Control of high-performance interior permanent magnet synchronousdrives

Control strategies for an interior permanent magnet (IPM) machine suitable for field weakening are considered. Different control approaches that identify a robust and fast torque control scheme are investigated. A flux-oriented frame based on a flux observer is chosen. An allowable operating area in the state plane is selected, and the related boundaries are implemented in the control scheme. Simulated behavior is given, together with the experimental behavior obtained with a prototype drive     

Machine parameters and performance of interior permanent magnet synchronous motors with different permanent magnet volume

Permanent magnet synchronous motors are widely used for several industrial applications. Some applications such as electric vehicles and compressor drives require a constant power operation. The operating limits and the constant power speed range deeply depend on the machine parameters. The relationships between the motor parameters and the operating performance have been theoretically examined. This paper examines the performances of the prototype synchronous motors, where the stator structure and the rotor structure of all motors are the same. The permanent magnets are inserted into the rotor slits and the volume of the permanent magnet is adjusted to control the magnet‐flux linkage. The effects of adding the magnet to the rotor on the machine parameters and the operating performance are examined based on the various experimental results. The prototype motor has flexibility as to speed versus power performance by adjusting the volume of the permanent magnet. The theoretical results with respect to the operating limits and the motor parameters are also confirmed experimentally. © 2000 Scripta Technica, Electr Eng Jpn, 131(4): 70–77, 2000     

Speed control of interior permanent magnet synchronous motor drivefor the flux weakening operation

A novel flux-weakening scheme for the interior permanent magnet synchronous motor (IPMSM) is proposed. This is implemented based on the output of the synchronous PI current regulator-reference voltage to the PWM inverter. The onset of flux weakening and the flux level are adjusted inherently by the outer voltage regulation loop to prevent saturation of the current regulator. Attractive features of this flux weakening scheme include no dependency on the machine parameters. The guarantee of current regulation at any operating condition, and smooth and fast transition into and out of the flux weakening mode. Experimental results at various operating conditions including the case of detuned parameters are presented to verify the feasibility of the proposed control scheme     

Cylindrical linear pulse motor with interior permanent magnet mover

The advantages of the conventional cylindrical linear pulse motor (C-LPM), which has a ring permanent magnet between the A- and B-phase stators, are its simple magnet shape and small motor diameter; the disadvantages are the thrust imbalance resulting from the magnetic flux path of the outer poles being longer than that of the inner poles. This thrust imbalance decreases the pull-in thrust and increases the positioning error. In this paper, a new C-LPM with an interior permanent magnet mover which reduces this thrust imbalance is proposed. Steady and dynamic thrust are also examined and a magnetic equivalent circuit is discussed. It is shown that a C-LPM with an interior permanent magnet mover effectively improves the thrust imbalance and the dynamic thrust     

永磁体不对称放置削弱内置式永磁同步电动机齿槽转矩

针对内置切向式转子结构磁极偏移时,每极磁密的大小和分布都不相同的问题,基于解析法研究了偏移角度的确定方法.与表面式永磁电机不同,内置切向式结构在永磁体不对称时,每极极弧宽度会发生变化,影响每极磁密的大小和分布,两者都对齿槽转矩有影响,因此确定永磁体位置时须考虑两者的影响.基于内置式永磁同步电动机齿槽转矩解析表达式,分析每极磁密大小与分布对齿槽转矩的影响,研究磁极偏移角度的确定方法,并与表面式永磁电机磁极偏移角度进行了对比.采用有限元法计算不同偏移角度对齿槽转矩有影响的磁密谐波和齿槽转矩,有限元计算结果表明,由于考虑了磁极偏移对每极磁密的影响,磁极偏移能有效地削弱齿槽转矩.     

Design of a new axially-laminated interior permanent magnet motor

The design of a new type of axially-laminated interior permanent magnet motor drive showing an extremely wide constant-power speed range which exceeds 7.5:1 is described. The effect on the field-weakening performance of the number of poles, the pole-piece material, the rotor bolt holes, the airgap size, the rotor insulation ratio, and the magnet type are analyzed using analytical and finite-element techniques. A 7.5-kW synchronous reluctance and a 7.5-kW interior permanent magnet axially-laminated rotor were built for a commercial induction motor stator and experimental low-speed and field-weakening results are presented     

内置式永磁同步电机的效率最优直接转矩控制

为提高内置式永磁同步电机驱动系统的运行效率,提出了一种内置式永磁同步电机的效率最优直接转矩控制方法。在建立计及定子铁心损耗的内置式永磁同步电机模型的基础上,分析了电机损耗与转矩、转速和定子磁链的关系,导出了不同运行工况条件下效率最优定子磁链幅值的计算式。通过动态调节定子磁链给定值,实现了内置式永磁同步电机直接转矩控制系统的效率最优控制。实验结果表明,给出的优化控制策略在保持直接转矩控制快速动态响应特性的同时,可有效提高电机的运行效率。     

内置式多层磁钢永磁同步电机振动噪声抑制措施

针对内置式多层磁钢的永磁同步电机提出通过优化电机转子结构抑制电机振动噪声的方法.首先通过基于直接耦合场的有限元仿真方法计算一台额定功率为20 kW的永磁同步电机的声压级.将仿真值与电机噪声实验测得的结果进行对比,其差值小于6.3％,由此验证了该方法仿真计算电机振动噪声的准确性.其次针对内置式多层磁钢永磁同步电机转子结构...     

