基于逆系统的光电平台非线性解耦控制

针对两轴两框架光电平台电机存在的非线性以及方位与俯仰轴系之间互相影响产生的耦合对控制精度的影响,提出一种基于逆系统的光电平台非线性解耦控制方法.根据两轴光电平台方位与俯仰框架的动力学模型,建立状态空间方程,然后设计逆系统,获取系统的状态变量,并将逆系统与原系统进行串联得到一个伪线性系统,使原来的单个耦合非线性多输入多输...     

基于SVM算法的真空断路器永磁机构故障诊断方法

永磁操动机构作为新式真空断路器常用的操动机构,其运行状态决定真空断路器的性能,因此有必要对永磁操动机构进行故障诊断研究。本文以ZW45-12型永磁机构真空断路器为研究对象,对真空断路器永磁机构行程曲线进行特征参数分析,选择断路器启动时间、动作时间、刚分合速度、分合闸平均速度等四个参数作为诊断特征参数;基于断路器分合闸实验数据,对比常用的故障诊断算法,结果表明SVM算法性能最优;基于Spark平台搭建使用SVM算法的永磁机构故障诊断模型,并通过不断调整SVM算法的惩罚参数C和核函数kernel,对诊断模型进行优化。优化的SVM故障诊断模型对永磁机构回路电阻增大、机构卡涩及分闸弹簧单根脱落故障诊断精确率均在90%以上,分闸弹簧单根脱落故障诊断准确率可达96%,可以满足永磁机构故障诊断精度需求。研究结果为永磁机构的故障诊断提供参考。     

基于BP神经网络的电磁轴承逆系统解耦控制

针对主动电磁轴承-转子系统多变量、非线性和强耦合的特征,提出了一种基于BP神经网络的逆系统解耦控制方法.建立了主动电磁轴承-转子系统的径向力数学模型,并对该模型进行可逆性分析.在证明系统可逆的基础上,采用BP神经网络构建逆系统,通过将此逆系统与原系统级联,使原系统解耦成4个独立子系统,实现了主动电磁轴承-转子系统的径向...     

感应电机自适应电流解耦逆控制

通过对感应电机状态方程的转换,将电机dq轴电流方程解耦,利用自适应逆控制思想,采用LMS(最小均方)算法,实现了对MIMO、多参量、强耦合感应电机的电流控制,电机长期运行会导致某些参数发生漂移,仿真验证了该算法对参数变化的鲁棒性.     

基于偏差解耦的永磁同步电动机控制研究

在分析永磁同步电动机数学模型的基础上,推导出基于最大转矩电流比的矢量控制,但动态耦合关系依然存在,这造成了动态过程中电流分量互相影响,尤其在高速过渡过程中动态耦合影响更为显著,使电动机的动态性能变差。本文推导出一种偏差解耦控制,并与传统的反馈解耦控制进行了对比分析。仿真结果表明偏差解耦控制具有很好的电流控制特性。     

感应电机调速系统的神经网络逆在线调整控制

以多变量、非线性、强耦合的感应电机调速系统为研究对象,在基于神经网络逆系统离线训练的基础上提出了在线调整的策略,通过静态神经网络加积分器来构造感应电机调速系统的逆模型,在实际运行中不断地修正神经网络权值,更精确地逼近其逆系统,实现了感应电机转速的高精度控制。仿真和实验结果表明系统具有优良的静态及动态性能,且对电机参数的变化与负载扰动具有较强的鲁棒性。     

永磁直驱风力发电系统内模解耦控制研究

针对永磁直驱风力发电系统中传统解耦策略易受系统参数变化的影响、对负载变化的适应能力差和抗干扰能力弱等缺点,本文将内模解耦控制引入双三电平永磁直驱风力发电系统网侧和机侧控制系统,并对机侧内模控制器的设计进行了详细的介绍。仿真实验结果表明电流内环采用内模解耦控制后,可有效抑制干扰及模型失配对输出的影响,克服传统的PI控制不能动态解耦以及对电机参数敏感的问题,并增强对给定信号的跟踪能力。     

基于SVM的油水两相流流型识别算法

油水两相流流型不仅影响两相流的流动特性、热传和传质性能,而且影响系统运行时的可靠性和效率.采用统计理论、小波包理论相结合的方法对垂直上升管内油水两相流的电导波动信号进行分析,得到8个能反应油水两相流流动特性的特征参数.设计支持向量机寻优函数,将这些参数作为流型的特征向量,利用支持向量机进行训练并识别流型.实验结果表明:...     

