An automatic torque ripple compensation system for direct drive motors

A serious problem in motion control is the occurrence of torque ripple. Since a direct drive (DD) motor with a magnet rotor uses a rare-earth magnet, the torque ripple is more serious than that of conventional servomotors. This paper presents an auto-compensation of torque ripple using a software-implemented torque observer. The frequency and amplitude of torque ripple can be obtained in the controller by using the estimated torque from an observer, and the autonomous generation of a compensating current component for a torque ripple is possible. The proposed algorithm has been verified by experiments.     

双耦合直驱力矩电机自适应RBF网络反演控制策略研究

电机作为机械手臂的核心元器件,已成为现代工业应用研究必不可少的技术,而双电机协同运动一直是该研究领域的一大热点.因此为解决多电机协同运动、精确位置跟踪和抗干扰等问题,以当下热门的直驱力矩电机组成双耦合电机系统作为研究对象;首先,进行了精确模型下的反演控制器设计和稳定性分析,证明所设计控制律稳定;其次,在未知模型下进行RBF网络反演控制器的设计,通过Lyapunov稳定性证明得到所设计系统稳定可靠;最后,以未知模型下的自适应RBF网络反演控制器为例,进行MTALAB/Simulink仿真分析可知:所设计控制器实现能够较好的位置跟踪、响应速度快,具有很好的应用研究价值.     

Development of torque and flux ripple minimization algorithm for direct torque control of induction motor drive

Direct torque control (DTC) is known to produce quick and robust response in AC drives. However, during steady state, notable torque and flux ripple occur. They are reflected in speed estimation, speed response and also in increased noise. This paper proposes a new control algorithm, which provides decoupled control of the torque, and flux with constant inverter switching frequency and a minimum torque and flux ripple. Compared to the other DTC methods, this algorithm is much simpler and has less mathematical operations, and can be implemented on most existing digital drive controllers. Algorithm is based on imposing the flux vector spatial orientation and rotation speed, which defines the unique solution for reference stator voltage. This paper contributes (a) Calculation of stator flux vector, torque and flux increments (b) The position of new stator flux vector determination (c) Calculation of the stator reference voltage (d) comparison of errors of different control strategies. In this paper, computer simulations and experimental results have been discussed for the proposed algorithm.     

电动汽车电机驱动系统寿命模型

针对电动汽车电机驱动系统在运行过程中承受剧烈的热应力容易导致系统出现故障的问题,从热应力疲劳失效的观点出发,分析了系统寿命影响因素及其薄弱环节的失效机理,提出了一种以电动汽车电机驱动系统运行工况和电机输出扭矩为输入建立系统寿命模型的方法。建立了100/160 kW纯电动大客车电机驱动系统寿命模型,并以北京121电动公交车的实际运行工况为模型输入预计了系统寿命。     

Control strategy for motor drive system of electric vehicle

An induction motor drive system is widely used in electric vehicles (EVs). However, most control strategies of these EVs focus only on control of the induction motor without considering the switching of different driving conditions and the changing of motor parameters. The upper limits of the torque generated by the motor are different under different motor parameters and driving conditions, which may lead to the fluctuation of the driving torque and affect the comfort and safety of the driver. This paper proposes a vector‐control‐based flexible control strategy to deal with this problem. First, the threshold values of the automatic speed regulator (ASR) and the automatic voltage regulator (AVR) could change with respect to the state variables of the motor including the change in driving conditions and some motor parameters; second, a backward proportional integral controller, which has a dynamically adjustable threshold, is added to the output of the ASR and AVR to achieve the flexibility of driving torque. Finally, a calculator that has threshold value is added to the input of the ASR and AVR controller. The results of simulation show that the designed flexible control strategy can achieve the stability of motor current, torque, and speed during the switching of different driving conditions. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Quasi-resonant inverter-fed direct torque controlled induction motor drive

A quasi-resonant inverter-fed induction motor operated under direct torque control (DTC) scheme is modeled and analyzed with SABER simulator. The dc link voltage is clamped to source voltage. All the devices in the resonant link and inverter except auxiliary switch in the resonant link are operated soft under zero-voltage switching (ZVS). The auxiliary switch is turned on under zero-current switching (ZCS), but turned off hard. This scheme has been implemented on a laboratory-sized experimental setup. A comparison of simulation and experimental results under identical operating conditions were presented.     

