Due to insufficient current tracking capability, traditional control methods generate significant torque and levitation force ripples, which are detrimental to system stability. This article proposes a novel predictive current control (PCC) algorithm by integrating the structural characteristics of a 12/8 bearingless switched reluctance motor with wider rotor teeth (BSRMWR). Compared to conventional predictive current methods, the proposed algorithm eliminates the need for prestored magnetic flux or inductance tables, significantly simplifying implementation. Furthermore, to minimize copper loss, the reference current criteria are optimized using a Lagrange function. A novel force sharing function (FSF) is also designed to compensate for computational delays. Finally, simulation and experimental results validate the effectiveness and feasibility of the proposed method.

In the high-power or high-speed permanent magnet synchronous motor drive system, the complex vector current regulator in the motor parameter mismatch and low carrier ratio conditions have shown excellent control performance, the traditional design of the complex vector current regulator in order to simplify the design process does not take into account the effect of the delay of the digital control system, resulting in the preset current loop bandwidth and the actual current loop bandwidth is distorted, relying on the preset current loop bandwidth of the design of the current regulator parameters can not make the current control effect as expected. The current regulator parameters designed based on the preset current loop bandwidth cannot make the current control effect reach the expectation. To this end, under the premise of fully considering the complex vector current regulator, the motor and the digital delay link, the Euler formula is used to expand the delay link in the frequency domain, and the current loop closed-loop transfer function is reconstructed by relying on the two important parameters of the current loop bandwidth and digital delay, and the algebraic relationship between the controller parameters and the current loop bandwidth and the digital delay is derived through the closed-loop transfer function, so as to propose an algebraic relationship between the controller parameters and the digital delay, and thus the design precision of the complex vector current regulator can be improved by the current loop bandwidth. Based on this, a complex vector current regulator parameter tuning method that can improve the design accuracy of the current loop bandwidth is proposed. The effectiveness of the proposed scheme is verified by both simulation and experiment.

Abstract In traditional magnetic bearing motors, the magnetic bearing and the motor are usually driven and controlled separately, resulting in higher controller costs and limiting further expansion of their applications. The author presents a four‐degree‐of‐freedom (4DOF) magnetic bearing switched reluctance motor (MBSRM), consisting of two 8‐pole active radial magnetic bearings (RMBs) and two two‐phase 4/2‐pole switched reluctance motors (SRMs), driven simultaneously by a set of asymmetrical power converters together. Firstly, the structure, winding configuration and co‐excitation working principles of the 4DOF‐MBSRM system are described in detail. Then the radial force formula for an 8‐pole RMB and the torque mathematical model for a 4/2‐pole SRM are briefly derived based on equivalent magnetic circuits, respectively. Furthermore, a co‐excitation control strategy for the 4DOF MBSRM is developed wherein an instantaneous radial force is used to control its rotor shaft levitation, an instantaneous torque is employed for rotational control at low and medium speeds, and an average torque is used for high speed operation. Finally, the good performance of the co‐excitation control for the proposed 4DOF‐MBSRM is proved by simulation analysis.

The research addresses the issue of fluctuation in non-conductive phase response current peaks due to unstable levitation force during the startup phase of the Bearingless Switched Reluctance Motor with Wide Rotor Teeth (BSRMWR) in traditional pulse injection methods. This fluctuation results in increased errors in logical judgment and rotor position estimation. To tackle this problem, an optimized rotor position estimation method based on pulse injection is proposed. This method utilizes an adaptive filtering LMS algorithm to construct a mathematical model for the variation in inductance caused by levitation force fluctuations. It dynamically adjusts filter parameters to effectively eliminate interference signals within the response current peaks. Simulation experiments confirm the method’s effectiveness in reducing rotor position estimation errors caused by interference signals, providing a viable technical approach to addressing instability during the startup phase.

