基于自抗扰控制技术的发电机励磁控制方法

采用合理的发电机励磁控制方案对改善电力系统扰动稳定性有着重要的作用.探讨了二阶自抗扰控制器,并将其技术应用于发电机励磁系统.经同步发电机自抗扰励磁控制仿真验证,设计的自抗扰励磁控制器,对不确定的模型和系统的内外扰表现出更强的适应性和鲁棒性,能快速抑制发电机端电压的大幅振荡,有效地改善系统的动态品质,提高系统的稳定水平.     

自校正PID方法在水轮发电机调速系统中的应用

建立了水轮发电机调速系统的CARMA模型 ,给出了模型参数的在线辨识方法 ,设计了调速系统的极点配置自校正PID控制器。仿真研究表明 ,这种控制方法能够有效地克服系统时变、非线性及干扰对控制性能的影响 ,使调速系统的动态性能及鲁棒性都得到明显地改善。     

灰色预测励磁控制同步发电机动态过程仿真

为了更准确地研究灰色预测励磁控制对发电机行为的影响,基于非线性派克模型构建了考虑PSS作用的同步发电机灰色预测励磁控制系统模型,并以单机无穷大系统为对象对其控制效果进行了仿真.与采用线性化模型相比,采用非线性派克模型可保证灰色预测控制输入数据的非负性,简化预测算法.考虑调速系统和PSS的作用后,能更加准确和全面的了解灰色预测励磁控制系统的控制效果.仿真结果表明,在大小扰动下,无论是否具有PSS,同步发电机励磁系统中引入灰色预测控制后均可明显地改善系统的稳定性.     

感应电机调速系统新型滑动模解耦与自校正控制

文音分析和设计了一类新型感应电机调速系统,整个系统分成内、外环。论文首先通过适当选择坐标框架,提出一个简明的鹫电机数学模型,并以此为基础,在内环设计了一个滑动模转矩控制器,因而它不但可实现转矩和磁通的解耦控制,而且对电机参数变化和外界干扰还具有较强的鲁棒性。外环的设计则引入自校正控制器－－－零极 点配置控制器（含实时参数辨识）。仿真结果表明,整个系统在外环采用自校正控制后能进一步提高系统的鲁棒性和     

STATCOM与发电机励磁非线性控制器设计

提出了一种有利于进行控制设计的STATCOM模型.采用直接反馈线性化、零动态原理,设计了STATCOM无功电流与发电机励磁非线性控制器,该控制可以同时满足发电机励磁与STATCOM装设处电压的稳定性.对单机-无穷大系统进行了数字仿真,结果表明该控制器具有很好的实用效果和优越性.     

考虑SCE-TOG的水电机组调节系统协同控制器设计

水电机组调节系统对维持电力系统的稳定起着不可或缺的作用。为了同时提高水电机组调节系统各状态变量的跟踪性能,改善调节质量,引入协同控制理论,设计了水电机组调节系统调速、励磁协同控制器。首先建立了考虑调压井效应（SCE）及三阶发电机（TOG）的水电机组调节系统非线性数学模型,并推导出上述两种控制器的控制规律;在此基础上,针对水电站并入电网的单机无穷大系统,进行负荷扰动和三相短路故障两种情况下的仿真试验,比较协同调速励磁控制策略、协同调速控制策略和经典PID控制策略的跟踪性能。结果表明,所设计的调速、励磁协同控制器在两种工况下都体现了优越的控制性能。     

带励磁限制环节混沌电力系统的励磁控制器设计∗

为带有励磁限制环节的电力系统动力学模型设计励磁控制器以抑制系统的混沌振荡.首先利用分岔图及相图对系统基本动力学行为进行分析,以此证实系统模型混沌行为的存在性.然后利用递归型滑模控制方法为混沌电力系统设计励磁控制器并给出控制输入的具体表达式.由于在控制输入中规避了复杂系统函数,从而规避了励磁限制环节对控制器设计的影响.最后利用数值仿真证实所设计控制器用于抑制电力系统混沌振荡的有效性.励磁控制能够为抑制电力系统混沌振荡提供一种实用的工程化方法.     

标量解耦在无传感器矢量控制系统中的应用

为了实现三相异步电机高性能的调速控制,引入了旋转坐标系矢量分析法,采用一种基于PI控制器和电压解耦原理的感应电机简化模型.分析了同步旋转坐标系下PI控制器在解耦方面的不足.通过在定子电压指令中增加解耦项,即在励磁和转矩信号输入端增加一个标量解耦环节,可以消除感应电机的内部耦合.基于系统仿真,在自行搭建的无传感器矢量控制系统实验平台上进行了调速实验.实验结果表明,系统具有良好的动静态调速控制性能.     

