无刷直流电机无位置传感器控制技术的研究

在探讨无刷直流电机无位置传感器的控制措施的同时,分析研究了反电势过零检测电路,在此基础上指出了反电势检测信号和功率开关期间二者的对应关系,同时实施了实验。最终结果显示,反电势检测信号能够充分实现对无刷直流电机的科学有效控制。     

无霍尔无刷直流电机电流环系统设计与实现

<正>无霍尔传感器无刷直流电机具有体积小、成本低、寿命长、安装简单等优点,在工业自动化、军工航天等众多领域中应用越来越广泛。电流环是无刷直流电机控制中关键的一环,对于维持恒定力矩输出起到重要作用,如何设计出动态和稳态性能好、带宽高的数字电流环是无刷直流电机控制的重点。本文设计了一种基于DSP2812数字信号处理器的无霍尔无刷直流电机电流环控制系统,重点解决无霍尔无刷直流电机电流环设计中的电角度精确标定、电流环建模与参数设计、系统软硬件实现等内容,在实际工程项目中取得了良好的应用效果。     

电动客车用无刷直流电机控制系统仿真分析

针对电动客车提出了一种新的纯电动客车用无刷直流电机的系统建模方法,该无刷直流电机模型可以实现无刷直流电机的性能、同时可以实现无刷直流电机的过流、欠压及霍尔传感器缺相等故障保护的综合仿真,将此无刷直流电机模型应用于纯电动客车驱动系统。通过分析无刷直流电机数学模型和纯电动客车动力学方程,采用S函数和模块化建模方法,在Matlab7.0/Simulink环境下,建立了无刷直流电机驱动纯电动客车车速控制系统模型,并对该控制策略在某档位下进行了静、动态性能验证。仿真结果表明:车速调速策略具有超调小、响应速度快、鲁棒性好、自适应能力强等优点,同时验证了带有故障保护功能模型的有效性,为无刷直流电机驱动纯电动客车系统仿真提供了新的方法     

无刷直流电机数字控制系统的研究与设计

在工业的发展道路上不同时期有着不同的发展,电动机的发展带动了我国许多工业的发展,我们从传统的直流电机慢慢的发展到了无刷直流电机。无刷直流电机指的是无机械电刷和换向器的直流电机,是随着电力电子技术,电机的控制技术,和高性能永磁材料的发展而出现的一种新型的电动机。无刷直流电机的研究主要包括电动机自身设计的研究和控制系统的研究,而现在主要应用的是无刷直流电机的数字控制系统,无刷直流电机的控制系统是采用无位置传感器用软件获得转子位置信号的反电势法和相关的预定位开环换相启动法。无刷直流电机数字控制系统运行效率高,性能好,具有一定的实际意义和广阔的应用。本文我们主要论述一下无刷直流电机数字控制系统的研究与设计,对数字控制软件系统进行简单的介绍。     

基于扰动观测器的内置式PMSM无传感器控制

针对两相静止坐标系下基于观测器进行IPMSM无传感器控制时存在电角度估算误差与交直轴电感和负载转矩耦合、电角度补偿复杂等问题,文中选择在同步旋转坐标系下采用电机原有电感参数进行IPMSM无传感器控制。通过建立PMSM 的矢量数学模型,对存在电角度估算误差时采用IPMSM原参数对反电动势估算的影响进行分析,分析结果验证了该方法的理论可行性。利用MATLSB/Simulink进行仿真,并进行了针对性实验。实验结果表明,文中所提算法无须电角度补偿,在扰动条件下仍能对电机转子位置和速度进行良好地跟踪。     

基于DSP电动汽车无刷直流电机相位测试

根据无刷直流电机的工作原理,采用霍尔传感器作为位置传感器,TI公司的DSP芯片TMS320LF2406非常适合作为无刷直流电机(BLDC)的控制芯片,建立了无刷直流电机相位检测手段,转子位置检测模块的软件设计流程,简述电动汽车无刷直流电机控制系统的相位测试的硬件控制策略和软件设计方案。     

小型倾转旋翼机的无刷直流电机驱动器设计

为了实现小型倾转旋翼机螺旋桨的可靠驱动,以ADuC7060微控制器为核心,采用反电势法设计了一种无位置传感器无刷直流电机驱动器。利用MOSFET作为开关器件,给出了桥式逆变电路和位置检测电路的原理图。针对螺旋桨负载的特点,利用MATLAB优化了三段式起动方法的起动加速曲线,并对转子位置检测电路中滤波电容产生的相移进行了补偿。通过调试表明,无刷直流电机能够带载可靠起动,并通过PWM平稳调速,验证了设计的有效性。本文网络版地址:http://www.eepw.com.cn/article/145573.htm     

