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CN-117277628-B - Two-phase brushless direct current motor with stable torque and control method thereof

CN117277628BCN 117277628 BCN117277628 BCN 117277628BCN-117277628-B

Abstract

The invention discloses a two-phase brushless direct current motor with stable torque and a control method thereof. The two-phase brushless direct current motor comprises a stator and a rotor, wherein the stator comprises a stator core and 4*n stator windings encircling the stator core, the rotor comprises a rotor core and 6*n permanent magnet poles encircling the rotor core, n is a positive integer, and the polarities of adjacent permanent magnet poles are opposite. The stator winding has high utilization efficiency, reduces the weight of the brushless direct current motor, has small torque pulsation, and is suitable for application scenes of continuous power output.

Inventors

  • YU YIYANG

Assignees

  • 贯月航空技术(杭州)有限公司

Dates

Publication Date
20260505
Application Date
20230913

Claims (8)

  1. 1. The two-phase brushless direct current motor with stable torque comprises a stator and a rotor, and is characterized in that the stator comprises a stator core (1) and 4*n stator windings (2) which are wound on the stator core (1), the rotor comprises a rotor core (3) and 6*n permanent magnet poles (4) which are wound on the rotor core, n is a positive integer, the polarities of adjacent permanent magnet poles (4) are opposite, the 4*n stator windings (2) are divided into n groups, each group of stator windings comprises 4 stator windings which are adjacent in sequence, the 4 sequentially adjacent stator windings are sequentially marked as A stator windings, B stator windings, C stator windings and D stator windings in a clockwise direction, all the A stator windings are sequentially and serially connected in a forward direction to form a first series circuit, all the B stator windings are sequentially and serially connected in a forward direction to form a second series circuit, all the C stator windings are sequentially and serially connected in a forward direction to form a third series circuit, all the D stator windings are sequentially and serially connected in a forward direction to form a fourth series circuit, and the current phase difference of the adjacent stator windings in each group of stator windings is 90 degrees; The winding directions of all the stator windings (2) are consistent, the first series circuit and the third series circuit are reversely connected in parallel to form a first parallel circuit, and the second series circuit and the fourth series circuit are reversely connected in parallel to form a second parallel circuit; Or the winding directions of the A stator winding and the B stator winding are consistent, the winding directions of the C stator winding and the D stator winding are consistent, the winding directions of the A stator winding and the C stator winding are opposite, the winding directions of the B stator winding and the D stator winding are opposite, the first series circuit and the third series circuit are serially connected in a forward direction to form a fifth series circuit, and the second series circuit and the fourth series circuit are serially connected in a forward direction to form a sixth series circuit.
  2. 2. A torque-stabilized two-phase brushless dc motor as claimed in claim 1, wherein said 4*n stator windings (2) are circumferentially and equally spaced along a circle, and said 6*n permanent magnet poles (4) are circumferentially and equally spaced along a circle.
  3. 3. The torque-stabilized two-phase brushless direct current motor as claimed in claim 1, wherein the rotor core (3) is disposed inside the stator core (1), the permanent magnet poles (4) are disposed on an outer side wall of the rotor core (3), the stator windings (2) are disposed on an inner side wall of the stator core (1), or the stator core (1) is disposed inside the rotor core (3), the stator windings (2) are disposed on an outer side wall of the stator core (1), and the permanent magnet poles (4) are disposed on an inner side wall of the rotor core (3).
  4. 4. The torque-stabilized two-phase brushless dc motor of claim 1, further comprising an electronic governor, wherein two ends of the first parallel circuit are electrically connected to a first input terminal and a first output terminal of the electronic governor, respectively, and two ends of the second parallel circuit are electrically connected to a second input terminal and a second output terminal of the electronic governor, respectively.
  5. 5. The torque-stabilized two-phase brushless dc motor of claim 1, further comprising an electronic governor, wherein two ends of the fifth series circuit are electrically connected to a first input terminal and a first output terminal of the electronic governor, respectively, and two ends of the sixth series circuit are electrically connected to a second input terminal and a second output terminal of the electronic governor, respectively.
  6. 6. A torque-stabilized two-phase brushless dc motor as claimed in claim 1,2 or 3, characterized in that the stator core (1) is provided with a detection assembly for detecting the rotor position, the detection assembly comprising two or more hall sensors arranged in the circumferential direction.
  7. 7. A torque-stabilized two-phase brushless dc motor as claimed in claim 1, wherein the current waveform is sinusoidal, square wave or trapezoidal.
  8. 8. A control method of a torque-stabilized two-phase brushless direct current motor is used for the torque-stabilized two-phase brushless direct current motor as claimed in claim 1 and is characterized by comprising the following steps of controlling currents input by an A stator winding, a B stator winding, a C stator winding and a D stator winding by an electronic speed regulator, and controlling the current phase difference of adjacent stator windings in each group of stator windings to be 90 degrees.

