Dual-decay converter for switched reluctance motor drives inlow-voltage applications

A modified converter topology for star-connected switched reluctance motors suitable for low-voltage applications is proposed. A dual-time-constant freewheeling circuit has been designed to improve the drive performance and efficiency over a wide range of speeds. The different modes of operation of the converter are discussed, and a comparison is made with other converter configurations     

A novel unipolar converter for switched reluctance motor

A configuration of a unipolar power converter with improved switching performance suitable for switched-reluctance motor supply is presented. The switched-reluctance motor operation principle is presented and its ideal characteristics are considered. The proposed converter is described and its operation is analyzed. The converter characteristics are studied with the aid of computer simulation. Current control of the proposed converter is considered. A prototype converter has been built to verify the analysis results and to validate the simulation. The design procedure is presented and experimental results which confirm the analysis are given and discussed     

Control of switched reluctance motor torque for force controlapplications

The paper presents a method for controlling switched reluctance motor (SRM) torque for force control applications. SRMs are used in AdeptOne robots, and the authors perform experiments with two robots, controlled in coordination, in grasping and manipulation of various objects. The object and robot parameters are not exactly known, and adaptive methods are used to control the overall system. These methods are model-based control techniques which require high bandwidth torque control. This requirement is typical for high precision mechanisms. SRM characteristics are very nonlinear. In particular the torque ripple, friction, and the torque versus position and current relationships were analyzed in the context mentioned above, and specifically, for force control applications. The proposed method is based on a new commutation algorithm and a measured torque versus position and current relationship, used to smooth the SRM's torque ripple, hence generating a torque output nearly independent of position. Furthermore, the internal friction is estimated on-line, and compensated for. This renders a high accuracy torque tracking. The torque control method is based on feedback from the motor angular velocity, motor angle, armature current, and feedforward for friction compensation and cancellation of nonlinear effects. The method has been tested experimentally on Adept motors and the results were very encouraging. The method has been also used for adaptive control of two coordinated Adept robots     

混合外转子磁悬浮开关磁阻电机的电磁分析

为了解决飞轮储能支撑系统体积庞大以及功率损耗大的影响,提出了一种转子由8个凸极和圆盘轴向叠加而成的12/8极混合外转子结构磁悬浮开关磁阻电机(Bearingless Switched Reluctance Motor,BSRM)。该电机的特征是转子直驱飞轮,提高了装置的紧密度并且圆盘提供了悬浮力。文中详细介绍了该电机的悬浮机理和发电原理。结合ANSOFT三维有限元仿真,分析该电机的电磁特性以及转矩、悬浮力特性,结果表明:该飞轮电机具有悬浮力承载力强、易于控制、耦合小等优点。     

Dynamic testing of switched reluctance motors for high-bandwidth actuator applications

This paper examines the testing and assessment of high-bandwidth switched reluctance motor torque control for actuator and motion control applications. It is claimed that the torque control is sufficiently fast and accurate and that it does not, in itself, impose any significant limits on the performance of the overall system. To provide proof of concept, an experimental test rig that emulates a motion control application has been designed and built. The quality of torque control permitted the design of conventional velocity and position control loops in a transparent fashion. The paper reports high-performance motion control, in particular, four-quadrant operation, high-bandwidth speed and position control, low- and zero-speed operation in the presence of a load torque, and trapezoidal profiled motion have all been demonstrated through extensive experimental tests.     

单绕组磁悬浮开关磁阻电机结构优化设计

针对单绕组磁悬浮开关磁阻电机结构参数的优化问题,提出了基于相关向量机与混合粒子群优化的方法。通过有限元分析计算了电机悬浮力和转矩与结构参数的关系,构建基于相关向量机非参数模型。以电机平均悬浮力和平均转矩最大输出为优化目标,采用混合粒子群优化算法获取最优结构参数,通过对比仿真实验说明了该算法的准确性与优越性,电机性能得到明显提升。     

4相8/6开关磁阻电机建模与仿真

由于开关磁阻电机的双凸极结构特点和开关性供电特点,使其难以简单地用传统电机的分析方法解析计算。在开关磁阻电机数学模型基础上,借助离线堵转实验得到的数据,分析得到了SRM的电感模型,并对该模型进行傅里叶分析,建立基于MATLAB/SIMULINK的开关磁阻电机非线性动态模型。仿真与实验结果证实模型的正确性、控制策略的有效性和系统运行可靠,为将来开关磁阻电机调速系统的优化改进提供了参照。     