基于龙贝格观测器的PMSM无位置传感器控制系统设计

针对基于低分辨率霍尔位置传感器的永磁同步电机系统在中高速时出现的估算精度低与响应速度慢等问题,在建立永磁同步电机数学模型的基础上,将龙贝格观测器与锁相环结构相结合,提出一种永磁同步电机无位置传感器控制算法。利用MATLAB/Simulink工具搭建控制系统仿真模型验证该控制系统的可行性,并通过搭建基于PAC5232的实物平台对比验证龙贝格观测器相对于霍尔位置传感器的优越性。实验结果表明,该无位置传感器控制系统有效地提高了系统的响应速度和估算精度,使其能够更好地跟踪转子速度以及转子位置信息。     

基于电磁耦合补偿反馈抑制的无刷直流电机控制仿真

永磁无刷直流电机的电气自动化控制是保障电机可靠工作的关键,无刷直流电机受到电磁耦合器时隙扰动导致控制指向性不好,电流输出失稳.提出一种基于电磁耦合补偿反馈跟踪抑制的无刷直流电机控制技术,首先进行了永磁无刷直流电机的等效电路模型设计,分析了无刷直流电机的感应电能传输原理,进行电机控制算法改进设计,分析控制约束参量模型并进行了控制目标函数构建.采用电磁耦合补偿反馈跟踪技术实现电磁耦合器时隙扰动误差补偿,提高电机输出的稳定性.仿真结果表明,该电机自动化控制模型具有较好的输出增益,对输出的电流、电压、功率等参量的调制性能较好.     

基于PLL技术的BLDCM转子位置检测

为了准确检测无位置传感器无刷直流电机(BLDCM)转子位置信号,通过分析无刷直流电机的PWM-ON-PWM调制方式,结合锁相环(PLL)技术,提出一种新型转子位置检测方法,首先对绕组的端电压和线电压差进行求和运算,然后再与3/2倍的电源电压作比较,得到悬空相的反电动势过零点,最后通过锁相环倍频技术锁定最佳换相时刻。从仿真结果来看,通过此方法能够检测到转子位置信号,从而实现电机绕组的准确换相,因此表明此方法可行有效。     

Damping a hybrid stepping motor with estimated position and velocity

It is well known that microstepping reduces the resonance behavior of stepping motors since the rotor moves in a sequence of very small steps. However, the under-damped nature of the motor does not change. In this paper, a scheme that uses microstepping and closed loop position control to stabilize and reduce resonance damping of the motor is proposed. The motor currents are controlled in a frame rotating synchronously with the excitation frequency. The d-axis current provides the torque to oppose the external load, and the q-axis current provides the transient torque to damp the motor. The motor velocity and position are estimated via an observer that tracks the angle of the motor back EMF voltage. The response of the closed loop system is independent of the external load level. Both simulation and experimental results have shown that the proposed control scheme is very effective in damping out the resonance of microstepping-controlled motors.     

基于线性霍尔传感器的角度测量的非线性校正方法研究

本文提出了一种基于线性霍尔传感器的角度测量的非线性校正方法,在固定磁铁上绕制一定匝数的线圈,线圈产生的磁场与磁铁产生的磁场垂直,空间磁场为上述两个磁场的叠加,固定霍尔传感器的位置,同时保持控制电流不变,让磁铁绕霍尔传感器旋转产生角度的变换,霍尔传感器输出电压也将产生变化。对增加线圈和不增加线圈两种结构进行理论分析和仿真,从仿真结果看,霍尔电压与夹角的关系曲线明显线性增加,测量范围扩大,在角度测量中具有独特的优点。同时设计了传感器硬件电路,进行了实验测量,仿真和实测结果表明：该方法具有电路简单、实时性好、频率相应快、抗干扰能力强、安装调试方便等特点。     

Instantaneous power control of a high speed permanent magnet synchronous generator based on a sliding mode observer and a phase locked loop

This paper proposes an instantaneous power control method for high speed permanent magnet synchronous generators (PMSG), to realize the decoupled control of active power and reactive power, through vector control based on a sliding mode observer (SMO), and a phase locked loop (PLL). Consequently, the high speed PMSG has a high internal power factor, to ensure efficient operation. Vector control and accurate estimation of the instantaneous power require an accurate estimate of the rotor position. The SMO is able to estimate the back electromotive force (EMF). The rotor position and speed can be obtained using a combination of the PLL technique and the phase compensation method. This method has the advantages of robust operation, and being resistant to noise when estimating the position of the rotor. Using instantaneous power theory, the relationship between the output active power, reactive power, and stator current of the PMSG is deduced, and the power constraint condition is analysed for operation at the unit internal power factor. Finally, the accuracy of the rotor position detection, the instantaneous power detection, and the control methods are verified using simulations and experiments.     