In the traditional control scheme of a 12/8-pole bearingless switched reluctance motor (BSRM), radial force and torque are usually controlled as a compromise due to the conflict between their effective output areas. Additionally, each phase requires individual power circuits and is excited in turn to produce a continuous levitation force, resulting in high power device requirements and high controller costs. This paper discusses a 12/8-pole single-winding hybrid-rotor bearingless switched reluctance motor (HBSRM) with a hybrid rotor consisting of cylindrical and salient-pole lamination segments. The asymmetric rotor of the HBSRM slightly increases the complexity of its structure and magnetic circuit, but makes it possible to generate the desired radial force at any rotor angular position. A control scheme for the HBSRM is developed to utilize the independent excitation of the four windings in one phase to generate the desired levitation force at any rotor angular position, and it requires only half the number of power circuits used in the conventional control scheme of a 12/8-pole single-winding BSRM. Different from the average torque chosen to be controlled in traditional methods, this scheme directly regulates the instantaneous total torque produced by all excited phases together and presents a current algorithm to optimize the torque contribution of each phase so as to reduce torque pulsation, and the improved performance of this bearingless motor is finally validated by simulation analysis.

The coupling between torque and radial force, and between the two radial forces is detrimental to the efficient control and performance improvement of the bearingless switched reluctance motor (BSRM). In the article, an 18/16-pole permanent magnet (PM) biased BSRM with radial force windings driven by a three-phase full-bridge inverter is presented. To solve the coupling between two radial forces in this proposed BSRM, three of its derived decoupled topologies have been developed, and the decoupled characteristics of these structures are proved by the radial force mathematical model and finite element analysis. Further, based on the space vector pulse width modulation (SVPWM) technique for three-phase full-bridge inverters, a one-cycle digital control scheme for the radial force control applicable to four types of BSRMs has been developed. Finally, a BSRM is prototyped and tested for experimental validation of radial levitation.

This paper mainly describes a segmented PWM control method to minimize commutation torque ripple to achieve smooth operation of the motor at high and low speeds. The reasons for commutation torque ripple generated by brushless DC motors in three-phase six-state and two-phase conduction mode were analyzed. and a commutation torque ripple suppression strategy under ON-PWM modulation is proposed. This strategy considers the influence of the change of back EMF on the torque ripple during the commutation process, and further improves the compensation effect of commutation torque ripple, so as to realize the low torque ripple operation of the motor at low speed and high speed. By establishing a system simulation model in Matlab/Simulink environment, it is confirmed that the new control strategy can effectively reduce the commutation torque ripple, and verify the effectiveness and theoretical correctness of the control method.

AbstractA backstepping controller based on a non‐linear disturbance observer (NDOB) was created to enhance the dynamic performance and reliability of three‐degree‐of‐freedom hybrid magnetic bearings. After the structure of three‐degree‐of‐freedom hybrid magnetic bearings is introduced, the mathematical model is established, and the equation of the state is derived by the equivalent magnetic circuit technique. Based on the mathematical model, non‐linear disturbance observer (NDOB) is designed and is used to predict the system disturbance, and the backstepping control algorithm is compensated. To verify the effectiveness of the proposed controller, the backstepping controller, proportion integration differentiation controller, and backstepping controller based on a NDOB were compared by simulation and experiment. Results show that the backstepping controller based on a NDOB has better dynamic performance and robustness.

脉振的径向电磁力作为激励源作用于12/8极单绕组宽转子齿无轴承开关磁阻电机(Bearingless switched reluctance motor with wider rotor teeth,BSRMWR)的定子齿面并传送至定子轭部及机壳,会引发较大的振动噪声,阻碍其推广应用.针对这一问题,本文从本体结构的角度入手对电机壳体进行优化改进.采用三维多物理场有限元模型,建立了BSRMWR电磁?结构?振动?声场耦合模型.通过对BSRMWR电磁场进行瞬态分析,得到径向电磁力.将模态应变能方法应用于BSRMWR的壳体得到电机外壳结构有较大的应变能,说明电机壳体结构的薄弱.基于此,通过形貌优化的方法对电机的壳体结构进行优化.结果表明,采用形貌优化后机壳结构的BSRMWR,其振动和噪声均有显著改善.