内置式永磁同步电机转子初始位置估计方法

针对无位置传感器永磁同步电机控制系统起动运行困难的问题,提出一种基于混合信号注入的内置式永磁同步电机改进转子磁极初始位置估计方法.采用注入高频旋转电压信号的方法检测磁极位置,设计一种通过PI跟踪观测器对所构建磁极位置误差信号进行控制的方案,当误差调节至零时将获得磁极位置初判值,降低了算法的复杂性.以磁极位置初判值为矢量角,往定子绕组注入2个方向相反的脉冲电压矢量,通过比较直轴电流大小可以简单、有效地判断出磁极极性,实现对位置初判值进行校正,从而获得转子初始位置估计值.应用所提出的估计方法对一台22kW内置式永磁同步电机进行实验,得到转子位置电角度平均估计误差为4.6°.     

内埋式永磁同步电机的弱磁控制策略

针对内埋式永磁同步电机的弱磁控制,提出一种修正电流设定值的方法.该方法由两部分组成:弱磁区域的确定和设定电流修正值的计算.电机运行所在的弱磁区域由恒转矩曲线方向和电流调节器输出电压递减方向之间的夹角来确定,输出电压的递减方向信息通过梯度下降法计算得到;设定电流修正值的大小根据该弱磁区域内转矩、电压变化量的方向信息和电流调节器输出电压与电压设定值的差值来确定.通过实验验证了该控制策略的正确性和可行性,实验结果表明所提出的控制策略控制精确度高、响应速度快、鲁棒性好.     

永磁同步电机系统线性化H∞鲁棒控制

针对内埋式永磁同步电机伺服系统,研究了一种线性化H∞鲁棒控制方法。该方法基于微分几何理论,利用输入输出解耦线性化技术将系统模型转化为线性模型;然后采用最大转矩比电流控制策略增加系统的转矩输出能力;针对负载干扰设计了负载转矩观测器;最后基于线性化模型设计了H∞鲁棒控制器,提高系统对内埋式永磁同步电机系统参数变化的鲁棒性。仿真实验结果表明基于微分几何输入输出解耦H∞鲁棒控制伺服系统有较好的动态性能、抗干扰性能、跟踪性能和鲁棒性能。     

内置式永磁同步电机牵引系统宽调速非线性控制器

针对内置式永磁同步电机(IPMSM)牵引系统机械参数时变、恒转矩区需高转矩输出、恒功率区需宽调速问题,运用非线性自适应控制理论,设计了一种电流滞环控制非线性自适应反步控制器。该非线性控制器在恒转矩区采用最大转矩比电流控制,提高转矩输出能力;在恒功率区采用弱磁控制策略,扩大调速范围;同时对电机参数摄动有较强的抑制能力,表现出较好的鲁棒性。仿真结果证明了IPMSM牵引系统非线性控制器的正确性和有效性。     

高速内置式永磁同步电机转子强度分析

内置式永磁同步电机高速运转时,隔磁桥处承受着永磁体和极靴所产生的巨大离心力,为了提高转子冲片的机械强度避免隔磁桥的损坏有必要对电机转子冲片的结构进行研究。首先,基于离心力产生的原理建立了转子冲片最大应力的数学表达式并与有限元仿真模型比较,验证了其准确性。然后,针对现有转子冲片机械强度不足的缺陷,提出了对永磁体沿径向分段的结构优化方案,并对该方案进行了模拟仿真。结果表明:分段桥可有效分担隔磁桥处的应力,提高转子的机械强度。最后,对比分析了分段桥数量对电机机械强度及电气性能的影响,得出了实例电机转子冲片的最优结构。研究结果为高速内置式永磁电机转子结构的优化设计提供了有力参考。     

大型定子内永磁风力发电机的设计

提出新型定子内永磁发电机的基本结构和工作原理,根据国内风力发电设备生产和应用的实际情况,进行1.5 MW定子内永磁风力发电机的设计工作.接着提出定子内永磁风力发电机的主要设计参数和设计原则,最后给出直接驱动定子内永磁风力发电机的设计实例.设计和分析结果表明大型定子内永磁风力发电机设计方案的可行性和正确性.     

