A method for manufacturing a damping winding of a salient-pole synchronous motor

Abstract

This invention discloses a method for manufacturing a damping winding for a salient-pole synchronous motor. First, the pole pitch of the salient-pole synchronous motor rotor is calculated as a reference for calculating harmonic wavelengths. Then, four damping conductors are arranged on each pole of the salient-pole synchronous motor to form a damping winding. Finally, the damping winding is arranged on the salient pole of the rotor of the salient-pole synchronous motor, so that the center point of the damping winding is located on the center line of the rotor magnetic pole. This invention effectively reduces the harmonic components of the air gap magnetic field during the operation of the salient-pole synchronous motor, correspondingly reducing the vibration and noise of the salient-pole synchronous motor, extending the motor's service life, and improving motor efficiency.

Description

Technical Field

[0001] This invention relates to the field of synchronous motor technology, specifically a method for manufacturing a damping winding of a salient-pole synchronous motor. Background Technology

[0002] Salient-pole synchronous motors are now widely used in various fields of industry and daily life. Conventional salient-pole synchronous motors are operated by adjusting the shape of the magnetic poles, such as... Figure 1 As shown, the air gap magnetic field can be made to approach a sine wave, but the harmonic components present in the air gap magnetic field are not further restricted. These harmonics are mainly odd-order harmonics such as the 3rd, 5th, 7th, and 9th, which mainly harm the efficient and stable operation of synchronous motors.

[0003] 1. Harmonic waves in the air gap magnetic field induce harmonic currents in the motor armature windings, thereby increasing motor heating and reducing motor efficiency and lifespan.

[0004] 2. The harmonic current and harmonic electromotive force induced in the armature winding of the motor by the air gap magnetic field harmonics increase the apparent power of the motor, thereby increasing the demand for power supply capacity and causing resource waste.

[0005] 3. Harmonics in the air gap magnetic field will increase the force waves acting on the stator of the motor, thereby aggravating the motor vibration and increasing the motor noise.

[0006] When a synchronous motor is in the process of starting or experiencing sudden load changes, the harmonic components of the air gap magnetic field are larger, and the adverse effects are more severe. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for manufacturing a damping winding of a salient pole synchronous motor, which effectively reduces the harmonic components of the air gap magnetic field during the operation of the salient pole synchronous motor.

[0008] The technical solution adopted by this invention to solve its technical problem is: a method for manufacturing a damping winding of a salient-pole synchronous motor, comprising the following steps:

[0009] Step 1: Calculate the pole pitch of the salient-pole synchronous motor rotor: The pole pitch of a salient-pole synchronous motor is half the wavelength of the fundamental wave of the air gap magnetic field. This pole pitch serves as the reference for calculating the harmonic wavelength.

[0010] Step 2: Set up a damping winding with 4 damping conductors on each pole of the salient pole synchronous motor. According to the relationship between the wavelength of each harmonic and the fundamental wave, determine the conductor spacing of the damping winding used to weaken each harmonic. Using the principle of Lenz's law, provide a path for the induced current generated on the rotor magnetic pole by the air gap harmonic magnetic field, thereby forming a corresponding induced current, and further forming an induced magnetic field with the opposite phase to the original harmonic magnetic field, which plays a damping role.

[0011] Step 3: Arrange the damping winding calculated in Step 2 on the salient pole of the rotor of the salient pole synchronous motor, so that the center point of the damping winding is located on the center line of the rotor magnetic pole.

