基于SVPWM五相感应电机直接转矩控制研究

针对感应电机直接转矩控制(DTC)采用开关表的滞环方法时,存在电流和转矩脉动等问题,提出在DTC中应用空间矢量脉宽调制(SVPWM)的方法。根据五相感应电机模型和DTC基本原理,推导出参考电压矢量。分析了五相逆变器的空间电压矢量,并从中选取出22个有效电压矢量,根据最近四矢量SVPWM算法,计算出第k扇区中工作电压矢量的作用时间。建立了基于双DSP控制的实验系统,实验结果表明,该方法减小了电流和转矩脉动,具有良好的稳态和动态性能。     

A closed-loop operation of super high-speed reluctance motor forquick torque response

The authors examine operating modes of the cageless reluctance motor and propose a new control method for quick torque response. It is shown that the control of sinusoidal phase current in magnitude with fixed current phase angle provides a simple means for achieving quick torque response and efficient operation. The flux linkage, current, torque. and the rated voltage of the inverter are calculated for a reluctance motor. A performance comparison is made between the proposed control method and the field-oriented control method. Analysis and computer simulation show that substantial improvements in dynamic response and efficiency are achieved for a reluctance motor when operated with constant current phase angle compared with operation at constant direct axis current or constant flux. Test data from a 24000 r/min. 1.3 kW reluctance motor drive system are provided     

五相容错永磁同步电机磁动势与转矩研究

为了分析五相容错永磁同步电机开路故障时转矩波动变化的原因,采用绕组函数研究定子磁动势的谐波分布。开路故障未调整时,通过主波磁动势的时空分布揭示了磁动势和转矩之间的关系,并解释转矩增大的主要原因;此时定子磁动势增加了5k和10k±3次谐波,但由于槽谐波幅值下降,转子总损耗减少。对开路故障采取电流控制策略进行调整后,平均转矩增加到正常值,但由于存在二次和四次纹波转矩,转矩波动相对于正常情况仍然较大。同时,定子磁动势10k±1次谐波幅值恢复到正常水平,但10k±3次谐波仍然存在且幅值增加,因而转子损耗相对于正常工作情形增大。     

五电平拓扑下开关磁阻电机直接瞬时转矩控制

针对开关磁阻电机转矩脉动,提出开关磁阻电动机五电平驱动拓扑结构和滞环控制策略.研究和分析五电平拓扑的五电平导通原理,并与不对称半桥驱动电路三电平导通进行比较.结合开关磁阻电机绕组导通和直接瞬时转矩控制原理,设计五电平驱动下开关磁阻电机直接瞬时转矩滞环控制策略,并且进行仿真实验.仿真结果证实与不对称半桥电路相比,五电平拓...     

A reluctance motor drive for high dynamic performance application

A reluctance motor drive giving high dynamic performances is proposed. The machine is sinusoidally wound, and the rotor belongs to the axially laminated type. The vector control technique used (utilizing a flux observer) is described. A prototype system has been realized, and the practical results obtained are given     

开关磁阻电机直接瞬时转矩控制的优化研究

为改善开关磁阻电机(SRM)的转矩脉动和效率,提出了一种改进的SRM直接瞬时转矩控制(DITC)方法。该方法采用了灵活的转矩分配方式获得各相参考转矩,用来对瞬时转矩进行闭环控制;同时增加了角度优化方案,根据每相绕组导通期间的累积转矩误差、转速和参考转矩等变量,通过模糊算法实现电机开通角度的在线调整,动态的改善转矩误差和电机的效率。在MATLAB/Simulink软件中分别根据改进前后的DITC方法建立SRM控制系统仿真模型,仿真试验结果表明所提的优化方法能够达到较小的转矩误差和相电流,实现了电机的平稳、高效控制。     

开关磁阻电动机互感特性及其对转矩的影响

开关磁阻电动机在两相励磁的工作条件下,定转子轭部磁场高度饱和使每相磁链有所减小.通过引入互感的方法可以定量计算磁链的减小量,并给出了互感计算式,利用有限元法分析了一台样机互感随转子位置和电流的变化规律,理论推导了互感对平均转矩影响的程度,研究了四相8/6极开关磁阻电动机稳态转矩波形在两种绕组连接方式下的不规则特性,结合互感特性,提出了改变不对称相绕组参数的技术方案.研究结果表明:电磁参数优化后,开关磁阻电动机的最小转矩和平均转矩均得以提高,转矩脉动减小,转矩波形规则.     

