A real-time predictive controller for automatic voltage regulation of a synchronous generator

The use of a predictive controller in automatic voltage regulation (AVR) of a synchronous generator is proposed for real-time control purposes. The controller consists of a fast-time linearized 2nd-order model of an alternator and control logic. The fast-time model is used to predict the time response of the controlled system (generator voltage output), and the control logic is responsible for choosing the necessary input to the controlled system. The principles of time-optimal control and linear regulator are used in controller design.

The effectiveness of such a controller is examined by digital simulation study for the response of a synchronous machine, connected to an infinite bus under various input and initial conditions. The effects on the stability of the overall system are analysed.     

A multi-task automatic generation control for power regulation

The conventional model of a power system control area used for automatic generation control (AGC) is crucially extended to include individual power producers. Taking into account the influence of the power network, a systematic method of obtaining a detailed model of a control area is presented. It is proved that within the framework of the model developed, both frequency control as well as regulation of the power of individual power stations becomes possible. To this end, new advanced optimal control methods are used for the design of suitable proportional–integral (PI) controllers. Using the proposed model and the new control strategy, the application of automatic generation control and its effectiveness is extensively studied and evaluated on a 6-bus illustrative power system example; furthermore, the method is tested on the New England power system, which is commonly used as a large test system.     

独立电压调节回路的最优分散协调励磁控制

提出一种新的励磁控制方法,解决了传统多机系统分散协调励磁控制中电压反馈增益偏低而达不到要求的问题。该方法将电压反馈作为独立的调节回路,无须依赖加权系数的二次优化,按调压要求独立设计电压反馈增益。将其余的多个输出量(转速、功率等)作为附加控制信号形成外环控制回路,利用分散协调控制思想,通过求解Levine-Athans方程组,实现对多个附加信号增益优化,从而保证全局稳定和性能最优。既根据稳态调节精度的要求设定电压反馈系数,又实现了多变量协调优化控制。最后,以电力科学研究院EPRI-36系统为实例,分别用所提方法和传统方法设计2种励磁调节器,在小干扰稳定性、暂态稳定性、电压调节精度等方面进行对比,结果显示所提方法的综合性能具有优越性。     

计及分布式电源集群不确定性的配电网分散鲁棒电压控制

随着光伏、储能等分布式电源广泛接入,导致配电网区域电压波动频繁。针对分布式电源分散接入带来的不确定性问题,提出了一种计及分布式电源集群不确定性的配电网分散鲁棒电压控制方法。将大规模分布式电源聚合成相互关联的集群,对电压控制进行分区域调节。首先,针对配电网结构复杂和分布式电源点多面广的问题,设计一种基于改进Louvain算法的配电网集群划分方案,利用模块度函数并兼顾了集群的电压灵敏度和分布式电源调控容量。然后,由于分布式电源接入后配电网潮流更加复杂多变,在划分集群的基础上提出一种考虑不确定性的分散鲁棒控制方法,协同各分布式电源集群的调控能力,抑制由于模型参数及功率波动等不确定性导致的配电网电压波动。最后,通过算例分析验证了所提方法的可行性和有效性。     

一种新型分散橹棒控制器的设计方法

文章在已有文献的基础上提出用分散本机量反馈的方法，利用模态矩阵优化设计了多机电力系统分散橹棒控制器，解决了稳定约束问题。根据定量分析控制器的橹棒性，求得一个适当的予定稳定度，使得控制系统具有较强的橹棒性，同时又具有较好的动态响应。同时用这种方法对一实际大区电力系统设计了分散橹棒控制器，结果表明这种方法简单，且有实用意义。     

火电厂厂级自动电压控制系统研制

为保证电网安全、优质、经济运行,将火电厂自动电压控制在现有厂级自动发电控制系统平台上扩展实施,构成了一体化专用子站.通过动态辨识系统阻抗,适当修正自适应PID调节器的增益,进行电压和无功的在线转换,实现无差、快速调节.在传统的等功率因数分配方法与无功容量系数分配方法基础上提出了偏置调整算法,给出了计算公式.针对实际应用...     

