CONTROL METHOD OF BRUSHLESS DC MOTOR AND THE CONTROLLER THEREOF

摘要

The present invention discloses a control technology for brushless DC motor, in which firstly it is to build or import a motor running parameters' database, then detect the signals always running and the signals closely relevant to the rotor's rotating state such as the voltage and the current, and process these signals and figure out the signals about the rotor's position. Wherein these detected signals should be filtered before being used, and the best filter is the low-pass filter to cut out the high frequency components, and the cut-off frequency of the low-pass filter are determined by the motor running voltage U and PWM signal width when the motor is running at no load, finally determine if the motor is working properly by means of the motor running parameters stored in the database in advance, that is to determine if the detected value is identical with the one predicted from the database. Depending on the results from the detecting and comparison above, the control signal is generated to adjust the motor running state. With the technical method in this invention, the position sensor is not needed. This reduces the motor's external wiring amounts and the wiring complexity. Also the motor's seal is improved. Meanwhile, it is possible to measure the rotor's position accurately in any state according to this invention technology. Thus the motor running state can be controlled properly.