Design of PSO‐based fuzzy logic controller for single axis magnetic levitation system

In this paper, a particle swarm optimization (PSO) method is proposed to design an optimal robust fuzzy logic controller (FLC). The objective of this paper is to design a nonlinear optimal robust controller for the single axis magnetic levitation system with high accuracy. PSO algorithm is applied to search globally optimal parameters of FLCs. Three different FLCs are designed. First, proportional derivative (PD)‐like FLC. Second, the FLC is based on the PSO algorithm to find the optimal range of the eight linguistic membership functions (FLC1 with PSO algorithm). Finally, the FLC is based on the PSO algorithm to find the optimal range and shape of the four linguistic membership functions (FLC2 with PSO algorithm). The performances of three different FLCs are compared. Simulation results show that PSO‐based optimal FLCs find the optimal range and shape of the four linguistic membership functions and achieved better performance than the other proposed controllers, minimizing 48 fuzzy rules. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

水轮发电机组GA模糊控制器研究

模糊控制器设计的困难之一就是确定量化因子和隶属度函数，它们对控制器性能具有重要影响。文中提出用遗传算法（GA）对水轮发电机组模糊控制器进行优化设计，描述了控制器结构，优化算法和动态仿真结果。仿真对比试验表明，经过GA优化的模糊控制器比经过MATLAB NCD工具箱优化的PID控制器具有更好的控制效果和更强的鲁棒性。     

多馈入HVDC的模糊自适应协调阻尼控制器设计

提出一种基于广域测量系统的多馈入高压直流（HVDC）模糊自适应协调阻尼控制器。该控制器在传统的单输入单输出控制结构基础上增加了一个模糊逻辑单元,自适应地在线调整系统的移相角。同时,增益K与模糊逻辑单元联调,以保证移相环节参数改变后整个控制通道的增益保持不变。利用Prony辨识算法和极点配置法对该阻尼控制器的固定参数进行了整定,并对整定后的参数进行了协调优化。以中国南方电网2007年网络结构为对象,给出了该模糊自适应协调阻尼控制器的设计过程及仿真结果。结果表明：该阻尼控制器能快速、有效地阻尼区域间振荡,提高交流联络线的传输能力,对不同的网络结构具有鲁棒性,可明显改善多馈入HVDc系统的稳定性。     

Two degrees of freedom dc voltage controller of grid interfaced PV system with optimized gains

This paper proposes the application of fictitious reference iterative tuning (FRIT) method to optimize the gains of dc voltage controller of grid connected photo-voltaic (PV) system. It may be difficult to achieve good control of dc voltage using conventional PI controller having only one-degree-of-freedom (1-DOF) due to the trade-off between overshoot (in step response) and disturbance response. In this paper, the optimal control of dc voltage is proposed with improved disturbance response by implementing 2-DOF PI controller structure. FRIT method has been programmed in MATLAB based upon the particle swarm optimization (PSO) algorithm. The fundamental idea related to FRIT method is the extraction of input and output data, reference model setting and range of controller gains. The performance of dc voltage control for the optimized 2-DOF PI controller is also compared with the fuzzy logic controller (FLC) response.     

A novel hybrid PSO-PS optimized fuzzy PI controller for AGC in multi area interconnected power systems

In this paper, a novel hybrid Particle Swarm Optimization (PSO) and Pattern Search (PS) optimized fuzzy PI controller is proposed for Automatic Generation Control (AGC) of multi area power systems. Initially a two area non-reheat thermal system is used and the gains of the fuzzy PI controller are optimized employing a hybrid PSO and PS (hPSO-PS) optimization technique. The superiority of the proposed fuzzy PI controller has been shown by comparing the results with Bacteria Foraging Optimization Algorithm (BFOA), Genetic Algorithm (GA), conventional Ziegler Nichols (ZN), Differential Evolution (DE) and hybrid BFOA and PSO based PI controllers for the same interconnected power system. Additionally, the proposed approach is further extended to multi source multi area hydro thermal power system with/without HVDC link. The superiority of the proposed approach is shown by comparing the results with some recently published approaches such as ZN tuned PI, Variable Structure System (VSS) based ZN tuned PI, GA tuned PI, VSS based GA tuned PI, Fuzzy Gain Scheduling (FGS) and VSS based FGS for the identical power systems. Further, sensitivity analysis is carried out which demonstrates the ability of the proposed approach to wide changes in system parameters, size and position of step load perturbation The proposed approach is also extended to a non-linear power system model by considering the effect of governor dead band non-linearity and the superiority of the proposed approach is shown by comparing the results of hybrid BFO-PSO and craziness based PSO approach for the identical interconnected power system. Finally, the study is extended to a three area system considering both thermal and hydro units with different controllers in each area and the results are compared with hybrid BFO-PSO and ANFIS approaches.     