Description

Two-phase brushless direct current motor with stable torque and control method thereof Technical Field The invention relates to the technical field of brushless direct current motors, in particular to a two-phase brushless direct current motor with stable torque and a control method thereof. Background Brushless DC motors are widely used in various industries, especially multi-rotor unmanned aerial vehicles, and basically use brushless DC motors as power sources. The usual brushless DC motor is mainly a three-phase brushless DC motor. The existing three-phase brushless direct current motor forms a basic unit by a three-phase stator winding and two permanent magnet poles, namely the stator winding and the permanent magnet poles are in a combination of 3:2, when the three-phase brushless direct current motor works, an electronic speed regulator simulates to generate three-phase alternating current and generates an alternating magnetic field through the stator winding, and the alternating magnetic field and the permanent magnet poles generate push-pull action, so that electric energy is converted into mechanical rotation energy, but the three-phase brushless direct current motor has the following defects that the magnetic field has only two poles, one winding in the three stator windings always does not work at any time, the utilization efficiency of the winding is not higher than 67 percent, and the weight of the brushless direct current motor mainly comes from a stator core and the stator winding wound on the stator core, so that the utilization efficiency of the stator winding is low, and the power-weight ratio of the motor is obviously reduced. The technical scheme of the two-phase brushless direct current motor with the same number of stator windings and permanent magnet poles is also provided, and the stator windings have the defects of high torque pulsation, maximum torque at the position where the step angle starts when one step angle advances, and near zero torque when the step angle ends, and are not suitable for the application scene of the multi-rotor unmanned aerial vehicle which needs continuous power output. Disclosure of Invention The invention aims to solve the technical problems, and provides a two-phase brushless direct current motor with stable torque and a control method thereof. In order to solve the problems, the invention is realized by adopting the following technical scheme: The invention relates to a torque-stable two-phase brushless direct current motor, which comprises a stator and a rotor, wherein the stator comprises a stator core and 4*n stator windings which are wound on the stator core, the rotor comprises a rotor core and 6*n permanent magnet poles which are wound on the rotor core, n is a positive integer, and the polarities of adjacent permanent magnet poles are opposite. In the scheme, every 4 stator windings which are adjacent in sequence form a group, the electronic speed regulator controls the current phase difference of the adjacent stator windings in each group of stator windings to be 90 degrees, and the specific combination that the ratio of the number of the stator windings to the number of the permanent magnetic poles is 4:6 is matched, when the torque generated by one stator winding is reduced, the torque generated by the adjacent stator winding is increased, and the torques generated by any two adjacent stator windings are in a complementary working state, so that stable torque output is generated, the technical problem of large torque pulsation of other two-phase brushless direct current motors is solved, and the electronic speed regulator is suitable for application scenes of continuous power output. In the scheme, the ratio of the number of the stator windings to the number of the permanent magnetic poles is 4:6, compared with the traditional three-phase brushless direct current motor, the number of the stator windings is reduced, the stator windings in the scheme are in a normal working state at any time, and the utilization efficiency of the stator windings is improved. The number of the stator windings used in the scheme is only two thirds of that of the traditional three-phase brushless direct current motor, and the weight of the permanent magnetic poles is much lighter than that of the stator windings although the number of the permanent magnetic poles is correspondingly increased, so that the weight of the brushless direct current motor is reduced, and the power-weight ratio is improved. Preferably, the 4*n stator windings are round and are arranged at equal intervals along the circle, and the 6*n permanent magnet poles are round and are arranged at equal intervals along the circle. Preferably, the rotor core is arranged on the inner side of the stator core, the permanent magnet poles are arranged on the outer side wall of the rotor core, the stator windings are arranged on the inner side wall of the stator core, or the stator core is arranged on the in