泵用永磁同步电动机变频调速控制系统设计

为了提高泵用永磁同步电机的工作效率,研制了一种永磁同步电机变频调速控制系统.该系统以80C196MC单片机为控制核心,采用简单的V/F变频控制方法达到较好的控制效果.针对该控制系统的硬件和软件实现进行了论述,并通过实验证明了该控制系统的可行性.     

基于PAC的液体冷却系统设计与实现

为了满足特定项目循环冷却的目的,采用了PAC控制的方法,设计了一种基于PAC的液体冷却控制系统。由于温度系统的非线性、时变、时滞等特性,设计结合了模糊控制系统鲁棒性强的特点,并利用PAC的优秀计算能力和控制性能解决了液体冷却系统的调节问题。通过大量实验,获得了循环冷却的良好控制结果。系统具有可靠性高、控制效果好的特点,满足了循环冷却设计的要求。     

热轧带钢生产中电气自动化控制系统的可靠性分析

在科学技术快速发展的背景下,电气自动化控制系统广泛的应用于工业生产中,大大的提升了工作效率,降低了劳动强度,改善了工作环境,对于企业的发展提升了经济效益。在电气自动化控制控制系统运行的过程中,应该加强可靠性研究,保证电气自动化控制控制系统能够安全可靠的运行。文章对于影响自动化控制系统可靠性的原因进行了分析,然后阐述了提升控制设备可靠性的措施,对电气自动化控制系统应用可靠性有重要的意义。     

基于FPGA的步进电机发射机控制系统设计

本文提出一种采用FPGA对步进电机速度与位置控制的方法,建立一种步进电机驱动控制系统,该系统采用脉冲频率实现步进电机速度控制,可防止失步和过冲,提高工作效率,并结合实际工作控制,结果表明该方法的可行性。     

亚轨道飞行器控制系统快速原型设计

为了实现对飞行器控制系统的快速、廉价、高效等设计需求,提出了一种基于快速控制原型技术的亚轨道飞行器控制系统设计方案,并完成系统的软硬件设计与实时仿真。该系统由总体控制计算机、两台实时数值仿真机、VMIC、硬件接口以及物理设备等组成,建立了亚轨道飞行器再入阶段六自由度运动模型,设计控制分配并采用经典控制方法进行姿态控制,通过Rt Fly平台进行分布式快速原型仿真。仿真结果表明,控制参数调节方便,系统实时性良好,快速控制原型技术可以有效应用于飞行器控制系统设计。     

可编程控制器在氮窑液压循环控制系统中的应用

本文介绍了一种以Ｃ６０Ｐ可编程控制器为核心的控制系统。该系统用于氮窑的液压循环控制。本文描述了控制系统的组成、控制原理、控制方法以及程序设计思想。     

基于STM32点钞机控制系统设计与实现

针对传统点钞机智能化程度低的问题,提出了基于STM32的智能点钞机控制系统设计方法,实现了对多种纸币计数、找零和长期不间断满负荷工作等功能,系统的创新点是设计并实现了简易电机驱动电路实现了电机长期不间断可靠控制,并且提出并通过程序实现了多种纸币鉴别和找零算法,实验结果表明基于STM32点钞机控制系统控制性能稳定、精度高、工作时间长和损耗小等特点.满足了大量多种纸币长期不间断计数工作的要求,有效地提高了纸币清点工作效率.     

一种钎焊炉实时温度控制系统的设计与实现

本系统以钎焊炉温度控制为研究对象,提出了一种基于上位机和现场控制器的分布式控制方法,设计了钎焊炉实时温度控制系统,给出了控制系统的整体结构,并对系统的硬件和软件进行了详细设计和实现。由于采用组态软件开发使得系统的设计得以简化,可靠性增加,实现了对钎焊炉的实时温度控制。结果表明,用该方法实现了对钎焊炉的实时温度控制,有效的提高了工作效率。     

基于快速控制原型的永磁同步电机控制系统设计及应用

为满足未来社会生产要求,设计了一套基于快速控制原型的永磁同步电机控制系统。在确定快速控制原型开发流程的基础上,提出了最大转矩电流比控制方案,并分别从硬件设计、软件设计以及矢量控制等几个方面入手,对永磁同步电机控制系统设计方案进行阐述。永磁同步电机控制系统设计方案充分彰显了快速控制原型的优势,具有技术可行性。在永磁同步电机控制系统设计中,应考虑到硬件与软件等几方面因素的影响,通过完善设计路径可以增强系统功能,值得关注。     

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.     

A new algorithm for rapid tracking of approximate maximum power point in photovoltaic systems

This paper presents a new algorithm for tracking maximum power point in photovoltaic systems. This is a fast tracking algorithm, where an initial approximation of maximum power point is (MPP) quickly achieved using a variable step-size. Subsequently, the exact maximum power point can be targeted using any conventional method like the hill-climbing or incremental conductance method. Thus, the drawback of a fixed small step-size over the entire tracking range is removed, resulting in reduced number of iterations and much faster tracking compared to conventional methods. The strength of the algorithm comes from the fact that instead of tracking power, which does not have a one-to-one relationship with duty cycle, it tracks an intermediate variable /spl beta/, which has a monotonically increasing, one-to-one relationship. The algorithm has been verified on a photovoltaic system modeled in Matlab-Simulink software. The algorithm significantly improves the efficiency during the tracking phase as compared to a conventional algorithm. It is especially suitable for fast changing environmental conditions. The proposed algorithm can be implemented on any fast controller such as the digital signal processor. All the details of this study are presented.     

