开关磁阻电动机平滑转矩及无位置传感器控制研究

发布时间：2018-05-05 08:13

本文选题：开关磁阻 + 非线性建模　；参考：《中国矿业大学》2014年博士论文

【摘要】：在当前世界各主要国家大力发展节能减排技术的背景下，电机能效标准不断提高，电动汽车产业迅速发展，具有高效、坚固、低造价等优点的开关磁阻电机(SRM)迎来良好的发展机遇。然而转矩脉动以及对位置传感器的依赖限制了SRM在诸多领域的应用推广。针对SRM的平滑转矩及无位置传感器控制，本文展开了一系列研究，主要内容如下：对SRM控制技术进行研究首先需建立精确的电机模型。本文给出一种开关磁阻电机磁链特性曲线快速测量方法，并以此建立SRM非线性模型。利用SRM特有的几何结构对称性，无需额外机械装置，通过导通单相或串联的多相绕组，转子可稳定在若干个对称位置，从而获取多条磁链曲线。受相间互感影响，多相励磁条件下获取的磁链曲线不能直接用于建模，对此本文提出通过等效磁路分析获取等效单相励磁条件下的磁链特性的方法。基于实测的多条磁链曲线，采用傅立叶级数建立电机磁链特性和转矩特性数学模型。为验证动态运行时模型的精度，本文引入硬件在环技术，使虚拟的电机模型与实际电机同步运行。实验结果表明电机模型具有较高精度，验证了方法的有效性。较大的转矩脉动是限制SRM应用于伺服控制领域的主要原因。对于一台给定的SRM，可通过控制消除转矩脉动，输出平滑转矩。受直流母线电压以及可允许最大电流限制，SRM系统只能输出有限的平滑转矩，且可输出的最大平滑转矩是转速的函数，被定义为“平滑转矩—转速特性”。为评估和充分利用SRM的转矩输出平滑转矩的能力，本文提出了一种确定电机平滑转矩—转速特性、以及实现最大平滑转矩输出的方法。平滑转矩—转速特性与平均转矩—转速特性分别代表电机输出平滑转矩与平均转矩的能力，二者比值则表明执行平滑转矩控制时对转矩的利用率。使用所提方法可获取电压需求最小的转矩分配函数，仿真与实验结果表明，与常用的四种转矩分配函数相比，优化后的转矩分配函数可输出更大范围的平滑转矩。相对转矩分配函数法，直接瞬时转矩控制无需预先规划参考相电流或相磁链，具有较强实用性与通用性。直接转矩瞬时转矩控制器主要由转矩观测器和转矩滞环控制器构成。本文采用常用的查表法实时获取总转矩，重点研究了转矩滞环控制器。在换相过程中，相邻两相的转矩滞环控制器各有一组阈值，两组阈值之间的大小关系决定了两相绕组的电平状态，基于对平滑转矩—转速特性的研究结果，本文通过设置合适的阈值，提出了一种可实现最大平滑转矩输出的新型直接瞬时转矩控制器。与传统直接瞬时转矩控制相比，所提方法可自行确定最优关断角，无需额外的角度优化策略，简化了控制过程。目前大多数无位置传感器控制技术依赖电机磁链模型，降低了其实用性与通用性。对此本文提出基于特殊位置检测的无位置传感器控制方法。任意一台具有常规结构的SRM，其梯形相电感存在三个特殊点，第一个为最小电感区始端位置，第二个为最小电感末端位置，第三个为最大电感始端位置。电流在该三个位置出现极值点，通过检测电流极值点可获取位置信息。现有的电流梯度法用于检测第二个特殊位置，本文提出的方法用于检测第一个和第三个特殊位置。仿真与实验结果表明，所提方法在无电机模型的条件下可实现无位置传感器控制。此外，，本文使用零相移滤波器对三种方法的检测精度进行了分析，对三种方法适用的转速范围以及其他性能进行了对比。
[Abstract]:In the background of the major countries in the world to develop energy saving and emission reduction technologies, the energy efficiency standards of motor are continuously improved, and the electric vehicle industry is developing rapidly. The switched reluctance motor (SRM) with the advantages of high efficiency, sturdy and low cost has a good development opportunity. However, the torque ripple and the dependence on the position sensor restrict the SRM in many ways. In this paper, a series of researches on smooth torque and sensorless control of SRM are carried out. The main contents are as follows:
It is necessary to establish an accurate motor model for the study of the SRM control technology. In this paper, a fast measurement method of the magnetic chain characteristic curve of the switched reluctance motor is presented, and the SRM nonlinear model is established. The rotor can be stable by using the symmetry of the geometric structure of the SRM, without additional mechanical devices and through the multiphase winding of single phase or series. In several symmetric positions, multiple magnetic chain curves are obtained. Under the influence of mutual inductance, the magnetic chain curves obtained under multiphase excitation can not be directly used for modeling. In this paper, the equivalent magnetic circuit analysis method is proposed to obtain the equivalent magnetic chain characteristics under the equivalent single-phase excitation condition. The mathematical model of the motor flux and torque characteristics is established. In order to verify the accuracy of the dynamic running model, the hardware in the loop technology is introduced in this paper to synchronize the virtual motor model with the actual motor. The experimental results show that the motor model has a high accuracy and the effectiveness of the method is verified.