A direct torque-controlled interior permanent magnet synchronousmotor drive incorporating field weakening

This paper presents a new control scheme for wide speed range operation of interior permanent magnet synchronous motor drives, where both torque and stator flux linkage are directly controlled. The proposed scheme possesses some attractive features when compared to the conventional current-controlled drives. Current controllers followed by pulsewidth modulation or hysteresis comparators and coordinate transformation are not used. This eliminates the delays through these networks and offers the possibility of dispensing with the rotor position sensor for the electronic commutator, if the initial rotor position is known only approximately. The scheme incorporates all the usual control regimes, such as the maximum torque per ampere operation in constant torque region, the flux-weakening region, and operates the drive within the voltage and current limits of the motor/inverter. The control scheme has been verified by simulation and experimental tests with a prototype interior magnet motor. This paper describes the scheme in detail, followed by results of its implementation     

采用拼接式转子的内置永磁同步电动机的优化设计

针对传统内置永磁同步电动机漏磁系数较大,隔磁桥机械强度较差等特点,提出一种拼接式转子,这种转子具有若干个独立的铁心,用高强度非铁磁部件通过鸽尾形槽把这些铁心拼接起来,这种转子不需要隔磁桥,所以这种转子能够有效限制漏磁。拼接式转子的铁心具有一些磁障(空气槽),这些磁障可以影响气隙内的磁场分布从而实现近似正弦分布的气隙磁密波形。初步设计了一台基于拼接式转子的3 k W电动机,采用田口法对转子磁障的关键参数进行了优化,并对拼接式转子和传统内置永磁转子进行了对比分析,结果表明所提出的拼接式转子优于传统内置永磁转子。     

嵌入式永磁同步电机自适应在线参数辨识

针对嵌入式永磁同步电机参数辨识问题,提出一种自适应在线参数辨识方法,可在同一模型中对定子电阻、d轴电感、q轴电感和永磁体磁链进行辨识.该方法基于模型参考自适应系统,在同步旋转d-q坐标系下,构造出q轴电流自适应观测器,利用q轴电流观测误差,借助Lyapunov超稳定理论建立参数的辨识模型并推导出待辨识参数的自适应律,保证了特定条件下系统的稳定性和辨识参数的收敛性,解决了参数在线辨识算法的鲁棒性差、算法复杂等问题.仿真和实验结果表明,辨识参数能够在较短的时间内收敛到真实值附近,并且具有较小的误差.     

高速内置式永磁电机转子机械强度研究

为了研究高速内置式永磁电机转子机械强度,根据受力平衡原理,推导了极端情况下内置式高速永磁电机转子隔磁桥最大应力的解析计算公式。利用该解析公式和有限元方法分别分析了隔磁桥宽度对最大应力的影响规律,得到解析解和有限元计算结果最大偏差在7.5%以内,证明了解析推导的正确性。通过将永磁体沿圆周方向进行分段,增加隔磁桥的数量,将应力分散到多个隔磁桥上,以减小应力最大值。利用有限元方法分析了永磁体不分段、分两段和分三段时转子强度和空载漏磁因数,通过与未分段进行对比,永磁体分两段和分三段时隔磁桥最大应力分别减小58.5%和71.2%,而空载漏磁因数随着分段数增加而增大。     

Adaptive and robust speed control of interior permanent magnet synchronous motor drives

This paper presents a robust speed controller for field oriented controlled interior permanent magnet synchronous motor (IPMSM) drives. The proposed controller is designed using integral variable structure control (IVSC) combined with linear quadratic regulator (LQR). The LQR scheme is used to decide the optimal feedback gain to shape the system dynamics by tuning the IVSC switching plane to guarantee the robustness of the control algorithm. The complete drive is implemented in real-time using digital signal processor (DSP) control board DS1102. The tracking properties and robustness of the proposed scheme are examined through both simulations and experimental work. It guarantees accurate control performance in the presence of parameter variations, step speed change and load disturbances. The performance of IPMSM drive system with a conventional proportional-integral (PI) controller is presented in comparison with the proposed controller. The results show a significant improvement in both the transient and steady state responses over the conventional PI controller.     

考虑铁芯损耗的内置式永磁同步电机模型参数测量

提出一种计及铁芯损耗的内置式永磁同步电机模型参数测量方法。基于实验室常用的永磁同步电机驱动控制平台,详细阐述永磁磁链、定子电阻、等效铁损电阻和d、q轴电感参数的测量原理及实现方法。所提方法具有理论概念清晰、实现简单、通用性强的特点。通过对内置式永磁同步电机进行实际测试,验证所提方法的有效性和可行性。