Daubechies复小波的生成及其在短时电能质量扰动检测中的应用

在分析比较了现有用于短时电能质量扰动检测的方法后,研究了用正交紧支复小波进行检测与抑制噪声的原理,提出用Daubechies正交紧支实小波派生其复小波的实用方法,并结合复小波变换提供的相位信息构造了多种新型复合信息形式.仿真表明,采用本文方法派生的复小波及其复合信息形式进行电能质量扰动检测,具有良好的噪声鲁棒性且提高了应用Mallat算法的实时性.     

旋转电磁致热器热网络模型及其温升计算

旋转电磁致热器是从电机损耗与温升的逆问题出发,将通常意义上的损耗转化为可利用热能的装置。文章介绍了旋转电磁致热器的结构及工作原理,根据其结构建立了7节点的集中参数热网络模型,给出了热网络模型中关键热阻参数的计算方法,并建立了其等效的集中参数热网络方程。针对一台实际样机,计算了其热阻参数及稳态运行时致热器的内部温升,而相应的实验验证了其有效性。     

压电陀螺用于火箭弹起始扰动测量的研究

根据火箭弹离轨时的具体环境，提出一种弹离轨姿态的新颖的智能化测试方法，该方法是将陀螺及数据采集电路置于试验弹的内部随弹体飞行，而后将采集系统回收，由计算机读出数据并进行分析，最终获得火箭弹起始扰动的有关参数，并着重解决了数据存储、保持及回收等问题。     

Determining the operating conditions of floating marine platforms based on the predicted motion control under conditions of wind and wave disturbances

A technique of determining the time when drilling operation must be halted on the basis of the predicted control of the movement of floating marine platforms is proposed. By means of the technique it becomes possible to adopt with a high degree of reliability a correct decision as to whether to continue or to halt drilling when the platform is functioning under conditions of random wind and wave disturbances. __________ Translated from Izmeritel’naya Tekhnika, No. 1, pp. 21–24, January, 2008.     

Robust nonlinear adaptive backstepping excitation controller design for rejecting external disturbances in multimachine power systems

This paper proposes a new approach to design a robust adaptive backstepping excitation controller for multimachine power systems in order to reject external disturbances. The parameters which significantly affect the stability of power systems (also called stability sensitive parameters) are considered as unknown and the external disturbances are incorporated into the power system model. The proposed excitation controller is designed in such a way that it is adaptive to the unknown parameters and robust to external disturbances. The stability sensitive parameters are estimated through the adaptation laws and the convergences of these adaptation laws are obtained through the negative semi-definiteness of control Lyapunov functions (CLFs). The proposed controller not only provides robustness property against external disturbances but also overcomes the over-parameterization problem of stability sensitive parameters which usually appears in some conventional adaptive methods. Finally, the performance of the proposed controller is tested on a two-area four machine 11-bus power system by considering external disturbances under different scenarios and is compared to that of an existing nonlinear adaptive backstepping controller. Simulation results illustrate the robustness of the proposed controller over an existing one in terms of rejecting external disturbances.     

Mismatched disturbance attenuation control for static var compensator with uncertain parameters

The use of a static var compensator (SVC) as a component of flexible alternating current transmission system (FACTS) devices to control power systems has been investigated for decades. Its aim is to regulate the system voltage and improve the stability and loadability of power systems. A typical assumption in such a system is that the parameters of the controlled system are known accurately, which is rarely satisfied in practice. This paper explores the development of a simple but effective controller for a single-machine infinite-bus power system with SVC subjected to both matched and mismatched disturbances where the controller derivation is based on the assumption that all parameters used in the system modeling are unknown, but bounded in size. The research in this paper illustrates how an indirect robust control can be incorporated with a modified disturbance observer-based feedforward term to attenuate the influence of parameter variations and disturbances from the outputs of the system. Simulation results are presented to confirm the effectiveness of the proposed scheme.     

基于PSR模型的潜江市后湖管理区生态系统健康评价

为评价城市小流域健康状况,以潜江市后湖管理区为例,于2019年10月对18个样点进行生态环境调查,采用压力—状态—响应模型构建包含压力、状态、响应指标3个层次的健康评价体系,利用熵权法计算评价指标权重,应用综合健康指数法评估后湖管理区健康状况。结果表明,全流域18个采样点中,6个处于健康状态,7个处于亚健康状态,5个处于不健康状态,后湖管理区健康状态处于中等水平;影响城市小流域生态系统健康的主要因素为人口密度和水资源利用率,未来的小流域生态修复工程应注重城市化进程与生态环境保护协调发展,正确处理人类行为与环境变化的相互关系。     

广义积分器型直接极点配置自适应控制

Elliott提出的直接极点配制自适应控制的突出的问题就是由于辅助参数的引入使所需辨识的参数增加了1倍。这时多数辨识的收敛及控制的初始特性不利。本文通过广义积分器的引入,不仅解决了辨识器阶数过高的问题,而且能消除确定扰动的影响,实现对参考输入信号的无稳态误差跟踪控制。     

带有不匹配干扰的多智能体系统有限时间积分滑模控制

针对动态多智能体系统协同控制问题,本文研究了带有不匹配干扰的二阶多智能体系统的有限时间包容控制,提出了基于非线性积分滑模控制（Integral sliding-mode control,ISMC）的复合分布式包容控制算法.首先利用Lyapunov稳定性和齐次性定理,分析了未受扰系统的有限时间包容控制问题;然后针对存在不匹配干扰的多智能体动态系统,设计非线性有限时间干扰观测器估算智能体的状态和干扰,提出基于干扰观测器的复合分布式积分滑模控制协议,结合现代控制理论和滑模控制理论,研究了带有不匹配干扰的多智能体系统有限时间包容控制问题.最后数值仿真证明了控制算法的有效性.     

具有正弦扰动的时滞系统前馈-反馈次优控制:灵敏度法

研究线性时滞系统在外部正弦扰动作用下的前馈-反馈最优减振问题,提出了一种最优控制律的灵敏度设计方法．通过引入灵敏度参数并围绕它展开幂级数,将系统的最优控制问题简化为不含超前项和时滞项的两点边值问题族．通过截取最优控制级数的有限和获得原系统的前馈-反馈次优控制律．仿真结果表明,与经典状态反馈最优控制相比,本文的算法更加鲁棒,能更加有效地抑制正弦扰动．