规则自适应模糊控制在同步发电机励磁系统中的应用

对于像电力系统这样的典型非线性系统,采用常规PID控制器很难保证系统在不同工作状态下均取得良好的控制效果.采用模糊参数自适应PID励磁控制器对解决小干扰下的励磁控制问题具有较好的控制效果.当系统工作状态变化较大以及遇到较强的干扰时,系统控制性能将趋于恶化.为解决此问题,提出了同步发电机励磁系统的规则自适应模糊控制方案.主要讨论在模糊集Ai、Bi 的比例因子K1、K2、K3给定的条件下,通过调整 di 的取值来实现控制规则的自适应问题, 该规则自适应机构由两组关于控制规则自生成与自校正的元规则组成.仿真结果表明,所提出的方案正确可行并具有良好的性能.     

云广直流孤岛运行机网控制特性实时仿真平台研发及其应用*

为了研究云广直流孤岛运行的机网控制特性,对送端机组的控制系统进行建模,将送端机组的励磁、调速和监控等控制系统接入RTDS仿真系统以及直流系统的控制保护系统和安稳系统,研发了一个新的云广直流孤岛运行闭环仿真平台。基于该平台对送端机组的调速、励磁控制器的逻辑和参数进行了辨识,进而搭建了调速、励磁系统的RTDS数字控制模型。纯数字控制模型与实际控制器的仿真对比,以及孤岛实时仿真结果与现场试验结果的对比表明,所建立的仿真平台与实际孤岛在响应特性和控制性能上具有很高的一致性。     

Damping control design based on time-domain identified models

This paper presents an integrated approach for designing damping controllers for large power systems. First, a low-order model is identified from a time simulation of the nonlinear power system model. Then an exact multi-modal decomposition is used to develop design indices for selecting on appropriate input signal to the controller. The method is illustrated with the design of thyristor-controlled series compensator damping controllers in two test systems     

参数模糊自整定PID在ZVZCS变换器中的应用研究

由于全桥软开关变换器为强非线性时变系统,工作特性复杂,传统的PID控制器不具有在线自整定功能,控制效果较差,不能满足过程控制日益发展的需求。为了得到良好的控制效果,提出了采用PID参数模糊自整定控制变换器。在变换器数学模型的基础之上设计控制器,通过MATLAB/Simulink对其仿真。仿真结果表明:PID参数模糊自整定控制系统比传统的PID控制器超调量小,调节时间短,控制效果有明显的改观。     

Simultaneously tuning decentralized nonlinear optimal excitation controllers in multimachine power systems

This paper proposes an approach to simultaneously designing multiple decentralized nonlinear optimal excitation controllers to achieve rotor angle stability improvement and good trade-off between voltage regulation and oscillation damping in multimachine power systems. The approach includes: (1) building a novel state-space mathematical model based on nonlinear feedback compensation, (2) properly formulating the control problem and (3) developing a more quick and accurate algorithm to solve the problem. Case studies are fulfilled in a two-area four-machine power system to verify the effectiveness of the approach. Digital simulation results show that the controllers designed with the proposed method gain much priority over traditional AVR/PSS in damping power oscillation, improving voltage regulation and enhancing transfer capability.     

Design of robust coordinated SVC supplementary controllers

A method for designing coordinated H_∞ SVC supplementary controllers is presented to improve the damping of interarea oscillations. A distributed controllers are designed considering overvoltage problem, which is thought to be a critical issue for SVC to design a supplementary damping controller. The proposed method contains a method to obtain dynamic equivalents of a power system model through an uncertainty minimization procedure. This method is aimed for realizing a tight design for distributed controllers so that a better performance of the total system can be gained. In addition, an uncertainty minimization process is used to regulate indirectly the controller's output so that the overvoltage problem is treated in the design step. The locations of SVCs are determined from the voltage stability point of view using bus participation factor. An effective input to damp oscillations is selected based on residue concept. The effectiveness of the proposed control design is demonstrated through nonlinear numerical simulations in five machine eight bus system under several critical operating conditions.     

