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1.
以国家人事部<中国政府绩效评估研究>课题组确定的33项评估指标为基础,运用以模糊数学理论为基础的多级模糊综合评判法评估地方政府绩效,依据相关专家对各项指标的重要性评价,以黑龙江省政府为例进行实证研究.研究结果表明:多级模糊综合评判法能将定性的信息定量化,能够解决地方政府绩效评估过程中的瓶颈,为地方政府计划、控制和决策提供分析工具.  相似文献   

2.
In this paper, speed control, torque ripple minimization and Power Factor Correction (PFC) of a Canonical Switching Cell (CSC) with Sinusoidal and Space Vector Pulse Width Modulated (SVPWM) sensorless Permanent Magnet Brushless DC (PMBLDC) motor drive system with varying load is discussed. The constant speed of operation with minimum torque ripples and Unity Power Factor (UPF) operation during transient state is the most difficult control part in the motor drive system. At the starting condition, the current is too high due to the absence of back EMF and therefore the motor will start with high torque ripples. In order to eliminate these torque ripples during starting condition by limiting the starting current of the motor, it is necessary to have properly designed Canonical Switching Cell (CSC) converter and an intelligent controller, which will improve the power factor of the supply system and reliability of the PMBLDC motor drive. Here, the speed control, torque ripple minimization and power factor correction of a sensorless PMBLDC motor during starting and running condition with conventional and fuzzy logic controllers are proposed. The performance parameters of a PMBLDC motor with these controllers is analyzed through MATLAB/Simulink software.  相似文献   

3.
A new and systematic method to design digital controllers for uncertain chaotic systems with structured uncertainties is presented in this paper. Takagi-Sugeno (TS) fuzzy model is used to model the chaotic dynamic system, while the uncertainties are decomposed such that the uncertain chaotic system can be rewritten as a set of local linear models with an additional disturbed input. Conventional control techniques are utilized to develop the continuous-time controllers first. Then, the digital controllers are obtained as the digital redesign of the continuous-time controllers using the state-matching approach. The performance of the proposed controller design is illustrated through numerical examples.  相似文献   

4.
This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dc-dc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the d-q reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller.  相似文献   

5.
The lateral stability is the crucial feature in a distributed drive electronic vehicle (DDEV). A high speed DDEV in a sharp turn may lose the lateral stability when it encounters fast varied road adhesion coefficients. To solve this problem, a BP-PID controller-based multi-model control system (MMCS) is designed for DDEV via direct yaw-moment control (DYC) in this paper. Firstly, according to the varied road adhesion coefficients, the working circumstance of DDEV is summarized as seven kinds of typical types. A sub-model set is established to accurately describe the operating mode of the working circumstance. Secondly, based on the sub-model set, a nonlinear sub-controller set is constructed with seven off-line tuning BP-PID controllers and an on-line tuning one. The off-line tuning controller can fast calculate the required direct yaw-moment, and the on-line tuning controller is aimed to achieve a high control accuracy. Thirdly, a controller switching policy is composed of an error judgement policy and a model matching policy. Such switching policy is utilized to precisely identify the working circumstance of DDEV and implement switching control. Finally, simulation experiments prove that the designed MMCS shows a significant control performance and guarantees the lateral stability of DDEV under varied road adhesion coefficients.  相似文献   

6.
如何对地方政府科技管理职能绩效进行有效的评估,以使地方政府更好的为社会经济发展服务,并促进科技创新体系的建设.把模糊综合评价方法应用到科技管理职能绩效评价中,通过建立评价指标体系并分析可知应用模糊综合评价法有助于科技管理部门全面科学地考核科技管理工作者的工作实绩.  相似文献   

7.
A novel adaptive sliding-mode control system is proposed in order to control the speed of an induction motor drive. This design employs the so-called vector (or field oriented) control theory for the induction motor drives. The sliding-mode control is insensitive to uncertainties and presents an adaptive switching gain to relax the requirement for the bound of these uncertainties. The switching gain is adapted using a simple algorithm which does not imply a high computational load. Stability analysis based on Lyapunov theory is also performed in order to guarantee the closed loop stability. Finally, simulation results show not only that the proposed controller provides high-performance dynamic characteristics, but also that this scheme is robust with respect to plant parameter variations and external load disturbances.  相似文献   

