单神经元PID控制器仿真及其PLC实现

简要分析了传统PID控制器与单神经元PID控制器原理,通过Matlab仿真及基于S7-200的单神经元PID控制器编程控制,验证方案可行并分析比较了两种控制器的优缺点.     

基于定量反馈理论的电压源换流器高压直流输电系统鲁棒控制器

PI控制是基于电压源换流器高压直流输电(VSC-HVDC)系统控制器的主流,但面对系统的不确定性时,PI控制器表现出较弱的运行性能。针对这一问题,在传统矢量控制策略的基础上,结合定量反馈理论,提出了一种新的鲁棒控制策略。该策略在设计中可以考虑相位信息,直观地权衡控制器复杂性与性能指标,设计方法简单,易于工程人员现场调节和操作。在不同的运行条件下,用PSCAD软件对控制系统进行了仿真,并与PI控制器下的系统性能进行对比。仿真结果表明,所设计的控制器具有良好的鲁棒性和动态性。     

Performance of current controllers for VSI-fed IPMSM drive

The current-controlled voltage-source-inverter-fed interior permanent-magnet synchronous motor (IPMSM) has received widespread interest in high-precision industrial drive applications. This paper presents a detailed comparison of various current controller schemes, particularly hysteresis and ramp comparator controllers for the IPMSM drive based on performance at different speeds. The hysteresis and the ramp comparator controllers are getting more attention due to their simplicity and high dynamic responses. In this paper, fixed, sinusoidal, and mixed-band hysteresis current controllers, as well as conventional ramp and improved ramp comparator controllers, are considered. The harmonic spectra of the motor line currents for various current controllers are obtained using a fast Fourier transform for comparison purposes. The comparison is based on experimental results. In order to compare the performance of various controllers, the complete drive system is implemented in real time using the digital signal processor controller board DS-1102.     

感应电动机交-交变频调速系统的双内模控制研究

基于先进的内模控制理论,提出了一种双内模控制结构,将内模控制拓展应用到多环控制的感应电动机交-交变频调速系统的外环;仿照调速系统调节器的工程设计方法,提出了基于内模控制原理的调速系统调节器设计原则,并进行了调节器设计.所设计的电流调节器为PI结构、磁链和转速调节器为PI或PID结构,但都只有一个可调参数,结构简单,参数调整方便.仿真实验表明,采用内模控制后,系统的输出动态性能优于工程设计方法设计的动态性能.     

基于模糊控制的PID调节器在减温水自动中的应用

充分利用计算机资源,结合模糊控制、常规PID控制、预估控制,完善减温水自动,提高自动投入品质,减轻运行人员劳动强度。     

A software tool for coordination of controllers in power systems

A report is presented on the theoretical background and the methodology of development of a software tool for offline coordination of power system controllers in either a high-frequency (5-55 Hz) or a low-frequency (0.2-2.0 Hz) range. The controllers considered for coordination are: voltage regulators, power system stabilizers (PSSs), speed governors, main and auxiliary controllers of HVDC converters, and main and auxiliary controllers of static VAr compensators (SVCs). The software package calculates the eigenvalues associated with a prespecified number of least-stable oscillatory modes of the system using a modified version of the S matrix method, and it adjusts the controller parameters to increase a damping of the least-stable mode, using a gradient optimization technique. The software tool is referred to as EICO (EIgenvalue program of COordination of controllers). EICO is coded in Fortran. The application of EICO is demonstrated by coordinating the controllers of a power system with 371 state variables and 140 controller parameters, in the high-frequency range. EICO results are verified by detailed digital simulation of the system, using the electromagnetic transients program (EMTP). The study results demonstrate the technical advantages of the coordinated controllers as compared with the noncoordinated scheme     

模糊PID控制在双闭环直流调速系统中的应用研究

分析了模糊PID控制的特点以及具体运用的环境,研究了应用模糊PID控制技术的直流双闭环调速系统,通过仿真论证了模糊PID控制应用于直流双闭环调速系统时具有响应速度快、鲁棒性强以及不依赖被控对象数学模型的优点,并且分析了采用的两种模糊PID控制方法的各自特点及其应用环境。     

An Evaluation of Different Controllers Based on the Network Frequency Maintenance Strategy for a Large and Multi-control-area Interconnected Power System