Phase current modulation of switched reluctance motor to minimize torque ripple

This paper presents a simple technique to minimize torque ripple of a switched reluctance motor (SRM). The technique is based on the control of the sum of the square of the phase currents by using only two current sensors and analog multipliers. The control characteristics of the SRM drives are analyzed for operation of the motor in the linear region of its magnetic characteristics. The simulation and experimental results of the proposed method are given. The advantages and limitations of the proposed circuit are explained.     

A novel high-torque reluctance motor with rare-earth magnet

An entirely new concept of an electromagnetic structure which exploits the excellent characteristics of a rare-earth magnet is proposed. Thin rare-earth metal magnet pieces are mounted on the surface of the stator teeth which face the airgap. The rotor has a variable reluctance structure type. This type of motor is suitable for low-speed high-torque applications by the action of tooth and slot structure. The relationship between the performance and electromagnetic geometry is investigated through the finite element method (FEM) analysis and experiments. The principle of torque generation and the associated characteristics is also introduced     

A synchronous reluctance motor with a laminated rotor

Optimal tooth factors and polar overlap are obtained using numerical calculations of an in-plane magnetic field in the active volume of a synchronous reluctance motor (SRM) with a laminated rotor using FEMM 4.01 (Finite Element Method Magnetics, Version 4.01) software. Recommendations for improving the technical and economic indices of an SRM with laminated rotors at the expense of cutouts in ferromagnetic rotor packs and placing compensatory permanent magnets on the way of transverse magnetic flux closure are given.     

A three-phase switched reluctance motor with two-phase excitation

A new excitation strategy for a switched reluctance motor (SRM) is described and tested. This scheme excites two phases of an SRM simultaneously, which is similar to the two-phase excitation method of a step motor. In this scheme, the torque is produced by mutual-inductance as well as by self-inductance. The abrupt change of a phase excitation produces mechanical stresses, resulting in torque ripple and noise. The acoustic noise is reduced through a sequential two-phase excitation. Noise reduction occurs because the scheme reduces abrupt changes in excitation levels by distributed, balanced excitation and freewheeling during commutation. The operational principle and a characteristic comparison to that of the conventional SRM show that this novel excitation scheme has some advantages, including torque ripple and noise reduction, as well as simple inverter topology     

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...     

Optimum design of a multilayer interior permanent magnet synchronous motor using reluctance torque

The report analyzes the results of experiments done with an inverter drive interior permanent‐magnet (IPM) motor. We examine results of both FEM (finite element method) simulation and experiments using a prototype motor with identical conditions set for stator and magnet volume. The results indicated that with magnets implanted inside the rotor, the values for the d‐axis inductance of the motor remained roughly the same, unaffected by the shape or number of layers. However, the q‐axis inductance exhibited significant change. This research report compares an IPM motor having two layers of permanent magnets with a motor having a single layer. The dual layer shows a 30% or greater increase in torque using the same current. These results indicate that this motor is especially effective for such applications as robots, plant machinery, compressor motors, and electric vehicles. © 1999 Scripta Technica, Electr Eng Jpn, 127(1): 64–72, 1999     

一种开关磁阻电机非线性磁链与转矩建模方法

开关磁阻电机(SRM)由于磁化曲线高度饱和非线性的特点,造成传统的电机性能分析和建模方法很难运用到SRM中。根据SRM磁链曲线的特点,提出了一种带修正因子的反正切函数来建立SRM模型的方法。在获得SRM 5个特殊转子位置处的9个磁链数据点的基础上,利用傅立叶级数分解和反正切函数来拟合SRM的磁链特性,并推导出电感和电磁转矩模型。该模型函数表达式简单、系数修改方便、计算精度高,并且能够直观的反映SRM的磁链、电感和转矩变化情况。以一台550 W、6/4极SRM为例,进行了仿真与实验比较,结果表明该模型能够很好的反映SRM的实际工作状况,验证了所建模型的精确性和有效性。     