Direct torque control of brushless DC motor with nonidealtrapezoidal back EMF

In this paper a method of the torque control attenuating the undesired torque pulsation for brushless DC motor with nonideal trapezoidal back EMF is presented. It is the direct torque control method in which the applied output voltage is calculated from the reference torque and the torque of the previous step in the two-phase conducting period and in the commutation period considering the back EMF waveform. The time delay due to the calculation is compensated by the one step ahead current prediction. To measure the instantaneous torque ripple, a torque observer is constructed using a high precision encoder of 50000 pulse per revolution. The simulation and experimental results show that the proposed method reduces the torque ripple significantly and that it keeps the torque control dynamics as well     

A Coupled Piezoelectric/Single-Hall-Sensor Position Observer for Permanent Magnet Synchronous Machines

In recent years, several control methods have been proposed to reduce the torque ripple produced by permanent magnet synchronous machines [sinusoidal and trapezoidal back electromotive force (EMF)]. In these approaches, a drive system is used to control current harmonics based upon measured machine parameters or measured torque ripple. In general, the methods presented have utilized high-precision position encoders and thus a common perception is that such encoders are required for successful mitigation. In this paper, a position observer is developed that is shown to be suitable for control-based torque ripple mitigation. Additional advantages of the observer are that it achieves excellent start-up performance, requires no knowledge of the machine parameters, and is applicable to machines with an arbitrary back EMF waveform and stator slot configuration.     

对运动目标的单站无源定位技术研究

实现对运动目标辐射源的单站无源定位是对新体制雷达对抗侦察系统的基本要求.固定单站通过测量角度、角速度和多普勒频率变化率可实现对运动目标的无源定位,该方法对角速度特别敏感,测量精度要求很高.为此,提出了一种利用波达方向、相位差变化率、载波频率及多普勒频率变化率的单站无源定位方法,结合某地面雷达对抗侦察系统,分析了其定位原理、测距误差和可观测性,给出了单次测距的计算机仿真结果和结论.仿真研究表明,通过增加相位差变化率信息降低了对角速度的高精度测量要求.     

基于单周期控制的PWM电流控制系统设计与实现

针对无刷直流电机（BLDC）驱动器的电流控制问题,在本文中提出了一种改进的基于单周控制的低成本转子位置估算方法。该估算方法以真实反电势过零点的检测为依据,这些真实反电势过零点可直接通过检测相端和直流环节中点之间的电压来提取,无需电机中性点电压。电流控制系统通过一种低成本的通用自动电压调整微控制器（Atmega8）来实现。MATLAB仿真和实验测试结果均显示相比传统的滞环控制器方法,改进后的PWM（脉冲宽度调制）无刷直流电机电流控制系统在稳态和瞬态两种情况下表现出更好的性能。     

Consideration on the measurement of current distribution on bentwire antennas

As part of the measurement of the current distribution on a bent wire antenna with a shielded loop, the electromotive force (EMF) induced on the loop is theoretically formulated, and the relation between the current distribution and the measured values is investigated. The EMF is expressed as a summation of terms involving the current and the derivative of the current with coefficients depending on the measurement point. The calculated EMF agrees well with the measured value. At points away from the antenna ends and bend, the EMF is proportional to the current, but near the ends and bend the difference between EMF and current increases. It is shown that the current distribution is easily estimated from the measured data. The authors also present the measurement of charge distribution using a small dipole. The expression for the open-circuit voltage of the dipole is formulated and compared with measured values     

无人机中磁航向自修正应用

以无人机组合导航系统为研究背景,针对磁传感器的误差校准方法,以及校准后磁航向误差进行研究。通过分析磁传感器误差来源,给出水平面内椭圆直接拟合模型。考虑磁传感器修正后的磁航向与GPS航迹角之间存在一定误差,建立航向误差角与磁航向之间的学习函数,从而辅助在GPS丢失情况下,采用学习后的磁航向来辅助无人机导航。飞行实验结果表明,利用该文采用的椭圆模型以及自学习函数,能够提高磁航向精度,从而可以辅助无人机在GPS丢失情况下航向解算。