基于滑模控制的含风储多域电力系统负荷频率控制

建立含风储多域互联电力系统负荷频率控制(LFC)模型,同时考虑系统参数不确定性、储能系统和传统机组控制信道延时问题.为提高系统鲁棒性,降低储能系统的容量配置,针对含风储的LFC模型,设计滑模负荷频率控制器,并提出滑模负荷频率控制器和储能协调的控制策略.算例分析表明,所提出的协调控制策略在新能源大规模渗透和系统负荷波动情况下能够有效减小系统频率偏差和区域控制偏差,同时降低储能系统的配置容量,提高电力系统安全稳定运行的经济性.     

计及时滞的互联电网负荷频率控制最优分数阶PID控制器设计

分数阶PID控制器相比于传统整数阶PID控制器,具有控制性能好、鲁棒性强等诸多优势,可应用于电网的负荷频率控制(load frequency control,LFC)中.针对网络化时滞互联电网的LFC问题,提出了一种基于计算智能的分数阶PID控制器参数优化整定方案.该方案选择时滞LFC系统时域输出响应构建优化目标函数,采用最近提出的灰狼优化算法获得最优的分数阶PID控制器参数,所设计的控制器能确保一定时滞区间内LFC系统的稳定性.仿真算例表明,所设计的LFC最优分数阶PID控制器比传统整数阶PID控制器的控制性能更优,时滞鲁棒性更强.     

基于一种改进型逆凸不等式的混合攻击下多区域时滞电力系统的分布式控制

本文研究了混合攻击下多区域时滞电力系统的分布式协调控制问题。首先,考虑了一种基于混合攻击下（包括拒绝服务攻击和欺骗攻击）的多区域时滞电力系统,在拒绝服务攻击下,时滞电力系统的各个区域之间的通信将恶化为一种切换残余拓扑结构,它的时间特性建模成了模型依赖的平均停留时间的模型。在以负反馈控制为目标的欺骗攻击下,将其建模成了基于符号函数的模型。然后,为了在低惯性和混合攻击下获得时滞电力系统的弹性性能,采用了负荷频率控制与虚拟惯性控制相结合的弹性分布式策略,并将时滞电力系统的负荷频率控制问题转换为切换非线性切换系统控制问题。再通过采用合适的Lyapunov-Krasovskii泛函、改进型逆凸不等式、线性矩阵不等式技术以及切换系统方法,得到了多区域时滞电力系统的稳定性定理。并基于此定理,设计了负荷频率控制和虚拟惯性控制下的分布式控制增益。最后,建立仿真,针对三区域电力系统进行了仿真,仿真结果体现了本文所提出来的稳定性定理和设计的分布式控制增益的优势和有效性。     

网络攻击下信息物理融合电力系统的弹性事件触发控制

本文将电动汽车（Electric vehicles，EVs）引入到典型的信息物理系统（Cyber-physical systems，CPS）智能电网中，采用负荷频率控制（Load frequency control，LFC）方法，能够快速抑制系统扰动所引发的频率变化.在考虑拒绝服务（Denial-of-Service，DoS）攻击的情况下，提出了一种弹性事件触发机制，使系统能够容忍攻击所造成的数据丢失.与此同时，PI型静态输出反馈控制器的输入按需更新，减少了通信负担.对于建立的闭环时滞系统模型，构造新型李亚普诺夫泛函，对系统进行稳定性分析，推导出系统所能承受的最大DoS攻击持续时间，并对控制器增益和弹性事件触发矩阵进行协同设计.最后，通过多域电力系统仿真，验证了所提出方法的有效性.     

基于大变异遗传算法进行参数优化整定的负荷频率自抗扰控制

本文将自抗扰控制(active disturbance rejection control,ADRC)应用到两区域互联电力系统的负荷频率控制(load frequency control,LFC)中,从具有非再热式汽轮机机组的电力系统模型推广到具有水轮机机组的以及考虑发电速率约束和调速器死区的再热式汽轮机组的电力系统模型,涉及线性、非线性和非最小相位特性3种控制对象,并使用大变异遗传算法对控制器的参数进行整定,与基于大变异遗传算法的PI控制进行仿真比较研究,仿真表明本文所提基于大变异遗传算法的负荷频率自抗扰控制动态响应快、偏差小、鲁棒性好、抗干扰能力强,对于LFC系统更为有效。     

电力系统小波神经网络负荷频率控制器的研究

将小波网络用于电力系统负荷频率辨识和控制中，建立了非线性的电力系统负荷频率控制LFC模型，用递归NARMA模型的小波网络辩识器对LFC模型进行了辩识，利用Akaike’s的最终预测误差准则FPE和信息准则AIC，进行了隐层节点数目和反馈阶次的计算，用辩识结果建立了NARMA模型的小波网络的控制器，对LFC模型进行控制，理论和仿真表明辩识和控制模型可取得较好效果。     

含混合储能的互联电力系统传感器容错负荷频率控制

为了改善多区域互联系统电能质量的问题,在原有负荷频率控制系统(LFC)的基础上引入由超级电容和蓄电池两者组成的混合储能系统(HESS),并针对电力系统中难以避免的传感器故障问题设计传感器主动容错策略.首先,建立含HESS的LFC系统模型用以减少负荷扰动对系统频率带来的影响;其次,针对带HESS的互联电力系统设计传感器主动容错策略,避免因传感器故障而引发的系统故障;最后,通过对一个三区域带HESS的互联系统进行仿真实验,验证HESS对改善互联系统电能质量的可行性和所提出的容错控制(FTC)的有效性.     

