摘要
无刷直流电机最主要的应用领域包括各种车辆的驱动、自动控制门和窗的驱动、小型一体化水泵的驱动、自动武器的驱动、计算机外围设备和音响影视设备的驱动、家用电器的驱动等等。此数字式无刷直流电机控制系统,采用无位置传感器而用软件设计获得转子位置信号的反电势法和相关的预定位开环换相起动法,从而代替机械位置传感器的作用,克服了机械位置传感器给无刷直流电机所带来的诸多不利影响,简化了整个控制系统的结构设计,从而不仅降低了成本,而且提高了系统的可靠性,所以此设计使无刷直流电机在其应用领域具有良好的实际意义和广阔的应用前景。本文所研究的内容是一个基于TMS320F240 DSP芯片设计的无刷直流电机数字控制系统。由于DSP 芯片的快速运算能力,可以实现更复杂、更智能化的算法,可以通过高速网络接口进行系统升级和扩展,可以实现位置、速度和电流环的全数字化控制。
本文根据无刷直流电动机的最大特点--以电子换向线路替代了由换向器和电刷组成的机械式换向结构,重点研究了一种无位置传感器而借助于DSP的强大功能用软件设计来获取转子位置信号的方法——反电动势过零检测法以及和其相关的预定位开环换相起动法,从而代替了机械位置传感器的作用,克服了机械位置传感器的存在给无刷直流电机所带来的诸多不利影响,简化了整个控制系统的结构设计,不仅降低了成本,而且提高了系统的可靠性。
整篇文章主要分析了整个控制系统的硬件结构及其软件设计,其中,硬件控制系统主要包括三相全桥逆变电路、功率驱动电路、转子位置检测电路以及功率器件的保护电路等。在软件设计中,充分利用TMS320F240 DSP芯片强大、高速的运算处理能力以及其片内集成的丰富的电机控制外围部件(事件管理器、PWM产生电路、ADC转换模块等),运用反电动势过零检测法实现无位置传感器电机的换相检测和预定位开环换相起动法实现电机的正确起动。
关键词:无刷直流电动机 TMS320F240 DSP
Abstract
Not brushes the direct current machine most main application domain including each kind of vehicles' actuation, the automatic control gate and the window actuation, the small integrated water pump's actuation, the automatic weapon actuation, the computer auxiliary equipment and acoustic film and television equipment's actuation, domestic electric appliances' actuation and so on. This digital not brushes the direct current machine control system, uses the non-position transducer to use the software design to obtain the rotor position signal the counter electromotive force law and the related pre-localization split-ring phase change method of starting, thus replaces the mechanical position transducer's function, overcame the mechanical position transducer for not to brush many adverse effects which the direct current machine brought, simplified the entire control system's structural design, thus not only reduced the cost, moreover enhanced system's reliability, therefore this design caused not to brush the direct current machine to have the good practical significance and the broad application prospect in its application domain. This article studies the content is one chip design not brushes the direct current machine numerical control system based on TMS320F240 the DSP. As a result of the DSP chip's fast operational capability, may realize is more complex, a more intellectualized algorithm, may carry on the system upgrade and the expansion through the high speed network interface, may realize the position, the speed and the electric current link's entire numerical control.
This article according to not brushes direct current motor's most major characteristic--Has substituted the mechanical commutation structure which by the electronic commutation line is composed of the commutator and the electronics brush, has studied one kind of non-position transducer with emphasis, but with the aid of gains the rotor position signal method - - counter electromotive force zero crossing detection law as well as with its related pre-localization split-ring phase change method of starting in the DSP formidable function with the software design, thus has replaced the mechanical position transducer's function, overcame the mechanical position transducer's existence for not to brush many adverse effects which the direct current machine brought, simplified the entire control system's structural design, not only reduced the cost, moreover enhanced system's reliability.
The entire chapter article has mainly analyzed the entire control system's hardware architecture and the software design, the hardware control system mainly includes the three-phase entire bridge inversion electric circuit, the power driving circuit, the rotor position examination electric circuit as well as the power component's protection circuit and so on. In the software design, fully using TMS320F240 the DSP chip formidable, high speed operation handling ability as well as its internal integration's rich motor control periphery part (event supervisor, PWM produces electric circuit, ADC transformation module and so on), realizes the non-position transducer electrical machinery's phase change examination and the pre-localization split-ring phase change method of starting using the counter electromotive force zero crossing detection law realizes electrical machinery's correct starting.
key word: Not brushes direct current motor TMS320F240 DSP