[0012] In the method for manufacturing a damping winding of a salient-pole synchronous motor, in step one, for the rotor of the salient-pole synchronous motor, p is defined as the number of pole pairs of the salient-pole motor rotor, and the pole pitch (expressed as an angle) τ is the angle spanned by one pole on the circumference. The following can be obtained:

[0013]

[0014] In the method for manufacturing a damping winding of a salient-pole synchronous motor, step two defines λ3 as half the wavelength of the 3rd harmonic, λ5 as half the wavelength of the 5th harmonic, and λ7 as half the wavelength of the 7th harmonic, where λ3, λ5, and λ7 are all represented by the angles spanned on a circle. The following relationship exists:

[0015]

[0016]

[0017]

[0018] Define α as the angle spanned by a single damped conductor on the circumference, and θ as the angle θ traversed by the conductor. 14 Let θ be the angle spanned by the center points of the first and fourth conductors on the circumference. 13 Let θ be the angle spanned by the center points of the first and third conductors on the circumference. 12 Let θ be the angle spanned by the center points of the first and second conductors on the circumference. 14 θ 13 θ 12 The expression is:

[0019] θ 14 =λ3±a

[0020] θ 13 =λ5±a

[0021] θ 12 =λ7±a.

[0022] In the method for manufacturing a damping winding of a salient-pole synchronous motor, the damping windings are arranged non-equidistantly in step two. Considering the width of the damping conductor, the multiple of half wavelength of higher-order harmonic components falls within the range of the damping windings, which also has a weakening effect on higher-order air gap magnetic field harmonics.

[0023] In the method for manufacturing a damping winding of a salient pole synchronous motor, step three involves placing the midpoints of the first and fourth conductors on the center line of the rotor magnetic poles, making the winding closer to the air gap, resulting in better damping and a more aesthetically pleasing arrangement.

[0024] The method for manufacturing a damping winding of a salient-pole synchronous motor describes a method where the magnetic poles of the salient-pole synchronous motor adopt an eccentric structure, with the air gap being the smallest at the center line position. Therefore, this arrangement brings the winding closer to the air gap, resulting in better damping effect and a more aesthetically pleasing layout.

[0025] The beneficial effects of this invention are: compared with the traditional undamped winding salient pole synchronous motor structure, this invention can effectively reduce the harmonic components of the air gap magnetic field during the operation of the salient pole synchronous motor, reduce the vibration and noise of the salient pole synchronous motor, and make the motor more efficient and have a longer service life. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the magnetic poles of an existing salient-pole synchronous motor.

[0027] Figure 2 A schematic diagram of the magnetic poles of a salient-pole synchronous motor having the damping winding of the present invention;

[0028] Figure 3 The waveform of the air gap magnetic flux density of an existing salient pole synchronous motor is shown.

[0029] Figure 4 The diagram shows the air gap magnetic flux density waveform of a salient-pole synchronous motor with the damping winding of the present invention.

[0030] Figure 5 The Fourier decomposition results of the air gap magnetic flux density waveform of an existing salient pole synchronous motor are shown.

[0031] Figure 6 The Fourier decomposition results of the air gap magnetic flux density waveform of a salient pole synchronous motor with the damping winding of the present invention are shown.

[0032] The attached figures are labeled as follows: 1—rotor magnetic pole, 2—damping winding. Detailed Implementation

[0033] This invention is applicable to salient-pole synchronous motors with various pole numbers. The embodiments of this invention will be further described below with reference to specific examples and accompanying drawings.

[0034] This invention relates to a method for fabricating the position of a damping winding for suppressing harmonics in the air gap magnetic field of a salient-pole synchronous motor. Based on the fundamental theory of electromagnetism, the method for fabricating a damping winding for a salient-pole synchronous motor includes the following steps.

[0035] Step 1: Calculate the pole pitch of the salient pole synchronous motor.

[0036] Let p be the number of pole pairs of the rotor of the salient-pole motor; τ be the pole pitch (expressed in angle), that is, the angle spanned by one pole on the circumference. Then:

[0037] p = 4

[0038]

[0039] Step 2: Set 4 damping conductors on each pole to form a damping winding. Determine the spacing of the damping windings used to weaken each harmonic based on the relationship between the wavelength of each harmonic and the fundamental wave.

