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The experts' opinions integration has always been an important part of group decision making. This paper analyses the consistency of general judgment matrix and proposes a model of group priority weight vector calculation. Through the analysis of this model, a genetic algorithms is designed, and values of some parameters are proposed. Since the Analytic Hierarchy Process in Generaliaed Judgemet(GJAHP)...
The periodic sampling strategy simplifies the analysis and implementation of generator excitation control in power system. However, it may lead to unreasonable distribution of the resources because the sampling frequency has to indicate the worst scenario of the system operation. The paper applies the self-triggered control algorithm to design the generator excitation controller of power system. The...
The electromechanical transient model of direct-drive wind farm is built through the reasonable simplification of electromagnetic transient model and its engineering application is realized through power system analysis software package (PSASP) user-defined (UD) model widely used in china. The transient characteristics of direct-drive wind farm connecting to power grid are acquired by combining theory...
This article provides a new control strategy of parallel regenerative brake system based on the requirement of new energy vehicles, and optimizes the control strategy according to ECE regulations, so that vehicles can use the maximized regenerative braking capability on the premise of ECE regulations. We verify the feasibility and braking performance of the optimized control strategy in MATLAB/Simulink-AMESim...
In order to increase the work efficiency of oil pumping system, the key problems in the operation process of oil pumping system are summarized. The experiment system for oil pumping is established, the mathematic models of oil pumping system are analyzed, objective function, boundary condition and calculated method in oil extraction system are discussed, the optimum control strategy in the operation...
As ship power system continues to expand the scale, the workload of the calculation and analysis is growing. Using computer technology to create an object-oriented ship power system simulation platform will play an important role on the overall power system design and performance evaluation. In this paper, we add simulation application algorithm further based on the established graphical simulation...
In this paper, a model of the wind turbine (WT) with direct-drive permanent magnet generator (DDPMG) and its associated controllers is presented, based on which the small signal stability analysis model is derived. As detailed models of wind farm can place and unbearable computational burden on simulations programs, there is a need to reduce wind farm order dimension. Focusing on the most relevant...
Modular multilevel converter (MMC) is a newly introduced topology of multilevel converter, which is based on cascade connection of chopper-cells per leg. This paper presents a novel topology of MMC, in which, based on traditional topology of MMC, H-bridge (HB) cells are used for more levels of output voltage. Corresponding control strategy is presented and explained in details, including phase-disposition...
Currently, DC motor of automatic doors speed regulating system utilizes PID control which has parameters tuning difficulties, poor stability, and imprecise control. To solve the above existent problem, this paper adopts the control strategy of fuzzy algorithm combining with PID control, introducing method of fuzzy PID control used in DC motor speed regulating system of automatic doors. Through establishing...
To acquire higher performance of direct-operated electro-hydraulic proportional-reducing valve, driving circuit and controller was developed. Simulation software, AMESim, was used to develop the model of the test bench according to construction and working principles presented in this paper. The results of simulation and experimental test, including pressure control characteristics and frequency response...
The paper analyzed the application of complex torque coefficient (CTC) approach based on the IEEE 2th benchmark of SSR. It deduced mechanical and electric CTC, and studied the influence of unstable model outside the shaft. If there is no unstable model, the CTC can be computed just by the transfer function. Otherwise, there is no rigid CTC, and additive simulations are needed to verify the analysis...
The paper analyzes the basic characteristics of the stable response of electromagnetic torque of synchronous generator, deduces the main calculation procedure of complex torque coefficient (CTC), and validates them by simulation. The study shows, the apply condition of CTC approach is the linearity and stability of the system. Under a stable system, the CTC can be calculated by the transfer function,...
Photovoltaic power generation system implements an effective utilization of solar energy, but generally has very low conversion efficiency. Maximum power point tracker (MPPT) control is essential to ensure the output of photovoltaic power generation system at the maximum power output as possible. Photovoltaic cells model of photovoltaic power generation system and basic control algorithm is discussed...
Calculating additional losses of the transformer driven by load harmonics is very significant to economic, safe and efficient operation of transformer. Based on the transditional model of additional losses driven by load harmonics, the simplified model is put forward, as well as the calculation equation. According to the simplified model, a method to monitor the transformer harmonic losses online...
Montmorillonite, iron oxide and the composite, were synthesized and characterized. The behavior and kinetics of arsenic sorption on the three kinds of adsorbent were investigated under neutral conditions. The results indicated that the sorption capacities of iron oxide are higher than those of montmorillonite and composite. The kinetic data of arsenic adsorption can be well described by Lagergren-second-order...
It was difficult for the traditional analytical method to analyze the acoustics characteristics of acoustics sensors. In order to solve the problem, a method based on the Finite Element Method (FEM) was investigated combining with the technology of harmonic response analysis. After presenting the basic math method theory of finite element, the harmonic response analysis model of ultrasonic liquid...
Ocean wave energy-harvester has important significance for energy supply of the ocean wireless sensor networks. In this paper, a type of drag board point wave energy converter is designed. Simulation result shows that the relative displacement is generated between the float and the drag board. The pack and pinion is used to transform super-low-frequency linear motion into low-frequency rotary motion...
Yearly natural streamflow data of five hydrologic stations over the upper of Weihe basin for 1945–2000 were utilized to analyze the drought characteristics by using Run-theory and Grey system. Based on the theory of run and intercept method, the hydrologic drought duration, drought severity and the value of conditional probability were calculated to evaluate the regional hydrological drought characteristics...
UTAUT model is used to analyze the IT user's acceptance behaviors. OER is a new educational information technology, it changes the traditional information transmission model of education. In this paper, we designed a model of learner's acceptance behavior to OER based on UTAUT. we made some research hypotheses, and designed the questions of survey. These will be a reference to the further research...
In order to evaluate the risks of information system, the paper proposed an information system grey evaluation model from the concept of “grey degree” and this can reduce the subjectivity of the evaluators. Fuzzy-AHP method was used to ensure the objectivity of the weight selection. The demonstration research proves the method is effectively.
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