计及电压调节和分布式电源的配电网潮流分析

在分布式电源和电压及无功调节装置的基础上,提出了放射形配电网的新型潮流计算方法。建立分布式电源在潮流计算中所采取的适当节点模型和调压设备模型;分析了分布式电源对馈线自动调压器(SVR)的调压性能的影响,建立了SVR的潮流计算模型。对传统前推/回代算法进行有效的改进,使之快速有效地适应于多节点类型、多设备的配电网系统潮流算法。最后以28节点配电系统为例进行计算分析,仿真计算结果检验了本文提出的算法的有效性,并通过仿真结果分析了分布式电源、无功调节电源对配电网电压分布、电能损耗的影响以及分布式电源对电压调节装置的影响。     

计及稳定断面安全的AGC协调控制

提出了以模型预测控制为基础的有功频率双层监督控制新模式。上层控制器根据系统的实时状态为下层控制器提供参考设定值轨迹,基于模式分析方法建立有功调度中的无功调节成本模型,使无功电压控制与有功频率控制相协调;下层控制器为最优负荷频率控制,将原有的滞后控制方式转化为基于预测的超前控制方式,在超短期负荷预测的基础上建立最优化模型,并采用线性模型预测控制求解,实现了满足CPS考核前提下机组调节量的经济分配,并减少了超调频动。新英格兰10机39节点系统的算例验证了控制策略的有效性。     

自动电压控制系统（AVC）在发电厂的应用

自动电压控制（AVC）是电网安全、优质和经济运行的重要手段，论述了发电厂实施AVC系统的必要性，提出了制定发电厂AVC的具体方案。     

分散励磁式船舶电力系统鲁棒控制器研究

给出了分散励磁式船舶电力系统柴油机发电机组的数学模型,明确了模型中各种干扰项的物理意义。将发电机组数学模型线性化后,增广为广义受控系统,应用H∞控制理论,设计了发电机的分散励磁鲁棒控制器,并应用线性矩阵不等式(LMI)方法,将H∞控制器的设计转化为一个线性矩阵不等式约束和线性目标函数的凸优化问题,对H∞控制器求解和优化。仿真结果表明,当电力系统受到干扰后,H∞鲁棒励磁控制器比传统的电力系统稳定(PSS)励磁控制器具有更强的抗干扰能力,并使电力系统在较短时间内恢复稳定。     

A self-tuning automatic voltage regulator

A self-tuning automatic voltage regulator (AVR) for a synchronous generator is presented. The regulator proposed improves the system stability; it is simple and can handle stochastic load changes. The algorithm for the proposed AVR combines a least-squares estimator with a minimum variance control strategy computed from an estimated model. It is shown that if the parameter estimates converge, the control law obtained is in fact the minimum variance control law that would be computed if the parameters of the system were known. The algorithm proposed has been tested by simulation and also by implementation on a minicomputer. Results show that, in general, the system performance is improved with a self-tuning regulator.     

An optimal allocation of distributed generation and voltage control devices for voltage regulation considering renewable energy uncertainty

Distributed generation (DG) may result in voltage fluctuation by changing line flow and reactive power injection, especially DG that generates power from renewable energy resources. To cope with this problem, this paper proposes an optimization process to optimally regulate the system voltage profile to lie close to the desired values by using the adaptive Tabu search (ATS) algorithm. The system voltages will be regulated by using dispatchable DG and voltage control devices, i.e. voltage regulator and capacitor. Moreover, probabilistic load flow calculation by using Monte Carlo simulation is chosen to evaluate the uncertainty of DG powered by renewable energy resources. The number of switching operations of the voltage regulator and capacitor are also accounted for in the optimization constraints, as excessive frequent switching operations can damage these devices. The optimal sizes and locations of dispatchable DGs and capacitors are considered as the optimization variables. The proposed method is demonstrated in an IEEE 34‐bus distribution test system and a modified 21‐bus Provincial Electricity Authority (PEA) system (Thailand). © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Stabilization control for multimachine system using decentralized H∞ excitation controller realizing terminal voltage control and damping control

In this paper, to achieve both damping of power system oscillation and terminal voltage control simultaneously on a multimachine power system, we propose a decentralized H_∞ excitation controller. In the proposed method, H_∞ control via the Normalized Coprime Factorization approach is used to achieve the proposed design idea. By the Normalized Coprime Factorization approach, the weighting function in H_∞ control design is simplified, and output feedback controllers that take into account the realities and constraints of the power systems are designed. The proposed controller is subjected to model reduction of H_∞ controllers, and is transformed to a discrete system to perform digital control by computer systems in consideration of application to a real system. We verify that the proposed excitation controller can achieve both damping of power system oscillation and terminal voltage control by computer simulations of a multimachine power system. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(1): 33–41, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10254     

Radial MV networks voltage regulation with distribution management system coordinated controller

The connection of a great number of distributed generation (DG) plants may cause a critical voltage regulation problem in actual medium voltage (MV) radial distribution networks. After a synthetic survey of different strategies reported in literature to solve this problem, a proposal for an active management of the distribution system which makes use of an innovative controller that coordinates the on load tap changer (OLTC) action with the regulation of reactive exchanges between DG plants and feeders, is presented.     

