【作者】 王晔湛；

【导师】 孙培德；

【作者基本信息】 东华大学 ， 电力电子与电力传动， 2009， 硕士

【摘要】 随着科技的飞速发展,电力电子器件、集成电路以及微处理器都经历了日新月异的变化,越来越多的工业场合诸如机器人、数控机床以及纺织行业的电子络筒技术等均对执行机构提出了高精度位置、转速伺服控制的要求。而电机作为伺服控制系统的执行机构在制动时的能量利用也成为国家节能工程的一个重点。无刷直流电机是一种集电机和电子一体化的高科技产品,具有结构简单,运行效率高,无励磁损耗、调速性能好以及维护方便等诸多优点,但是位置传感器增加了结构的复杂性和成本,降低了系统运行的可靠性,因而无位置传感器控制成为研究的热点;另一方面,由美国TI公司专门为电机的数字化控制设计的16位定点DSP控制器TMS320LF2407集高速处理能力及适用于电机控制、优化的外围电路于一体,为高性能传动伺服控制提供了可靠高效的信号处理与硬件控制支持。因此,为满足对伺服系统高精度位置、转速控制的要求,并且有效回收利用电机制动产生的能量,本文采用无刷直流电机(BLDCM)作为执行机构,主要研究了基于TMS320LF2407 DSP的无位置传感器无刷直流电机伺服系统。内容包括伺服系统的控制部分设计、硬件控制电路设计和系统软件设计等。本文首先对课题研究背景络筒机的概况与发展进行了简要阐述,同时也介绍了无刷直流电机、伺服控制系统及其控制策略的现状和发展;接着,研究了无刷直流电机的基本结构和工作原理,并建立了数学模型;然后详细介绍了反电动势过零法实现转子位置检测和换相的原理,对反电势过零点检测公式进行了推导和计算,并提出了位置检测的误差补偿方法。在伺服系统的控制部分论证中,本文以三相桥式MOSFET逆变电路作为控制主电路,采用120°导通方式;本文采用电流霍尔传感器实现对电流的检测,无位置传感器的设计使得系统通过反电势过零法获取三相电压信号,经过软件计算和延时处理为逆变电路提供了换相信号,同时由过零点之间的时间间隔和相位关系得到转速的检测;本文设计了电流、转速的双闭环控制,电流环采用比例-积分(PI)调节,转速环在采用PI调节的基础上加入了微分环节,并采用模糊PID控制的方法以达到最优控制;另一方面,为达到络筒卷绕的精确性,采用了位置和转速双目标控制;然后,深入研究并设计了无刷直流电机的能量回馈系统,从背景开始分析,提出了可行的解决方案,设计了由超级电容器、双向DC-DC变换电路和逆变电路构成的能量回馈主电路,对升/降压模式的工作原理进行了分析,并根据控制方式建立了模型,说明了相关参数的设定。在伺服系统的硬件控制部分的设计中,先进行了整体系统的设计,然后论述了系统主回路、功率模块、通讯模块以及各个接口电路的设计,重点介绍了几个主要电路的设计和一些器件的选择和参数的计算。在伺服系统软件控制部分的设计中,则先讨论了DSP的开发流程和本系统的软件需求,然后设计了主程序和各个功能模块子程序的流程图,并根据流程图针对每个模块在CCS环境下利用C语言和汇编语言编写了程序。在理论研究的基础上,采用MATLAB7.1对反电动势过零法,电流、转速、位置的闭环调节以及能量回馈系统模型进行了阶跃响应和伯德图的仿真验证,并结合实际实验设备以及调试软件进行调试,得出实验结果,最后对实验结果进行了分析和总结,证明系统工作性能良好且能达到预期目标。更多还原

【Abstract】 With the rapid development of science and technology,power electronics devices,integrated circuits and microprocessor all have progressed each passing day. The implementation of high degree of accuracy of position and velocity servo-control is posted by increasing industrial occasions such as robust and electronic winding technology.In addition,the thesis that utilizing energy at the moment when motor is braking also becomes a focus in the project of country’s saving energy.Brushless DC motor(BLDCM),which has many good performances,such as simple structure,high running efficiency and convenient maintainability,is a kind of mechatronics products.The position sensor increase the complexity and costs of structure,made the lower reliability of running,so controlling without position sensor become a hot topic for researching.On the other hand,the 16-bits DSP, TMS320LF2407,which is manufactured by TI for motor’s digital controlling,can give reliable and efficient signal process as well as hardware support by its high processing speed and improved surrounding circuits.Therefore,this paper is mainly engaged in researches on velocity and position servo-system of BLDCM without position sensor based on TMS320LF2407 to meet the requirements of high accuracy control and energy saving.The controlling, hardware and software design of the servo system are included in this paper.The general survey of winding and BLDCM as well as servo-control system included its’ control strategies are simply introduced at the beginning of this paper. The basic structure and working principles are presented with math models established secondly.The fundamentals of position detecting and phase-switching are detailedly demonstrated finally.The BEMF zero crossing point detection formulas are deduced with phase difference compensations as well.Three-phase full-bridge MOSFET inverter is chosen as the main control circuit, and a control scheme with 120°switching mode is adopted in the argument of controlling.Current is detected by current-hall sensor,three-phase voltage are fetched via BEMF zero crossing point detection method which can not only supply the phase switching signal after software calculation and time delay but also obtain the velocity by the relation of time span.The speed and current dual closed-loop control strategy is adopted in this control system in order to construct a high performance permanent magnetic brushless DC motor full digital control system.Further more,double goals involved position and speed control strategy is adopted to achieve winding accuracy. Then,the design of energy feedback system is deeply studied with the background analysis followed by a feasible solution presented.The energy feedback system which consists of super capacitors,bi-directional DC-DC converter and inverter circuit is designed,and the principles of buck/boost working principles are explicated with related parameters’ setting for the model established.In the hardware design of servo-system,the overall system is firstly designed, then the main circuit,power module,communication module and other interface circuits are designed,the focus is elements’ selection and parameters’ calculations. In the software design of servo-system,the development process of DSP and the requirements are firstly discussed,the flow of main program and function sub-program are designed and programmed in C and assembly language.In the software design of servo-system,the development process of DSP and the requirements are firstly discussed,the flow of main program and function sub-program are designed and programmed in C and assembly language.On the basic of theory research,the algorithm of BEMF zero crossing point detection,the adjusting of the closed loops named current,velocity and position as well as energy feedback technology model are all validated by simulation using MATLAB7.1.Then,experiments are implemented on the equipments and debugging software to obtain results.Finally,analysis and summary are made based on the results to prove that the performance of the whole system is perfect and can meet all the objectives in this paper.更多还原