Nonlinear control design for excitation controller and power system stabilizer

The paper focuses on the design of excitation controller and power system stabilizer (PSS) control schemes to enhance voltage regulation and transient stability. To design the excitation controller, the nonlinear models of the synchronous generator and electrical system are suitably arranged to give an input-output nonlinear model, which is subsequently made linear by a compensating law. The PSS control scheme is designed according to a new approach, based on the inverse system theory, which guarantees satisfactory swing damping by reducing the mutual influence between transient stability and voltage regulation. The results obtained by numerical simulations in different operating conditions confirm the effectiveness of the proposed design, also in the presence of model parameter inaccuracy.     

基于PSB的迭代学习励磁控制的仿真研究

基于迭代学习控制理论提出了一种非线性迭代学习律,并将它应用于同步发电机的励磁控制中,采用SIMULINK／PSB软件对单机-无穷大系统进行仿真,结果表明该方法的有效性和一般性,改善了控制性能、具有很强的维持机端电压的能力,与常规的PID控制器和线性迭代学习律相比较,收敛速度得到很大提高,有利于提高电力系统稳定性。     

虚拟同步发电机参数自适应调节

虚拟同步发电机技术借由控制器设计达到模拟同步发电机外特性的效果, 改善了含有新能源的电网系统 的稳定性. 根据虚拟同步发电机参数可调的特点, 可采用参数自适应调节优化系统动态性能. 但传统虚拟同步发电 机参数自适应调节仍存在两方面不足: 一方面, 大范围调整阻尼下垂系数和虚拟转动惯量, 对系统储能裕量要求高; 另一方面, 暂态调节过程中存在功率超调现象, 对电力设备不利. 本文引入输出速度反馈调节系统阻尼, 为改善系 统暂态稳定性提供了方便的调节手段; 其次, 根据系统暂态功角特性, 提出了参数自适应控制策略, 缩短了调节时 间, 将频率偏差减小至允许范围内, 改善了电网频率调节的暂态性能, 同时抑制了功率超调. 最后, 对比实验结果表 明本文控制策略优于现有的自适应控制策略.     

基于交流跟踪的同步发电机最优励磁控制技术研究

针对同步发电机采用传统PID控制不能很好地满足电力系统对抑制振荡、提高动态稳定极限等方面要求的问题,提出了一种基于交流跟踪的同步发电机最优励磁控制方法;给出了基于拉格朗日方法的同步发电机励磁系统偏差线性化模型,分析了最优励磁控制量的确定方法,建立了基于最优励磁控制方法的同步发电机系统仿真模型。仿真结果表明,与传统PID控制方法相比,最优励磁控制方法能够实时控制同步发电机励磁系统,确保了同步发电机的输出稳定性。     

静止无功补偿器的自适应逆推无源反馈控制设计

通过将耗散系统理论和自适应逆推(adaptive backstepping)非线性控制算法相结合, 克服了无源反馈方法只能为输入输出相对阶为1的系统设计控制律的限制, 为带有静止无功补偿器的单机无穷大电力系统设计了鲁棒自适应控制器. 设计中兼顾了系统遭受不确定扰动以及阻尼系数难以精确测量情况下控制器的鲁棒性和自适应能力. 理论分析证明所提算法可保证系统内所有状态变量一致有界且渐近稳定, 系统误差全局渐近稳定. 仿真结果也表明, 所提算法使系统母线电压, 发电机功角以及转子角速度的暂态响应性能优于传统逆推算法, 系统误差迅速收敛至零, 与理论证明结果一致.     

同步发电机非线性励磁控制的逆系统方法

本利用非线性控制的逆系统方法，将大型同步发电机非线性励磁控制问题变换为一个相应的线性最优控制问题，设计出便于实现的非线性励磁控制规律。经仿真研究表明，所设计的控制律显地改善了电力系统暂态过程的动态响应，较大提高了静态稳定极限，有效地提高了电力系统的暂态稳定水平。     

基于先进复合控制算法的同步发电机励磁分布式微机控制系统设计

设计一种新型同步发电机励磁系统,除了采用串联型PID控制算法外,还辅助以PSS、LOEC、NOEC控制算法分别用于改善电力系统小干扰稳定性、抑制各种频率的低频振荡和系统暂态稳定、静态稳定并抑制电力系统功率振荡。给出了系统硬件框图、算法和主程序流程图,并对系统运行过程进行了阐述。     

