CN104578661B - An Axially Distributed Doubly Salient Brushless DC Motor - Google Patents

Abstract

A kind of doubly-salient brushless DC generator of axially distribution proposed by the present invention, the number of phases of the motor is m, and axially equidistant correspondence is distributed along motor for the stator poles and rotor pole of every phase motor, forms the m sub-motor being axially distributed；There is gap for installing armature winding between stator poles on axial direction, the stator poles and rotor number of poles of each sub-motor are all 2n；360 °/2nm mechanical angles are differed between the rotor pole of each sub-motor, stator poles are alignd with corresponding rotor pole on motor circumferencial direction；Centralized armature winding is wound with the stator poles of each sub-motor respectively, the outside of armature winding is provided with field element at circumference, 2n field element is had in a circumferential direction.Each phase magnetic circuit of the motor is completely independent, and fault freedom is good；It is each to be mutually distributed in the axial direction, it is adapted to slender type motor；Each punching is identical and position angle is different, realizes the modularization of design of electrical motor production maintenance；The distribution of motor radial load is more extensive, and stator radial strain is smaller.

Description

An Axially Distributed Doubly Salient Brushless DC Motor

technical field

The invention relates to an axially distributed double salient pole brushless DC motor, which belongs to the technical field of special motor body design.

Background technique

Double salient pole motor is a new type of motor composed of position sensor, power electronic power converter, permanent magnet or electromagnetic excitation unit, controller and motor body with salient pole stator and rotor structure. As a new type of variable reluctance motor, the ratio of the maximum value to the minimum value of the reluctance is large, and it has better electromechanical energy conversion characteristics, and has a good application prospect in all walks of life. The unit motor of the traditional double salient pole motor adopts the 6N/4N pole structure of the inner rotor, the number of stator poles is 6N, the number of rotor poles is 4N, and N is a natural number, indicating the number of unit motors. Due to the small number of rotor poles and high speed, the motor usually adopts a larger slenderness ratio to increase the power of the motor. This kind of motor is very suitable as an aviation starter generator. In some special applications, such as oil field wells with slender space and fast speed response occasions, motors with higher slenderness ratio are also required, and these slender motors are not easy to embed wires during manufacture, and are not easy to dissipate heat during operation, so It is of great practical value to exploit the high reliability of doubly salient motors to develop new slender motors.

Among the existing technologies at present, the most researched is the three-phase 6N/4N structure doubly salient motor. There are also some other new doubly salient motor research, such as the announced Chinese invention patent: three-phase 6K/4(N+1)K structure doubly salient motor, application number: 200710191018.4, which discloses a new type of stator and rotor pole number Matching doubly salient motors. The Chinese invention patent with application number 201010560410.3: Axial Excitation Hybrid Excitation Double Salient Pole Motor discloses three axial excitation hybrid excitation double salient pole motors, which can use axial excitation windings and axial magnetization permanent magnets Steel provides excitation; or adopts axial excitation winding and non-axial magnetization permanent magnet to provide excitation; or adopts axial magnetization permanent magnet steel and radial excitation excitation winding to provide excitation. The Chinese invention patent with application number 201010592364: Axially Excited Doubly Salient Motor discloses two kinds of axially excited doubly salient motors, both of which include at least two axially arranged doubly salient pole motors The stator core of each single structure of the motor forms a magnetic circuit through the stator axial magnetically conductive back iron, and the rotor core forms a magnetic circuit through the rotor axial magnetically conductive back iron; the stator core, the stator axial magnetically conductive back iron and the permanent magnetic steel are 2n (n is a natural number) equally divided arc-shaped structures.

Contents of the invention

Technical problems to be solved:

The present invention aims to propose a double-salient pole brushless DC motor with a slender structure with axially distributed phases, which can be operated as a generator and a starter.

Technical solutions:

In order to achieve the above functions, the present invention provides an axially distributed doubly salient pole brushless DC motor, including stator core, rotor core, shaft 2, position sensor, excitation element and armature winding, stator core and rotor The iron core adopts a salient pole structure, the stator iron core is inside, the rotor iron core is set on the shaft 2 outside, the end is provided with a motor end cover 4, and the rotor iron core is provided with a motor casing 15; it is characterized in that:

The number of phases of the motor is m, m is a natural number, and the stator poles and rotor poles of each phase motor are equidistantly distributed along the motor axis, forming m axially distributed sub-motors;

There is a gap between the stator poles in the axial direction for installing the armature winding. The number of stator poles and the number of rotor poles of each sub-motor are 2n, and n is a natural number indicating the number of unit motors of the sub-motor;

There is a 360°/2nm mechanical angle difference between the rotor poles of each sub-motor, and the stator poles are aligned with the corresponding rotor poles in the circumferential direction of the motor;

Concentrated armature windings are respectively wound on the stator poles of each sub-motor, and an excitation element 6 is provided on the outer side of the armature winding near the circumference, and there are 2n excitation elements 6 in the circumferential direction.