基于双率采样的智能车辆弯道轨迹跟踪控制

本文研究在双率采样下智能车辆弯道轨迹跟踪问题.首先,针对车辆车道保持的转向控制,建立相对路面误差的侧向动力学模型.其次,假设系统状态变量被分为两个子向量并分别由两类传感器以不同的采样周期采样,针对这类双率采样系统,充分考虑这两类传感器的采样时刻特征,设计一类基于采样时刻的切换控制器.然后,利用输入时滞方法,将最终的闭环系统建模为带有两个模态的切换时滞系统,并以线性矩阵不等式(LMI)形式给出闭环系统指数稳定性条件和切换控制器的设计方法.最后,在Matlab/Simulink环境下对汽车模型的路径跟踪控制进行仿真,验证本文所提方法的有效性,并与单率采样方法进行比较,说明本文方法相比于单率采样方法的优势.     

多区域时滞电力系统稳定判据的优化

在大规模互联电力系统进行全网动态分析与控制的过程中,通信时滞的存在易导致动力系统产生控制设备失效、系统性能恶化及失稳等现象.而现有时滞系统稳定判据的研究多基于Lyapunov分析方法,研究过程中需采用不等式放缩及构造Lyapunov泛函,使得稳定判据具有较高保守性,增加了系统的控制成本.针对这一问题,本文以多区域时滞电力系统为研究对象,通过引入Wirtinger不等式优化稳定判据推导过程和构造新的Lyapunov泛函两种方式,降低系统稳定判据的保守性.最后,利用典型的二阶时滞系统和两区域负荷频率控制系统,验证了本文算法的正确性和有效性.     

计及温控负荷响应的二维云模型分布式频率控制

为改善电力系统频率稳定性,充分调用需求侧可控负荷资源,本文提出一种计及温控负荷响应的二维云模型分布式频率控制方法。建立了多区域互联电力系统负荷频率控制模型,设计了基于福克普朗克方程的温控负荷分布式控制策略,同时采用云模型算法与分数阶微积分理论,设计了二维云模型分数阶PID分布式频率控制器。最后通过控制仿真比较与分析,验证了在不同运行场景下所提出的综合控制方法具有较优的动稳态性能。结果表明该控制方法是可行和有效的。     

PID controller design for interval load frequency control system with communication time delay

In load frequency control (LFC), the data from measurements sensors are transmitted from far-off remote terminal units (RTUs) to the controlling center and control signals are transmitted from the controlling center to the plant location. These transmissions of various signals are possible via communication channels which are characterized by constant delays. Modern day power systems are quite complex in the present deregulated environment. This complexity has been further enhanced by the inherent delay introduced by the communication channels. Because of the communication delay, the conventional load frequency control design techniques give unacceptable performance. Further, in case of severe delay, the load frequency control system may become unstable. In view of this, a proportional–integral–derivative (PID) controller is designed using stability boundary locus (SBL) approach for interval single area power system with non-reheated thermal turbine and reheated thermal turbine having communication delay and then the proposed approach is validated on the multi-area IEEE 39-bus New England test system. The simulation results indicate the efficacy of the proposed methodology.     

Decentralized Resilient H∞ Load Frequency Control for Cyber-Physical Power Systems Under DoS Attacks

This paper designs a decentralized resilient H_∞ load frequency control (LFC) scheme for multi-area cyber-physical power systems (CPPSs). Under the network-based control framework, the sampled measurements are transmitted through the communication networks, which may be attacked by energy-limited denial-of-service (DoS) attacks with a characterization of the maximum count of continuous data losses (resilience index). Each area is controlled in a decentralized mode, and the impacts on one area from other areas via their interconnections are regarded as the additional load disturbance of this area. Then, the closed-loop LFC system of each area under DoS attacks is modeled as an aperiodic sampled-data control system with external disturbances. Under this modeling, a decentralized resilient H_∞ scheme is presented to design the state-feedback controllers with guaranteed H_∞ performance and resilience index based on a novel transmission interval-dependent loop functional method. When given the controllers, the proposed scheme can obtain a less conservative H_∞ performance and resilience index that the LFC system can tolerate. The effectiveness of the proposed LFC scheme is evaluated on a one-area CPPS and two three-area CPPSs under DoS attacks.      

Distributed Model Predictive Load Frequency Control of Multi-area Power System with DFIGs

Reliable load frequency control (LFC) is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-area interconnected power system with wind turbines, this paper presents a distributed model predictive control (DMPC) based on coordination scheme. The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The generation rate constraints (GRCs), load disturbance changes, and the wind speed constraints are considered. Furthermore, the DMPC algorithm may reduce the impact of the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and without the participation of the wind turbines is carried out. Analysis and simulation results show possible improvements on closed-loop performance, and computational burden with the physical constraints.      

