基于Hamilton能量整形的多机电力系统励磁控制

基于广义Hamilton理论,提出将非线性微分-代数系统表示为一种改进的Hamilton系统的实现方法.通过重构结构矩阵,对所提系统的Hamilton函数进行能量整形,给出了镇定控制器的设计方法.以此为基础,研究了结构保留多机电力系统的Hamilton实现问题,运用能量整形方法,提出了可作为系统Lyapunov函数的H...     

基于Hamilton系统理论的结构保持多机电力系统非线性励磁控制

基于广义Hamilton系统理论,提出了将非线性微分-代数系统表示为广义耗散Hamilton系统的实现方法,并证明可通过适当的控制策略镇定该动态系统.文中应用Hamilton实现方法进行了结构保持多机电力系统的非线性励磁控制器的设计,仿真结果验证了文中所提出方法的正确性和控制策略的有效性.     

多机电力系统励磁控制的人工神经网络逆系统方法

基于各发电机的完整的实用三阶模型，通过将发电机内部的不可测变量转化为发电机端的可测变量，在未做任何近似或简化的情况下，实现了仅采用本地可测量的多机系统中各发电机励磁控制的精确线性化。在具体的励磁控制器设计中，选取机端电压作为被控量再附加电力系统稳定器(PSS)环节进行辅助控制，使得同时满足系统对电压稳定性和功角稳定性的控制要求；采用人工神经网络(ANN)逆系统方法实现精确线性化，避免了对系统精确数学模型的依赖，使文中方法更实用。针对一个2区域4机系统的仿真结果表明，安装ANN逆励磁控制器可以极大地提高被控机组的稳定性能，同时，全系统的稳定性也可以得到明显的提高。     

电力系统的多机分散变结构励磁控制

本文提出一种非线性变结构励磁控制器,它结合了非线性微分几何方法及变结构控制理论的优点。     

基于Hamilton理论的广域非线性时滞多机电力系统的稳定与控制

针对非线性时滞多机电力系统,将局域信号与远程信号都纳入控制器设计中,根据全局条件下信号时滞的差异性,建立广域时滞非线性多机电力系统的端口可控Hamilton (PCH)模型。该模型以汽门开度为控制量,考虑了扰动给系统带来的影响。以此模型为基础,针对某个形式的H函数给出了含有该H函数作为部分能量函数的Lyapunov泛函及一系列相应的稳定条件。通过“能量整形”技术,将一般电力系统的PCH模型转化为具有特定形式H函数的PCH模型,并应用给出的稳定条件设计相应的全状态反馈控制。最后以3机9节点系统为例,以时域仿真的结果验证了扰动下非线性时滞控制器的有效性。     

多机电力系统神经网络最优励磁控制器

针对多机电力系统，提出了一种基于辨识的神经网络实时最优控制器(NNOEC)，在所设计的控制器中，神经网络被用来根据系统状态量的变化实时调整最优控制的反馈增益矩阵，使控制器能够适应不同的运行点和干扰种类。并始终提供最优控制输出。针对多机系统中神经网络训练样本不易获得的问题，提出了一种等效的设计方法，并采用非线性最小二乘辨识法对系统参数进行辨识，在辨识的基础上通过线性最优控制理论计算出用于神经网络训练的样本。三机系统中的数字仿真结果表明，所训练出的NNOEC能够适应系统运行方式的大范围变化，在大小扰动下均表现出良好的控制性能。     

多机电力系统非线性励磁控制的研究

本文根据励磁稳定控制中的非线性问题,应用微分几何控制理论,提出了多机电力系统发电机励磁非线性反馈解耦控制器的设计方法及相应的闭环非线性解析励磁控制规律。通过对六机系统的仿真结果表明,所设计的控制方式不仅可以有效地改善多机系统的动态响应,而且可以显著地提高多机系统的暂态稳定极限。与其它励磁控制方式相比,具有明显的优越性。     

基于Hamilton理论的电力系统Lyapunov函数的研究

利用广义Hamilton理论对电力系统镇定性进行了分析,得到了一个关于系统镇定性的方法,在该方法的基础上,利用一种能量-Casimir函数方法求得扩展函数表达式,并利用Lyapunov稳定定理对该函数进行了判定。利用Lyapunov理论证明了所求的扩展函数是系统的Lyapunov函数。     

基于Hamilton能量函数含TCSC的电力系统非线性控制

采用Hamilton能量函数理论设计非线性控制器的方法,设计了晶闸管控制的可控串联补偿电容器非线性控制器,并以单机无穷大系统为例进行了仿真试验.仿真结果表明,所提出的控制方法可以提高系统的暂态稳定性,并能较好地适应系统运行方式的变化.     

多机电力系统中发电机励磁控制设计的数学模型分析

在N机电力系统的原始动力学模型基础上得出一个新的励磁控制设计的数学模型,它克服了以往设计模型的不足之处,体现了发电机的双轴动态特性。仅包含代数运算可分散实现的非线性反馈补偿规律保证了控制器本身的稳定性,真实完整地反映了各机组间的相互耦合作用,从而使模型适用于大型组合电力系统中励磁控制设计的需要。     

Robust excitation control of multi-machine multi-load power systems using Hamiltonian function method

Using an energy-based Hamiltonian function method, this paper investigates the robust excitation control of multi-machine multi-load power systems described by a set of uncertain differential algebraic equations. First, we complete the dissipative Hamiltonian realization of the power system and adjust its operating point by the means of pre-feedback control. Then, based on the obtained Hamiltonian realization, we discuss the robust excitation control of the power system and put forward an H _∞ excitation control strategy. Simulation results demonstrate the effectiveness of the control scheme.     

