Unknown piecewise constant parameters identification with exponential rate of convergence

The scope of this research is the identification of unknown piecewise constant parameters of linear regression equation under the finite excitation condition. Compared to the known methods, to make the computational burden lower, only one model to identify all switching states of the regression is used in the developed procedure with the following two-fold contribution. First of all, we propose a new truly online estimation algorithm based on a well-known DREM approach to detect switching time and preserve time alertness with adjustable detection delay. Second, despite the fact that a switching signal function is unknown, the adaptive law is derived that provides global exponential convergence of the regression parameters estimates to their true values in case the regressor is finitely exciting somewhere inside the time interval between two consecutive parameters switches. The robustness of the proposed identification procedure to the influence of external disturbances is analytically proved. Its effectiveness is demonstrated via numerical experiments, in which both abstract regressions and a second-order plant model are used.     

避雷器阀片检测用L-C恒流充放电装置

研制了一种检测氧化锌避雷器阀片的重复频率充放电装置,采用L C恒流充电技术,通过电压反馈法控 制充放电运行过程。电压反馈控制单元由指轮拨码开关、高压分压器、触发控制器及大功率可控硅组成,可数码连 续预置充电电压值,有充电电压值调节方便、精度高,抗干扰能力强等特点     

超高亮LED的驱动

在简要介绍超高亮LED的特点以及特性的基础上，详细介绍了LED的电阻限流、线性调节器和开关调节器等驱动方式，在此基础上介绍了超高亮LED的驱动芯片MLX10801的功能和应用，并给出了当前主要超高亮LED驱动芯片的主要特点：     

变速恒频双馈风力发电机的H_∞控制

研究了变速恒频双馈风力发电机的H∞控制,利用其定子磁场定向矢量控制的非线性方程组,应用直接反馈线性化建立了双馈风力发电机的鲁棒控制模型,采用H∞控制理论得出控制律,算法简明,适合工程应用。仿真表明,H∞控制可以改善双馈风力发电机的运行性能,使其具有高精度抗干扰的特性。     

基于80C196KC单片机的内燃动车组恒功控制系统实现

介绍一种利用80C196KC单片机实现的内燃动车组恒功率控制系统,系统通过自动控制牵引发电机励磁机的励磁电流,自动控制牵引发电机功率,间接控制柴油机功率输出。试验结果表明系统结构合理,硬件和软件的设计满足要求,具有较高的控制精度和动态稳定性。     

Electrical properties of Ga2O3-based dielectric thin films prepared by plasma enhanced atomic layer deposition (PEALD)

Ga₂O₃ and Ga₂O₃-TiO₂ (GTO) nano-mixed thin films were prepared by plasma enhanced atomic layer deposition with an alternating supply of reactant sources, [(CH₃)₂GaNH₂]₃, Ti(N(CH₃)₂)₄ and oxygen plasma. The uniform and smooth Ga₂O₃ and GTO thin films were successfully deposited. Excellent step coverage of these films was obtained by chemisorbed chemical reactions with oxygen plasma on the surface. The dielectric constant of GTO thin film definitely increased compared to Ga₂O₃ film, and the leakage currents of GTO films were comparable to Ga₂O₃ films. The leakage current density of a 40-nm-GTO film annealed at 600^∘C was approximately 1×10⁻⁷ A/cm² up to about 600 kV/cm.     

补偿参数对串/串补偿型无线电能传输系统特性的影响分析

以串/串补偿型无线电能传输(S/S-WPT)系统为研究对象,为了给补偿电容参数的优化选择提供一定的指导,基于变压器T模型等效电路对S/S-WPT系统进行建模分析,得到了系统实现输出恒压时补偿电容参数需满足的约束条件。在该约束条件下,进一步分析补偿电容参数对输入阻抗、输出电压增益和系统效率的影响,并得出了输入阻抗为感性的条件、输出电压增益的调节方法以及系统效率的优化途径。实验结果验证了理论分析的正确性。     

无刷直流电机恒功率调速技术的研究

在对无刷直流电机进行恒功率调速时,采用常规的超前角调制存在调速范围小,相电流大的缺点.介绍了一种新颖的功率变换器,即在传统的三相桥电路后串人品闸管整流器.由于晶闸管电流的单向流动性,从而避免了电机恒功率调速时的馈能现象,并且在保证相电流有效值不增大的同时大大扩展了电机的调速范围.实验结果表明,采用该电路,可以保证相电流...     

风电发展现状与控制技术综述

主要介绍了国内外风力发电的应用现状,分析了风力发电系统的运行特点与关键控制技术.针对目前应用较多的双馈感应发电机变速恒频发电系统,介绍了双馈感应发电机数学模型与控制方法,并给出了不同变换器拓扑结构的对比结果.     

Black-Start Decision Making Based on Affinity Propagation and TOPSIS

Abstract

Finding the optimal black-start alternative plays an important role in speeding up the restoration process of a power system after a complete blackout. In this article, a clustering method, affinity propagation, is adopted to deal with the black-start decision making problem. A novel black-start decision making method based on affinity propagation and TOPSIS is proposed. The standard deviation method is used to calculate the weights of the indexes, and a weighted normalized decision matrix is constructed. Then affinity propagation is used to cluster the black-start schemes of the weighted normalized decision matrix, and the optimal cluster is determined. Finally, for each black-start scheme in the optimal cluster, the relative closeness value is computed according to the TOPSIS method, and the best black-start scheme is selected. Compared with the existing black-start decision making methods, the proposed method can not only rank the black-start schemes but also determine which grade each black-start scheme should belong to. Based on the data of an actual power system, experiments were carried out to evaluate the performance of the proposed method. The results show that the proposed method is effective.