Delay-discretization-based sliding mode $$H_{\infty }$$ load frequency control scheme considering actuator saturation of wind-integrated power system

This paper investigates the combined effect of actuator saturation and time-delay on load frequency control (LFC) of a wind-integrated power system (WIPS). Actuator saturation is represented in two different approaches such as polytopic and sector bounding. Delay-discretization-based sliding mode \(H_{\infty }\) control approach is proposed to design a novel LFC scheme. The proposed control scheme requires present as well as delayed states information as input to the controller. This requirement of control scheme is fulfilled by adopting a finite known delay. This finite known delay used in controller design is discretized into delay intervals. Lyapunov–Krasovskii functional is defined for each delay interval, and \(H_{\infty }\) stabilization criteria for the closed loop WIPS are derived in linear matrix inequality framework using Wirtinger-based inequality. The proposed control scheme is tested by considering a numerical example of two-area WIPS.

     

Maiden application of colliding bodies optimizer for load frequency control of two-area nonreheated thermal and hydrothermal power systems

This article presents a novel load frequency control (LFC) approach using colliding bodies optimizer (CBO) for frequency stabilization of interlinked multiarea electric power systems. The optimal parameters of the suggested CBO-based proportional–integral–derivative-filter controller ascertain an effective LFC solution. First, a well-known and widely used linearized two-area nonreheated thermal power system is examined to demonstrate the efficacy of the proposed approach. The effectiveness of the proposed method is analyzed by comparing the outcomes of several recently presented LFC schemes. The performance analysis shows a settling time improvement of 3.10%, 14.29%, and 18.66% in the case of area-1 and area-2 frequencies and tie-line power deviations compared with an imperialist competitive algorithm (ICA)-based controller. The robustness of the proposed scheme is also evaluated in the presence of various operating scenarios. Additionally, the work is extended to a two-area nonreheated hydrothermal power system. The proposed method shows an improvement of over 60% in the performance index compared with several existing techniques-based controllers such as optics-inspired optimization, gray-wolf optimization, quasi-oppositional differential search algorithm, bacterial foraging optimization algorithm, and ICA.     

Non-linear sliding mode load frequency control in multi-area power system

This paper addresses non-linear sliding mode controller (SMC) with matched and unmatched uncertainties for load frequency control (LFC) application in three-area interconnected power system. In conventional LFC scheme, as the nominal operating point varies due to system uncertainties, frequency deviations cannot be minimized. These lead to degradation in the dynamic performance or even system instability. In this paper, an effective control law is proposed against matched and unmatched uncertainties.. The proposed controller has ability to vary closed-loop system damping characteristics according to uncertainties and load disturbances present in the system. The frequency deviation converges to zero with minimum undershoot/overshoot, fast settling time, significantly reduced chattering and ensures asymptotic stability. In addition, the controller is robust in the presence of parameter uncertainties and different disturbance patterns. It also guarantees high dynamic performance in the presence of governor dead band (GDB) and generation rate constraint (GRC). Simulations are performed to compare the proposed controller with linear SMC. Using proposed control strategy, undershoot/overshoot and settling time gets reduced by approximately 30% with respect to linear SMC. The computed performance indices and qualitative results establish the superiority as well as applicability of the proposed design for the LFC problem. Further, the proposed controller scheme is validated on IEEE 39 bus large power system.     

Application of intelligence-based predictive scheme to load-frequency control in a two-area interconnected power system

This paper describes an application of intelligence-based predictive scheme to load-frequency control (LFC) in a two-area interconnected power system. In this investigation, at first, a dynamic model of the present system has to be considered and subsequently an efficient control scheme which is organized based on Takagi-Sugeno-Kang (TSK) fuzzy-based scheme and linear generalized predictive control (LGPC) scheme needs to be developed. In the control scheme proposed, frequency deviation versus load electrical power variation could efficiently be dealt with, at each instant of time. In conclusion, in order to validate the effectiveness of the proposed control scheme, the whole of outcomes are simulated and compared with those obtained using a nonlinear GPC (NLGPC), as a benchmark approach, which is implemented based on the Wiener model of this power system. The validity of the proposed control scheme is tangibly verified in comparison with the previous one.     

互联电力系统鲁棒分布式模型预测负荷频率控制

负荷频率控制是现代互联电力系统运行的重要保障.本文针对含有不确定因素和负荷扰动的多区域互联电力系统提出了一种基于线性矩阵不等式参数可调节的鲁棒分布式预测控制算法.设计各个区域控制器目标函数引入相邻区域的状态变量和输入变量,同时考虑发电机变化速率约束和阀门位置约束,将求解一组凸优化问题转化成线性矩阵不等式求解,得到各个区域的控制律,在线性矩阵不等式中引入一组可调参数,将优化一个上限值转化成优化吸引区,降低算法的保守性.仿真结果验证了该算法在负荷扰动、系统参数不确定和结构不确定性情况下具有鲁棒性.