A power system nonlinear adaptive decentralized controller design

In this paper, a novel excitation control is designed for improvement of transient stability of power systems. The control algorithm is based on the adaptive backstepping method in a recursive way without linearizing the system model. Lyapunov function method is applied in designing the controller to ensure the convergence of the power angle, relative speed of the generator and the active electrical power delivered by the generator when a large fault occurs. Compared with the existing nonlinear decentralized control approaches, the proposed controller has no requirement for the bounds of interconnections in the power system. And the new approach does not need the existence of solution of a designed algebraic Riccati equation. Furthermore, the transient stability performance of power systems can also be improved by the designed control approach. The efficacy of the designed controller has been demonstrated in a multimachine power system. Simulation results show transient stability enhancement of a power system in the face of a large sudden fault.     

柴油发电机组状态反馈H2/H∞调压器的研究

独立电力系统电压的稳定性主要取决于柴油发电机组的电压响应特性.同步发电机调压系统是一个非线性控制系统,为了分析系统的动态特性,首先建立同步发电机调压系统的非线性数学模型,然后以此为基础设计状态反馈H2/H∞调压器.将H2/H∞控制理论应用于柴油发电机组调压器的设计,把系统性能要求转化为标准H2/H∞控制问题,获得了柴油...     

Robust transient stabilisation problem for a synchronous generator in a power network

The robust transient stabilisation problem (with stability proof) of a synchronous generator in an uncertain power network with transfer conductances is rigorously formulated and solved. The generator angular speed and electrical power are required to be kept close, when mechanical and electrical perturbations occur, to the synchronous speed and mechanical input power, respectively, while the generator terminal voltage is to be regulated, when perturbations are removed, to its pre-fault reference constant value. A robust adaptive nonlinear feedback control algorithm is designed on the basis of a third-order model of the synchronous machine: only two system parameters (synchronous machine damping and inertia constants) along with upper and lower bounds on the remaining uncertain ones are supposed to be known. The conditions to be satisfied by the remote network dynamics for guaranteeing ?₂ and ?_∞ robustness and asymptotic relative speed and voltage regulation to zero are weaker than those required by the single machine-infinite bus approximation: dynamic interactions between the local deviations of the generator states from the corresponding equilibrium values and the remote generators states are allowed.     

电力系统非线性切换励磁控制

针对反馈线性化方法难以同时提高电力系统的功角稳定性和电压调节特性的问题,提出了基于分层设计思想的非线性切换励磁控制方法.首先采用逆系统方法实现了系统的反馈线性化,然后根据Lyapunov函数方法对包含零动态的部分线性化系统设计了切换励磁控制器.在电力系统专用仿真平台上的仿真结果证明了所设计的切换控制器能够有效改善功角稳...     

计及螺旋桨负载的船舶电力系统协调控制设计

推进负载对船舶电网的暂态稳定性影响是船电系统的主要特征之一.本文基于非线性鲁棒L2干扰抑制控制方法,研究了具有螺旋桨负荷的船舶电力系统中的励磁与调速的协调控制问题,在充分分析了柴油发电机组的非线性数学模型及其螺旋桨负载的相互耦合的非线性动态结构特性的基础上,提出backstepping控制技术与L2干扰抑制相结合的综合协调控制策略来设计控制器.该控制器在保证系统稳定的条件下,有效地抑制干扰对发电机系统电压和频率的影响.仿真表明,在给系统突加螺旋桨负载的情况下,该控制器能有效地抑制负载对系统性能的影响,验证了控制器的有效性.     

基于哈密顿能量理论的发电机励磁与ASVG协调控制

针对含有先进静止无功发生器(ASVG)的单机无穷大系统,建立了4阶非线性状态空间数学模型.基于Hamilton能量函数理论,设计了ASVG安装点电压与发电机励磁的新型非线性协调控制器.数字仿真结果表明,在系统遭受到较大干扰的情况下,所设计的控制器可同时满足发电机励磁与ASVG装设处电压的暂态稳定性要求.     