Damping control of inter-area oscillations in the European power system using aggregated models

In the first part of the paper, a new approach to the reduction of large dynamic network models is presented. This method is implemented in the program package PSD and is used here in an exemplary fashion to reduce the model of the European power system to a model usable for the solution of a number of problems. In the second part, the paper describes a new damping concept of inter-area oscillations in large power systems. Additionally installed second-level damping controllers are acting on the voltage regulator reference inputs of selected generators. They are using global information about the swing profiles of the inter-area oscillations to be damped. The damping controllers are designed as a H_∞-norm optimal decentral control system based on both a topological and a frequency range decomposition of the control task. The solution is demonstrated for the reduced model of the European system. Received: 30 April 2001/Accepted: 8 June 2001     

Bat inspired algorithm based optimal design of model predictive load frequency control

Bat inspired algorithm (BIA) has recently been explored to develop a novel algorithm for distributed optimization and control. In this paper, BIA-based design of model predictive controllers (MPCs) is proposed for load frequency control (LFC) to enhance the damping of oscillations in power systems. The proposed model predictive load frequency controllers are termed as MPLFCs. Two-area hydro-thermal system, equipped with MPLFCs, is considered to accomplish this study. The suggested power system model considers generation rate constraint (GRC) and governor dead band (GDB). Time delays imposed to the power system by governor-turbine, thermodynamic process, and communication channels are accounted for as well. BIA is utilized to search for optimal controller parameters by minimizing a candidate time-domain based objective function. The performance of the proposed controller has been compared to those of the conventional PI controller based on integral square error (ISE) technique and the PI controller optimized by genetic algorithms (GA), in order to demonstrate the superior efficiency of the BIA-based MPLFCs. Simulation results emphasis on the better performance of the proposed MPLFCs compared to conventional and GA-based PI controllers over a wide range of operating conditions and system parameters uncertainties.     

利用多端统一潮流控制器阻尼多模态振荡

研究了多机系统中使用统一潮流控制器(UPFC)抑制电力系统多模态振荡的可行性.首先推导了作为UPFC概念延伸的多端统一潮流控制器(MUPFC)的非线性动态模型和线性化的Phillips-Heffron模型.利用UPFC和MUPFC具有多个控制回路的特点,提出在其多个控制回路上附加多个阻尼控制器来阻尼多模态振荡.通过模态分析,采用可控性指标对系统中的各个弱阻尼模态选取有效的控制回路,并设计了附加阻尼控制器.仿真结果表明,通过该方法确定的在一个UPFC或MUPFC上设置的多个附加阻尼控制器能够成功实现对电力系统多模态振荡的抑制.     

A fuzzy logic-based adaptive damping controller for static VAR compensator

This paper presents an approach for designing a fuzzy logic-based adaptive SVC damping controller for damping low frequency power oscillations. The proposed approach uses linear optimal controllers and, in addition, a fuzzy signal tuner is introduced to achieve adaptiveness. Two linear damping controllers are designed to accommodate two extreme operating conditions and a fuzzy logic mechanism is used to generate one single control signal by properly combining the outputs of the linear controllers. The fuzzy controller is optimized using a least squares error criterion and, as a result, a higher-order adaptive controller is achieved. Simulation studies of the proposed fuzzy adaptive damping controller show that it provides satisfactory damping against low frequency oscillations under different operating conditions. Results are given for a one-machine infinite-bus and a four-machine two-area test system, which show improvement over the use of a fixed parameter controller.     

基于稳定域的阻尼控制器设计及其抑制多频段振荡

首先提出了一种多频段稳定域的方法用于优化设计机侧/网侧多通道附加阻尼控制器。在此基础上,以TC-SC导通角组成的多频段稳定域最大为优化目标建立协调优化模型,并采用遗传算法对其进行求解,得到能最大程度提高系统阻尼的控制器参数。特征值计算和时域仿真表明,经过协调优化的阻尼控制器能有效地抑制包括低频振荡与次同步振荡在内的多频段振荡。     

利用水电机组水压反馈改善电力系统稳定性

通过对水电机组复杂非线性模型的仿真,研究了水轮机调速器控制规律对电力系统稳定性的影响,并提出了采用水压反馈改善电力系统稳定的控制思想。仿真研究结果表明：由于水电机组引水系统的水击效应,原动机的自动调节会恶化系统阻尼,使转子摇摆曲线的衰减速度明显减慢,而引入水压的微分反馈可加快振荡过程的衰减,有效改善电力系统的稳定性。文中所提方法简单,易于在水电机组调速器上实现。