用于静止无功补偿器的变结构控制器的设计

本文提出了能同时改善电力系统功角稳定和装设点电压动态特性的用于静止无功补偿器的变结构控制器设计方法。控制器对系统工作点的变化具有鲁棒性。     

静止无功补偿的一种有效控制方法

提出一种用于稳定供电电压的静止无功补偿的有效控制方法。该方法在计算机内存中以表格形式建立ΔＱ＝ｆ曲线，根据电压偏移量查表控制静补装置的无功功率输出，并在无功调节过程中动态修改曲线，使之趋近真实情况。仿真结果和动模实验验证了其可行性和有效性。     

A method for closed-loop identification of Nyquist curve in three quadrants

This paper proposes a generalization of Ziegler–Nichols' (ZN) experiment that allows the closed-loop identification of Nyquist curve of a linear plant in three quadrants. As in the standard ZN method, no extra equipment is needed. Moreover, sustained undamped oscillations in the plant are not required, since the identification may be accomplished with damped oscillations only. The plant may even be unstable, assuming the used controller is able to stabilize the plant.     

江苏电网无功电压现状分析

首先简要介绍了江苏电网无功电压的基本情况,接着针对2003年江苏电网的情况进行了无功平衡分析,指出目前无功电压存在的问题,并提出了相应的解决措施和建议,最后,对江苏电网无功电压的运行与控制进行了展望。     

Transmission capacity of longitudinal power systems and SVC voltage control

Power transfer between systems is important due to uneven distribution of generating plants. This paper investigates the relation between the transfer capacity of a longitudinal power system and voltage control of static var compensators. The transfer capacity is basically limited by the thermal capacity of transmission lines. However, the practical systems, it is much restricted by stability and the power transfer level is considerably lower than the thermal capacity. In this paper, we consider a basic case in which SVCs are applied to all buses except generator terminals. In this case, it is possible to transfer power up to the reciprocal of the transmission reactance. Two modifications are then applied to the basic case. One is removal of SVCs on the high-voltage sides of the generator transformers. In this case, generator damping torques deteriorate, and the local oscillation mode becomes unstable. The other is removal of SVCs at intermediate buses on the trunk system. In this case, the shapes of the oscillation modes change greatly, and the global mode becomes unstable. The voltage control of SVCs maintains the generator damping torques and prevents deformation of mode shapes. By investigating different system sizes and transmission circuits, we show that the system transfer capacity is determined by the capacities of the individual transmission lines. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 119(3): 49–60, 1997     

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。     

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.     

静止无功补偿器(SVC)的一种新型非线性鲁棒自适应控制设计方法

为提高提高多机电力系统的暂态稳定性,该文首先建立了静止无功补偿器(static var compensator,SVC)系统的一个含有时变参数不确定性的二阶非线性动态模型,然后在SVC动态模型的基础上,利用自适应控制技术和鲁棒控制技术设计了SVC系统的控制器。为了验证所设计的控制器的有效性,以一个经典的三机九母线电力系统作为测试系统,对鲁棒自适应SVC控制器与PID SVC控制器和反馈线性化SVC控制器分别进行了比较研究。仿真结果表明,与PID SVC控制器和反馈线性化SVC控制器相比,所提出的鲁棒自适应SVC控制器具有良好的性能。     

基于广域测量信号的双馈风电机组阻尼控制策略

为了抑制电力系统的区域间低频振荡,本文提出了一种应用于双馈风电机组(DFIG)的附加阻尼控制策略。首先,建立了双馈风电机组的动态模型及其控制策略。然后阐明了动态有功功率注入和动态无功功率注入提高系统阻尼的原理,在此原理的基础上提出了双馈风电机组附加阻尼控制器的设计方法。阻尼控制器基于电力系统稳定器(PSS),将广域测量信号区域间同步机组电压相角差作为输入信号。考虑到DFIG有功功率和无功功率可解耦控制,控制器输出信号附加到DFIG有功功率控制环和无功功率控制环。最后,建立了四机两区域电力系统仿真模型,通过特征值分析和时域仿真分析验证了附加阻尼控制策略的有效性及动态功率注入提高系统阻尼原理的正确性。     

扩展二级电压的多Agent协调控制

基于多Agent系统的分布式协调机制,研究了发生事故的紧急情况下综合考虑多种类型电压控制器(AVR,SVC,STATCOM)的扩展二级电压协调控制。在应用一种慢相关技术将电力系统划分为多个电压控制区的基础上,提出了多Agent间进行任务协助请求时的选择原则,确定了Agent间的协调机制。以装设2台SVC,2台STATCOM和10台发电机AVR的新英格兰系统为例进行数字仿真,结果验证了该控制方案的有效性和灵活性。     