A fuzzy logic controlled superconducting magnetic energy storage,SMES frequency stabilizer

This paper presents application of fuzzy logic controlled superconducting magnetic energy storage device, SMES to damp the frequency oscillations of interconnected two-area power systems due to load excursions. The system frequency oscillations appear due to load disturbance. To stabilize the system frequency oscillations, the active power can be controlled via superconducting magnetic energy storage device, SMES. The error in the area control and its rate of change is used as controller input signals to the proposed fuzzy logic controller. In order to judge the effect of the proposed fuzzy logic controlled SMES, a comparative study is made between its effect and the effect of the conventional proportional plus integral (PI) controlled SMES. The studied system consists of two-area (thermal–thermal) power system each one equipped with SMES unit. The time simulation results indicate the superiority of the proposed fuzzy logic controlled SMES over the conventional PI SMES in damping the system oscillations and reach quickly to zero frequency deviation. The system is modeled and solved by using MATLAB software.     

Robust decentralized load frequency control of interconnected power system with Generation Rate Constraint using Type-2 fuzzy approach

The Load Frequency Control (LFC) problem has been a major subject in electrical power system design/operation. LFC is becoming more significant recently with increasing size, changing structure and complexity in interconnected power systems. In practice LFC systems use simple Proportional Integral (PI) controllers. As the PI control parameters are usually tuned, based on classical approaches. Moreover, they have fixed gains; hence are incapable of obtaining good dynamic performance for a wide range of operating conditions and various load changes, in multi-area power system. Literature shows that fuzzy logic controller, one of the most useful approaches, for utilizing expert knowledge, is adaptive in nature and is applied successfully for power system stabilization control. This paper proposes a Type-2 (T2) fuzzy approach for load frequency control of two-area interconnected reheat thermal power system with the consideration of Generation Rate Constraint (GRC). The performance of the Type-2 (T2) controller is compared with conventional controller and Type-1 (T1) fuzzy controller with regard to Generation Rate Constraint (GRC). The system parametric uncertainties are verified by changing parameters by 40% simultaneously from their typical values.     

A fuzzy logic-based droop control for simultaneous voltage and frequency regulation in an AC microgrid

Modern power systems require increasing intelligence and flexibility in the control and optimization to ensure the capability of maintaining balance between generation and load under violent disturbances. There are several inverter interfaced distributed generations (IIDGs) with local and global control loops in a microgrid (MG). Voltage and frequency of MGs are strongly impressionable from the active and reactive load fluctuations. A change in load leads to imbalance between generation and consumption. The output voltage and frequency of the IIDGs are primarily controlled by the droop characteristics. But, in case of severe changes in load, the IIDGs may be failed and the MG is collapsed. In this paper, for optimally tuning of a generalized droop control (GDC) structure and also secondary voltage and frequency controllers, the fuzzy logic technique is utilized. It is shown that the proposed fuzzy logic controller exhibits high performance and desirable response for different scenarios of change in load.     

Bat inspired algorithm based optimal design of model predictive load frequency control

Bat inspired algorithm (BIA) has recently been explored to develop a novel algorithm for distributed optimization and control. In this paper, BIA-based design of model predictive controllers (MPCs) is proposed for load frequency control (LFC) to enhance the damping of oscillations in power systems. The proposed model predictive load frequency controllers are termed as MPLFCs. Two-area hydro-thermal system, equipped with MPLFCs, is considered to accomplish this study. The suggested power system model considers generation rate constraint (GRC) and governor dead band (GDB). Time delays imposed to the power system by governor-turbine, thermodynamic process, and communication channels are accounted for as well. BIA is utilized to search for optimal controller parameters by minimizing a candidate time-domain based objective function. The performance of the proposed controller has been compared to those of the conventional PI controller based on integral square error (ISE) technique and the PI controller optimized by genetic algorithms (GA), in order to demonstrate the superior efficiency of the BIA-based MPLFCs. Simulation results emphasis on the better performance of the proposed MPLFCs compared to conventional and GA-based PI controllers over a wide range of operating conditions and system parameters uncertainties.     

