Speed adjusting method for direct-current brushless motor without position sensor

Abstract

The invention provides a speed adjusting method for a direct-current brushless motor without a position sensor. The method comprises the following steps: (1) inputting alternating-current 220V voltage via an alternating-current power supply and a driving board, and rectifying the voltage to output direct-current 310V voltage; (2) outputting, by a switching power supply, 3.3V, 5V or 12V voltage output by rectifying to a control end, an amplifying circuit or a sampling circuit of a singlechip, an insulated gate bipolar transistor or an intelligent power module to supply power; (3) meanwhile, connecting 310V direct-current voltage output by rectifying to the insulated gate bipolar transistor or the intelligent power module to drive the direct-current brushless motor; (4) sampling counter electromotive forces of three phases U, V and W of the motor by the sampling circuit, and amplifying signals by the amplifying circuit; (5) performing analog-digital conversion on the acquired current signals by an AD of the singlechip; and (6) analyzing the revolving speed and the position of a rotor by adopting a perception algorithm without position detection to carry out closed-loop control. The method at least has the advantages that the revolving speed of the direct-current brushless motor can be accurately adjusted, the structure design is simplified, the size of the motor is reduced, the requirement of the assembly process is low and the like.

Description

Technical field [0001] The invention relates to a speed regulating method of a DC brushless motor, in particular to a position sensorless DC brushless motor speed regulating method. Background technique [0002] In recent years, with the rapid development of power electronic technology, microelectronic technology, new motor control theory and rare earth permanent magnet materials, permanent magnet synchronous motors have been rapidly promoted and applied. Compared with traditional electrically excited synchronous motors, permanent magnet synchronous motors, especially rare earth permanent magnet synchronous motors, have the advantages of less loss, high efficiency, and obvious power saving effects. The permanent magnet synchronous motor uses permanent magnets to provide excitation, which makes the motor structure simpler, reduces the processing and assembly costs, and saves the slip ring and brush that are prone to problems, which improves the reliability of the motor operation; ...

AI Technical Summary

Problems solved by technology

At present, the mainstream brushless DC motor speed controller uses Hall element to detect the position of the rotor, which has high requirements for the structural design of the motor and the position and accuracy of Hall element assembly. At the same time, there is a certain degree of magnetic insensitivity. area; even, in some harsh working environments, such as in sealed air-conditioning compressors, conventional position sensors cannot be used at all due to the strong corrosion of the refrigerant

Images