Abstract—Maintaining the network frequency at its nominal value due to the load changes is one of the most important issues in the control and operation schedule of a large and multi-area interconnected power system. For the effective control solution, two types of tie-line bias control strategy-based controllers have been applied, i.e., classical and improved controllers. The classical controllers using conventional regulators, including integral, proportional–integral and proportional-integral-derivative, have achieved initial control results to bring the steady state back to the network. However, due to the very poor control features (e.g., large overshoots and long settling times), they need to be replaced with improved controllers, such as fuzzy logic and artificial neural network. To obtain an entire evaluation of the application of different load-frequency controllers, a five-control-area interconnected power system was built as a typical case study. Three improved controllers using proportional-plus-integral-based fuzzy logic and artificial neural network-based non-linear autoregressive moving average (NARMA-L2) architectures as well as their hybrid combination will also be investigated in this study. Simulation results obtained reveal that the improved controllers have obtained smaller overshoots (from 13.95 to 84.18%) and shorter settling times (from 19.91 to 65.71%) compared with the classical controllers.     

用FACTS技术提高电力系统静态负荷裕度能力

以连续潮流法为工具,研究静止无功补偿器(SVC)、静止同步补偿器(STATCOM)以及可控串联电容器补偿(TCSC)3种柔性交流输电(FACTS)器件对系统静态负荷裕度提高能力的影响,建立了SVC、STACTOM和TCSC用于潮流和稳定分析的模型。介绍了用节点参与因子和支路参与因子作为指标,选择并联补偿设备和串联补偿设备最佳安装地点的模态分析法。IEEE 14节点系统实现的算例表明:3种装置都可以提高系统静态负荷裕度,但影响程度不同。     

HVDC中发电机控制与直流控制之间的MAS协调策略

针对交直流电网中因为直流控制与发电机控制欠协调而导致的交流联络线功率低频振荡问题,运用MAS与参数约束非线性优化算法结合来解决直流控制与送端机组间的协调。该方法将直流控制与发电机控制分别用Agent代理,参数约束非线性优化算法嵌入各Agent模块进行局部参数优化计算,并向协调Agent提供各自的整定参数,通过协调Agent统一调整,最终实现直流控制与送端机组间控制参数的优化调节,在全局协调的方式下增强交流联络线低频振荡的阻尼。文章以南方电网贵广直流和天广直流线为实例验证了该方法的有效性。     

Comparative evaluation of sliding mode fuzzy controller and PID controller for a boost converter

Nonlinear controllers such as fuzzy controllers and sliding mode controllers have been applied to boost converters because of their nonlinear properties. Although both fuzzy and sliding mode controllers have desirable characteristics, they have disadvantages in practice when applied individually. A sliding mode fuzzy controller is proposed to control boost converters. The sliding mode fuzzy controller combines the advantages of both fuzzy controllers and sliding mode controllers. It also has advantages of its own that are well suited for digital control design and implementation. A sliding mode fuzzy controller is designed and verified with experimental results using a prototype boost converter with a DSP-based digital controller. Experimental results of the boost converter using sliding mode fuzzy control are evaluated in comparison with experimental results using a linear PID and PI controller. The comparison indicates that the sliding mode fuzzy controller is able to obtain the desired transient response under varying operating points without chattering. The startup response using sliding mode fuzzy control is superior to the response using PID and PI control, while the load transient response shows no obvious advantage.     

Example applications of the linear adaptive design technique

Adaptive controllers can be designed by a variety of different methodologies that have been developed over the past 35 years. However, all these methodologies have one thing in common; they lead to adaptive controllers that are intriniscatly non-linear in structure. Recently a new, unorthodox approach to the adaptive control problem has been developed. This new methodology leads to a new class of adaptive controllers that, in many cases, are entirely linear and have all-constant parameters (constant gains). In the present paper this new approach to adaptive control is used to design‘linear adaptive controllers’for two example applications, and the closed-loop adaptive performance obtained in each case is illustrated by digital simulation tests. These results demonstrate that the new linear adaptive controllers are able to produce a surprisingly high-degree of adaptation over significant ranges of plant parameter variations and disturbances.     

Neuro-fuzzy controller for gas turbine in biomass-based electric power plant

Biomass gasification is a technology that transforms solid biomass into syngas. The gas turbine controller regulates both the gas turbine and the gas turbine generator. Two fuzzy logic controllers have been developed using speed and mechanical power deviations, and a neural network has been designed to tune the gains of the fuzzy logic controllers based on the operating conditions of the biomass-based electric power plant. It is shown that by tuning the fuzzy logic controllers, optimal time domain performance of the system can be achieved in a wide range of operating conditions compared to fixed parameter fuzzy logic controllers and PID controllers.     