The start and commutation of the bearingless switched reluctance motor are all through the real-time position detection of the motor rotor, while the traditional position detection relies on the displacement sensor to obtain an accurate position signal, but also brings many drawbacks and shortcomings. The first is to increase the hardware cost and reduce the economy of the system; the vibration of the motor and the vibration of the external environment may cause the sensor to loosen and fall off, reducing the reliability of the system; the harsh working environment such as high dust, high temperature, high humidity will affect the accuracy of the displacement sensor, or even damage it, reducing the environmental adaptability of the system. In order to solve this problem, this paper proposes an optimal control method without a position sensor, and compares it with the existing high-frequency pulse injection method to verify the effectiveness and feasibility of the proposed method.

To achieve levitation in active magnetic bearing (AMB) systems, levitation coils must be driven by a switch power amplifier (SPA). Therefore, SPA performance is important to stable levitation. In previous studies, five-phase six-leg (5P6L) SPA topology was proposed to reduce hardware costs. However, current tracking performance degrades due to the coupling problem of the five-phase current and freewheeling loss. Then, the rotor may deviate markedly from the balance position, affecting rotor stability. The keys to solving these problems lie in the duty cycle control of the common leg and the compensation of freewheeling loss. This article proposes an improved one-cycle control (OCC) algorithm in which the duty cycle of the common leg is optimized by finite control set model predictive control (FCS-MPC), and the freewheeling loss is compensated for by a high-precision mathematical model. In addition, the parameter uncertainty of the FCS-MPC model is analyzed, and the convergence of the optimization algorithm is investigated. Simulations and experiments show that the proposed algorithm is effective, and the high dynamic response and low steady-state error performance of SPA are achieved.

A bearingless switched reluctance motor (BSRM) has the combined characteristics of a switched reluctance motor (SRM) and a magnetic bearing. The hybrid-rotor BSRM (HBSRM) discussed in the paper has a twelve-pole stator and an eight-pole hybrid rotor, which is composed of a cylindrical rotor and a salient-pole rotor. Although the asymmetry of the hybrid rotor makes the structure and magnetic field of the HBSRM more complex, it can always produce a significant amount of magnetic pulling force to levitate a rotor shaft at all the rotor angular positions of each phase, which is not available in a traditional BSRM. The classical mathematical model for a conventional BSRM is valid only when its rotor rotates from the start of the overlap position to the aligned position, and the radial force and torque derived from this model are discontinuous at the aligned positon, which is harmful to the motor’s stable operation. In this paper, a full-period mathematical model on the assumption that the gap permeance is cut apart by straight lines or improved elliptical lines for a 12/8-pole HBSRM is provided. On the basis of this mathematical model, the continuity of the radial force and torque at all the rotor angular positions can be guaranteed, and the fine characteristics of this mathematical model have been verified by simulations.

针对无轴承开关磁阻电机在换相时励磁电流建立速度过慢,本文提出了一种结构简单的升压型功率变换器,电机在换相时,通过利用绕组退磁能量来为后一相绕组迅速建立励磁电流,在保证电机稳定悬浮的基础上实现电机换相时的低转矩脉动运行.分析了该功率变换器的拓扑结构以及工作状态,在此基础上,构建了基于该新型升压功率变换器的12/8极单绕组宽转子齿无轴承开关磁阻电机驱动系统,通过Matlab/Simulink系统仿真,验证了该功率变换器的可行性和有效性.

针对混合径向磁轴承用的位移传感器容易发生故障可靠性不高的问题,依据冗余位移传感器检测思路,采用坐标变换矩阵技术,提出一种位移传感器的故障识别与容错控制方法.通过将位移传感器非对称安装在混合径向磁轴承的外围,根据位移传感器的故障状态选取不同的坐标变换矩阵,实现转子在水平和竖直两个自由度上的位移检测.传感器位置的非对称安装降低了由于传感器数量增加而引起的电磁干扰影响并且提高了容错能力,对冗余位移传感器最优安装位置的分析提高了传感器可检测范围,能够实现4种传感器故障状态的容错控制.通过在两对极混合径向磁轴承系统中的仿真验证,表明所述方法能够有效、快速实现位移传感器的容错控制,具有结构简单、容错能力高和适用范围广的优点.