The larger torque ripple is the main reason that limits the application of SRM to servo control. For a given SRM, the torque ripple can be eliminated and the output is smooth. The SRM system can only output a limited smooth torque by the DC bus voltage and the allowable maximum current limit, and the maximum output smooth torque is the speed. The function is defined as a "smooth torque speed characteristic". In order to evaluate and make full use of the torque output of the torque output of SRM, this paper presents a method to determine the smooth torque speed characteristic of the motor and the maximum smooth torque output. The smooth torque speed characteristic and the average torque speed characteristic represent the motor respectively. The ability to output the smooth torque and the average torque is output, and the ratio of the two shows the utilization ratio of the torque to the smooth torque control. The proposed method can obtain the torque distribution function with the minimum voltage demand. The simulation and experimental results show that the optimized torque distribution function can be more model than the four common torque distribution functions. The smooth torque peri.
In the relative torque distribution function method, the direct torque control does not need to plan the reference phase current or phase magnetic chain in advance. The direct torque torque controller is mainly composed of torque observer and torque hysteresis loop controller. This paper uses common table lookup method to obtain the total torque in real time. The torque hysteresis loop is focused on the torque hysteresis loop. In the process of commutation, the two phase two phase torque hysteresis controller each has a set of thresholds. The size relation between the two sets of thresholds determines the level state of the two phase winding. Based on the research result of the smooth torque and speed characteristic, a new type of maximum smooth torque output is proposed by setting the appropriate threshold. Direct instantaneous torque controller (DTC). Compared with the traditional direct torque control, the proposed method can automatically determine the optimal turn off angle without additional angle optimization strategy, which simplifies the control process.
At present, most of the sensorless control technologies are dependent on the motor flux linkage model, which reduces the practicality and generality. This paper proposes a position sensorless control method based on special position detection. Any SRM with conventional structure has three special points for the phase inductor of the ladder, the first is the location of the beginning of the minimum inductance region. The second is the position of the end of the minimum inductor and the third is the beginning of the maximum inductor. The current is at the extreme point of the three positions. The position information can be obtained by detecting the extreme point of the current. The current current gradient method is used to detect the second special positions. The method proposed in this paper is used to detect the first and third special positions. Simulation and The experimental results show that the proposed method can achieve sensorless control under the condition of no motor model. In addition, this paper uses zero phase shift filter to analyze the detection accuracy of the three methods, and compares the applicable speed range and other performance of the three methods.

【学位授予单位】：中国矿业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM352

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