七相感应电机直接转矩控制技术研究

发布时间：2018-07-29 08:32

【摘要】：直接转矩控制作为一种高性能控制策略,被广泛应用于调速系统中,本文从七相感应电机着手,根据七相感应电机自身特点,对直接转矩控制系统中矢量选择、磁链估计、转矩估计、消谐波、控制器设计等问题做了研究,具体包括以下几个内容:首先,本文从七相感应电机绕组理论出发,对电机自然坐标下数学模型和解耦模型进行了推导,并根据其特点对谐波转矩进行了分析。其次,根据七相感应电机矢量分布特点,运用集合法在基波平面将七相感应电机电压矢量分为三组,并从多维空间角度出发,对3、5次谐波空间电压矢量进行了分析。考虑到七相感应电机在运行过程中3、5次谐波空间电流较大,本文通过推导得出了七相逆变器SVPWM消谐波算法,针对七相逆变器电压矢量较多这一问题,本文结合三相逆变器UVM调制算法,推导出了七相逆变器UVM调制算法。在七相感应电机直接转矩控制系统控制方案选取上,首先按照电压矢量最大利用率原则,选取V6组电压矢量,综合考虑电机转矩和磁链响应速度,对"基于磁链圆的七相感应电机直接转矩控制系统"进行了设计。随后,通过运用UVM调制算法,将3、5次谐波空间电流作为反馈,引入到直接转矩控制系统中,对直接转矩控制系统进行了改进。针对系统中存在较多的PI控制器,本文对系统PI控制器进行了设计,并根据其数学模型关系,对PI控制器进行了系统简化。最后,本文以DSP28335为主控芯片,对七相感应电机调速平台分别从软件和硬件上进了设计。并在仿真的基础上,对调制算法、电机启动和直接转矩控制系统进行了实验验证。实验结果表明,本文所设计的七相感应电机直接转矩控制系统转矩转速和转矩脉动较小,和理论相吻合。
[Abstract]:As a kind of high performance control strategy, direct torque control (DTC) is widely used in the speed regulation system. In this paper, the vector selection and flux chain estimation in the DTC system are studied according to the characteristics of the seven-phase induction motor. The problems of torque estimation, harmonic elimination and controller design are studied, including the following contents: firstly, the mathematical model and decoupling model in natural coordinates of the motor are derived from the winding theory of the seven-phase induction motor. The harmonic torque is analyzed according to its characteristics. Secondly, according to the characteristics of vector distribution of the seven-phase induction motor, the voltage vector of the seven-phase induction motor is divided into three groups in the fundamental wave plane by means of the set method, and the space voltage vector of the 3rd harmonic wave is analyzed from the perspective of multi-dimensional space. Considering the large space current of 3 ~ 5 harmonics in the operation of a seven-phase induction motor, this paper deduces the SVPWM harmonic elimination algorithm of the seven-phase inverter, aiming at the problem that there are more voltage vectors in the seven-phase inverter. In this paper, a seven-phase inverter UVM modulation algorithm is derived by combining three-phase inverter UVM modulation algorithm. In the selection of the control scheme of the seven-phase induction motor direct torque control system, firstly, according to the principle of maximum utilization of voltage vector, V6 groups of voltage vectors are selected, and the motor torque and flux response speed are considered synthetically. The direct torque control system of seven-phase induction motor based on magnetic chain circle is designed. Then, by using the UVM modulation algorithm, the fifth harmonic space current is introduced into the direct torque control system as feedback, and the direct torque control system is improved. In view of the existence of more Pi controllers in the system, this paper designs the Pi controllers of the system, and simplifies the Pi controllers according to their mathematical model. Finally, using DSP28335 as the main control chip, the seven-phase induction motor speed control platform is designed in software and hardware respectively. On the basis of simulation, the modulation algorithm, motor startup and direct torque control system are verified experimentally. The experimental results show that the torque rotation speed and torque ripple of the seven phase induction motor direct torque control system designed in this paper are small, which is consistent with the theory.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM346

【相似文献】