电动车用开关磁阻电机转矩控制器设计与优化

电动汽车用开关磁阻电机转矩动态特性对电动汽车整车动力性能与乘坐舒适性能起着至关重要的作用。为了降低开关磁阻电机转矩脉动,提高其平均转矩,达到优化转矩动态特性的目的,在MATLAB/Simulink环境中建立了开关磁阻电机非线性动态模型;利用动态模型仿真数据确立了电机转矩动态性能与转速、关断角之间的函数关系;以降低转矩脉动,提高平均转矩为目标,建立了最优关断角与转速之间的函数关系;设计了基于可变关断角的转矩优化控制器。仿真结果表明,本文建立基于可变关断角的转矩优化控制器能很好地降低转矩脉动,提高平均转矩,达到了优化开关磁阻电机转矩动态特性的目的。     

A simple hardware realization of switching table based direct torque control of induction motor

A simple hardware realization of direct torque control (DTC) scheme for fast control of induction motor torque has been presented. The proposed hardware scheme mimics the conventional switching table based DTC scheme and does not require use of any online fast computing device like microprocessor, PC or DSP. The controller uses only commonly used discrete hardware components. The experimental results of the proposed hardware implementation have been presented and supported with simulation results. Another alternate hardware scheme without using the switching table has also been proposed and the experimental results of both the schemes have been compared and found to be in agreement with each other.     

转盘独立电驱动系统反扭矩缓释技术研究

钻井井下钻具卡钻后,独立电驱动转盘系统需要进行反扭矩缓释操作。机械式气胎离合器进行反扭矩缓释时,机械气胎式离合器惯性刹车的制动效果差,使用周期短。不带能耗制动系统的独立转盘电驱动反扭矩缓释系统,只有延长缓释时间才能避免变频器跳闸。带能耗制动的独立转盘电驱动系统,只要按最大转矩、正向制动进行能耗制动系统设计,当其缓释反扭矩时,可保证能耗制动系统安全可靠。但其手动缓释系统操作时要求司钻注意力高度集中,而其自动缓释系统操作简单、安全可靠。     

升船机电气传动系统方案的研究

针对升船机电气传动系统,提出了三种电气传动系统方案,就升船机的多电机传动速度控制和出力均衡控制进行了分析,并阐述了国内升船机传动方案应用及调试效果。     

A current sensorless drive system of a synchronous motor with a low‐resolution position sensor

High‐performance drive of synchronous motors such as a permanent magnet synchronous motor and a synchronous reluctance motor can be achieved by current vector control. In such drive systems, the armature current is controlled as a sinusoidal waveform based on rotor position information from a high‐resolution position sensor, and the current vector (d‐ and q‐axis currents) is suitably controlled by current feedback control. This paper proposes a current sensorless drive system with a low‐resolution position sensor in order to simplify the SM drive system. High‐performance current control is achieved in the proposed drive system, where the current sensors are eliminated and the simulated currents are used for current control. The low‐resolution position sensor is used instead of a conventional high‐resolution position sensor, and the higher position information is estimated. The steady‐state and transient characteristics are examined in several experiments with respect to the synchronous reluctance motor and the interior permanent magnet synchronous motor. It is confirmed that sinusoidal current drive, high‐performance current vector control, and speed control can be achieved by the proposed drive system. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 34–43, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10072     

基于分段解析建模的开关磁阻电机在线转矩估算方法

针对目前开关磁阻电机采用单一解析模型进行在线转矩估算存在模型复杂、精度低的问题,提出一种基于分段解析建模的开关磁阻电机在线转矩估算方法.根据开关磁阻电机在一个电周期内磁链特性曲线的对称性及其定转子极弧的结构特点,提出将其半个电周期划分为5个区间,分别建立了每个区间的磁链与转矩简化解析模型,并通过有限元分析及构建基于DS...     