开关磁阻电机的实时仿真平台研究

文中主要介绍了开关磁阻的实时仿真平台。基于PC机直接控制开关磁阻电机的运行的目的,采用Matlab中的实时代码生成工具箱将Simulink中的程序编译成C程序,由PC机发出信号,经PCI数据采集卡被传送至驱动电路,驱动电路再提供一个12 V的驱动电压的方法控制电机运行。实验结果显示PC机控制电机运行正常,仿真波形图显示A、B、C三相脉冲间隔相等,分别在0°、30°、60°时开通,每次开通角为10°符合设定值。本仿真平台达到实时控制电机的要求。     

Indirect angle estimation in switched reluctance motor drive usingfuzzy logic based motor model

In this paper, a novel rotor position estimation scheme is described that was developed to overcome the drawbacks of the previous sensorless techniques, which were proposed for switched reluctance (SR) motor drives. It is based on fuzzy-logic, and does not require complex mathematical models or large look up tables. The scheme was implemented by using a digital signal processor. The real-time experimental results given in this paper show that the position estimation method proposed can provide accurate and continual position data over a wide range of speeds (zero/low/high), and can also function accurately at different operating conditions (chopping/single pulse mode and steady state/transient operation)     

开关磁阻电机全数字控制系统中FPGA的应用

提出了基于数字信号处理器（DSP）和现场可编程门阵列（FPGA）的开关磁阻电动机全数字控制系统,对DSP和FPGA的功能进行了分配。根据开关磁阻电动机的驱动要求,分析控制逻辑,由FPGA实现了电流斩波、角度位置和PWM电压斩波相结合的控制方案。仿真结果表明,设计的开关磁阻电动机调速系统具有高效、实时、动态性能好等优点。     

Bifurcation and chaos analysis of power converter for switched reluctance motor drive

Bifurcation and chaos characteristics of single phase power converter in switched reluctance motor (SRM) drive system are studied by establishing its corresponding discrete iterative map model in this article. The discrete iterative map model of the converter is first derived. The stability theoretical analysis shows that the system may lose stability as the variation of system parameters in periodic-1 operation. With the bifurcation diagrams and Lyapunov exponents’ analyses, the operation state regions of current-controlled single phase of SRM drive can shift among stable periodic-1 region, chaos region and multi-periodic region. To verify the theoretical analysis results, time-domain waveforms and power spectra of current-controlled single phase of SRM drive are obtained by Runge–Kutta algorithm. Moreover, theoretical analysis and simulation results are verified by experimental circuit.     

基于虚拟仪器的开关磁阻电机监控系统

为了提高开关磁阻电机控制系统的实用性和可靠性,利用NI虚拟仪器构建了监控系统,可以实时监测和调整电机运行时的重要参数。该方案以装有数据采集卡的PC机和DSP作为硬件基础,利用LabVIEW软件将各类传感器传送的信号进行实时处理,同时记录和显示各项数据,然后再利用相应的算法完成对数据的分析。DSP则作为PC机故障时的备用系统。实验证明,该控制系统的实用性和可靠性比之前大大提高。     

High-precision position control of a novel planar switched reluctance motor

This paper presents the position control of a novel two-dimensional (2-D) switched reluctance (SR) planar motor. The planar motor consists of a six-coil moving platform and a flat stator base made from laminated mild steel blocks. Unlike conventional x-y tables, which stack two moving slides on top of each other, the proposed 2-D planar motor has the advantages of simple mechanical construction, high reliability, and the ability to withstand harsh operating conditions. Together with the two linear encoders attached to the x-axis and y-axis, the motor can be controlled under closed-loop mode. To combat the problem of force nonlinearity, this paper proposes a cascade controller with force linearization technique to implement the drive controller. Due to the unique structure of the planar motor's magnetic circuit, there is very little coupling between the x-axis and y-axis, and no decoupling compensation is needed. Preliminary results show that the proposed SR planar motor has a positional accuracy of 5 /spl mu/m and a maximum acceleration/deceleration rate of 2 G.     