The excitation element 6 is an excitation winding, and adjacent excitation windings have opposite winding directions, and the winding direction of the armature winding of each stator pole is consistent with the winding direction of the excitation winding on the stator pole.

The excitation element 6 is a permanent magnet, and the permanent magnet is installed on the yoke between the stator poles of each phase. The motor works in a single-phase energization mode or a two-phase energization mode of a permanent magnet double salient pole motor.

The excitation element 6 includes an excitation winding and a permanent magnet, and the winding directions of adjacent excitation windings are opposite, and the winding direction of the armature winding of each phase stator pole is consistent with the winding direction of the excitation winding on the stator pole; the permanent magnet is installed on each On the yoke between each stator pole of the phase; the motor operates in a single-phase energization mode or a two-phase energization mode of a hybrid excitation double salient pole motor.

Beneficial effect:

The invention proposes an axially distributed double-salient pole brushless DC motor with a slender structure, which can be operated as a generator and as a starter. The magnetic circuit of each phase is completely independent, which realizes the magnetic isolation, thermal isolation and physical isolation of each phase, and has good fault tolerance performance; the radial force distribution of the stator is wide, the radial strain is small, and the noise is low; the excitation winding path is short and the excitation efficiency is high. advantage.

The phases are distributed axially, which is suitable for slim motors. The number of turns of the phase winding of the DSEM motor is very small, so the length of the end of the phase winding is small, and the space utilization rate in the axial direction of the motor is high.

The stator and rotor of each phase are the same, which is easy to modularize production and maintenance; the stamping plates are the same but have different position angles, and can be quickly assembled into motors with various phases, realizing the modularization of motor design and production; if one phase of N-phase motors is damaged, By changing the position angle of the stator or rotor, it can even quickly become an N-1 phase motor.

The radial force in the circumferential direction of the same position of the traditional motor is distributed in two positions, and the stator is easily deformed into an ellipse. The radial force distribution of the motor is wider, and the radial strain of the stator is smaller. And it overcomes the defect that the internal space of the rotor cannot be effectively used when the traditional motor adopts a large number of poles in order to increase the power.

The phases of the stator are aligned, the field winding only spans one stator pole, and the coil is short.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the present invention is further described:

Fig. 1 is a cross-sectional view when the axially distributed doubly salient brushless DC motor phase number provided by the present invention is 3;

Fig. 2 is the side sectional view of the double-salient pole brushless DC sub-motor of the three-phase axial distribution provided by the present invention;

Fig. 3 is the three-dimensional diagram of the rotor when the phase number of the double-salient brushless DC motor with axial distribution provided by the present invention is 3;

Fig. 4 is the inductance figure of each phase when the phase number of the doubly salient brushless DC motor with axial distribution provided by the present invention is 3;

Fig. 5 is a schematic diagram of the position of the six-phase stator and rotor of the axially distributed doubly salient brushless DC motor provided by the present invention when the number of phases is 6;

Fig. 6 is a three-phase side sectional view of a permanent magnet axially distributed doubly salient brushless DC motor with three phases provided by the present invention;

Fig. 7 is a three-phase side sectional view when the number of phases of the double-salient pole brushless DC motor with mixed excitation and axial distribution of each phase is 3;

Among them: 1. Bearing; 2. Shaft; 3. Position sensor; 4. Motor end cover; 5. A-phase armature winding; 6. Excitation winding; 7. A-phase rotor core; 8. A-phase stator core; 9. B-phase armature winding; 10. B-phase rotor core; 11. B-phase stator core; 12. C-phase armature winding; 13. C-phase rotor core; 14. C-phase stator core; 15. Motor casing; A. A Phase armature winding; B. B phase armature winding; C. C phase armature winding; F. field winding; PM. permanent magnet.

detailed description

The present invention provides an axially distributed double-salient pole brushless DC motor. In order to make the object, technical solution and effect of the present invention clearer and clearer, the present invention will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific implementations described here are only used to explain the present invention, not to limit the present invention.

