-基于DSP无位置传感器无刷直流电机控制系统研究.doc

PAGE 56 PAGE 53 PAGE I 摘 要 无位置传感器无刷直流电机凭借其简单的结构、较高的运行效率、良好的调速性能及避免了位置传感器给系统带来的种种弊端等一系列优点，广泛应用于军事、民用领域，特别是配合TI的电机控制芯片DSP2812及其驱动技术，使得无位置传感器无刷直流电机能够达到较高的控制精度。本文主要对无位置传感器无刷直流电机控制系统中的若干问题做了研究，主要内容包括： 首先，本文介绍了几种无位置传感器无刷直流电机常用的位置检测手段，重点分析了利用电机绕组端电压实现电机转子位置估测的方法，并对该方法中所用到的换相延迟时间算法进行了稳定性分析。 其次，本文设计了以DSP2812为核心，由功率驱动电路、电源电路、外部存储器电路、I/O接口驱动电路、外扩液晶显示屏电路及反电动势采样电路等组成的系统硬件电路，重点分析了各部分电路的设计理念、芯片选取及时序匹配问题。 再次，本文选取地铁屏蔽门作为电机负载，参考实际屏蔽门门机系统得出课题中所需电机的电气参数，分析并采用S型曲线拟合出电机的理想加速曲线。 此外，为了改善电机的换相转矩脉动，本文从调制方式和电流调节两方面详细分析了改善转矩脉动的方法，并给出了相关软件算法的程序流程图。 最后，本文给出了系统实验的波形和结果，并对波形进行了比较分析。实验证明，所设计的软硬件系统能够实现无位置传感器条件下电机的加速、状态切换及基于电机绕组端电压检测法的无刷直流电机双闭环控制。 关键词：无传感器，无刷直流电机，控制系统，反电动势检测 Research on Sensorless Control System of BLDCM Based on TMS320F2812 Abstract The sensorless BLDCM is widely used in military and civilian fields with its simple structure, high operating efficiency, good speed performance and some advantages without position sensor. Especially with the development of current mainstream motor control chip DSP2812 and its drive technology, the sensorless BLDCM can achieve increasingly high control accuracy. This paper studied on sensorless BLDCM control system and mainly includes: Firstly, some common position detection means using in sensorless BLDCM are introduced in this paper. Among these position detection means, the terminal voltage detection method is detailed analyzed and the stability of the commutation time algorithm using in terminal voltage detection is analyzed. Then, based on the TMS320F2812, the hardware circuits of power drive, power supply, external memory, I/O interface driver, external expansion LCD and terminal voltage detection circuit are designed. In addition, the design concept of each part, the chip selection and timing matching are elaborated. Furthermore, selecting metro platform screen doors as load and referring to its actual door system, the electrical parameters of motor is given. Then an ideal acceleration curve is fitted according to the S-shaped curv