Brushless motor controller development direction of digital control
to improve the performance of permanent magnet brushless dc motor and improve, in addition to related to motor noumenon and electronic drive circuit, is more closely related with its controller. Since the 1980 s as a microcomputer technology, control technology, the rapid development of control theory and so on, people from the way to improve properties controller to improve the performance of permanent magnet brushless dc motor, and has obtained some encouraging results. After entering the 90 s, especially the emergence of high-speed microprocessors and DSP device, rapidly improve the performance of BLDCM. In addition advanced control methods such as sliding mode control, variable structure control, fuzzy control and expert control and so on were introduced successively brushless motor controller, controller, so as to drive the permanent magnet brushless dc motor development in the direction of high intelligence, flexible, fully digital, opened up a new era for its into the digital age. Brushless dc motor controller operation process to be two kinds of control, a speed control, which is provided to stator winding current; Commutation control, another is to specify the arrival of the rotor position change the conduction of the stator, the stator magnetic field change, this kind of control actually realized the physical mechanism of brush. So the motor controller needs a position feedback mechanisms, such as hall element, the light code disc, or the use of trapezoidal counter electromotive force characteristics for counter electromotive force zero crossing detection, etc. Using the hall element system more convenient on the software implementation. Motor speed control is also according to the position feedback signal controller, calculate the rotor speed, the reuse of PI or PID control method, such as real-time adjust PWM ( Pulse width modulation) Duty ratio and so on to realize stator current regulation. Therefore, the control chip to be more calculation process. Of course, there are special brushless dc motor controller control chip; But generally speaking, in most applications, in addition to the motor controller to control, always need to do some other control and communication, etc. So, choose with PWM, at the same time, has the strong mathematical function of the chip is also a good choice. Because DSP has strong computing power and good real-time performance, the algorithm of complex modern control theory to obtain the very good application in practical, especially the high requirement of real-time system, can also be realized by DSP complicated intelligent control algorithm. Series of fixed-point digital signal processor TMS320LF2407 of TI company, integrates the general digital signal processor fast operation function and the characteristics of microcontroller peripheral rich, especially suitable for high performance control of brushless dc motor controller.