新型五相步进电机控制技术

五相步进电机已被广泛应用于控制旋转角度、速度、位置和同步性的诸多领域。通过对新型五相步进电机工作原理的研究,采用Luminary公司LM3S615芯片设计完成步进电机的控制组件,由其内部自带的脉宽调制(PWM)模块产生驱动组件所需的接收时序信号,实现对驱动组件进行细分驱动。通过配置驱动组件,可以产生占空比不同的方波,从而在电机线圈内能够产生多种不同幅值的电流来实现细分驱动。选用的五相步进电机平台型号是SGSP(MS)20-85(X)。通过实验表明可以实现对步进电机的步进角、角位移量以及转动速度和加速度的精确控制。     

模糊PID神经网络逆控制多电机系统分析

本文围绕模糊PID神经网络逆控制多电机系统展开一系列探究分析。在工业生产技术进一步发展的时代背景下,生产线凸显出复杂化特点,因此会在一定程度上受到电机功率大小的影响。受到科技进步和社会需求增大的影响,传统的单电机控制模式明显已经无法满足工业生产需求,多台电机协同控制已经成为社会工业生产的必然要求,特别是在轧钢、造纸、经纱和印花等现代工业领域中获得了一定运用。     

Vector control of a permanent-magnet synchronous motor using AC-ACmatrix converter

This paper uses a recently proposed dqo transformation to analyze a permanent-magnet synchronous machine (PMSM) driven by a nine-switch matrix power converter. The matrix transformation used leads to a new equivalent circuit where its parameters are independent of the frequency of the other side to which the circuit is referred. From this equivalent circuit, a set of command algorithms is deduced in order to control, in an independent way, the flux and torque of the machine. It is shown that the control of the gain and the displacement power factor at either set of terminals is dependent only on the choice of the phase angle in the matrix transformation. In order to verify the validity of the proposed algorithms, a full PMSM drive has been simulated with the assumption of perfect switch behavior for the matrix power converter     

Sensorless speed control of nonsalient permanent-magnet synchronous motor using rotor-position-tracking PI controller

This paper presents a new velocity estimation strategy of a nonsalient permanent-magnet synchronous motor (PMSM) drive without a high-frequency signal injection or special pulsewidth-modulation (PWM) pattern. This approach is based on the d-axis current regulator output voltage of the drive system that has the information of rotor position error. Rotor velocity can be estimated through a rotor-position-tracking proportional-integral (PI) controller that controls the position error to zero. For zero and low-speed operation, the PI controller gains of rotor position tracking controller have a variable structure according to the estimated rotor velocity. In order to boost the bandwidth of the PI controller around zero speed, a loop recovery technique is applied to the control system. The proposed method only requires the flux linkage of the permanent magnet and is insensitive to parameter estimation error and variation. The designers can easily determine the possible operating range with a desired bandwidth and perform vector control even at low speeds. The experimental results show the satisfactory operation of the proposed sensorless algorithm under rated load conditions.     

Decoupling control for two-axis inertially stabilized platform based on an inverse system and internal model control

This paper describes a decoupling control scheme for a two-axis inertially stabilized platform (ISP) used in the airborne power line inspection system. The dynamic model of the ISP has been obtained by using the Newton–Euler equation first. The inverse system method combining with the internal model control has been proposed to deal with the nonlinearity and coupling of the ISP. The key idea is to design an inverse system with measured system states such as angular positions, rates and accelerations. Then a pseudo-linear system is constructed when the inverse system is connected with the original system in series. As a result, the coupled nonlinear MIMO (Multiple-Input Multiple-Output) system is converted to two linear decoupled SISO (Single-Input Single-Output) subsystems. Model uncertainties or unmeasurable disturbances existing objectively can be solved by introducing internal model control. Better decoupling effect and disturbance rejecting ability are demonstrated by numerical simulations and experiments carried out on a two-axis ISP system.     