The stator and rotor of the bearingless switched reluctance motor are both double salient pole structures, when the traditional current chopping control method is used, the torque and levitation force of the motor will have large fluctuations. To solve this problem, this paper studies a direct instantaneous torque control and direct levitation force control (DITC&DFC) method suitable for single-winding bearingless switched reluctance motors. This method takes the instantaneous torque and the instantaneous levitation force of the motor as the directly controlled object, eliminates the current loop, and simplifies the control algorithm while suppressing the fluctuation of the motor torque and levitation force. A 12/8-pole singlewinding bearingless switched reluctance motor with wide rotor teeth drive system is constructed, the Matlab/Simulink system simulation verifies the effectiveness and feasibility of the method.

磁阻电机的振动噪声问题阻碍其推广应用.针对12/8极单绕组宽转子齿结构无轴承开关磁阻电机(BSRM-WR),提出一种利于减振的发电运行控制策略.基于数学模型和悬浮运行原理,介绍了工作区间划分;以提高铁芯材料利用率为目的,推导出励磁电流计算方法;并给出了悬浮电流、开通关断角等其它相关控制参数的计算公式及系统控制框图.利用Matlab/Simulink搭建系统仿真模型,对比分析电机在该策略下与低铜耗发电运行控制策略下的悬浮力、输出电压以及振动响应,仿真结果表明该控制策略悬浮力跟踪良好、输出电压稳定、并具有显著的减振效果.

A dynamic model of the rotor system supported by active magnetic bearings at both sides is established, the fourth-order Runge-Kutta method is used to simulate. The periodic motion transition of the system and its evolution to chaotic motion are discussed from bifurcation diagrams and phase diagrams. It emphatically analyse the change of crack influencing factor and eccentricity on the system response and stability. The results show that the system presents period motion with appropriate parameter conditions. Large crack fatigue damage and value of eccentricity increases the amplitude and chaotic motion window in the low speed region, decrease the system stability. When the rotor crosses the critical speed range and reaches the high rotational speed region, the stable period-1 motion is dominant.

无轴承开关磁阻电机(BSRM)由于其定、转子的双凸结构和脉冲式的电源供电方式,存在转矩脉动较大的问题,选择合适的开通角与关断角有望改善其转矩性能.针对宽转子齿无轴承开关磁阻电机(BSRMWR),提出了一种改善型控制算法.该算法通过分析换相时的绕组上升与下降电流,在保证悬浮力跟踪良好的前提下,调节换相时的开通角与关断角,以达到抑制其转矩脉动的目的.基于该电机磁阻的双相导通原理,建立转矩和悬浮力的数学模型,分析了该控制策略的基本原理,给出了其参数计算方法.仿真结果验证了该控制算法的可行性和有效性.

For the advantages of easy realization and rapidly intelligent response,the one-cycle control was applied in five-phase six-leg switching power amplifier for magnetic bearing. This paper improves the one-cycle control considering resistance voltage drop and derives its mathematical models. The improved algorithm is compared with the former one. The simulation and experimental results show that the improved algorithm can effectively reduce the output current ripple,achieve good tracking of the given current,improve the control accuracy,and verify the effectiveness and superiority of the method.

随着磁轴承技术的发展,转子转速越来越高,随之而来的稳定性问题日益突出.磁悬浮轴承柔性转子动力学研究成为目前专家学者的研究重点.该文综述磁悬浮轴承–柔性转子的稳定控制理论及过程,包括分析方法及优化方法,同频振动、倍频振动,并提出磁悬浮轴承–柔性转子动力学研究的发展趋势和关键问题,为磁悬浮轴承–柔性转子动力学研究提供参考.