惯性飞轮电机力矩伺服控制系统

惯性飞轮是航天空间飞行器姿态控制系统的执行元件。姿态控制需要对惯性飞轮做四象限力矩伺服控制。本文采用双重电流闭环方法,即同时进行桥壁脉宽调幅与三相半桥脉宽调制综合控制,实现了飞轮电机的四象限精确力矩伺服控制。     

基于神经网络的模糊控制在开关磁阻电机中的应用研究

把神经网络与模糊逻辑结合起来,利用神经网络的学习控制算法调节模糊逻辑隶属函数,通过对开 关磁阻电机运行特性的分析,提出了一种可应用于开关磁阻电机驱动系统的智能控制方法,理论和仿真结果均证明了这种基于神经网络模糊控制方法在开关磁阻电机驱动系统中应用的可行性和可靠性。     

Modified direct torque control method for induction motor drives based on amplitude and angle control of stator flux

This paper proposes design and implementation of a direct torque controlled induction motor drive system. The method is based on control of separation between amplitude and angle of reference stator flux for determining reference stator voltage vector in generating PWM output voltage for induction motors. The objective is to reduce electromagnetic torque ripple and stator flux droop which result in a decrease in current distortion in steady-state condition. In addition, the proposed technique provides simplicity of a control system. The direct torque control is based on the relationship between instantaneous slip angular frequency and rotor angular frequency in adjustment of the reference stator flux angle. The amplitude of the reference stator flux is always kept constant at rated value. The system has been implemented to verify its capability such as torque and stator flux responses, stator phase current distortion both during dynamic and steady state with load variation, and low speed operation.     

两相开关磁阻电动机转矩特性的研究

研究了两相开关磁阻电动机的转矩特性以减小转矩波动。首先通过推导近似转矩数学模型，进而通过磁场有限元计算得到了两相开关磁阻电动机的较为平滑的固有矩角特性。在磁场计算的基础上，对两相开关磁阻电动机的转矩特性进行了仿真计算。样机实验验证了计算及仿真结果。结果表明，两相开关磁阻电动机可以在较宽的转速范围内保持连续的转矩特性。     

Direct torque control of doubly fedinduction motor using three-level NPCinverter

This article presents the direct torque control (DTC) strategy for the doubly fed induction motor (DFIM) connectedto two three-level voltage source inverters (3LVSIs) with neutral point clamped (NPC) structure. This control methodallows to reduce the torque and flux ripples as well as to optimize the total harmonic distortion (THD) of motorcurrents. The use of 3LVSI increases the number of generated voltage, which allows improving the quality of itswaveform and thus improves the DTC strategy. The system modeling and control are implemented in Matlab/Simulink environment. The analysis of simulation results shows the better performances of this control, especially interms of torque and flux behavior, compared to conventional DTC.     

永磁游标直线电机磁场解析计算

永磁游标直线电机(linear permanent magnet vernier motor,LPMVM)依靠磁场调制原理工作,其电枢开槽引起气隙磁导变化,为考虑齿槽效应的影响,将其气隙磁场等效为无槽气隙磁场与有槽时气隙相对磁导函数共同作用结果。用气隙磁导波法分析其基本工作机理,给出结构关系式。用分层模型法建立无槽LPMVM求解场域矢量磁位解析模型,推导出各区域磁场解析表达式。结合气隙相对磁导函数建立考虑齿槽效应时的LPMVM磁场解析模型,计算出考虑齿槽效应时气隙磁密分布曲线。解析解与有限元解结果表明:无槽时气隙磁密在切向分量和法向分量计算准确,考虑齿槽效应后基于气隙相对磁导函数的磁场解析模型适用于求解气隙磁密法向分量,且主要谐波磁场与永磁体极对数和电枢绕组极对数有关。     

一种前端级联DC/DC变换器的开关磁阻电机驱动拓扑

针对开关磁阻电机传统不对称半桥功率变换器在电动汽车应用中的不足,提出了一种新型 DC/ DC 变换器级联在不对 称半桥功率变换器前端,以实现母线电压的调节以及制动能量的可控回馈。 首先,理论分析了变换器的工作模式;其次,分别建 立了励磁电压、退磁电压和关断角关于转速、负载的查找表,从而根据电机工况匹配合适的母线参考电压,并给出了系统整体的 闭环控制方案;最后,在一台三相 6 / 4 结构开关磁阻电机上进行了实验,实验结果验证了提出的新型功率变换器的有效性。     

永磁同步电机直接转矩控制不合理转矩脉动

针对永磁同步电机直接转矩控制转矩脉动问题,依据永磁同步电机直接转矩控制理论,建立了永磁同步电机直接转矩控制系统模型,并分析了电压矢量对转矩的作用,得出以下结论:当定子磁链幅值与转矩角变化矛盾时,一定条件下转矩变化与定子磁链幅值的变化一致;此时传统开关表选择的电压矢量对转矩的实际作用与系统期望值相反,从而产生了不合理的转矩脉动.仿真结果验证了理论分析的正确性.