基于自适应模糊PID算法的光伏系统MPPT控制

为进一步提高光伏发电系统MPPT控制品质,对常规模糊跟踪算法进行了改进,提出自适应模糊PID双模控制策略,分析了控制算法的原理,并对控制系统做了设计。实验结果显示,自适应算法能迅速感知外界环境变化,快速跟踪光伏电池最大功率点,具有良好的鲁棒性,同时引入的PID控制能有效消除最大功率点附近的振荡现象,提高系统稳定性。整个双模控制实现了MPPT精确性与快速性的兼备。     

光伏电池的自适应占空比扰动MPPT算法研究

环境温度、光照强度和负载等因素对光伏电池的输出特性影响很大,为了提高光伏电池的工作效率,需要准确快速地跟踪光伏电池的最大功率点。在分析了光伏电池的输出特性的基础上,建立了光伏电池的仿真模型;针对传统爬山法的不足,采用了自适应占空比扰动法对最大功率点进行了跟踪控制。给出了上述两种算法的工作原理及设计过程。仿真结果表明:自适应占空比扰动算法跟踪迅速,减少了系统在最大功率点附近的振荡现象,提高了系统的跟踪速度和精度。     

应用于光伏发电系统的最大功率点跟踪控制器设计

为了提高光伏发电系统的效率和稳定性,从而有力促进可再生能源的推广,提出一种应用于光伏电池系统的最大功率点跟踪控制器。首先,对光伏电池系统进行Matlab/Simulink建模和仿真,并完成输出特性分析;然后,采用动态步长对最大功率点跟踪算法中的传统扰动观察法进行优化,以减少误判;最后,基于DSP TMS320F2812设计了控制器的硬件电路。实验结果显示,提出的最大功率点跟踪控制器具有更高的稳定性,有效地提高了太阳能的利用率。     

光伏发电中最大功率点跟踪控制方法综述

在光伏发电系统中,光伏电池输出特性具有明显的非线性特征,其输出功率受光照强度及环境温度影响很大。因此,为了提高光伏电池的利用效率,需要快速准确地对光伏电池的最大功率点进行跟踪控制。本文简要介绍了十多种常用的光伏电池最大功率点跟踪控制方法的原理,说明了各种控制方法的优缺点,指出了选择某一方法时需要综合考虑的因素,并展望了光伏发电系统最大功率点跟踪方法的发展方向。     

一种应用于光伏系统的双模式MPPT控制方法研究

光伏发电对于气象条件的依赖比较严重.为了使光伏电池产生尽可能多的电能,需要对其进行最大功率点跟踪控制.本文提出了一种双模式最大功率点跟踪控制方法,此方法结合了短路电流法和电阻增量法的优点,通过Simlink仿真可知,应用这种双模式控制方法的光伏系统在阳光突变时能够快速地重新达到最大功率点,并有效降低光伏系统在最大功率点处的震荡,减少了系统功率损耗.     

基于模糊-PID双模控制的MPPT技术研究

太阳能电池发出的功率不稳定,但其必存在一最大功率,为了提高光伏电池的利用率,需要采用一定的控制措施使光伏电池始终工作在最大功率点处。研究方案以独立光伏发电系统为研究对象,建立了光伏电池的数学仿真模型,并在传统模糊算法的基础上,提出一种模糊-PID双模控制方案,仿真结果显示模糊-PID算法与传统模糊算法相比,消除了在最大功率点处震荡的问题,提高了跟踪精度。     

一种数字PID控制的扰动观察法光伏电池MPPT仿真

光伏电池的最大功率点(MPP)随着光照强度和环境温度的变化而变化,因此最大功率点跟踪(MPPT)成为光伏系统中的重要研究内容。本文选用PSIM仿真软件,搭建Boost电路,采用数字PID控制的扰动观察法来实现光伏电池最大功率点的跟踪,并进行了仿真验证。     

基于变步长电导增量法的光伏最大功率跟踪控制

太阳能光伏发电的最大功率跟踪控制是小型太阳能发电系统中的核心控制之一.针对光伏电池功率曲线的特点,本文在分析最大功率跟踪原理的基础上,提出了基于变步长电导增量法,实现光伏电池最大功率跟踪的优化控制,最大程度的提高光伏电池效率.并通过与定步长算法的仿真对比实验,验证了该算法跟踪迅速,控制精度高和稳定无振荡的特点.     

