Fuzzy logic rotor position estimation based switched reluctance motor DSP drive with accuracy enhancement

This paper describes a novel angle estimation scheme for a real time digital signal processor (DSP) based switched reluctance motor drive using fuzzy logic where several unique techniques are implemented to improve the estimation accuracy. First, an optimized fuzzy model of the motor was created using an adaptive neuro-fuzzy inference system (ANFIS) based on accurately measured flux linkage data. Secondly, an improved fuzzy optimal sensing phase selector was developed based on the analysis of both modeling error and measurement error. Lastly, a delayless polynomial predictive filter and an online phase winding resistance estimator are also implemented to further improve the position estimation accuracy. Both simulation and experiment results on a DSP based real time drive are presented to show the effectiveness of this scheme.     

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.     

A novel switched reluctance motor drive with optical graphicalprogramming technology

Due to magnetic nonlinearities, switched reluctance motor (SRM) drive control is complicated and normally requires a microprocessor or a digital signal processor. This paper presents a simple and reliable SRM drive using an innovative encoder based on optical graphical programming technology. There is no microprocessor in the drive, no A/D or D/A circuitry, with a drive system that matches the simplicity of the motor construction. It features a simple and effective control capability. Current waveform optimization for the encoder is carried out offline, for high efficiency, and programmed directly into the encoder. Experimental results validate the concept     

Rotor position estimation in a switched reluctance drive usingrecursive least squares

This paper describes a new algorithm for the estimation of rotor position in a switched reluctance motor. It is based on a recursive least-squares estimator deducing both position and speed. A particular advantage of the algorithm is its ability to extract information about rotor position at very low speeds (one electrical cycle per minute) from voltage and current waveforms sampled only at the converter switching frequency. Experimental results for a 12/8 motor demonstrate that estimation is possible over the full range of operating conditions, including the field-weakening region, with a typical accuracy of better than two mechanical degrees. The paper also illustrates the performance of the algorithm by showing it operating within a sensorless position controller     

Fuzzy logic torque ripple reduction by turn-off angle compensationfor switched reluctance motors

A fuzzy-logic-based turn-off angle compensator for torque ripple reduction in a switched reluctance motor is proposed. The turn-off angle, as a complex function of motor speed and current, is automatically changed for a wide motor speed range to reduce torque ripple. Experimental results are presented that show ripple reduction when the turn-off angle compensator is used     

High robustness and reliability of fuzzy logic based positionestimation for sensorless switched reluctance motor drives

In many applications where motor drives are used, concern. Thus, a major consideration is the reliability of position estimation schemes when sensor less SR motor drive control is employed. Hence, in this paper, the robust of a fuzzy logic based angle estimation algorithm for the switched reluctance motor (SR) motor is described. It is shown using theoretical analysis and experimental results, that by using logic, the angle estimation scheme gains a high level of robustness and reliability. A theoretical and quantitative analysis of the noise and error commonly found in practical motor drives is given, and how this can affect SR motor position estimation. An analysis is also given on the concepts of robustness and reliability. It is shown that the fuzzy logic based scheme is robust to erroneous and noisy signals commonly found in motor drives     

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.     

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.     

基于TMS320F240的开关磁阻电机调速系统设计

提出了一种基于数字信号处理器(DSP)的开关磁阻电机控制系统,系统充分利用了DSP周边接口丰富、运算能力强、速度快的特点,简化了系统硬件,并实现了模糊控制策略.     

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。     

Novel rotor position estimation technique for switched reluctance motor (SRM)

This article presents a new and novel method which is designed to detect the rotor position at standstill and at low speeds in switched reluctance motor. Since the inductance parameter plays a significant role both in the steady state and in the dynamic characteristics of an electromagnetic device, the rotor position can be determined using inductance bridge systems to measure unknown inductance and resistance values. In this method we use motor winding in Maxwell–Wien Bridge, with the standard capacitor and the resistor in parallel with it adjusted to achieve balance in an aligned position when the maximum inductance occurs. The supply voltage, in conjunction with the drive transistor, produces short pulses for this AC bridge. The condition of the balanced bridge v ₀?=?0 leads to the relation between the impedances of the bridge branches. The phase inductance varies with the rotor position. Therefore the motor goes into an unaligned position and the Maxwell–Wien Bridge goes into an unbalanced condition thus causing variation in the state of the bridge output. It then continues to sense the rotor position with the motor running by applying the same procedure, but only to the un-energised phases winding. The simulation and experimentally obtained results demonstrate the feasibility and practicability of this method.     

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。     

基于改进的支持向量机的开关磁阻电机的模型建立

开关磁阻电机具有结构简单、工作可靠、运行效率高等优点。但开关磁阻电机的磁路高度饱和、非线性化,很难建立准确的数学模型,难以实现高精度控制。在研究开关磁阻电机的电磁与转矩特性的基础上,结合支持向量机算法在解决小样本、非线性、高维数、局部极小值问题上的优势,建立了径向基函数核函数的支持向量机的开关磁阻电机的数学模型,通过仿真与传统BP神经网络算法对比,证明该算法具有较高的性能,实验平台检测的数据表明,所构建的开关磁阻电机模型是可行的,证明了模型的正确性和有效性。     

A current modulation scheme for direct torque control of switched reluctance motor using fuzzy logic

The paper addresses a fundamental control issue in switched reluctance motor (SRM) drives — the torque ripples. Normally, torque ripple minimization is achieved by using a look-up tables, i.e., the look-up tables uses stored magnetic characteristics to provide the reference current, on-angle, and off-angle for a given torque. A number of techniques for the generation of reference current profiles that minimize the torque ripples have also been suggested in the past. But due to highly nonlinear characteristics of the SRM, all these schemes are not fully successful. Moreover, their performance depends greatly on the accuracy of the magnetic characteristics measurements of the motor on which most of these algorithms work. Our work is primarily motivated to modulate the reference phase current pattern with the aid of fuzzy logic which is well suited to compensate for the nonlinearities of the system, so that the torque ripples are further suppressed. Performance of the proposed strategy is verified by computer simulation.     

High robustness of an SR motor angle estimation algorithm usingfuzzy predictive filters and heuristic knowledge-based rules

In this paper, the operation of a fuzzy predictive filter used to provide high robustness against feedback signal noise in a fuzzy logic (FL)-based angle estimation algorithm for the switched reluctance motor is described. The fuzzy predictive filtering method combines both FL-based time-series prediction, as well as a heuristic knowledge-based algorithm to detect and discard feedback signal error. As it is predictive in nature, the scheme does not introduce any delay or phase shift in the feedback signals, In addition, the fuzzy predictive filter does not require any mathematical modeling of the noise and, therefore, can be used effectively to control nonGaussian impulsive-type noise. An analysis of the noise and error commonly found in practical motor drives is given, and how this can effect position estimation. It is shown using experimental results that the FL-based scheme can cope well with erroneous and noisy feedback signals     

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     

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。     

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     

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。     

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。