基于GPS技术的电力系统同步相量测量装置

提出了一种采用全球定位系统(GPS)同步相量测量装置(PMU)的硬件方案。其设计基于双DSP结构，具有高速的运算能力和丰富的外围电路，并配置了网络接口，通信方便，可以实现电力系统大量节点的同步相量测量。叙述了PMU的原理、结构以及在电力系统中的应用。     

基于相量测量的等效电流量测变换状态估计的研究

针对同步相量测量单元(PMU)测量的特点,分析了引入PMU测量值对电力系统状态估计的影响,引入PM U量测信息的状态估计模型.在该等效电流量测变换状态估计模型的基础上引入旋转变换,不需对电压的相角和幅值及有功和无功的量测权重作出任何假设,即可实现方程的实、虚部严格解耦.同时,该方法可以充分利用PMU的信息, 包括支路电流相量量测,并且所需的存储量较小、计算速度较快和计算精度高,具有较好的工程应用前景.     

非线性离散时间系统的自适应函数观测器

针对一大类非线性离散时间系统提出了一种自适应函数观测器(AFO)。通过引入状态变换，得到了一类降阶形式的状态估计问题。采用一种稍加修改的强跟踪滤波算法估计降阶状态向量，然后利用降阶状态向量估计非线性状态函数。给出了AFO局部渐近收敛的充分条件。数值仿真示例显示AFO是一种具有强跟踪性质的自适应观测器，能在估计非线性状态函数的同时准确估计未知时变参数。     

IRIG-B时间码在同步相量测量装置（PMU）中的应用

IRIG-B时间码以其优越的性能成为时间统一系统的首选码型,被广泛应用于时间信息传输系统中。针对电力系统中同步相量测量装置（PMU）对同步时钟的需求,讨论了IRIG-B时间码在PMU的时钟同步中的应用。电力系统要求PMU的时钟同步误差不大于1μs,本文利用IRIG-B时间码数据全面、对时精度高、不需要人工预置等优点,设计了面向PMU的时钟同步系统,同时给出了其主、从时钟的设计框架,以及利用FPGA进行IRIG-B（DC）码编码、解码的方法。经验证,IRIG-B应用于PMU中可以提高其测量精度。     

扩张状态观测器在非线性系统故障诊断中的应用

介绍了扩张状态观测器理论,提出了一种应用于非线性系统的基于扩张状态观测器的故障诊断新方法,给出了多阶系统的故障观测器的设计方法,最后通过仿真实验证明所提供的方法相对于传统方法具有以下优点:一是可以得到故障的近似函数,便于识别故障。二是具有优良的即时性和反应能力。     

自动化技术、计算机技术

TP132007062199一类非线性系统有限时间函数观测器设计方法/丁玉琴,刘允刚(山东大学控制科学与工程学院)//山东大学学报(工学版).―2007,37(1).―56～60.研究了一类非线性系统的有限时间函数观测器设计问题,发展了现有文献中的相关结果:(1)得到了非线性系统的渐近收敛函数观测器设计方法;(2)在所设计的非线性系统渐近收敛函数观测器的基础上,并结合有限时间观测器理论,给出了将要研究的非线性系统的有限时间函数观测器的设计新方法。所设计的有限时间函数观测器在任意给定的时间段内实现了对将要研究的非线性系统状态函数的精确重构。仿真…     

一类MIMO非线性系统的自适应模糊输出反馈控制

针对一类MIMO非线性状态不可测系统,提出了一种稳定的基于观测器的自适应模糊控制方法.该方法不需要系统状态可测的条件,而是通过设计模糊观测器来估计系统的状态.证明了所提出的控制方法可保证闭环系统的稳定性和跟踪误差的收敛性.仿真结果进一步验证了该控制方法的实用性和有效性.     

参数未知环境下PMU装置相角差校准方法设计

PMU装置相角量测的准确性将直接影响相角差校准的有效性,且在参数未知环境下,相角量测的误差将有所增大。为此,文中设计一种面向参数未知环境的PMU装置相角差校准方法。根据PMU装置的内部结构建立测量装置ms级的内守时钟,结合互感器、采样保持器和比较器获得相位,并计算相量,再根据相位和相量获得相角值与周期同步时标的偏移量,通过对偏移量进行修正实现对PMU装置相角差的校准。实验结果表明,文中设计的PMU装置相角差校准方法得到的相角质量更高,且相位测量精度权重更集中,说明该校准方法更适合应用在实际的工程项目中。     

基于非线性观测器的永磁同步电机无传感器控制

为实现永磁同步电机(PMSM)无传感器控制,设计一种对两相静止坐标系下的PMSM模型进行状态重构的非线性观测器来估计转子位置和速度。设计的非线性观测器中不含转速,可使转速变化对观测器性能基本无影响,从而提高了观测精确度。采用基于积分切换的滑模变结构控制器代替了传统的比例-积分-微分(PID)控制中转速环,增强了电机控制系统对自身某些参数变化和外界扰动的鲁棒性。仿真结果证明,所设计的非线性观测器具有较高的观测精确度,控制系统具有良好的动静态性能。     

一类非线性互联系统的H∞模型参考跟踪分散输出反馈模糊控制

本文对一类不确定状态不可测非线性互联系统,给出了一种基于观测器的H_∞模型参考跟踪分散输出反馈模糊控制方法.设计中,首先采用模糊不确定T-S模型对非线性互联系统进行模糊建模,在此基础上,给出模糊分散观测器的H_∞设计和基于观测器的模型参考跟踪分散模糊控制的设计.应用李亚普诺夫和线性矩阵不等式方法给出了模糊分散系统稳定的充分条件.仿真结果进一步验证了所提出的模糊分散控制方法的有效性.     