高速SRM无位置传感器控制

针对简化磁链法开通角和关断角无法灵活且精确控制的问题,限制SRM(swithed reluctance motor)效率和高速运行性能,根据不同转速,提出实时调整开关角的无位置检测控制策略,通过建立电机有限元仿真模型,计算得到样机不同转子位置磁链模型.为提高角度位置控制精确度,针对SRM磁链模型的特点,给出参考磁链选取原则,在此基础上,根据不同转速实时调整开关角,实现SRM变角度位置控制.为验证提出的无位置控制策略的有效性,分别选取低速和高速样机进行试验.结果表明,提出的无位置检测法适用于低速和高速SRM,具有较高位置估算精确度.     

Studies of torque ripple in a switched reluctance motor under a controlled average torque value in a low-velocity mode

In the case of adjusting the average torque value of switched reluctance motors, torque ripple is most pronounced in a low-velocity mode. In this mode, the motor phase-currents are usually forcibly limited; therefore, owing to the available voltage margin, by properly selecting the positions of phase switching, one can influence the shape of the phase-currents within certain limits and, thereby, achieve a decrease in the torque ripple. This paper considers the possibilities of reducing torque ripple using very common methods for restricting the phase-current, such as voltage control and current control. Using simulation modeling in the Matlab–Simulink environment, the best combinations of control actions are found, with which torque ripple is minimal. It is shown that, by using the first method of phase-current restriction, the reduction in torque ripple under certain conditions is achieved via a forced pulling of the range of phase-current increase due to a later switching on of the phase with a simultaneous increase in the voltage across this phase. In a number of cases, the desired effect can be achieved only owing to a certain delay in the command for switching the phase off with respect to the position corresponding to a single-switching mode. For the second method of phasecurrent restriction, the best switching conditions are found for fixed levels of current restriction determined from the desired values of the average motor torque, and independent adjusting of the switch-on and switchoff positions of its phases.     

Robust torque and torque-per-inertia optimization of a switched reluctance motor using the Taguchi methods

This paper presents the use of Taguchi methods in optimizing a switched reluctance motor (SRM) for applications requiring fast actuation. In these applications, the SRM is designed to provide a high electromagnetic torque-to-inertia ratio required for high rates of mechanical acceleration. This is accomplished using two simultaneous robust optimizations of an SRM, namely: 1) an optimization of the motor torque and 2) an optimization of the torque per inertia (mechanical acceleration). The Taguchi two-step optimization method and the zero-point-proportional dynamic response were used successfully in the double optimization. Two orthogonal arrays were used to lead the design of experiments (DOE). Finite-element analysis was used to compute the performance of the motor designs generated by the Taguchi DOE.     

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。     

High-precision torque control of reluctance motors

The high-precision torque control of a reluctance motor for servo applications is described. The prototype is a three-phase, eight-pole reluctance motor driven by a MOSFET inverter. The current control and the speed control are performed by software of the digital signal processor TMS 32010. The motor is supplied by sinusoidal current, and two current control methods are proposed. One is based on a vector control principle to achieve the linearity between current and torque, and another is developed to obtain the maximum torque/current ratio. Due to the saliency, the instantaneous torque contains a large ripple component. In the case of the test motor, the torque ripple was as much as 26% of the rated torque under sinusoidal current drive. The experiment showed that the ripple component could be reduced to 6% by superimposing a compensation current component on the current reference     

新型高起动转矩高效单相感应电动机研究

作为三相感应电动机单相运行的一种特殊接线方式,与三相感应电动机在三相对称电源上运行相比,采用本文提出接法的电动机具有大起动转矩、高功率因数和高频率的特点,可以取代现有的单相感应电动机。为便于这种电动机的推广使用,进行了理论分析,给出了性能计算的具体方法,计算结果和试验结果吻合较好,证明本文给出的方法是正确的、有效的。