多机电力系统模糊自适应控制

发电机组的励磁控制对于提高电力系统的暂态稳定性起着至关重要的作用。针对多机电力系统励磁控制模型,设计模糊自适应控制器。考虑到电力系统的状态不可测及多变量、非线性等特点,设计状态观测器,而后根据多机电力系统互联的实际情况,运用蚁群算法的寻优功能优化模糊规则,一定程度上改善了多变量系统控制中模糊规则繁多的问题。此方法使系统在保证了良好暂态稳定性的同时,降低了控制器的设计难度。仿真结果表明所设计的控制器能够快速有效地改善系统在大干扰下的暂态稳定性。     

多机电力系统自适应模糊稳定器的协调

本文提出了一种多机系统模糊稳定器的逆调－顺调协调方法。受扰后，对频率偏移振幅大的机组采用逆调；而频率偏移振幅小的采用顺调。所提的自适应模糊稳定器使调节方式随着频率偏移振幅的变化而变化。仿真试验证明了所提方法的有效性。     

模糊自适应控制在电力系统中的应用初探

本文就模糊自适应控制在电力系统中的应用作了一些初探，并在此基础上采用了部分解耦控制，从而能实现有功，无功分别调节。对以上的研究，作者作了数字机模拟，其结果与设想基本吻合，并且证明了系统的抗干扰能力有所提高。     

多机电力系统间接自适应模糊分散 H∞ 控制研究

针对多机电力系统励磁控制模型,考虑到系统的多变量、强耦合非线性等特性,提出了基于模糊逼近的间接自适应模糊分散H∞跟踪控制方案。该方案通过构建模糊自适应系统来逼近未知函数,然后设计H∞补偿器来抵消外部扰动和模糊逼近误差,从而实现了对多机电力系统的稳定性控制并且具有H∞性能。仿真结果表明,当多机电力系统发生三相可恢复故障和三相不可恢复故障时,发电机的转子运行角趋于某一固定值,相对转速和跟踪误差都趋于零。所提方案与电力系统稳定器(PSS)方案对比可知,PSS方案虽然能使系统稳定,但是其超调量大、过渡时间长,而所提方案不仅可以使系统在故障之后迅速稳定,而且超调量更小。     

多机电力系统模糊稳定器的协调

本文提出一种新的控制方法，解决了多机电力系统模糊稳定器之间的协调问题，该法由逆调、顺调组成、对受扰后频率偏移振幅大的机组采用逆调，而频率偏移振幅小的采用顺调。仿真计算证明了所提方法的有效性。     

多机电力系统参数自适应控制的设计理论与方法

针对一般形式的多输入多输出（MIMO）非线性微分代数系统的跟踪和系统参数的不确定性，利用M导数和M括号及其MIMO反馈线性化技术，在当系统的M关系度小于系统的阶数及其满足某些指定的条件下，得到微分代数系统模型的标准形式。根据线性系统控制理论及其跟踪目标的要求，给出了一般非线性控制规律的表达式。考虑到实际系统中的参数不确定性或未知性，难以预先构造非线性反馈控制规律来保证整个系统的稳定性，对于微分代数系统中存在参数不确定时，运用Lyapunov稳定性理论方法，采用适当的参数自适应方法来估计未知的不确定的参数值并加以修正，很好地实现了系统跟踪的控制目的。     

多机电力系统参数自适应控制设计的模型与应用

针对具有非线性负荷的多机电力系统（MMEPS）励磁控制的跟踪和系统参数的不确定，采用非线性分代数系统（DNAS）的反馈线性化技术，得到相应的以电磁功率作为输入量的标准化控制方程，并给出相应的非线性控制规律的表达式，提出了参数自适应控制方程，并得到相应的非线性控制器的表达式，实现了具有非线性负荷的MMEPS的目标跟踪及其稳定性。     

基于ESO-backstepping的多机电力系统非线性鲁棒励磁解耦控制

通过构造扩张状态观测器(extended state observer,ESO)对发电机励磁系统模型误差和不确定外扰进行动态补偿,并运用反步法对补偿后的模型设计非线性解耦控制律。由于该方法对系统模型的非线性部分有选择地利用ESO进行动态补偿,既避免了运用反步法设计时自适应参数的引入,又能充分利用系统的特性,减轻ESO的估计负担,有效地兼顾了控制器鲁棒性及控制精度这两方面的要求。仿真表明：该方法鲁棒性强,参数易于选取,与比例–积分–微分(proportion-integration- differentiation,PID)+电力系统稳定(power system stabilizer,PSS)控制器励磁控制器相比较,具有更为优秀的动态品质,方法简单有效。     

模糊逻辑稳定器在多机电力系统环境下的应用

本文述了多机环境下基于模糊的电力系统稳定器应用。     

基于观测器的仿射型多机耦合电力系统H∞模糊跟踪控制

模型未知的仿射型多机耦合电力系统用一系列T-S模糊模型逼近,且模糊模型的结论部分具有常数偏差项.由于系统状态具有不可测性,采用模糊观测器来估计系统的状态.基于该系列模糊模型和观测器,考虑仿射模型固有的常数项偏差,提出一种新型模糊跟踪控制方法,并用线性矩阵不等式的凸优化方法求解控制器参数,实现了仿射型多机耦合电力系统的稳定跟踪控制.仿真验证了方案的有效性.     

