A new high‐frequency voltage injection method for sensorless drive of permanent‐magnet synchronous motors with pole saliency

This paper proposes a new sensorless vector control method for salient‐pole permanent‐magnet synchronous motors. In regard to rotor phase estimation, the sensorless vector control method is characterized by a new high‐frequency voltage injection method distinguished from the conventional ones by a unique ellipse shape of the spatial rotation, and by a new PLL method whose input is a high‐frequency current autocorrelated signal. The new vector control method established by two innovative technologies can have the following high‐performance and attractive features: (1) it can allow 250% rated torque at standstill; (2) it can operate from zero to the rated speed under the rated motoring or regenerating load; (3) it accepts instant injection of the rated load even for zero‐speed control; (4) it accommodates a load with huge moment of inertia; (5) phase estimation is very robust against inverter dead time; (6) the computational load for estimating rotor phase is very small, would be the smallest among the methods with comparable performance. This paper presents the new vector control method by focusing on two innovative technologies from its principles to design rules. Usefulness of the new vector control method is verified through extensive experiments. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(4): 62–77, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20632     

Pulsating Signal Injection-Based Axis Switching Sensorless Control of Surface-Mounted Permanent-Magnet Motors for Minimal Zero-Current Clamping Effects

In this paper, we propose an injection-based axis switching (IAS) sensorless control scheme using a pulsating high-frequency (HF) signal to minimize position detection error and velocity estimation ripple resulting from the zero-current-clamping (ZCC) effect for surface-mounted permanent-magnet motors. When a pulsating carrier-signal voltage is injected in an estimated synchronous frame, the envelope of the resulting HF current measured in the stationary reference frame follows an amplitude-modulated pattern. Using this information, the IAS technique allows one to avoid multiple zero crossings of HF currents by adjusting the current phase angle according to the load condition. At no-load condition, the pulsating voltage is injected only on the $d$-axis, while the $d$-axis current is controlled to a certain nonzero value. Under a load condition, the injection voltage is switched to the $q$-axis, while the $d$ -axis current drops back to zero. Thus, the proposed sensorless control enforces a much better estimation performance in a region of ZCC without a predefined offline commissioning test than the standard pulsating injection scheme. Experiments illustrate the effectiveness of the proposed method in suppressing the estimation error caused by the ZCC disturbance and in extending the system bandwidth.      

A New Self‐Tuning Power‐Factor‐Based Vector Control Method for Efficient Wide‐Speed Range Sensorless Drive of Permanent‐Magnet Synchronous Motors

As a simple sensorless vector control method for permanent‐magnet synchronous motor (PMSMs), a power‐factor‐based vector control (PFVC) method has been reported. This method has the attractive characteristics that three functions such as current limit, efficiency and sensorless drive can be performed simultaneously in a simple manner. However, it was developed under the assumption that there is no practical voltage limit, and that it cannot be applied over the rated speed. This paper proposes a new PFVC method that allows PMSMs to be driven even over the rated speed under application of a practical voltage limit, while keeping the desired characteristics. The effectiveness and usefulness of the proposed method are verified through extensive experiments.     

Sensorless drive of surface-mounted permanent-magnet motor by high-frequency signal injection based on magnetic saliency

This paper presents a new sensorless control scheme of a surface-mounted permanent-magnet (SMPM) motor using high-frequency voltage signal injection method based on the high-frequency impedance difference. In the SMPM motor, due to the flux of the permanent magnet, the stator core around the q-axis winding is saturated. This makes the magnetic saliency in the motor. This magnetic saliency has the information about the rotor position. The high-frequency voltage signal is injected into the motor in order to detect the magnetic saliency and estimate the rotor position. In this paper, the relationship between the high-frequency voltages and high-frequency currents is developed using the voltage equations at the high frequency, and the high-frequency impedance characteristics are analyzed experimentally under various conditions. The proposed sensorless control scheme makes it possible to drive the SMPM motor in the low-speed region including zero speed, even under heavy load conditions. The experimental results verify the performance of the proposed sensorless algorithm.     

