【作者】 朱军；

【导师】 辜承林；

【作者基本信息】 华中科技大学 ， 电机与电器， 2006， 硕士

【摘要】 多相异步电机调速系统由于具有诸多优点,如可用低压功率器件实现大功率调速、具有多相冗余结构使调速系统的可靠性得以改善(如多相异步电机调速系统在损失一相或几相定子激励情况下能继续起动和运行)、转矩脉动小等等,已在一些特殊场合获得成功应用。然而,作为一种新技术,在用多相异步电机替代三相异步电机时,还存在许多问题需要研究和解决。本文以五相异步电机调速系统为研究对象,对五相异步电机的模型、五相逆变器PWM算法、五相异步电机调速系统的调速控制策略、不平衡运行状态下电机特性以及系统的仿真和实验进行了较为全面、深入的分析和研究。采用广义瞬时对称分量变换建立了五相异步电机的数学模型和等效电路。基于广义两相实变换,推导了五相异步电机静止坐标系下的广义α?β模型和等效电路。通过研究三相PWM算法的统一数学模型,基于空间矢量理论和统一调制理论,提出了一种适用于五相异步电机的统一电压调制〔UVM)算法。由于这种算法充分利用了五相逆变器众多的空间电压矢量,从而可以获得谐波含量较小的电机电流波形和畸变较小的电机磁链,有利于减小转矩脉动,提高系统的转矩快速响应性能。综合矢量控制和直接转矩控制的优点,考虑五相异步电机的特点,提出一种新型的异步电动机按定子磁场定向的矢量控制方法。对平衡和不平衡运行状态下的五相异步电机特性进行了分析和仿真研究。五相异步电机在不平衡运行时,虽然运行性能下降,但优于三相电机。采用Matlab/Simulink对五相异步电机变频调速系统进行了仿真。采用数字信号处理器(DSP)进行控制,搭建了一个全数字化五相异步电机变频调速系统实验平台,对五相异步电机变频调速系统进行了实验,并给出了实验结果和分析。更多还原

【Abstract】 Multiphase induction machine adjustable speed drive system has many advantages. In addition to has high power handling capability, the multiphase winding structure provides a multiphase induction machine with capabilities of starting and running even with one or more of its stator excitation sets failed. It has been applied to some special situation successfully. However, as a new technology, there are many problems and issues to be investigated and solved related to the use of multiphase induction machines as a potential alternative to the conventional three-phase induction machines.This thesis chooses the five phase induction machine as the subject to be investigated. A detailed theoretical analysis and research have been carried out on the model of five phase induction machine drives, the five phase inverter PWM algorithms, the control strategies of five phase induction machine adjustable speed drives and the behaviors of the machine under unbalanced operation conditions.The dynamic state models and their equivalent circuits for the five phase induction machine are developed by means of the generalized symmetric component transformation. Based on the generalized two phase real transformation, the generalizedα?βmodel and their equivalent circuits of the machine is developed in stationary reference frame.Based on space vector theory and unified modulation theory, a unified voltage modulation (UVM) algorithm applied to the five phase induction machine is proposed under studying the unified mathematical model of three phase PWM algorithms. Because this algorithm makes use of lots of space voltage vectors of the five phase inverter, which result in machine currents with lower harmonics and flux linkage with lower distortion, it contributes to the decrease of toque ripple and the fast torque response performance.With the specialty of five phase induction machine considered, a new control strategies of five phase induction machine adjustable speed drives has been proposed by synthesizing the virtue of FOC(Field Oriented Control) and DTC(Directed Torque Control).Steady-state performances of five phase induction machines under balanced and unbalanced operation conditions are analyzed and simulated. Although the operation performance of five phase induction machines at unbalanced operation conditions are degraded, the machine is superior to that one of three phase induction machines.A computer simulation of the five phase induction machine adjustable speed drives has been carried out by using MATLAB/SIMULINK. A digital experimental system for the five phase induction machine drive controlled by digital signal processor (DSP) has been constructed, Experiments on five phase motor adjustable speed drives have been performed. Finally, the experiment results have been presented.更多还原