8.
In this study, an adaptive interval type-2 Takagi-Sugeno-Kang fuzzy logic controller based on reinforcement learning (AIT2-TSK-FLC-RL) is proposed. The proposed controller consists of an actor, a critic and a reward signal. The actor is represented by the IT2-TSK-FLC in which the antecedents and the consequents are interval type-2 fuzzy sets (IT2FSs) and type-1 fuzzy sets (T1FSs), respectively, which are named A2-C1. The critic is represented by a neural network, which approximates the optimal guaranteed cost in the control design to ensure the system stability for all admissible uncertainties and noise. The use of a reward signal to formalize the idea of a goal is one of the most distinctive features of RL. Thus, the proposed controller evolves in time as a result of the online learning algorithm. The parameters of the proposed controller are learned online based on the Lyapunov theorem to guarantee the stability, overcome the shortcomings of the gradient descent, such as the local minima and instability, and determine the learning rate of the IT2-TSK-FLC controller. Furthermore, the critic stability is discussed for determining the optimal learning rate. The proposed controller is applied to uncertain nonlinear systems to show its robustness in reducing the effect of system uncertainties and external disturbances and is compared to other controllers.  相似文献   

9.
In order to improve the anti-disturbance performance of a bearingless induction motor (BIM) control system, a fractional-order sliding mode control (FOSMC) strategy based on improved load torque observer is proposed on the basis of the sliding mode speed regulation system. Using the information memory and genetic characteristics of the fractional calculus operator, the fractional integral term of the speed error is introduced in the design of the traditional sliding surface, which reduces the influence of disturbance on the speed regulation system. The fractional-order sliding mode control law is derived based on the BIM mathematical model, and the stability of the control law is proved by Lyapunov theorem. An improved observer is constructed based on the BIM state equations, and the real-time observed load torque is introduced into the fractional-order sliding mode controller. To improve the observer's convergence speed, the proportional integral form is used to replace the integral form in the traditional reduced order load observer. And the state error feedback coefficients of the improved load observer are calculated. Both simulation and experimental results verified the effectiveness of the proposed control strategy.  相似文献   

10.
基于模糊积分的科技成果评价研究   总被引:2,自引:0,他引:2       下载免费PDF全文
以科技成果的评价为例,首先分析了现有的科技评价方法中存在的不足。针对这些不足,提出了科技评价指标选取的原则,进而根据科技评价的特性提出相符合的评价计算方法:构建数值评估值与Choquest模糊积分。这一方法不仅让专家更直观地在定性指标上定性评价,而且也解决了指标间的出现相关性的问题。  相似文献   

11.
基于模糊层次分析法的协同项目风险评价模型   总被引:2,自引:0,他引:2  
协同项目风险复杂,一般没有历史数据可参考,应用对传统项目的风险评估方法对其进行评估不够准确。针对协同项目的特点,结合三角模糊数和层次分析法,建立了基于模糊层次分析法的协同项目风险评价模型,并用实例验证了该模型的有效性。  相似文献   

12.
将模糊数学引进评价系统对专业学位硕士的创新能力进行评价,创建多级指标体系,构建评价模型,并通过实例说明评价的过程及可行性.该模型对全日制专业硕士培养目标的设定,培养方案的制定及导师的培养都有一定的指导意义.  相似文献   

13.
In this paper, a command filtered fault-tolerant control (CFFTC) approach is investigated for induction motors (IMs) discrete-time system in the presence of actuator faults and unknown load disturbances. Firstly, the IMs system discrete-time model is obtained by Euler method. Then, the fuzzy logic systems (FLSs) is utilized to compensate for unknown actuator faults. Besides, introducing the error compensation mechanism into discrete-time systems via command filters, “complexity of computation” and noncausal problem can be conquered, and the filtering error is avoided concurrently. Finally, simulation results demonstrate the validity of the presented fault-tolerant method for IMs system.  相似文献   

