基于BP网络的开关磁阻电机变磁链DTC方法研究

文章针对传统定磁链双闭环DTC调速系统稳态时定子电流幅值较大、电机铜耗增加的问题,提出了变磁链给定的解决方案,建立了变磁链三闭环DTC调速系统。仿真结果证明,此调速系统动、静态性能良好,既能充分抑制SRM的转矩脉动,又能在稳态时降低定子电流的幅值,解决了电机高速时铜耗较大的问题。另外,针对变磁链三闭环DTC调速系统控制参数复杂,实时性要求高的特点,文章将BP神经网络PID控制器与传统PI控制器复合,构成了BP-PI控制器。仿真表明,BP-PI控制器有效克服了单一神经网络DTC控制器存在的缺陷,动、静态性能明显优于传统PI调节器,显著提高了调速系统的自适应性和鲁棒性。     

无模型控制方法在异步电动机控制中的仿真研究

在异步电动机的转差频率矢量控制中,其控制不需要复杂的磁通检测,且运算和控制简单,因而在基频以下的调速系统中得到较多的应用。但该系统存在比较明显的缺陷。基于此,本文设计了一种无模型自适应控制器,将该控制器引入原系统,与原系统构成前馈补偿。仿真试验表明,该方法有效减小了转矩脉动,改善了定子电流波形,具有良好的动、静态性能。     

MATLAB仿真在直流电机双闭环调速系统中的应用

在分析了直流调速系统原理的基础上,在MATLAB/SIMULINK仿真环境下对转速、电流双闭环调速系统建模并进行了仿真分析。仿真结果表明,该控制系统模型具有转速、转矩响应好和仿真速度快的优点。     

基于神经滑模变自抗扰控制的感应电机变频调速系统设计

基于强化感应电机变频调速系统的调速质量及响应速度的考量,文章设计出建立在神经滑模变自抗扰控制的感应电机变频调速系统。应用ADRC控制,在基础上提升了调速系统控制品质与控制精准性能。综合神经逆控制思想,创建起神经滑模变自抗扰控制器,减少系统的抖振现象,实现对感应电机调速系统转速、转矩、磁链等参数的最优化控制。     

基于神经网络的异步电动机直接转矩控制系统

直接转矩控制是继矢量控制变频技术后发展起来的一种新型具有高性能的交流变频调速技术。针对基于直接转矩控制的异步电动机运行时存在较大的电流及转矩脉动问题,提出了利用神经网络构造逆变器的开关状态选择器用于直接转矩控制,摒弃了滞环,系统实现更简单。仿真结果表明,该调速系统具有良好的动态性能,该设计是可行的。     

基于DITC开关磁阻风力发电系统MPPT2-SMC控制

针对开关磁阻发电机(SRG)转矩波动大及难以快速精确调速的缺点,提出了二阶滑模控制(2-SMC)与直接瞬时转矩控制(DITC)相结合的复合控制方案,设计二阶滑模控制器,基于Matlab/simulink搭建风力发电系统模型。仿真结果表明,所用控制方案不仅实现了最大功率跟踪,有效降低了发电机转矩脉动,同时减小了输出功率的波动。     

无刷直流电机调速系统转矩脉动抑制方法研究

通过对无刷直流电机开通期间的相电流和关断期间的相电流分析,经过实际计算得到电磁转矩的表达式,得到相应的电磁转矩脉动曲线。基于电流预测方法通过将预测模型分为模型建立、反馈调整和性能优化3步,通过控制换相电流保持在稳定的状态,从而实现对转矩脉动的抑制。通过仿真和实际实验表明,该无刷直流电机调速系统在实际运行中具有转矩脉动小、响应速度快等优点。     

基于模糊控制的感应电机直接转矩控制系统

根据直接转矩控制理论,在Matlab 6.5/Simulink下构造了一个感应电机直接转矩控制系统的仿真模型。为改善感应电机系统的动、静态品质,设计了模糊自适应PI速度调节器,根据速度偏差与偏差变化率,通过模糊推理在线调整PI参数,提高系统的调速性能。仿真结果表明,这种模糊控制器具有比常规PID控制器更好的控制效果。     

内置式永磁同步电机弱磁控制策略

随着电动汽车的发展,要求电动车驱动系统尽可能高的转矩密度,良好的转矩控制能力,较高的运行可靠性以及调速范围尽可能的高。内置式永磁同步电机(IPMSM)有着高效率、高功率密度、高转矩电流以及宽的调速范围等优点而在电动汽车上有着广泛的应用。针对永磁同步电机的特点,分析永磁同步电机弱磁控制策略的相关理论,在基于MTPA的传统的空间矢量控制方法的基础上,分析了弱磁控制的时刻,即当速度高于转折速度时,此时电机端电压达到极限,采用弱磁控制,从而扩大调速范围,最后建立弱磁控制系统的MATLAB/SIMULINK仿真模型并且优化该控制策略。     

煤矿皮带机变频调速系统的实现

为解决煤矿皮带机系统传动效率低、起动电流冲击及机械冲击大、功率不平衡、维护成本高等问题,本文设计了一套皮带机变频调速电控系统。详细介绍了皮带机变频调速电控系统组成,分析了ACS800系列变频器的直接转矩控制技术、主从控制技术、Profibus DP通讯技术,给出了ACS800变频器在工程中的具体应用及相关参数的设置,并采用Siemans公司生产的S7-300可编程序控制器实现了电控系统的自动化控制。     

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.     

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.     

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.     

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.