Torque ripple minimization in switched reluctance motor drives byPWM current control

Higher torque ripple is one of the few drawbacks of switched reluctance motor (SRM) drives which otherwise possess excellent characteristics for applications in many commercial drives. This paper begins with an extensive review of torque ripple reduction methods that appear in the literature and then presents a new strategy of PWM current control for smooth operation of the drive. This method includes a current control strategy during commutation when torque ripple minimization is of utmost importance     

Fault-tolerant switched reluctance motor drive using adaptive fuzzy logic controller

An adaptive fuzzy controller has been designed to develop a high-performance fault-tolerant switched reluctance motor (SRM) drive. The fuzzy controller continuously adapts its properties to regulate the machine torque as desired by the drive system even under fault conditions. The adaptation of the fuzzy membership functions results in extended conduction period and increased peak current of the healthy phases to deliver the commanded torque, as much as possible. The adaptive fuzzy controller provides smooth torque output with minimum ripple, even under fault conditions, yielding a high-performance SRM drive with fault-tolerant capability.     

基于有限元法的开关磁阻电机磁场特性分析

为了准确掌握开关磁阻电机的磁场特性,建立了其磁场二维模型,采用电磁场有限元方法对开关磁阻电机的磁场分布特性和参数进行分析计算。结果表明：在定子齿极与转子齿极完全不重合时,有限元分析因端部磁场的作用产生较大的误差,相对误差约为40%;随着定子齿极与转子齿极重合量的增加,有限元的计算误差逐步减小,到对齐位置时,漏磁很小,自感漏磁几乎为零。研究结果为电机结构的优化设计提供了理论依据。     

Modeling, Simulation, and control of switched reluctance motor drives

This paper presents the modeling, simulation, and control aspects of four-quadrant switched reluctance motor (SRM) drives. The design of SRM drive systems must be focused on application-based appropriate control and engineering solutions needed to overcome the practical issues. A complex model is described for the physical motor simulation to incorporate the important dynamics of the SRM. A simpler, but quite accurate, model is presented for the SRM controller. Various practical limitations have been incorporated in the simulation model to make it closer to the experimental setup. The SRM control parameters are chosen based on torque-per-ampere maximization requirement. Experimental results for a 1.0-kW SRM obtained on a digital platform are presented along with useful guidelines for prototype implementation.     

Performance analysis of photovoltaic pumping systems using switched reluctance motor drives

A photovoltaic (PV) pumping system using a switched reluctance motor (SRM) is investigated in this work. the motor is supplied by a DC voltage through a simple switching circuit. This drive circuit is much simpler than the normal DC/AC inverter required to supply an induction motor. the efficiency of the SRM is considerably higher than that of equivalent DC or induction motors. In addition, because of its simple construction, the SRM is cheaper than these conventional drives. These advantages give the proposed system higher efficiency and lower cost compared with other systems. In this paper, which has a substantial tutorial content, a design example is studied in detail to explore the advantages of PV pumping systems based on the new drive. Study of the performance of the proposed system showed that the operating efficiency of the motor is about 85% during most of its working time. the matching efficiency between the PV array and the proposed system approaches 95%. the major part of the losses takes place in the pump and the riser pipes; this loss represents one-third of the total available energy.     

Power-factor correction for switched reluctance drives

This paper evaluates the need for power-factor correction (PFC) in switched reluctance drive systems supplied from single-phase mains. The aim is to achieve interference values lower than the prescribed norms at minimal system costs and volume. It is shown that for certain applications, a PFC circuit has to be implemented, but simpler technical solutions are often possible. Finally, a suggestion is presented as to how a low-cost power-factor-corrected system should be built for high-volume production     

Inductance model-based sensorless control of the switched reluctance motor drive at low speed

A sensorless control scheme for the switched reluctance motor (SRM) drive at low speed is presented in this paper. The incremental inductance of each active phase is estimated using the terminal measurement of this phase. The estimated phase incremental inductance is compared to an analytical model, which represents the functional relationships between the phase incremental inductance, phase current, and rotor position, to estimate the rotor position. The presented sensorless control scheme requires neither extra hardware nor huge memory space for implementation. It can provide accurate rotor position information even as the magnetic characteristics of the SRM change due to aging. Combined with other inductance model-based sensorless control techniques, the proposed method can be used to develop an inductance model-based sensorless control scheme to run the SRM from standstill to high-speed. Simulation and experimental results are presented to verify the proposed scheme.