14.
In this study, the problem of observer-based control for a class of nonlinear systems using Takagi-Sugeno (T-S) fuzzy models is investigated. The observer-based model predictive event-triggered fuzzy reset controller is constructed by a T-S fuzzy state observer, an event-triggered fuzzy reset controller, and a model predictive mechanism. First, the proposed controller utilizes the T-S fuzzy model and is constructed based on state observations and discrete sampling output, which can greatly reduce the occupation of communication resources. Then, the model predictive strategy for reset law design is designed in this paper. With a reasonable reset of the controller state at certain instants, the performance of the reset control systems is improved. Finally, the validity of the proposed method is illustrated by simulation. The merits of the proposed controller in improving transient performance and reducing the communication occupation are demonstrated by comparing its results with the output feedback fuzzy controller and the first-order fuzzy reset controller.  相似文献   

15.
通过科学分析大豆精准生产技术系统、大豆精准生产技术系统外部环境以及两者之间的互动关系,建立了大豆精准生产技术系统环境效益评价指标体系,并根据大豆精准生产技术系统黑龙江省示范区的实验数据和相关专家打分,采用模糊评价法对大豆精准生产技术系统的环境效益进行了评价。评价结果表明:相对于传统大豆生产系统,大豆精准生产技术系统具有较好的环境效益。  相似文献   

16.
This paper investigates rotor-side field oriented control of a wound-rotor induction motor using the slip energy recovery principle. The proposed drive system uses a matrix converter to transfer the slip energy from the rotor into the mains instead of using ac-dc-ac converter whilst the stator side is fixed to the grid. Operation at both subsynchronous and supersynchronous regions is possible with the proposed drive system. Simulation studies of the proposed doubly fed induction motor drive system verify the good control performance of the system in transient and steady-state conditions.  相似文献   

17.
从实体行为可信性的主观角度出发,针对传统主观逻辑理论没有考虑主观评测结果随时间动态变化的问题,提出对主观逻辑理论进行动态化多维扩展的思想,将传统的二维观点空间扩展为多维动态观点空间.在综合考虑实体行为的声誉和风险的基础上构建起实体可信度评价体系,提出一个基于主观逻辑扩展的实体行为动态可信评测模型.实验结果表明,该模型对实体恶意行为的反应更加灵敏,检测更加准确,抑制更加有效.  相似文献   

18.
基于平衡记分卡的加权海明距离模糊评估研究   总被引:1,自引:0,他引:1  
应用加权海明距离公式通过对平衡记分卡的定性指标进行模糊处理,丰富了BSC的内涵,使基于BSC的绩效评估体系可以进行模糊评估,并可采用计算机进行结果处理,使其具有了实际可操作性。  相似文献   

19.
专利价值的评估指标体系及模糊综合评价 /FONT /P   总被引:20,自引:2,他引:20  
万小丽  朱雪忠 《科研管理》2008,29(2):185-191
专利是企业一项重要的无形资产,有效评估其价值对企业具有重大意义。基于专利价值的时效性、不确定性和模糊性,本文尝试建立一个科学的专利价值评估指标体系,用层次分析法计算指标的权重,再用模糊综合评价法得出专利的现时货币价值量,以期为企业专利价值评估提供一种新思路。  相似文献   

20.
This paper proposes the design of a reset fuzzy observer for the class of nonlinear systems able to be described by a Takagi–Sugeno fuzzy model. The observer uses both continuous and discrete measurements and in contrast with the observers based on the First Order Reset Element (FORE), it updates its states resetting the initial condition of the integrator at each instant when the discrete measurements are available. The proposed fuzzy observer is applied to estimate the substrate and biomass concentration of an anaerobic wastewater treatment process and the effectiveness of the proposed method is tested by simulations comparing the results of a reset fuzzy observer with two fuzzy observers using continuous measurements only. Finally, the estimation scheme is validated using experimental data from an actual anaerobic digestion process, suggesting that the proposed reset fuzzy observer is a practical and encouraging approach to the state estimation of the class nonlinear processes under study.  相似文献   

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