Position-controlled synchronous reluctance motor without rotationaltransducer

This paper presents a position sensorless control scheme of a synchronous reluctance motor (SynRM) combining a high-frequency current injection method in the low-speed region and the flux estimation method based on the stator voltages in the high-speed region. The rotor has inherent saliency, and its angle can be estimated from d-axis stator current injection and the appropriate signal demodulation in a low-speed region. In the high-speed region, the rotor can be estimated by the stator flux from the voltage information. The scheme gives a robust and dynamic estimation of the rotor angle, independent of the operating conditions, including speed and load conditions. Experimental results of closed-loop speed and position control with a 3.75 kW axially laminated SynRM are given to verify the proposed scheme     

New "mirror-phase vector control" for sensorless drive of permanent-magnet synchronous motor with pole saliency

This paper proposes a new sensorless vector control method for a salient-pole permanent-magnet synchronous motor (SP-PMSM). The proposed method is directly based on a new principle called "mirror-phase characteristics" and has the following high-performance and attractive features: 1) it can allow 250% rated torque at standstill, under which strong flux saturation usually occurs; 2) it can allow ultralow-speed control (the observed minimum speed ratio to the rated speed under the rated motoring or regenerating load is 1/1800); 3) in spite of the ultralow-speed performance, it can operate up to the rated speed; 4) it accepts instant injection of the rated load even for zero-speed control; 5) it accommodates a load with huge moment of inertia.; 6) it is insensitive to all motor parameters; 7) it is also insensitive to saturation phenomena of stator flux; and 8) it is so simple that it can be implemented with no additional hardware. The high performance and usefulness of the new "mirror-phase vector control" method are verified through experiments.     

Position Sensorless Control for IPMSM Based on Extended EMF and Voltage Injection Synchronized with Pulse‐Width Modulation Carrier

This paper presents a new position sensorless control system for an interior permanent magnet synchronous motor (IPMSM). The proposed method is based on the extended electromotive force (EMF) and voltage injection synchronized with a pulse‐width modulation carrier. The proposed method does not need to switch the estimation method by speed in order to estimate the magnetic pole position by extended EMF, even at low speeds. Further, the amplitude of the superimposing voltage is changed according to the extended EMF; the applied voltage is not saturated in the high‐load and high‐speed regions. The effectiveness of the proposed sensorless control system was verified experimentally.     

Usefulness of a frequency‐hybrid vector control for a sensorless induction motor drive

This paper examines and demonstrates the usefulness of a frequency‐hybrid vector control scheme for sensorless induction motor drive through actual‐machine‐based performance evaluation tests. The new approach utilizes a new indirect orientation scheme and a stable‐filter‐embedded direct orientation scheme, and exploits their advantages. It is confirmed through extensive tests with small and large standard motors such as 0.3, 3.7, 30 kW and special low‐voltage motors dedicated to electric vehicles that the sensorless vector control scheme has the following potential usefulness: (1) it can make machines that produce more than 200% rated torque at standstill, (2) in both motoring and regenerating modes, the rated torque can be produced even in the very slow speed range, including zero speed and zero frequency, (3) for constant speed, good linearity of torque response is attained, (4) it has the ability to track variable speed acceleration commands up to ±5000 rad/s² in the mechanical frequency sense, (5) it can accept a zero‐speed command and settles the machines to a stable standstill with no vibration, (6) it accepts instant injection of rated load even for zero‐speed control, and (7) it accommodates a load with huge inertia. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 44–58, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10073     

Speed- and current-sensorless field-oriented induction motor drive operating at low stator frequencies

This paper aims to demonstrate that, exploiting the sensorless zero-sequence (SZS) air-gap flux estimation technique, it is possible to realize field-oriented induction motor drives without speed and current sensors, able to operate down to zero speed. According to the SZS technique a zero-sequence stator voltage component is generated as a result of the injection of a suitable high-frequency signal on the stator voltage. By manipulation of such a zero-voltage component, that is unaffected by speed and load changes, it is possible to detect both the amplitude and the angular position of the air-gap flux. In the present paper, it is shown that such a technique allows for the estimation of the motor speed and the phase currents, enabling implementation of a field-oriented control as well as speed and current closed control loops using a simple hardware which, with minor modifications, resembles that of an inexpensive constant Volt/Hertz drive. Experimental tests are shown in order to practically confirm the expected features of the proposed approach.     

带相位补偿的PMSM脉振高频信号注入转子位置估计方法

本文针对在零低速区域内表贴式永磁同步电机的高频信号注入位置估计问题,分析了由带通滤波器和零阶保持器引起的相位偏移对位置估计精度的影响,提出一种带相位补偿的永磁同步电机脉振高频信号注入位置估计方法.该方法采用一种考虑相位补偿的解调函数,有效地消除带通滤波器和零阶保持器造成的位置估计误差.实验结果表明,在零低速范围内,带相...     