基于动态模糊神经网络逆系统的焦炉集气管压力解耦控制

焦炉集气管压力系统具有多变量、强耦合、非线性和纯滞后等特点,难以建立准确的数学模型。文章采用基于动态模糊神经网络的逆系统方法对集气管压力系统进行解耦,建立逆系统解耦器,并且设计了集气管压力单神经元PID控制器。该方法有效地实现了多焦炉集气管压力解耦控制,能较好地满足多焦炉集气管压力控制的工艺要求。     

Decoupling control of induction motor drives

The decoupling control of induction machines is investigated. Three different schemes for decoupling-control methods based on stator flux, airgap flux, and rotor flux field regulation are developed. The control dynamics of each scheme are outlined and studied. Simulation results are presented to verify that these schemes provide decoupling control with excellent dynamic behavior. The transient and steady-state relationships between slip frequency and torque, under constant stator flux, airgap flux, and rotor flux operations, are simulated and compared. The sensitivity characteristics of the three methods of flux-control, machine fed by impressed currents and voltages, are also compared and studied. A prototype torque-drive system is implemented to demonstrate the decoupling control of a squirrel-cage induction machine     

A model for fault-tolerant networked control system using TTP/C communication

Safety-critical aerospace functions are generally required to have failure rates less than 10/sup -9/ per hour (FAA, 1988) and an architecture that supports several such functions is required to have failure rates less than 10/sup -10/ per hour. Although the requirement for an individual automobile may be more relaxed, similar requirements apply for automobiles in general (Rushby, 2001), because of their large number as compared to aircraft. Consumer-grade electronics have failure rates that are orders of magnitude worse than this. Hence, redundancy to improve failure rates and fault tolerance to prevent faults from propagating both are essential elements of a safety critical networked control system (NCS). TTP/C is a member of the time-triggered protocol (TTP) family that satisfies Society of Automotive Engineers Class C requirements for hard real-time fault-tolerant communication. A model is presented for a fault-tolerant NCS using TTP/C communication. Appropriate features of TTP/C are incorporated in the model. A simulation is presented for the electric power steering node with switching controller, which makes the node tolerant to the parameter faults column.     

Development and testing of the torque control for the permanent-magnet synchronous motor

Hybrid electrical vehicles and electrical vehicles are being actively developed. A hybrid electric vehicle motor design requires high efficiency, high power/weight ratio, and reliability from low rotor speed to high rotor speed. The permanent-magnet synchronous motor is used in order to fulfill these requirements. The purpose of this paper is to develop a permanent-magnet synchronous motor control method for all rotor speeds. This method increases the torque and the efficiency at high speed when compared to the ordinary current error feedback method. A method composed of two compensators is proposed to achieve this objective. One of the compensators controls the torque using the voltage phases. The other one is the ordinary current error feedback. Several correcting methods for the voltage phase compensator have been proposed for the compensator for many control demands. The validity of the proposed method was confirmed using simulation and experimental evaluations.     

A fault-tolerant control architecture for induction motor drives in automotive applications

This paper describes a fault-tolerant control system for a high-performance induction motor drive that propels an electrical vehicle (EV) or hybrid electric vehicle (HEV). In the proposed control scheme, the developed system takes into account the controller transition smoothness in the event of sensor failure. Moreover, due to the EV or HEV requirements for sensorless operations, a practical sensorless control scheme is developed and used within the proposed fault-tolerant control system. This requires the presence of an adaptive flux observer. The speed estimator is based on the approximation of the magnetic characteristic slope of the induction motor to the mutual inductance value. Simulation results, in terms of speed and torque responses, show the effectiveness of the proposed approach.     

大迎角控制的一种神经网络逆系统方法

提出了一种用于大迎角控制的基于神经网络补偿和逆系统反馈的控制方案,并用e-修正方法对神经网络的权值进行了限幅。基于Lyapunov稳定性理论证明了该控制方法的跟踪误差是收敛的。大迎角控制的仿真实例表明该控制方法具有良好的大迎角跟踪性能。     

A state observer for the permanent-magnet synchronous motor

An identity state observer for the permanent-magnet synchronous motor is derived which reconstructs the electrical and mechanical states of the motor from current and voltage measurements. The observer operates in the rotor frame and estimates direct and quadrature stator currents, rotor velocity, and rotor position. Since the rotor position is estimated, the rotor reference frame is approximated using the latest rotor position estimate. The motor dynamics and the transformation into the estimated rotor frame are nonlinear, and thus the observer and observer error dynamics are nonlinear. Therefore, stability is analyzed using a linearized error model. Simulations including realistic measurement disturbances are used to investigate the global stability and accuracy of the observer