感应电机直接转矩控制系统中的模糊控制研究

对模糊控制在直接转矩控制系统中的应用做了全面分析和总结,重点讨论了各种模糊直接转矩控制方案的特点和不足之处。最后指出,这些方案都能改善系统性能,但无疑增加了系统的复杂性。     

基于TMS320F2808的感应电机直接转矩控制系统的研究

介绍了直接转矩控制的基本原理及DSP-TMS320F2808的特点,且给出了以该DSP为核心的感应电机直接转矩控制系统的设计方案和软件实现方案,正确的定子电流、转矩、磁链、速度响应实验波形表明,系统具有良好的动静态性能,所提方案是可行的。     

基于DSP的无速度传感器直接转矩控制系统设计

直接转矩控制是一种新颖的异步电机调速方案,它是在定子坐标系下,通过检测定子电流、电压等变量直接计算和控制电动机的磁链和转矩,获得转矩的高动态性能.DSP具有运算速度快、处理能力强和实时性好等特点,这使得很多复杂的控制策略和算法得以实现.本文提出了一种基于THS32OF2812的无速度传感器直接转矩控制系统,给出了硬件设计和软件设计方案.     

永磁同步电机直接转矩控制系统的仿真研究

文章分析了永磁同步电机直接转矩控制的原理,阐述传统直接转矩控制系统转矩脉动的缺点,本文将空间矢量脉宽调制技术引入永磁同步电机的直接转矩控制系统中,利用空间矢量的调制过程,可在相同的系统硬件条件下得到更多的、连续的电压空间矢量,进而得到对电机更准确的控制。仿真结果表明,该方案既保持了直接转矩控制快速动态响应,又减小了电机转矩的脉动。     

基于SVPWM的永磁同步电机直接转矩控制系统的建模与仿真

文章介绍了永磁同步电机直接转矩控制的原理,分析了传统直接转矩控制系统转矩脉动的缺点,并且将空间矢量脉宽调制技术引入永磁同步电机的直接转矩控制系统中,利用空间矢量的调制过程,可在相同的系统硬件条件下得到更多的、连续的电压空间矢量,进而得到对电机更准确的控制。仿真结果表明,该方案既保持了直接转矩控制快速动态响应,又减小了电机转矩的脉动。     

基于空间矢量调制的PMSM直接转矩控制研究

针对传统的直接转矩控制（DTC）出现的开关频率不恒定,磁链和转矩脉动大的问题,提出一种基于空间矢量调制的直接转矩控制（SVM-DTC）方法。该方法集合了直接转矩控制响应快、矢量控制连续平滑的优点,以永磁同步电机（PMSM）数学模型为基础,建立转矩、磁链双闭环PI控制回路。采用空间电压矢量调制策略,将转矩和磁链作为控制量。仿真结果表明,相对于传统的直接转矩控制,基于空间矢量调制的直接转矩控制方案的开关频率恒定,转矩、磁链脉动小,系统具有良好的动、静态性能,验证了该方法的可行性和有效性。     

基于TMS320LF2407的永磁同步电机直接转矩控制

直接转矩控制是一种高性能的电机控制方法,它根据磁通和转矩的要求,直接选择逆变器的开头顺序,使电机在最佳状态下运行。本文提出了一套基于TMS320LF2407DSP的永磁同步电机直接转矩控制系统的设计方案,介绍了其硬件结构、控制策略及软件设计,并建立永磁同步电机的数学模型,计算出定子电压、磁链、转矩方程。在此基础上,通过仿真实验分析比较了基本电压矢量直接转矩控制和矢量细分直接转矩控制的原理,实验结果表明该方案合理、结构通用,能够满足系统的各项要求指标。     

基于模糊神经网络的异步电机DTC研究

针对异步电机直接转矩控制在低速时脉动大、开关频率不固定等缺陷,提出了一种基于模糊神经网络的直接转矩控制方案,该方案采用模糊神经网络调节器分别对转矩和磁链进行控制。该控制方法综合了模糊控制和神经网络的优点,原理简单、无需大量专家经验、具有优良的非线性逼近和自适应能力。最后通过仿真实验证明,采用该控制器的异步电机系统动态性能良好、低速脉动小。     

交流电机直接转矩控制改进方案

从直接转矩控制的原理出发,介绍直接转矩控制减小脉动方法以及特点.虽然这些方法在一定程度上可改善直接转矩控制性能,但增加系统的复杂性.提出改善直接转矩控制性能而不增加系统复杂度,则是未来的研究重点.     

基于神经网络技术的电机直接转矩控制系统研究

传统的电动机直接转矩控制系统存在一些问题,比如转矩脉动较大、磁链观测不精确、开关频率不固定等,影响了控制系统整体性能的进一步提升。为此,结合神经网络技术,设计了近似圆形磁链的直接转矩控制系统优化方案,探讨采用BP神经网络实现电压矢量选择的功能。该方案采用滞环比较器对磁链进行调节并实现转矩调节,建立了空间电压矢量选择的最优方式,设计了神经网络空间电压矢量选择器结构,提出采用神经网络理论取代传统开关表的方法。系统仿真结果表明,优化后的系统能够有效降低转矩脉动,定子磁链轨迹的脉动成分也明显下降,在低速运行状态下同样取得了较好的效果,表明该系统达到了调速性能改善和整体性能提升的目的。     

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.     

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.     

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.