nonlinear can debase the performance even lead the closed-loop system to an unstable behavior. In this paper, neural net-based actuator hard-nonlinear...
In this paper, the problem of finite-time H∞ fuzzy control for both continuous-time and discrete-time nonlinear systems is considered. The definitions and explanations about finite-time H∞ fuzzy control for both continuous-time and discrete-time nonlinear systems are offered. Some theorems are obtained to guarantee the provided performance requirements. The optimization algorithms are also designed...
Submerged arc furnace is a system with strong coupling, nonlinearity and time-variability. In this paper, a logistic-interpolation-based fuzzy controller for electrode regulation of submerged arc furnace is proposed. The proposed controller is based on fuzzy logic control strategy, and interpolation algorithm is employed to improve the control accuracy without raising complexity of the controller...
A kind of membership function, called as generalized linear membership function(GLMF), is designed in the paper, and the triangular and trapezoid ones are as its special cases. It is derived that the fuzzy-PID Controller with GLMF is equivalent to the sum of a nonlinear PID controller and a compensation value, based on the analytical structure of the controller. With the definition of fuzzy Lyapunov...
The search method based on the way combined self-organizing competitive neural network with nearest neighbor algorithm was proposed. A data preprocessing method applying to the retrieval method was proposed in this paper. The implementation process of the search method based on the way combined self-organizing competitive neural network with nearest neighbor was showed. Eventually, through a practical...
The image brightness and contrast changes remain invariant when phase congruency changes. Specifically the monogenic filters, a new image feature detection method is proposed, which is based on phase congruency and the monogenic signal theory in this paper. The performances of Monogenic filters are excelled to that of Log-Gabor filters in theory, hence a greater amount of feature vectors are generated...
Towards the situation that the traditional fractional difference always has the same order in various regions of image for image processing, this paper presents a novel approach that the fractional order is automatically adjusted according to the gradient of every image pixels. The main contribution of this work is that Otsu algorithm is used to design the adaptive image enhancement operator, and...
A generic tiered warehouse (GTW) often features in adaptive layout and diversified efficiencies of transportation equipments or devices and so on. The storage optimization in GTW usually involves in storage allocation or assignment, transportation batching, routing and operational efficiency as well, which is comparably complicated more than in an automated storage and retrieval system (AS/RS). This...
For a class of linear time-varying system with non-uniform sample, we discrete the system by combination of both norm invariant and step invariant transformation, taking the problem of non-uniform sample transformed into discrete time varying system problem. Based on designed the fault estimator, we construct Lyapunov function, to get the essential condition of the error equation asymptotic stability...
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