同步发电机励磁非线性预测控制技术

以功角、有功功率、角速度这些可测量作为反馈量,基于非线性预测控制理论,设计出具有闭合解析形式控制律的励磁控制器．该控制器的设计参数只有滚动预测时间T和控制阶r,便于工程实现和调试．仿真结果表明,该控制器能使系统提高稳定性,具有良好的动态品质,较好地维持了发电机机端电压的静态调节精度．     

Development of a Fuzzy Rule-Based Multi-Objective Hybrid Controller for Static Synchronous Compensator

Static synchronous compensator (Statcom) is a powerful new device for power systems, which can be used for various purposes. The multi-objective demands are quite different in nature, e.g. continuous linear control for voltage maintaining, and discrete bang-bang control for oscillation damping. Unfortunately, they often conflict with each other. In this respect, a supplementary damping control together with an independent voltage control is normally used. However, inevitable small disturbance and uncertainties will cause problems in the coordination of the two functions. To overcome such difficulties, a fuzzy rule-based hybrid controller is proposed in this paper, which incorporates conventional linear voltage control along with the fuzzy rule-based supplementary power damping control to form a unified global controller for Statcom. Because only simple fuzzy rules and a few input signals are involved, it is very easy to implement in a practical power system. The simulation performed on a Single- Machine-Infinite-Bus (SMIB) power system and an actual large power system demonstrates the effectiveness of the proposed approach.     

具有同步发电机特性的储能型光伏并网发电系统研究

基于虚拟同步发电机(virtual synchronous generator,VSG)控制的并网逆变器可以对电网的频率和电压起到一定的支撑作用.但是,仅由光伏供电的逆变器难以模拟同步发电机的特性.本文提出一种具有同步发电机特性的储能型光伏并网发电系统,并给出了相应的VSG控制策略、DC–DC控制策略以及协调控制方法;建立了系统的小信号模型,分析了参数取值对动态性能和稳定性的影响.仿真结果不但表明该系统具有同步发电机特性,可实现光伏阵列的最大功率跟踪(maximum power point tracking,MPPT)和储能的充放电控制;而且验证了理论分析的正确性.     

基于Hamilton函数方法的船舶发电机组综合协调控制

推进负载对船舶电网的暂态稳定性影响是船电系统的主要特征之一,船舶电力系统的稳定性研究也因此比陆上电力系统更具有挑战性.本文基于Hamilton能量理论控制方法,研究了具有螺旋桨推进负载的船舶电力系统的励磁与调速的综合协调控制问题.在充分分析了柴油发电机组及其螺旋桨负载的非线性耦合模型的结构基础上,通过构造Hamilton能量函数,给出保持系统稳定的综合协调控制律.特别地,不同于已有的结果,该控制律清晰地给出了螺旋桨转速对控制器性能影响的函数关系.仿真表明,在分别给系统突加螺旋桨负载的情况下,该控制器能有效地抑制负载对系统性能的影响,验证了控制器的鲁棒性.     

A new adaptive backstepping method for nonlinear control of turbine main steam valve

A new approach for nonlinear adaptive control of turbine main steam valve is developed. In comparison with the existing controller based on ＂classical＂ adaptive backstepping, this method does not follow the classical certaintyequivalence principle in the design of adaptive control law. We introduce this approach, for the first time, to power systems and present a novel parameter estimator and dynamic feedback controller for a single machine infinite bus （SMIB） system with steam valve control. This system contains unknown parameters such as reactance of transmission lines. Besides preserving useful nonlinearities and the real-time estimation of uncertain parameters, the proposed approach possesses better performances with respect to the response of the system and the speed of adaptation. The simulation results demonstrate that the proposed approach is better than the design based on ＂classical＂ adaptive backstepping in terms of properties of stability and parameter estimation, and recovers the performance of the ＂full-information＂ controller. Hence, the proposed method provides an alternative for engineers in applications.     

TCSC控制的一种新自适应Backstepping方法

针对带有TCSC（Thyristor Controlled Series Compensator）的单机无穷大电力系统,提出一种新的TCSC自适应非线性控制Backstepping方法．该方法不仅保留了系统的非线性特性和对未知参数的实时在线估计,而且突破了经典的确定性等价性原理来设计参数估计器和动态反馈控制器．仿真结果表明,与基于传统自适应Backstepping得到的控制设计相比较,这种新方法在系统响应和自适应速度方面具有更优越的性能,从而为工程应用提供了一种有效的选择．     

基于混合调制的同步发电机交流励磁电源研究

同步发电机交流励磁技术可提高发电机的进相能力,是无功补偿最有效的方法之一。文章提出了一种基于混合调制的同步发电机交流励磁电源的设计方案,分析了同步发电机交流励磁系统的组成及工作原理,介绍了混合调制方式的控制原理,并给出了该励磁电源控制电路关键参数的选择和计算方法。实验结果验证了该方案的正确性和有效性。