A double salient pole brushless DC motor with axial distribution, including stator core, rotor core, shaft 2, position sensor, excitation element and armature winding, the stator core and rotor core adopt a salient pole structure, the stator The iron core is inside, the rotor iron core is set on the shaft 2 outside, the end is provided with a motor end cover 4, and the rotor iron core is provided with a motor casing 15; it is characterized in that:

The number of phases of the motor is m, m is a natural number, and the stator poles and rotor poles of each phase motor are equidistantly distributed along the motor axis, forming m axially distributed sub-motors;

There is a gap between the stator poles in the axial direction for installing the armature winding. The number of stator poles and the number of rotor poles of each sub-motor are 2n, and n is a natural number indicating the number of unit motors of the sub-motor;

There is a 360°/2nm mechanical angle difference between the rotor poles of each sub-motor, and the stator poles are aligned with the corresponding rotor poles in the circumferential direction of the motor;

Concentrated armature windings are respectively wound on the stator poles of each sub-motor, and an excitation element 6 is provided on the outer side of the armature winding near the circumference, and there are 2n excitation elements 6 in the circumferential direction.

The excitation element 6 is an excitation winding, and adjacent excitation windings have opposite winding directions, and the winding direction of the armature winding of each stator pole is consistent with the winding direction of the excitation winding on the stator pole.

Example 1

As shown in Figure 1, the cross-sectional view of the double salient pole brushless DC motor with axial distribution when the number of phases is 3, the motor includes 3 stator cores 8, 11 and 14, and 3 rotor cores 7, 10 and 13 , 3 armature windings 5, 9 and 12, excitation winding 6, motor end cover 4, motor housing 15, shaft 2, bearing 1 and position sensor 3. The stator core of the motor is equally divided into three independent parts of the A-phase stator core 8, the B-phase stator core 11 and the C-phase stator core 14, and the motor rotor core is equally divided into the A-phase rotor core 7 and the B-phase rotor core 10. and C-phase rotor core 13 are three independent parts. The stator cores and rotor cores of each phase are distributed equidistantly along the axial direction of the motor. There is a certain gap between the stator cores of each phase in the axial direction for installing armature windings. The iron core is fixed in the motor casing 15, and the motor end caps 4 are fixed on both ends of the motor casing 15. The shaft 2 is positioned by the bearings 1 in the two motor end caps 4, which can drive the rotor core fixed on the shaft 2 to rotate.

FIG. 2 is a side sectional view of a three-phase sub-motor when the phase number of the three-phase axially distributed doubly salient brushless DC motor of the present invention is three. The stator poles and rotor poles of the motor adopt a salient pole structure, and the number of stator poles and rotor poles of each phase sub-motor is 4 poles; the A-phase rotor core 7, the B-phase rotor core 10 and the C-phase rotor core 13 are in the circumferential direction of the motor The phase difference is 360°/2nm=30°, the stator poles of A-phase stator core 8, B-phase stator core 11 and C-phase stator core 14 are aligned in the circumferential direction of the motor, and A The phase armature winding 5, the B-phase armature winding 9 and the C-phase armature winding 12 are concentrated windings; a total field winding 6 is wound outside the three aligned stator poles in the axial direction, and 4 field windings in the circumferential direction 6 is wound into 2 S poles and 2 N poles, the polarity of the adjacent field winding 6 is opposite, and the winding direction of the 4 armature windings of each phase stator core is consistent with the winding direction of the field winding. The radial force of the double salient pole motor with the traditional 6/4 structure is distributed in two positions, and the radial strain is large; the radial force of the motor of the present invention is distributed in four positions, and the radial strain is small.

Fig. 3 is a three-dimensional view of the rotor of the doubly salient pole brushless DC motor with 3 phases in the axial distribution of the phases of the present invention. The rotor pole adopts a salient pole structure, and the rotor poles of each phase differ by 30° in the circumferential direction of the motor. The motor rotor core can be formed by stacking silicon steel sheets of the same punch.

Fig. 4 is an inductance diagram of each phase when the number of phases of the doubly salient brushless DC motor with axial distribution of each phase is 3 according to the present invention. It can be seen from the figure that while the inductance of one phase is increasing, the inductance of the other phase is decreasing in the same proportion. Therefore, the self-inductance of the total excitation winding of the motor is basically unchanged, and the positioning torque of the motor is small. Its output torque is mainly excitation torque.

Example 2

The excitation element 6 can also be a permanent magnet, and the permanent magnet is installed on the yoke between the stator poles of each phase, and the motor works in a single-phase energization mode or a two-phase energization mode of a permanent magnet double salient pole motor. Fig. 6 is a side sectional view of a three-phase sub-motor of a permanent magnet type double salient pole brushless DC motor with three phases distributed in the axial direction of the present invention. The permanent magnet three-phase axially distributed doubly salient pole brushless DC motor shown in Fig. 6 has all its excitation windings replaced by permanent magnets, that is, permanent magnets are installed between the four stator poles of each phase motor, and the motor can use The permanent magnet doubly salient motor works in a single-phase energization mode or a two-phase energization mode.