Transient stabilization of structure preserving power systems with excitation control via energy-shaping

In this paper, the transient stability of multimachine power systems based on structure preserving model (SPM) is considered. The interconnection and damping assignment passivity-based control (IDA-PBC) methodology is extended to solve the excitation regulation problem of SPM represented by a set of differential-algebraic equations. By shaping the total energy function via the introduction of a virtual coupling between the electrical and the mechanical dynamics of the power system, a decentralized excitation control law is proposed to ensure the asymptotic stability of the closed-loop system. The controller is proved to be effective in damping the oscillations and enhancing the system stability by the results of simulation research.     

Robust control of multi-machine power systems with compensation of disturbances

The paper is devoted to the robust control with compensation of disturbances for power systems under parametric uncertainties. It is shown that problem can be solved when only relative speed of each generator is available for measurement. The proposed control algorithm synchronizes the power system with the required accuracy in the normal mode and under symmetrical 3-phase short circuit faults which occur on transmission lines. Efficiency of the proposed scheme is illustrated by modeling of a power systems consisting of three and fifty generators.     

Excitation control for multimachine power systems

The control of power systems on the basis of energy analysis offers many advantages. An essential condition to achieve this control is the measurement of the angles of the major generator groups, which are available using satellite Global Positioning Systems.This paper develop two strategies based on energy function higher order derivatives to design nonlinear excitation controllers for multimachine power systems taking into consideration field flux decay effects.The design is based on maximum reduction of energy and can be successfully implemented with as many controllers as major modes, when few controllers are available control on the basis of energy function higher order derivatives produce good results.The first strategy is based on energy function higher order derivatives design where one controller is required to control one mode of oscillation.The second strategy capable of suppressing the oscillation modes with only one controller is based on a linear optimal control design where a linear quadratic regulator (LQR) control component added to energy function higher order derivatives design.     

Multi-scale simulation of multi-machine power systems

The proposed method enables the modeling and integration of synchronous machinery models in accurate and efficient simulation of power systems over diverse time scales that cover electromagnetic and electromechanical transients. The underlying models make use of frequency-adaptive simulation of transients (FAST) where analytic signals are used since they lend themselves to the shifting of the Fourier spectra. The shift frequency appears as a simulation parameter in addition to the time step size. When setting the shift to the common carrier frequency of either 50 or 60 Hz, the method emulates phasor-based simulation that is very suitable for extracting envelope information at relatively large time step sizes. At zero shifting, instantaneous values are being tracked. It is shown how this shifting plays a critical role in integrating synchronous machine models that are represented using the Park transformation with the network model. In a further step, it is illustrated how the modeling approach is modified if the Park transformation is not applied. For illustrative purposes, the integration is first validated for a single-machine-infinite-bus system. In a following multi-machine test case involving four machines in two areas, the added value of the proposed methodology becomes clear as both electromagnetic transients and electromechanical transients are emulated accurately and efficiently within one simulation run.     

基于观测解耦状态空间的多机励磁非线性分散最优控制策略

为进一步改善多机系统的暂态稳定性,结合直接反馈线性化原理和最优控制理论推导出多机系统中励磁的分散控制规律。该控制策略是根据多机电力系统观测解耦状态空间得出,只需要当地信号实施控制,驱动子系统到达局部平衡点,就能使全系统达到稳定。仿真结果表明,该控制规律能够较好地提高多机电力系统的暂态稳定性。     

基于观测解耦状态空间的多机励磁非线性分散最优控制策略

为进一步改善多机系统的暂态稳定性,结合直接反馈线性化原理和最优控制理论推导出多机系统中励磁的分散控制规律.该控制策略是根据多机电力系统观测解耦状态空间得出,只需要当地信号实施控制, 驱动子系统到达局部平衡点,就能使全系统达到稳定.仿真结果表明,该控制规律能够较好地提高多机电力系统的暂态稳定性.     

Two-level optimal stabilization in multi-machine power systems

The control signals needed for the optimal stabilization of an interconnected multi-machine system are obtained using a two-level control strategy. At the lower level, local control signals are derived assuming no interaction between different machines. Then a global control signal is generated at a higher level to minimize the effect of interactions.Computer simulation of a real power system shows that the stability of the system may be enhanced substantially by adopting the two-level scheme. Response of the system with an integrated control scheme is included for comparative analysis.     

多机系统多变量励磁控制下的阻尼守恒、阻尼竞争与阻尼协调

本文从多机电力系统总阻尼的概念出发,证明了多变量励磁控制并不增加电力系统总阻尼.在AVR的基础上附加转速、功角、功率,乃至于附加远方机组任意信号的复杂多变量励磁控制方式下,电力系统总阻尼保持守恒,其数值与单纯AVR控制时相等.由于电力系统所有模式阻尼之和为常数,所以在试图增加某一模式阻尼时必然导致削弱其他模式的阻尼.这是设计多变量励磁规律时的阻尼竞争现象.附加励磁控制的实质仅仅是在各模式阻尼相互竞争、彼此消长中寻求协调与平衡.当系统满足阻尼守恒条件时,给所有模式增加阻尼的企图是不可实现的.