Method for controlling motor to work at multiple rotating speeds

Abstract

The invention provides a method for controlling a motor to work at multiple rotating speeds. A motor controller and motor coils are provided, and the method changes the back electromotive force of the motor coils and controls the motor to work at different speeds by changing the serial and parallel connection structure among the phases of motor coils, so that the motor can have various characteristics and have more than two shift levels without the need for a mechanical speed changer, and the cost is saved.

Description

technical field [0001] The invention relates to a control method for a motor, in particular to a control method for realizing multi-rotational speeds of the motor. Background technique [0002] Due to the advantages of small size, light weight, high efficiency and adjustable speed, brushless DC motors are widely used at present, but they have obvious disadvantages: the high-efficiency operating range is small, which makes brushless DC motors in the field of large speed changes The comprehensive efficiency used in the motor is not high, so the adaptability of the DC brushless motor is poor. [0003] In the prior art, in order to solve the technical problem of the high-efficiency operation range of the DC brushless motor, a mechanical multi-speed transmission is generally used, but the mechanical transmission is large in size, structurally loaded, and expensive to use. Therefore, people have gradually proposed a direct Transform the coils of brushless motors, such as the tech...

AI Technical Summary

Problems solved by technology

[0002] Due to the advantages of small size, light weight, high efficiency and adjustable speed, brushless DC motors are widely used at present, but they have obvious disadvantages: the high-efficiency operating range is small, which makes brushless DC motors in the field of large speed changes The comprehensive efficiency used in the motor is not high, so the adaptability of the DC brushless motor is poor

[0003] In the prior art, in order to solve the technical problem of the high-efficiency operation range of the DC brushless motor, a mechanical multi-speed transmission is generally used, but the mechanical transmission is large in size, structurally loaded, and expensive to use. Therefore, people have gradually proposed a direct Transform the coils of brushless motors, such as the technologies disclosed in patent documents with application numbers 2009200191450, 20131036612768, and 201310048749. These technologies mainly tap or segment the coils of each phase, but this method can only achieve double speed. However, there is still a low utilization rate of the coil, and more importantly, the range of the maximum multiple of the back electromotive force of the coil in the prior art is small, so that the motor with a relatively single characteristic can be obtained.

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