At first , the dissertation analyses the principles , the operation theory and the control techniques of bldcm ( brushless dc motor ) . then according to the different bemf of different bldc motor , the dissertation analyses the torque ripple in the bldcm with ideal 120 掳 trapezoidal waveform bemf and non - ideal bemf waveform respectively . further more the dissertation presents different novel control techniques of the torque ripple minimization in bldcm 首先，对永磁无刷直流电机的定义，工作原理，控制方法进行了分析，然后根据永磁无刷直流电机的反电动势波形的不同，对理想方波型无刷直流电动机的换相转矩脉动，非理想方波反电动势的无刷直流电动机的换相转矩脉动进行了详细的分析，并分别提出了不同的控制策略，对其换相转矩脉动进行抑制。
The thesis first probably explains brushless direct current motor ( bldcm ) , and discusses the related control methods , explains the background and meaning of back electromotive force ( back - emf ) which is used in the thesis . then the thesis expounds the basic component parts , the basic running principle , the running characteristic and transfer function of the bldcm . and then the thesis detailedly dissertates its research pivot : the simulation of bldcm system in matlab based on the method of back - emf and the control system of digital signal processor ( dsp ) based on the method of back - emf 本文首先对无刷直流电机进行了概述,并对其相关控制方法进行了讨论,说明本文所采用反电动势法的背景和意义;接着论述了无刷直流电机基本组成环节、基本工作原理、运行特性和传递函数,然后是详述本文研究的重点:基于反电动势法的matlab调速系统的仿真以及基于反电动势法的dsp控制系统的实现。
Furthermore , this dissertation also gives a comprehensive analysis and comparison to the torque ripple factor , torque - current ratio and other aspects for pseudo - sinusoidal emf bldcm drived by 120 conduction mode , 180 conduction mode and self - synchronous svpwm mode respectively . the simulation and the experimental results indicate that self - synchronous svpwm method is more effective for minimizing the torque ripple without any expense of the torque - current ratio when the crest width of the back - emf waveform is less than 107 electrical angles 对准正弦波反电动势无刷直流电动机在120导通方式、 180导通方式和自同步svpwm三种控制方式下的转矩脉动系数、转矩电流比等方面进行了全面的分析与比较，仿真研究和实验结果表明，当反电动势的平顶宽度小于107电角时，采用自同步svpwm控制方法可以在不损失转矩电流比的基础上，更有效地抑制电磁转矩脉动。
In order to minimize the commutation torque ripple of traditional trapezoidal bldcm using 120 cconduction mode , firstly , analytical formulae of commutation torque in the condition of perfect back - emf waveforms are developed in this thesis , based on which the effects to the torque ripple by the pwm modes , overlapping commutation techniques and so on are analyzed , and the applicable speed ranges of the motors using the overlapping commutation techniques are derived 为了抑制传统的三相六状态120导通方式控制下方波型无刷直流电动机的换相转矩脉动，本文首先在理想反电动势的条件下推导了换相转矩脉动的解析公式，并由此分析了调制方式、重叠换相技术等对换相转矩脉动的影响，得出了采用重叠换相技术抑制换相转矩脉动适用的电机转速范围。
Secondly , the effects of the crest width of the back - emf waveform to the torque ripple in the 120 ? conduction mode are analyzed , among which the effects of the advance commutation angle to the torque ripple are quantificationally analyzed for the bldcm drives whose back - emf waveform crest width is less than 120 ? , 其次分析了120导通方式下反电动势平顶宽度对转矩脉动的影响，对于平顶宽度小于120电角的非理想梯形波反电动势，定量分析了换相超前角对换相转矩脉动的影响。
On the base of ananlysing and studying the run mode of bldcm , we introduce the detecting back electromotiveforce , the method of phase judging and compensation in detail . in order to improve the speeding performance we adopt the digital closed _ loop speed control strategy 在对无位置传感器无刷直流电动机运行方式进行全面分析研究的基础上，详细的介绍了反电动势过零检测、相位判断及相位补偿的原理及实现方法，并且为了在较宽范围内提高bldcm的调速性能，采用了数字式转速闭环控制。
The speed sensorless techniques for dtc system are very fascinating and challenging subjects recently , they are received wide attention in the literature . some brief description is provided . the proposed approaches are based on speed model of dtc , motor reference adaptive control , the instantaneous reactive power of motor and the extended kalman filter 无速度传感器调速系统是直接转矩控制研究领域内一个非常热门的研究方向，本文介绍了无速度传感技术的发展历史及目前的研究状况，分别利用直接转矩控制的转速模型方法，模型参考自适应方法、电机定子反电动势以及扩展的卡尔曼滤波器等方法设计了无速度传感器系统，对于其数学模型和系统构成作了比较详细的推导。
In this chapter , the method of bldcm rotor position detection is first discussed . then the principle and algorithm of bemf zero crossing point detection is explained . in succession , the chapter dissertates the software realization of the bemf zero crossing point detection algorithm , the software disturbance filter and the modification of phase displacement , and the software realization of commutation point 在这一章中，先简述了无刷直流电机的转子位置器检测方法；然后论述了反电动势过零检测原理和算法以及该算法的软件实现、软件滤波和相移修正、换相点的软件实现；最后对软件开环换相起动策略作了详细论述。
Regard how to structure the control system of sensorless bldcm with dsp - tms320f240 as the centre in this paper , the detailed argumentation course of the motor startup , bemf terminal voltage measurement and control strategy is given out , give and pay concrete details for the software and hardware realization and experimental result . in order to treat the bldcm control system with dsp clearly , the full paper divides into six chapters altogether : chapter one , introduceing the development course , the structure characteristic and operation principle , etc . of bldcm in the introduction ; chapter two , directed against the startup issue of bldcm , the chapter give and publish the rotor measure pulse orients technology for motor startup in detail ; chapter three , proceed with mathematics model of the bldcm , expounding the control schemes ; chapter four , two important devices introducing : dsp ( 240 tms320f ) and power invertor control chip ( ir2131s ) ; chapter five , give and publish the detail of hardwares of control system ; chapter six , by ccs ide of ti , realize the control schemes in the front chapters with software , offere the procedure flow chart of main subroutine and some key place of programming , the experiment result in addition 全文共分六章：第一章、绪论中介绍了bldcm的发展历程、电机本身的结构特点和工作原理等；第二章、针对五位置传感器bldcm的起动问题，文中详细给出了检测脉冲转子定位起动技术；第三章、从电机的数学模型入手，详细论述了反电动势端电压法和系统的控制策略；第四章、介绍了硬件实现中的两个重要器件： dsp ( tms320f240 )和功率管逆变器控制芯片( ir2131s ) ；第五章、详细给出了控制系统的硬件实现细节；第六章、利用ti提供的ccs集成开发环境，将前面章节的控制方案用软件加以实现，给出了主要部分的程序流程图和一些编程要点以及实验结果。
For the bldcm which has a neither sinusoidal nor trapezoidal back - emf , that is , for a general shape back - emf bldcm , this dissertation proposes a novel id = 0 vector control method . by this method , the iq for a constant torque to produce is calculated through coordinate transformation , and the reference iq is tracked by vector control in the dq0 frame 对于实际反电动势波形既非正弦又非梯形波的无刷直流电动机，提出一种新型的任意波形反电动势无刷直流电动机的i _ d = 0矢量控制方法，通过坐标变换浙江大学博士学位佑文摘要求解产生恒定电磁转矩所需的q轴电流，并在dqo坐标系下通过矢量控制对q轴参考电流进行跟踪。