SVC 与发电机励磁协调非线性控制

用直接反馈线性化方法设计ＳＶＣ与发电机励磁协调非线性控制器。所设计的控制器能实现当地信号控制,并对系统运行点和网络结构的变化具有很强的鲁棒性。数字仿真验证了该控制器的优越性。     

Real-time implementation of an indirect adaptive robot controller

Adaptive controllers applied to high-speed and high-precision robot manipulators give excellent tracking performances because they take into account the full dynamics of the robot. Recent publications have shown that on-line estimation of the dynamic constant parameters can be obtained by the joint tracking error (direct adaptive control) or by the torque prediction error (indirect adaptive control). In direct adaptive controllers the estimation law is derived from Lyapunov stability or Popov hyperstability methods. These controllers are simple and their real-time implementation is easy; however, the estimation is not so accurate. In indirect adaptive controllers the estimation law is based on a least squares algorithm. These controllers give accurate estimates of the manipulator parameters; however, they involve much more computation than the direct approach. Therefore no real-time implementations of indirect adaptive tracking controllers for robots have been reported in the literature until now. This paper describes a real-time implementation of an indirect adaptive scheme applied to a two-degree-of-freedom (2DOF) direct-drive SCAM robot. the controller is implemented at low cost by the use of a single-chip digital signal processor (DSP).     

On the use of fuzzy logic in control systems for technological equipment

The possibilities and prospects of using fuzzy logic in control systems for electro-technological equipment are analyzed based on a comparative study of standard temperature controllers of resistance furnaces and fuzzy logic controllers. It is shown that it is effective to use fuzzy logic control systems for different kinds of technological equipment. The development of fuzzy logic control systems and characteristics of their application are analyzed. The basic structures of systems constructed using fuzzy logic control are considered, is the way in which they are classified. The simulation models of temperature controllers for resistance furnaces are studied using the Matlab/Simulink software including the Fuzzy Logic Toolbox application. It is shown that a use of fuzzy controllers for simple deterministic control systems like temperature controllers of resistance furnaces does not lead to any substantial improvement in accuracy and control quality, but needs a sophisticated algorithm for control and response speed of the control system. It is assumed that a use of fuzzy logic controllers to control more sophisticated equipment characterized by the multifactor processes with a high degree of uncertainty and difficulties in determination of output parameters will allow one to obtain better results than do conventional systems.     

DSP数字交流调速系统的硬件设计

交流电机调速系统正向数字化方向发展，一般的微控制器缺乏进行复杂计算（如矢量运算）的能力，而32位微处理器相对又较昂贵，32位数字信号处理器DSP由于其运算速度快，性能价格比高，效能超出其他计算机机处理器10－50倍，这使得交流调速系统的性能和精度更优于传统的交流调速系统。论文讨论了高速DSP在交流调速系统中的外部硬件设计。     

Load frequency control using Bat inspired algorithm based dual mode gain scheduling of PI controllers for interconnected power system

This paper highlights the load frequency control using dual mode Bat algorithm based scheduling of PI controllers for interconnected power systems. The bat inspired algorithm based on the echolocation of bats has been developed in 2010. In this study, the bat inspired algorithm based dual mode PI controller is applied to the multi-area interconnected thermal power system in order to tune the parameter PI controllers. The proposed controller is simple in structure and easy for implementation. The proposed controller was compared with those from conventional the PI controllers and Fuzzy gain scheduling of PI controllers. The simulation results show the point that the proposed bat inspired algorithm, based dual mode gain scheduling of PI controllers (BIDPI), provides better transient as well as steady state of response. It is also found that the proposed controller is less sensitive to the changes in system parameters.     

Current controllers for devices of microplasma oxidation

Questions of the development of current controllers for microplasma oxidation devices with a wide set of functions are considered. Different variants of implementation of controllers based on a thyristor controlled rectifier and transistor power converter are presented. Mathematical modeling and investigation of operational modes of power units of controllers are performed. The results of testing the experimental samples are presented.     

Tuning of industrial controllers from the transient responses of control systems without approximating them by analytical expressions

We describe a method for adaptively tuning closed-loop control systems constructed on the basis of industrial controllers from transient responses of the systems. Central to the method is application of the Fourier transform to time characteristics in making transition to the frequency domain without preliminarily approximating them by analytical expressions. Results of checking the operability of the method are presented taking as an example the tuning of systems equipped with PLK-150 controllers of Oven and R-380 controllers used in the Kvint SI computerized automation suite.