Sensorless IPMSM position estimation based on multi SVPWM with elimination of inverter nonlinear effects

This paper presents a position‐sensorless interior permanent magnet synchronous motor (IPMSM) control system at low and zero speed based on a multi‐space‐vector pulse‐width modulation (MSVPWM) pattern with the elimination of nonlinear inverter effects. In conventional sensorless methods based on the MSVPWM pattern, the high‐frequency (HF) components of voltage and current are used to estimate the rotor position information. However, the inverter nonlinear effects, such as forward voltage drops and deadtime, distort the HF components of the voltage and current so that an error occurs in the position estimation. Therefore, an improved position estimation scheme is developed in this paper. The compensated HF components of the voltage taking account of the inverter nonlinear effects can be used to decrease the estimation error. The proposed method can be implemented without increasing any hardware cost. Experimental results confirm the effectiveness of the proposed method. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

无位置传感器表面式永磁同步直线电机初始位置估计新方法

由于表面式永磁同步直线电机没有凸极性,无位置传感器控制时,估计动子初始位置非常困难。该文针对表面式永磁同步直线电机,提出了一种新的初始位置估计方法。在电机静止时,给电机注入幅值和相位可以控制的电压矢量。保持电压矢量一定的幅值不变,使其相位以较低的频率旋转。电压相位和电机直轴重合时,产生的电磁推力超过负载阻力,电机有一微动,由于反电势的作用电流就会降低,通过检测电流矢量的变化来估计动子的初始位置。这种估计方法不受电机参数的影响,也不需要增加任何硬件。仿真和实验表明给电机注入可控的电压矢量可以估计出动子初始位置,实现零速平稳起动。     

基于高通谐振滤波器的高频脉振电流注入法研究

当高频脉振电流注入法利用电机的凸极效应实现无位置传感器控制时,为了避免注入信号幅值选取的不当,导致提取转子位置信息的高频响应信号解调失败和转矩脉动,提出一种将高通谐振滤波器引入转子位置提取通道的方法。利用高通谐振滤波器在低频段的高度衰减性,在谐振点对解调信号放大增幅的特性,提高了含有转子初始位置信息的信噪比。对转子位置信号的滤波优化,使得电机无位置算法在解调响应信号的难度降低,转子位置和转速的估算可以实现零误差。最后通过仿真对比研究验证了方法的正确性和有效性。     

基于三维空间矢量的三角形联结级联SVG直流侧电压控制方法研究

三角形联结级联H桥拓扑静止无功发生器(SVG)能够动态补偿无功负序功率,提高功率因数,抑制电压闪变和波动,改善电网电能质量,近年来得到了广泛研究。对于级联H桥结构的静止无功发生器,其直流侧电压控制问题一直是研究的热点问题。空间矢量调制相对于载波调制,便于微机实时控制,具有电压利用率高和开关损耗小等特点。基于空间矢量调制的直流侧电压控制的方法在三角形联结级联H桥还没有应用。提出了基于三维空间矢量的直流侧电压三层控制结构:第一层为总的直流侧电压控制;第二层为相间均压控制,将每一相视为一个H桥,三相之间采用三维空间矢量法,在开关周期内通过能量函数选择合适的零序分量注入调制波中产生零序电流,实现三相之间的实时均衡控制;第三层为模块间均压控制,实现每相内部各H桥模块直流侧电压等于给定值。基于三维空间矢量的零序电流选择方法能够在单位开关周期内产生零序分量,从而产生任意次零序电流实现对直流侧电压控制,具有较快的动态响应速度,仿真和实验结果验证了该方法的正确性和有效性。     

A new generalized high‐frequency voltage injection method and mirror‐phase estimation method for sensorless drive of salient‐pole PMSMSs

This paper proposes a new generalized high‐frequency voltage injection method for sensorless drive of salient‐pole permanent‐magnet synchronous motors. The injected high‐frequency voltage has a unique spatially‐rotating elliptical shape, with the amplitudes of both the major and minor axes varying with the motor speed, and can be designed by selecting a design parameter. The high‐frequency current caused by the injected voltage, which has information on the rotor phase to be estimated, is speed‐independent, that is, is not affected by the motor speed at all. Consequently, the rotor phase can be estimated in a wide speed range from zero to the rated speed. By selection of the design parameter, the properties of the high‐frequency current can be adjusted appropriately to the associated motor‐drive system consisting of a motor and an inverter. As a versatile phase estimation method for estimating rotor phase using the high‐frequency current, the “mirror‐phase estimation method” is reconstructed and reproposed. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(3): 67–82, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20803     