基于进化策略的多机系统PSS参数优化

该文提出了一种基于进化策略的多机系统PSS参数优化的新方法。在这种方法中，目标函数设定为度量所有机电振荡模态性能的函数，将PSS的参数优化表示为带不等式约束的非光滑优化问题。进化策略用于该优化问题的求解，从而找出PSS的优化参数。进化策略属现代全局优化方法的一种，它对优化问题本身几乎无任何限制，冈其具有全局寻优能力，故可得到比常规优化方法更好的结果。且进化策略直接采用实型编码，因而可提高优化计算的效率。Anderson 3机系统和New England 10机系统的仿真结果表明，该方法是一种有效的参数优化方法，得到的优化参数对系统运行方式的变化具有良好的鲁棒性。     

含TCSC的多机系统非线性最优控制

运用逆系统方法将含可控串联补偿器（TCSC）的非线性多机系统线性化,并且对该线性化的系统运用具有二次型性能指标的线性最优控制方法设计了TCSC的稳定控制器。仿真结果表明,该控制器在提高系统的稳定性、阻尼系统振荡方面有明显的改善．     

静止无功补偿器在电力系统Hopf分岔控制中的应用

分析研究了电力系统中的静止无功补偿器(SVC)在抑制功率/频率振荡问题中的应用。这些振荡现象都与Hopf分岔有关,因此可以根据分岔理论分析该现象并设计相应的控制器。通过一个实际系统,研究了SVC对分岔临界特征值的影响,进而研究了其对功率/频率振荡的影响。     

SVC与发电机励磁的非线性变结构协调控制

针对电力系统的强非线性和不确定性特点及精确反馈线性化的不足,引入自抗扰控制技术设计了能同时改善电力系统功角稳定和电压动态特性的静止无功补偿(SVC)与发电机励磁的变结构协调控制器。扩张状态观测器的动态补偿作用不仅使励磁控制与SVC控制实现解耦,而且使二者均能实现当地信号控制。仿真结果表明提出的非线性鲁棒变结构协调控制器能有效地改善系统的动态稳定性。所设计的控制器对系统运行点和网络结构的变化具有良好的适应性和鲁棒性。     

基于逆系统方法TCR-FC型静止无功补偿器非线性控制的研究

提出了对于由晶闸管控制电抗器与固定电容器所组成的静止无功补偿系统基于触发角控制的数学模型。根据非线性控制的逆系统方法,设计了相应的非线性组合控制器。通过计算机仿真证明此方法能够有效保持接入点电压稳定,提高系统的暂态稳定性。     

DFIG Oscillation Modes Causing Strong Dynamic Interactions to Degrade the Damping of Power System Low-Frequency Electromechanical Oscillations

Open-loop modal coupling is the closeness of an open-loop oscillation mode of a grid-connected DFIG to an open-loop electromechanical oscillation mode of a power system on the complex plane. When the open-loop modal coupling occurs, the dynamic interactions between the DFIG and the power system become strong and may degrade the damping of the low-frequency electromechanical oscillations (LEPOs) of the power system. In this article, analysis is carried out to explain why the open-loop modal coupling may cause the damping degradation of the LEPOs. By deriving the simplified open-loop transfer function matrices of the DFIG, existence of open-loop DFIG oscillation modes to cause the open-loop modal coupling is analytically examined. Conclusions of analytical examination are: (1) If the rotor speed is used as the input signal to the active power control outer loop of the rotor side converter (RSC) or the generic type 3 model is adopted by the reactive power control outer loop of the RSC, the DFIG may have an open-loop oscillation mode to cause the open-loop modal coupling; (2) The PLL may also contribute to an open-loop oscillation mode of the DFIG. Study cases are presented to demonstrate and evaluate the analysis and conclusions.     

SVC的模糊变结构控制对电力系统稳定性的影响

在非线性变结构控制理论与模糊控制理论的基础上 ,将二者结合起来进行SVC模糊变结构控制器(FVSC)的设计。该控制器引入经可调整模糊控制规则推理得出的附加控制信号来改善系统的阻尼特性 ,同时结合自动电压调节器改善电压特性的。针对输电线上装设SVC的单机—无穷大系统进行的仿真计算表明 :SVC的模糊变结构控制方式与变结构控制、常规控制方式相比 ,在能够明显地改善电力系统的稳定性的同时 ,可以抑制暂态响应中的电压波动 ,并且能够适应系统运行工作点的变化     

Distribution voltage rise at dense photovoltaic generation area and its suppression by SVC

An SVC is proposed as a reactive power compensation device to suppress the rise in the customer voltage due to photovoltaic power generation systems. The SVC produces a reactive power by controlling a thyristor. The effect of the SVC on the rise in the customer voltage has been investigated. Calculation results show that installing an SVC on the low‐voltage side is more effective for suppressing the rise in the customer voltage compared to an SVC located on the high‐voltage side. As far as the calculation conditions are concerned, it is found that the rated capacity of the SVC needed to maintain the customer voltage within 101±6V is over ±11.1kVA. The slope reactance required to suppress the customer voltage lower than 107 V is found to be under 1.28%. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(2): 47–53, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20478