光伏并网逆变器的仿真研究

为了提高光伏发电效率和电能质量,对光伏并网逆变器进行了相关研究,针对光伏最大功率点跟踪问题,对传统的电导增量法进行融合和改进．提出一种改进的电导增量控制算法。该控制算法能够快速精准地跟踪最大功率点;有效改善系统在最大功率点附近的震荡现象;提高了光伏电池的发电效率。在逆变控制方面,采用电压外环、电流内环的双PI环控制,电压外环实现中间直流母线电压的稳定控制。电流内环用于控制输出电流的稳定,两者通过中间直流母线耦合,匹配简单,系统控制具有较好的快速性和稳定性;减少了谐波含量,输出电流具有良好的正弦度,且与电网电压同频同相．因而提高了电能质量。最后用matlab对光伏并网逆变器进行建模仿真,实验结果表明该系统工作稳定．性能良好。达到了预定的设计效果。     

Maximum Efficiency Point Tracking (MEPT) Method and Digital Dead Time Control Implementation

An adaptive control method, to be called maximum efficiency point tracking (MEPT), is presented in this paper. This method tracks system efficiency, which is dc–dc converter efficiency in this paper, and adaptively optimizes system parameters to maximize efficiency. The MEPT method is used in this paper to optimize the primary-to-secondary switches' dead-time parameter in an isolated topology to reduce the switches' body diodes conduction during commutation periods and to reduce body diodes conduction and reverse-recovery related losses in order to improve efficiency. MEPT tracks converter efficiency while changing the dead-time and detects the optimized dead-time value at the maximum efficiency point at different load and line conditions. In this paper, the MEPT method is discussed and analyzed, and its digital control algorithm and experimental implementation are presented.     

Analytic Solution to the Photovoltaic Maximum Power Point Problem

Photovoltaic (PV) power has been successfully used for over five decades. Whether in dc or ac form, photovoltaic cells provide power for systems in many applications on earth and space. Its principles of operation are therefore well understood, and circuit equivalents have been developed that accurately model the nonlinear relationship between the current and voltage of a photovoltaic cell. With the improved efficiencies of power electronics converters, it is now possible to operate photovoltaic system about its maximum power point (MPP) in order to improve the overall system efficiency. Hitherto, this problem has been tackled using tracking (MPPT) algorithms that iteratively find the point of maximum power and respond to changes in solar irradiance accordingly. A mathematical manipulation that uses the mean value theorem is presented here that provides the analytic solution of a point in a close neighborhood of the MPP. It is thoroughly proved that this point is enclosed in a ball of small radius that also contains the MPP and therefore can practically be considered as the MPP. Since the solution is analytic, no iterative schemes are necessary, and only a periodic measurement is required to adjust to changes in solar irradiance. A circuit is implemented that shows the validity of the theory and the accuracy of the solution.     

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。     

Fuzzy Switching Technique Applied to PWM Boost Converter Operating in Mixed Conduction Mode for PV Systems

Due to the variation of the maximum power point (MPP) of photovoltaic (PV) generators with solar radiation and temperature, boost DC-DC converters placed between PV modules and inverters in grid-connected PV systems have to be controlled in a variable operating-point condition. In addition, inductor current dynamics changes suddenly when moving from continuous to discontinuous conduction mode. The previous difficulties make the design of reliable and fast control laws for the input voltage of boost converters complicated. The aim of this paper is to propose a control algorithm based on cascaded-loop control. The input voltage is controlled by the outer loop. The inductor current is controlled by an inner loop strategy which is able to perform in mixed conduction mode, owing to the fuzzy switching technique. Simulation and experimental results for a 10-kW boost converter show that the proposed strategy achieves an accurate and robust performance at every operating point, even if the inductor value varies in a wide range; thus, fast MPP tracking techniques can be implemented. An additional advantage is that constant switching frequency is achieved.     

A novel analytical model for determining the maximum power point of thin film photovoltaic module

Achieving the maximum power output from photovoltaic (PV) modules is indispensable for the operation of grid‐connected PV power systems under varied atmospheric conditions. In recent years, the study of PV energy for different applications has attracted more and more attention because solar energy is clean and renewable. We propose an efficient direct‐prediction method to enhance the utilization efficiency of thin film PV modules by tackling the problem of tracking time and overcoming the difficulty of calculation. The proposed method is based on the p–n junction recombination mechanism and can be applied to all kinds of PV modules. Its performance is not influenced by weather conditions such as illumination or temperature. The experimental results show that the proposed method provides high‐accuracy estimation of the maximum power point (MPP) for thin film PV modules with an average error of 1.68% and 1.65% under various irradiation intensities and temperatures, respectively. The experimental results confirm that the proposed method can simply and accurately estimate the MPP for thin film PV modules under various irradiation intensities and temperatures. In future, the proposed method will be used to shed light on the optimization of the MPP tracking control model in PV systems. Copyright © 2012 John Wiley & Sons, Ltd.     

光伏并网系统中的最大功率点追踪控制

太阳能电池阵列输出特性具有强烈的非线性,为了提高系统的整体效率,一个重要的途径就是实时调整光伏电池的工作点,进行最大功率点跟踪(MPPT),使之始终工作在最大功率点附近。对并网系统的DC-DC电路原理和控制方法进行了研究,利用增量电导算法,通过脉宽调制的办法实现最大功率点的追踪,并用实验证实了其可行性和正确性。     

自动清洗的变速控制方法

全自动划片机是融合精密机械、电子、软件、材料、自控、光电、元器件等多学科技术为一体的IC装备。高速清洗系统作为全自动划片产品的重要组成部分,直接影响着设备整体工作的质量和效率。本文对清洗系统的变速控制和精确回零技术做了初步的探讨。伺服系统采用内部速度模式的变速控制方法,解决了大转动惯量下位置控制无法稳定的问题。清洗完成后,系统寻址高精度传感器,完成清洗台上下料的回零定位。