基于双并联Boost电路的光伏系统最大功率点跟踪控制方法

光伏电池的输出功率取决于外界环境（温度和光照条件）和负载状况,需采用最大功率点跟踪（MPPT）电路,才能使光伏电池始终输出最大功率,从而充分发挥光伏器件的光电转换效能.在比较了常用光伏发电系统控制的优缺点后,依据MPPT控制算法的基本工作原理,主电路采用双并联Boost电路,具有电压提升功能,并且能够提高DC-DC环节的额定功率和减小直流母线电压的纹波.针对传统扰动观察法存在的振荡和误判问题,提出了一种新型的基于双并联Boost电路的改进扰动观察法最大功率跟踪策略.在Matlab/Simulink下进行了建模与仿真,仿真结果表明,当外界环境发生变化时,系统能快速准确跟踪此变化,避免算法误判现象的发生,通过改变当前的负载阻抗,使之与光伏电池的输出阻抗等值相匹配采满足最大功率输出的要求,使系统始终工作在最大功率点处,并且在最大功率点处具有很好的稳态性能.最后通过实验验证了该算法的有效性.     

基于扰动观察法的MPPT控制优化策略

为了提高光伏发电系统的充电效率,系统控制器采用高性能低功耗的ATmega16单片机为核心,通过调节PWM波占空比实时改变Buck变换器的输出电压,采用扰动观察法的MPPT控制策略,实现对光伏发电系统最大功率点的跟踪。针对扰动观察法跟踪过程中可能由于快速扰动导致功率振荡和误判的问题,系统对MPPT算法进行优化,并通过友好的人机界面实时显示最大功率曲线图。测试结果表明,该方法能够保证光伏发电系统快速、稳定、精确地跟踪最大功率点,提高了充电效率。     

模糊PID控制在锅炉燃烧系统中的应用

针对目前锅炉存在的能耗高、燃烧不完全、污染环境、热效率低的缺点,设计了一种新型锅炉燃烧系统.该系统采用PID串级和Vague集分时控制,有效地提高了锅炉控制质量.     

Suboptimal digital control systems with bounded control inputs

Bounds on the control inputs to a linear system are dealt with in a manner suitable for online computer control. The method guarantees that for r control inputs the constrained optimum will be located in, at most, r steps.     

Content-based deep communication control for networked control system

In smart cities, the networked control system plays a significant role in transportation systems, power stations or other critical infrastructures, and it is facing many security issues. From this point, this paper proposes a content-based deep communication control approach to guarantee its security. Based on the layer architecture, this approach analyzes the interactive content in depth according to different industrial communication protocols, and implements the access control between two distinct enclaves. For OPC Classic, we acquire the dynamic port provided by OPC server, and open a new connection belonging to this port; for Modbus/TCP, we not only analyze the ordinary function codes and addresses, but also check the register or coil values by using the multi-bit Trie-tree matching algorithm. Besides, the white-listing strategy is introduced to satisfy the special requirements of industrial communication. Our experiment results show that, on the one hand the proposed approach provides OPC and Modbus/TCP defenses in depth; on the other hand it has less than 1 ms forwarding latency and 0 packet loss rate when the rule number reaches 200, and all these meet the availability requirements in the networked control system. In particular, this approach has been successfully applied in several real-world petrochemical control systems.     

基于自适应模糊理论的某型无人机起飞控制方法

基于合理简化的无人机纵向模型,设计了一种自适应模糊控制器,该控制器将Takagi-Sugeno模糊系统与等效控制器相结合,以增强系统的鲁棒性.只要求预先知道系统的相对阶以及未知函数的上下界即可,不需要精确的数学模型.Lyapunov合成方法证明了跟踪误差能趋近于零且其余的控制信号均有界.最后,结合优先级按比例分配的控制分配器,给出了存在扰动情况下飞行控制系统的仿真结果,表明即使在模型部分未知的情况下,该系统仍然能够达到飞行控制的指标性能和品质要求,验证了该方法的有效性.     