基于变论域模糊逻辑的互联电力系统负荷频率控制

随着风电在电力系统中的渗透率不断提高,其出力不确定性对系统频率稳定造成威胁。针对风电接入系统后的频率波动问题,提出变论域模糊PI负荷频率控制策略。为克服传统模糊控制器由于论域固定导致自适应能力有限的缺点,设计的变论域模糊PI负荷频率控制器通过变论域方法实现输入、输出论域的动态调整。为满足风电接入系统后复杂的论域调整需求,基于模糊推理设计新型变论域伸缩因子。典型两区域互联系统仿真实验表明,在不同形式的扰动下,该新型控制器较PI控制器、模糊PI控制器有更好的控制表现,能更好地处理风电出力不确定性对互联电力系统频率稳定的影响。     

Frequency Stabilization for Multi-area Thermal–Hydro Power System Using Genetic Algorithm-optimized Fuzzy Logic Controller in Deregulated Environment

Abstract—This article develops a model of load frequency control for an interconnected two-area thermal–hydro power system under a deregulated environment. In this article, a fuzzy logic controller is optimized by a genetic algorithm in two steps. The first step of fuzzy logic controller optimization is for variable range optimization, and the second step is for the optimization of scaling and gain parameters. Further, the genetic algorithm-optimized fuzzy logic controller is compared against a conventional proportional-integral-derivative controller and a simple fuzzy logic controller. The proposed genetic algorithm-optimized fuzzy logic controller shows better dynamic response following a step-load change with combination of poolco and bilateral contracts in a deregulated environment. In this article, the effect of the governor dead band is also considered. In addition, performance of genetic algorithm-optimized fuzzy logic controller also has been examined for various step-load changes in different distribution unit demands and compared with the proportional-integral-derivative controller and simple fuzzy logic controller.     

交流伺服系统的一种新型位置控制器

文章将模糊逻辑控制和滑模变结构控制两者有机结合,为矢量控制交流伺服系统提出并设计一种新型位置控制器.它由一维模糊控制器和一维模糊逻辑推理机构两部分组成,模糊控制规则由滑动模态到达条件得到.该控制器具备模糊控制与滑模控制两者的优点,同时较好地解决了滑动模态的抖动.仿真结果表明:它能明显增强系统的动静态性能.     

Power-Frequency Balance in Multi-generation System Using Optimized Fuzzy Logic Controller

This paper emphasizes the development of control strategy for inter-area oscillation suppression for a unified two-area hydro–thermal deregulated power system. A proportional derivative-type fuzzy logic controller with integral (PDFLC+I) controller was proposed for automatic generation control. Further comparisons among conventional integral controller, proportional integral derivative controller, and PDFLC+I are carried out, where the PDFLC+I controller is optimized by four different optimization techniques namely, algorithm, ant colony optimization, classical particle swarm optimization, and adaptive particle swarm optimization. In PDFLC+I controller optimization, scaling parameters of controllers are optimized. A comparative study shows that the proposed PDFLC+I controller has a better dynamic response following a step load change for the combination of PoolCo and bilateral contract-type transaction in deregulated environment. Proposed controller performance has also been examined for ±30% variation in system parameters. Non-linearity in the form of governor dead band is taken into account during simulation.     

采用模糊控制的转差频率控制变频调速系统

针对转差频率控制变频调速系统设计了模糊控制器，给出了模糊控制器的设计方法，包括具体的模糊集、模糊规则和模糊推理。仿真结果表明，该模糊控制器响应快、超调小、控制曲线平滑，其动态响应性能与稳态精度均优于PI控制器。     

采用模糊控制的转差频率控制变频调速系统

针对转差频率控制变频调速系统设计了模糊控制器,给出了模糊控制器的设计方法,包括具体的模糊集、模糊规则和模糊推理.仿真结果表明,该模糊控制器响应快、超调小、控制曲线平滑,其动态响应性能与稳态精度均优于PI控制器.     