基于独立电压控制的多电平光伏逆变MPPT研究

针对太阳能光伏发电系统中由于光伏阵列局部阴影和不匹配导致输出功率降低的问题,采用二极管钳位多电平逆变器方案,提出等效变换脉宽调制控制策略,通过独立控制每一个光伏阵列的工作电压,允许通过不同的电流,保证每个光伏阵列输出最大功率,使整个系统输出功率最大.采用多电平逆变器,降低设备的额定电压,减少输出电压失真,降低输出电流谐波含量,提高转换效率.MATLAB仿真实验验证了该控制策略的可行性和有效性.     

A new two-degree of freedom combined PID controller for automatic generation control of a wind integrated interconnected power system

Frequency control of an interconnected power system in the presence of wind integration is complex since wind speed/power variations also affect system frequency in addition to load perturbations. Therefore, improving existing control schemes is necessary to maintain a stable frequency in such complex power system scenarios. In this paper, a new 2-degree of freedom combined proportional-integral and derivative control scheme is applied to a wind integrated interconnected power system. In designing the controller, several inputs used for a secondary frequency control loop are considered along with the merits of the existing controllers. The combined controller provides better control action than existing controllers in the presence of wind as is evidenced by the wide variety of results pre sented. For tuning of the controller gains, a crow search optimization algorithm (CRSOA) is used. Results are obtained via the MATLAB/Simulink software.     

晶闸管电压调节器控制器设计

为解决长线路和带有分散发电设备配电网的电压调节问题,开发、研制了一种用于中低压配电网、能双向调节电网电压的晶闸管电压调节器TVR(Thyristor Voltage Regulator)。重点介绍TVR控制器的设计思想和方法,包括控制器的总体设计、软硬件设计和抗干扰措施等;同时给出了控制器在380V电压调节器样机上的试验结果。试验结果表明：设计的TVR控制器能很好地实现调压操作、故障保护、定值设置、显示等功能。     

10kV配电变压器自动调压的研究以及试验分析

针对配电变压器机械式有载调压装置复杂、调压不方便等问题,提出一种基于电力电子开关的5档自动调压技术方案。采用启动保护电路,避免电力电子开关承受合闸电压和励磁涌流冲击,保证电力电子开关退出时变压器的正常运行;考虑变压器高压侧绕组不同接线方式,分析开关器件两端承受的电压以及分接头对地电压的分布情况,为电力电子开关器件的参数选择提供参考。结果表明高压侧为星形接线的中性点调压方式更加有利于电力电子器件的工作,高压侧为三角形接线的中部调压方式对于电力电子器件的工作电压以及隔离电压均有较高的要求。在完成电路设计与器件选型的基础上,研制了基于电力电子开关的自动有载调压变压器,并安装于现场试运行。理论研究、仿真分析、样机试验以及上网试运行均表明所提方案具有可行性与可靠性。     

混合燃烧机组自动发电和一次调频控制系统完善与优化

介绍了宝钢电厂1、2号机组自动发电控制和一次调频功能现状,通过系统设计、实现、调试,功能得到了完善和优化,达到了电网要求,机组运行可靠性得到提高.     

基于集中校核与分散控制的备自投系统

备自投对保障电力系统供电可靠性非常重要,站内备自投孤立运行,缺乏电网全局信息,不利于充分发挥备用电源投入功能。提出基于集中校核与分散控制的备自投系统,该系统包括监视分析、在线投退和离线校核3个方面的功能。同时介绍了与备自投系统技术实施相关的若干关键技术,包括备自投模型、基于风险评估的备自投投退策略、数据可靠性校核和网络备自投控制校核。应用实例表明,备自投系统可以综合全网信息,降低电网运行风险。