基于TRICON控制系统防喘振控制算法

喘振是造成压缩机损坏的重要原因,在此针对某厂70万吨/年烯烃项目,根据丙烯工艺流程,设计了一套压缩机的防喘振控制系统。该控制系统以TRIEW软件为人机界面,利用TRICON独有的防喘振控制软件包,将喘振PID控制、喘振超驰、手动控制算法相结合,通过喘振PID参数的在线优化,有效地实现了压缩机的防喘振控制,现场实际运行结果表明了该系统的稳定性和可靠性,同时,验证了该喘振控制算法的有效性。     

Modeling and control for smart Mesoflap aeroelastic control

This paper introduces a novel concept termed Smart Mesoflaps for Aeroelastic Recirculation Transpiration (SMART) to render mass and momentum transfer for controlling shock/boundary-layer interactions in supersonic jet inlets. The SMART concept consists of a matrix of small flaps designed to undergo local aeroelastic deflection to achieve proper mass bleed or injection when subjected to shock loads. To optimize the performance of this system, NiTi shape memory alloy is used as an actuator for the flaps to control the amount of recirculation. The focus of this paper will be the subsystem modeling and control of a single flap. After a relatively detailed model is developed, a simpler model is generated, and it is experimentally shown that this approximation is adequate for control purposes. Next, the control strategy for this subsystem, subject to hysteresis and actuator saturation, is presented. A basic proportional integral derivative (PID) controller is enhanced using a hysteresis compensator (HC) and an error governor (EG). A generalized error governing scheme for PID controllers to compensate for actuator saturations is also developed. This EG method is generalizable to any stable process controlled by a PID. Finally, the PID with HC and the error governing method is experimentally applied to a benchtop SMART subsystem.     

Throttle actuator control system for vehicle traction control

Accurate and quick positioning of the throttle valve in a gasoline engine is required to implement various systems such as traction control systems (TCS), cruise control systems and drive-by-wire systems. In this research, the throttle actuator system for TCS application was developed. Unlike other systems, this system consists of only one throttle body to obtain small volume and low manufacturing cost, and uses a DC servo motor for quick and accurate responses. In order to drive the DC motor, a PWM signal generator and PWM amplifier were built and interfaced to the motor and controller. This paper also presents the position control logic of the throttle actuator with the TDC (time delay control) scheme with a variable reference model. By varying the reference model based on the size of the step changes in the target throttle angle, the TDC scheme yields good transient response characteristics in that both overshoot prevention and a quick response time are achieved. Actual vehicle tests with this developed system incorporated with the TCS system show that it satisfies all the conditions required for the TCS operation.     

水泥配料控制中控制算法的研究

配料是水泥生产过程的重要环节,在一些连续称量配料工艺过程中,以往大多通过控制每种物料的瞬时流量来满足工艺要求,但往往误差较大,给生产带来不良影响。为提高控制精度,提出了一种偏差加权累积量控制PID算法,并在水泥生料配料控制中进行了实施,实验结果表明该算法能有效地抑制和消除系统过量超调和不停振荡,且对于某些不要求每个瞬时值都控制给定值的量,该算法可以避免调节阀的频繁动作并大大提高调节品质。偏差加权累积的PID控制算法具有简单、方便、易于实现的特点,且在水泥生料配料控制中取得了理想的效果,有很好的推广前景。     

Adaptive ABR congestion control with active buffer control

ATM Forum has defined that the ABR service is designed mainly for data traffic. The design of a simple and efficient congestion control scheme is a problem that network managers have to face. In this paper, we propose a control scheme for ABR service for better scalability and response. The scheme uses both the load level and an increase in queue length to detect the presence of congestion. Continuous control functions are designed for the bandwidth allocation. A better buffer control is achieved by incorporating the percentage of buffer occupancy into the control function. All of the control functions are designed in such a way that they are sensitive to the change of the system states when they are far from the optimal level to get a fast response, but insensitive and change slowly when the states are close to the optimal level to keep the system around the steady state. Our simulation results show that the algorithm is fair to all the connections and it converges fast when the network's condition changes. Copyright © 2001 John Wiley & Sons, Ltd.