含抽水蓄能电站的互联电网负荷频率自抗扰优化控制研究

针对发电能源结构的多元化发展给互联电网负荷频率的稳定性控制带来较大的挑战,建立含抽水蓄能电站的两区域互联电网多元混合发电的负荷频率控制模型,提出一种基于粒子群优化算法的负荷频率线性自抗扰控制器参数整定优化策略,通过粒子群算法的迭代寻优计算获得最优的线性自抗扰控制器参数。考虑互联电网各区域发生不同的负荷扰动,在抽水蓄能电站的抽水和发电2种工况下,对所提出的控制方法进行系统仿真。仿真结果表明,通过粒子群算法优化的负荷频率线性自抗扰控制器,与传统PI控制器对比,前者具有更强的抗扰动能力和适应性,系统动态稳定性更好。     

基于ASAPSO的火炮随动系统模糊控制策略

针对传统PID控制器因参数无法随负载变化而实时改变,导致火炮随动系统控制效果不佳的问题,设计了以空间矢量控制为理论基础的三闭环随动控制系统。该随动控制系统采用永磁同步电机(PMSM)作为执行电机,并在系统位置环上加入了经自适应模拟退火粒子群优化算法(ASAPSO)优化参数后的模糊控制器。通过搭建系统仿真模型,将这2种控制器分别运用在该随动控制系统的位置环上,对比了2种控制器的位置响应、抗转矩扰动能力和目标跟踪能力。结果发现,模糊控制器的参数经ASAPSO优化后,系统的静态特性和动态特性比传统PID控制器更好,能够有效克服转矩扰动等非线性因素的影响,系统具有较好的目标跟踪性能。     

Damping of low‐frequency oscillations using an SVC‐based supplementary controller

In this paper, the optimal tunning problem of parameters of a conventional lead–lag controller (LLC) and a fuzzy logic controller (FLC) based on the static Var compensator (SVC) is considered. The solution is obtained using an improved particle swarm optimization (IPSO) algorithm. The membership functions and scaling factors of the FLC and LLC parameters are optimized using the above‐mentioned technique. The proposed controllers are settled down to an SVC that is installed at the middle of a transmission line connecting a single machine to an infinite bus system. Simulation results show the superiority of the optimized FLC compared to the optimized LLC and also when the SVC is without the supplementary controller under different disturbances and loading conditions. The simulations and analyses are implemented in MATLAB environment. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

新型模糊逻辑二级电压控制器

摘要： 设计了一种新型的基于极坐标二值模糊逻辑规则的模糊逻辑二级电压控制器。该控制器有效地将模糊逻辑规则和二次电压控制相结合：将引导节点的电压偏差及其微分作为模糊逻辑控制规则的前项输入，与规则作用后，推理出相应的电压控制信号，然后引入比例积分器，得到区域无功控制信号，通过发电机的励磁控制，实现对引导节点电压的控制。该控制器通过引入控制发电机的参与因子，实现了区域内各控制发电机之间的相互协调和补充。以New England 39节点系统为例进行仿真计算，结果表明：所设计的二级电压控制器在系统发生电压扰动的期间，能够从区域电压稳定的角度出发，调整各级电压控制器的电压参考值从而调整其无功出力，为系统提供所需的电压支持，使得系统的负荷电压水平维持在较好的状态，提高了系统的电压稳定性。它比常规PID二级电压控制器具有更好的控制性能。     

矩阵变换器驱动异步电机模糊自适应PI控制

在间接空间矢量调制的矩阵变换器和矢量控制原理的基础上,搭建了异步电机调速系统.为了进一步提高该系统的动态性能和抗干扰能力,在调速系统的矢量控制部分引入模糊自适应PI控制器,代替传统的PI控制器,对控制器参数进行实时校正.仿真结果表明,采用模糊PI控制器的矩阵变换器驱动的调速系统能够使能量回馈到电网,达到了节能目的,同时...