[0040] Let λ3 be half the wavelength of the 3rd harmonic; λ5 be half the wavelength of the 5th harmonic; and λ7 be half the wavelength of the 7th harmonic, where λ3, λ5, and λ7 are all represented by the angles spanned on a circle. Then the following relationship exists:

[0041]

[0042]

[0043]

[0044] Define 'a' as the angle spanned by a single damped conductor on the circumference. Figure 2 The damping conductor in the circuit is a circular copper strip with a diameter of 5 mm, and the angle spanned by the circumference is 0.012°. Then:

[0045] a = 0.012°

[0046] θ 14 θ is the angle spanned by the center points of the first and fourth conductors on the circumference. 13 θ is the angle spanned by the center points of the first and third conductors on the circumference. 12 Let θ be the angle spanned by the center points of the first and second conductors on the circumference. 14 θ 13 θ 12 The expression is:

[0047] θ 14 =λ3±a=15°±0.012°

[0048] θ 13 =λ5±a=9°±0.012°

[0049] θ 12 =λ7±a=6.43°±0.012°.

[0050] Step 3, as Figure 2As shown, the damping winding 2 is arranged on the salient pole of the synchronous motor rotor, so that the midpoint of the first conductor and the fourth conductor are located on the center line of the rotor magnetic pole 1, making the winding close to the air gap, resulting in better damping effect and a more aesthetically pleasing arrangement.

[0051] This invention can effectively suppress harmonic components of the air gap magnetic field in a salient pole synchronous motor, optimize the air gap magnetic field waveform, improve motor efficiency, and reduce motor vibration and noise.

[0052] Figure 3 and Figure 4 This is a waveform diagram of the air gap magnetic flux density of a salient-pole synchronous motor. Electromagnetic field calculations were performed on the air gap magnetic flux density of the two structures, and their waveform diagrams are shown below. Figure 3 and Figure 4 As shown.

[0053] Figure 5 and Figure 6 Yes Figure 3 / Figure 4 The harmonic content of air gap magnetic flux density of each order is obtained by Fourier decomposition of the medium air gap magnetic flux density waveform. Figure 1 and Figure 2 The air gap magnetic flux density harmonic content of the two structures shown are respectively as follows: Figure 5 and Figure 6 As shown.

[0054] Depend on Figure 5 and Figure 6 It can be seen that the damping winding described in this invention reduces the content of each harmonic order in the air gap magnetic flux density waveform to varying degrees.

[0055] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some of the application examples. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A method for manufacturing a damping winding of a salient-pole synchronous motor, characterized in that: Includes the following steps Step 1: Calculate the pole pitch of the salient-pole synchronous motor rotor. Define p as the number of pole pairs of the salient-pole motor rotor, and τ as the angle spanned by one pole on the circumference. As a reference for calculating harmonic wavelengths; Step 2: On each pole of the salient-pole synchronous motor, four damping conductors are arranged to form a non-equidistant damping winding. λ3 is defined as the half-wavelength of the 3rd harmonic, λ5 as the half-wavelength of the 5th harmonic, and λ7 as the half-wavelength of the 7th harmonic. λ3, λ5, and λ7 are all represented by the angles spanned on the circumference. Define α as the angle spanned by a single damped conductor on the circumference, and θ as the angle θ traversed by the conductor. 14 Let θ be the angle spanned by the center points of the first and fourth conductors on the circumference. 13 Let θ be the angle spanned by the center points of the first and third conductors on the circumference. 12 Let θ be the angle spanned by the center points of the first and second conductors on the circumference. 14 θ 13 θ 12 The expression is θ 14 =λ3±a,θ 13 =λ5±a,θ 12 =λ7±a; Step 3: Arrange the damping winding on the salient pole of the rotor of the salient pole synchronous motor, so that the center point of the damping winding is located on the center line of the rotor magnetic pole, wherein the midpoint of the first conductor and the fourth conductor are located on the center line of the rotor magnetic pole, and the magnetic pole adopts an eccentric structure.

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