基于无滤波器方波信号注入的永磁同步电机初始位置检测方法

针对无位置传感器内置式永磁同步电机(IPMSM)初始位置检测中,传统的基于凸极跟踪的短脉冲电压注入法难以确定脉冲宽度和幅值、实现困难、二次谐波分量法信噪比低的缺点,提出一种基于无滤波器方波信号注入的IPMSM初始位置检测方法。首先通过向观测的转子d轴注入高频方波电压信号,采用无滤波器载波信号分离方法解耦位置误差信息,通过位置跟踪器获取磁极位置初定值;然后基于磁饱和效应,通过施加方向相反的d轴电流偏置给定,比较d轴高频电流响应幅值大小实现磁极极性辨识;最后,通过2.2k W IPMSM矢量控制系统对提出的基于无滤波器方波信号注入的初始位置检测方法进行实验验证。结果表明,所提方法收敛速度较快,可在IPMSM转子静止或自由运行状态实现初始位置辨识和低速可靠运行,位置观测误差最大值为6.9°。     

基于转子凸极跟踪的无位置传感器永磁同步电机矢量控制研究

在分析高频电压信号激励下永磁同步电机数学模型的基础上,研究了一种基于凸极跟踪的转子位置自检测方法.文中讨论了高频电压信号的注入方式、提取,包含转子位置信息的高频负序电流的外差解调算法以及转子位置跟踪观测器的构成,并对一台内插式永磁同步电机采用旋转高频电压信号注入方式检测转子空间凸极的信号提取全过程进行了实验研究,成功地实现了该电机的无位置传感器矢量控制运行.实验研究表明,基于凸极跟踪的转子空间位置检测方法能准确地观测出转子的空间位置和速度,以此机理实现的永磁同步电机无传感器矢量控制也具有良好的静、动态运行性能.     

基于基波PWM激励和简化电流斜率测量的多相永磁同步电机转子位置估测技术

当前基于逆变器基波脉宽调制激励的双三相永磁同步电机（DTP-PMSM）无位置传感器的算法无需注入高频信号即可实现低速和零速控制。但是,该方法在非零电压矢量期间需要多次对电流进行采样,算法的实施比较复杂,对硬件要求较高,阻碍了这种方法在工业中的实际运用。为此,本文研究了一种改进算法。该方法直接利用DTP-PMSM本身的凸极效应,从静止坐标系下,以同步采样的方式提取相邻两个PWM周期内平均电流变化率,进而实现转子位置估测。此新方法实现了为位置估测进行的电流采样与为电流环控制进行的电流采样之间的同步,大幅降低了算法的实施难度。论文最后通过仿真验证了所提新方法在低速和零速运行条件下的有效性。     

基于扩展卡尔曼滤波器的永磁同步电机转速估计方法研究

研究了利用扩展卡尔曼滤波器(extended kalman filter, EKF)对永磁同步电机(permanent magnet synchronous motor, PMSM)矢量控制系统进行参数精确估计的方法。通过引入定子电流和电压,在线估计电机的定子磁链、电机转速和转子位置,进而实现永磁同步电机的无传感器控制。仿真结果表明EKF准确地观测了电机转速和磁链,所构建的无速度传感器矢量控制系统具有良好的控制性能。     

基于Buck变换器的无刷直流电机无位置传感器控制

针对无位置传感器控制中换相时刻不准确及三相桥式逆变电路调压过程对前后级电路产生冲击的问题,提出一种基于Buck变换器的无刷直流电机无位置传感器控制方法。改用Buck变换器代替三相桥式逆变电路调压,有效削弱了PWM调制过程中高频谐波信号对前后级电路的冲击,线电压中高次谐波含量明显减少,母线电流及相电流波形更加平稳。设计的3次谐波滤波器滤波效果良好,且3次谐波电动势过零点易于检测。提出的90°-α相位补偿方式能够有效解决无位置传感器控制中换相时刻不准确的问题,并且可以明显减小感应电流对相电流产生的影响,使得相电流更加稳定。仿真和实验结果验证了该方法的可行性和有效性。