基于功角测量和等面积法则的发电机暂态稳定在线判别研究

基于相量测量单元(PMU)的广域测量系统将电力系统的安全稳定监测提高到了动态水平,其中一个关键功能是发电机功角的直接测量.本文将功角测量和等面积法则相结合,用以快速判别电力系统的暂态稳定.该方法能够在线实时判别电网故障的发生和切除、根据实测功角数据计算加速面积、预测最大可能的减速面积,从而根据加速面积和减速面积的差值来判断暂态稳定性.该方法预测耗时短,可在故障切除后80ms内给出判断结果并提供稳定裕度信息.仿真结果一方面证明了其可行性;另一方面也表明,受PMU本身数据上传速率的影响,加速面积的预测值可能偏小,当加速面积和减速面积非常接近时,应采用其他辅助分析手段协助判别暂态稳定性.     

Decentralized nonlinear adaptive control for multimachine power systems via high-gain perturbation observer

This paper presents two novel decentralized nonlinear adaptive controllers (DNAC) for large-scale interconnected power systems, via state-feedback and output-feedback strategies respectively. In the both controllers, system perturbation, which includes all subsystem nonlinearities and interactions between subsystems, is estimated by a high-gain observer and then involved the decentralized adaptive feedback linearizing control law. For the first DNAC, when all subsystem states are available, a second-order high-gain perturbation observer is designed to estimate the system perturbation, which leads to a decentralized nonlinear adaptive state-feedback controller. For the second, a decentralized nonlinear adaptive output-feedback controller is designed using a high-gain states and perturbation observer, when only one subsystem state is measured. The stability of the closed-loop controller/observer system is analyzed by the Lyapunov direct method. Both the controllers have been evaluated in a simulation study based on a three-machine power system. The results show that with a simple structure, both the controllers have robust performance of improving the transient stability and damping of multimode oscillations, under different power-system operation and fault conditions.     

基于状态观测器的混沌动态系统跟踪控制

针对一类连续混沌动态系统,提出一种基于状态观测器的跟踪控制方法来进行混沌控制.在引入状态观测器观测混沌动力学系统状态变量的基础上,采用反馈线性化方法将非线性混沌系统转换为线性系统,再针对反馈线性化后的线性系统设计轨迹跟踪控制器,实现被控混沌系统的跟踪控制.仿真结果进一步验证了该方法的有效性.     

Vibration reduction of seat suspension using observer based terminal sliding mode control with acceleration data fusion

In this work, a disturbance observer and state observer based terminal sliding mode (TSM) controller with acceleration data fusion is proposed for the active control of a seat suspension. In practical applications, the driver's body and the friction forces are difficult to be accurately described with a mathematical model; for this reason, the proposed controller is designed based on a model simplified from a 6-degree-of-freedom (6-DOF) seat-driver model with nonlinear friction. The disturbance observer and state observer are designed together with Linear Matrix Inequality (LMI) method. For improving the observer's performance, a complementary filter is applied to fuse the estimation of the seat suspension velocity from the acceleration measurement and the state observer. The proposed controller is validated using simulations with various bump excitations applied, and the conventional state feedback TSM controller is implemented for comparison. The proposed controller is also implemented in a practical active seat suspension prototype, and a well-tuned commercial heavy duty vehicle seat suspension is applied for comparison. The power spectral density (PSD) value and ISO 2631–1 standard are used to evaluate the active seat suspension system's performance under random vibration. Both the simulation and the experimental results indicate that with the proposed controller, the vibration magnitude caused by a rough road can be greatly reduced, and the driver ride comfort is greatly improved.     

Synchrophasor communication

Synchronized phasor measurements provide the basis for fine-grained wide area power quality monitoring in electric grids. Time-synchronized phasor measurement units (PMUs) are deployed at different locations in the grid and report 10–60 measurements/second to energy management systems or other applications. For control applications it is crucial to receive measurement data as soon as possible after a state change in order to trigger corrective actions in time to prevent incidents in the grid. In this paper we analyze characteristics of synchrophasor M2M communication for different network technologies, including VDSL, HSPA and LTE networks. We briefly review synchrophasor communication approaches and real-time demands. We then emulate PMU traffic and perform measurements on different networks. We show how the underlying technology influences one-way delay patterns for synchrophasor communication, which has direct implication on the achievable real-time properties.     

基于电力调控数据挖掘的混合IDS研究

为适应大数据背景,提出一种基于电力调控数据挖掘的混合IDS自动构建方法。该系统利用公共路径挖掘算法,将同步相量测量数据和调控日志相融合,自动学习各类场景,并将系统状态遍历匹配到公共路径做出分类决策。为验证该方法,搭建了一个包含25个场景的试验平台,并对三母线两馈线系统进行训练和评估,其中90.2%的场景被正确分类。结果表明该IDS具有较高检测精度,可适用于电力调控要求的任务环境。     

Nonfragile Observer for Discrete-Time Switched Nonlinear Systems with Time Delay

This paper investigates the problem of the nonfragile observer design for discrete-time switched nonlinear systems with time delay. Based on the average dwell-time approach and linear matrix inequality (LMI) techniques, an exponential stability criterion for the discrete-time switched delay system with Lipschitz nonlinearity is derived. Based on several technical lemmas, the discrete-time observer design can be transferred to the problem of solving a set of LMIs. Furthermore, in cases when the gain of the state observer varies, a kind of nonfragile observer is proposed, and the solution to the observer gain is also obtained by solving a set of LMIs. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.