多机电力系统无源化反步控制研究

随着国内外电力工业改革和互联电网的发展,电力系统的安全性、可靠性、稳定性、经济性就显得尤为重要。研究表明,发电机组的励磁控制对于提高电力系统的暂态稳定性起着至关重要的作用,本文针对多机电力系统励磁控制模型,考虑到系统的多变量、强耦合、非线性等特性,设计使系统渐近稳定的无源化控制器。无源性和稳定性是密切相关的,系统无源可以保持其内部稳定。该方案物理意义明确,能有效简化控制器的结构,提高系统鲁棒性。对三相可恢复故障和三相永久性故障的仿真结果表明了所设计的控制器的有效性。     

An adaptive neuro-control approach for multi-machine power systems

We investigate an adaptive neuro-control approach, namely goal representation heuristic dynamic programming (GrHDP), and study the nonlinear optimal control on the multi-machine power system. Compared with the conventional control approaches, the proposed controller conducts the adaptive learning control and assumes unknown of the power system mathematic model. Besides, the proposed design can provide an adaptive reward signal that guides the power system dynamic performance over time. In this paper, we integrate the novel neuro-controller into the multi-machine power system and provide adaptive supplementary control signals. For fair comparative studies, we include the control performance with the conventional heuristic dynamic programming (HDP) approach under the same conditions. The damping performances with and without the conventional power system stabilizer (PSS) are also presented for comparison. Simulation results verify that the investigated neuro-controller can achieve improved performance in terms of the transient stability and robustness under different fault conditions.     

Decentralized nonlinear coordinated excitation and steam valve adaptive control for multi-machine power systems

In this paper, a decentralized nonlinear coordinated excitation and steam valve adaptive control combined with a modified high-order sliding mode differentiator is designed for multi-machine power system stability enhancement. The proposed control scheme is based on Lyapunov’s direct method and requires only local information on the physically available measurements of relative angular speed, active electric power and terminal voltage with the assumption that the power angle and mechanical power input are not available for measurement. Each synchronous generator is considered as a classical fifth order model that includes turbine dynamics. The simplicity of the proposed scheme and its robustness with respect to large perturbations, change in operating point and parameter uncertainties constitute the main positive features. Simulation results in the case of the Kundur 4-machines 2-area power system show the effectiveness, robustness and superiority of the proposed scheme over the classical AVR/PSS.     

Rule-based stabilizer for multi-machine power system

An application of the rule-based stabilizing control scheme to improve the overall stability of electric power systems is presented. Several simple rules are prepared for each generator in the system. The stabilizing signal for each generator is of the discrete type; it is renewed at every sampling time to control the generator excitation levels depending on the speed/acceleration state of the generator, using the measured speed deviation and the control rules. The efficiency of the proposed rule-based stabilizer is demonstrated by using a sample three-machine power system     

A new-fangled adaptive mutation breeder genetic optimization of global multi-machine power system stabilizer

This paper presents the design and implementation of Power System Stabilizers in a multimachine power system based on innovative evolutionary algorithm overtly as Breeder Genetic Algorithm with Adaptive Mutation. For the analysis purpose a Conventional Power System Stabilizer was also designed and implemented in the same system. Simulation results on multimachine systems subjected to small perturbation and three phase fault radiates the effectiveness and robustness of the proposed Power System Stabilizers over a wide range of operating conditions and system configurations. The results have shown that Adaptive Mutation Breeder Genetic Algorithms are well suited for optimal tuning of Power System Stabilizers and they work better than conventional Genetic Algorithm, since they have been designed to work on continuous domain. This proposed Power System Stabilizer is demonstrated through a weakly connected three multi-machine test systems.     

电力系统机电暂态仿真多机控制系统诊断分析

为了提高电力系统机电暂态控制能力,提出了以主导轨迹断面阻尼比灵敏度条件来分析仿真关键参数的方案,从而将轨迹特征根处理思想引入工程分析中。系统通过二个典型模式发生振荡,仿真测试后以Prony方法处理发电机的功角曲线生成振荡变化的特征量组,判断模式二属于主导仿真模式。通过时段主导模式得到的轨迹断面阻尼比灵敏度更高。在相同的模式下,当参与因子提高后,机组控制系统可以形成更高的轨迹断面阻尼比灵敏度。对于复杂多机系统,可以利用轨迹断面阻尼比灵敏度来诊断控制系统的各项参数,从而更高效地处理复杂振荡模式并降低计算量。经过3.5 s仿真后,考虑到Dy比规定门槛值更大,机组励磁控制系统具有增幅振荡的特性。当T_A上升后能够达到更高的稳定性,参数T_A提高形成了更平稳的励磁电流与功角曲线。     

An adaptive controller for power system load-frequency control

An adaptive controller is presented for load-frequency control of power systems. It uses a PI (proportional-integral) adaptation to satisfy the hyperstability condition for taking care of the parameter changes of the system. Only the available information on the states and output are required for the control. No explicit parameter identification is needed. The controller can be designed by using a reduced plant model to simplify the design without degrading the performance much, so it is very easy to implement practically. The simulation results indicate that good control performance can be obtained and that the performance is sensitive to the plant parameter changes. The control remains effective in the presence of generation rate constraints     

多机系统发电机时滞反馈励磁与STATCOM的非线性鲁棒协调控制

广域反馈信号的时滞性使得包含广域信号的电力系统变成时滞动力系统。利用Pade近似逼近时滞环节,将时滞影响隐含在系统动态方程的系数中,静止同步补偿器(STATCOM)的动态特性用一阶微分方程形式的可控无功电流源表示,推导了含多台STATCOM的多机系统的电磁功率表达式。基于伪广义Hamilton系统理论,将包含STATCOM和时滞反馈励磁的多机系统表示成伪广义耗散Hamilton系统形式。利用L2干扰抑制控制方法得到考虑广域信号时滞性及转移电导的发电机励磁和STATCOM的协调控制策略。4机2区域系统的仿真结果表明,与传统的分散控制器相比,所提考虑时滞影响的非线性鲁棒协调控制器能够有效地抑制系统振荡,且具有一定的时滞不敏感性。