Fig. 5 is a schematic diagram of the position of the stator and the rotor of the six-phase sub-motor when the number of phases of the axially distributed double-salient brushless DC motor of the present invention is 6. The stator poles of each phase are aligned in the circumferential direction of the motor, and the six-phase armature windings of phase A, phase B, phase C, phase D, phase E and phase G are respectively wound on the poles of the stator of each phase, and there are 6 aligned stator poles in the axial direction There is a general excitation winding on the outside, and the six-phase rotor poles differ by 360°/4m =15° in the circumferential direction of the motor. The working principle of the six-phase axially distributed doubly salient brushless DC motor shown in Figure 5 is similar to that of the three-phase, the difference is that by increasing the number of phases, the fault tolerance of the motor is improved and the commutation torque ripple is reduced.

Example 3

The excitation element 6 can also be used in combination with field windings and permanent magnets. The winding direction of adjacent field windings is opposite, and the winding direction of the armature winding of each phase stator pole is consistent with the winding direction of the field winding on the stator pole; The magnets are mounted on the yoke between the stator poles of each phase; the motor operates using a hybrid excitation doubly salient motor single-phase energization mode or a two-phase energization mode. Fig. 7 is a side cross-sectional view of a three-phase sub-motor of a mixed-excitation double-salient pole brushless DC motor with three phases in the axial distribution of the phases of the present invention. The hybrid excitation three-phase axially distributed doubly salient pole brushless DC motor shown in Figure 7 has both excitation windings and permanent magnets as its excitation components. Work.

The working principle of the motor is:

Since the stators of the sub-motors in Figure 2 are aligned, and the rotors are 30° mechanically different, the phases between the phases are 120° electrical differently. This is consistent with conventional three-phase doubly salient BLDC motors.

When the current is passed through the excitation winding of the motor, a magnetic field will be established inside the motor, and the generated magnetic flux will pass through the stator yoke, stator teeth, air gap, rotor teeth, and rotor yoke of each phase to form a closed loop. .

The motor can be run as a generator or as a motor. When the motor is run as a motor, it can work in single-phase energization mode or two-phase energization mode of an electrically excited double salient pole motor.

Taking the commonly used two-phase power-on mode as an example to illustrate its electric operation principle. The three-phase armature windings are respectively connected to the middle points of the three bridge arms of the three-phase full-bridge converter, and the controller controls the six power transistors to be turned on and off according to the signals detected by the position sensors. When the stator pole of a certain phase meshes with the rotor pole, a positive current is supplied to the phase; when the stator pole of a certain phase is disengaged from the rotor pole, a negative current is supplied to the phase, and the motor can output torque externally.

During power generation operation: the prime mover drives the motor to rotate in a certain direction, and the flux linkage of the three-phase armature winding turns changes with the change of the rotor position, thereby generating a three-phase alternating induced potential. When it is used as a DC generator, an external three-phase full-bridge converter is used to rectify and output DC power to supply various electrical loads or charge batteries.

It can be understood that those skilled in the art can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention, and all these changes or replacements should belong to the protection scope of the appended claims of the present invention.

Claims (4)

1. An axially distributed double-salient pole brushless DC motor, including a stator core, a rotor core, a shaft (2), a position sensor, an excitation element and an armature winding, the stator core and the rotor core adopt salient poles Type structure, the stator core is outside, the rotor core is set on the shaft (2), the end is provided with a motor end cover (4), and the rotor core is provided with a motor casing (15); it is characterized in that: The number of phases of the motor is m, m is a natural number, and the stator poles and rotor poles of each phase motor are equidistantly distributed along the motor axis, forming m axially distributed sub-motors; There is a gap between the stator poles in the axial direction for the installation of armature windings, and the number of stator poles and rotor poles of each sub-motor is 2n, and n is a natural number; There is a 360°/2nm mechanical angle difference between the rotor poles of each sub-motor, and the stator poles are aligned with the corresponding rotor poles in the circumferential direction of the motor; Concentrated armature windings are respectively wound on the stator poles of each sub-motor, and excitation elements (6) are arranged on the outer side of the armature windings close to the circumference, and there are 2n excitation elements (6) in the circumferential direction. 2. An axially distributed double-salient pole brushless DC motor according to claim 1, characterized in that: the excitation element (6) is an excitation winding, and adjacent excitation windings have opposite winding directions, and each stator The winding direction of the armature winding of each pole is the same as the winding direction of the field winding on the stator pole. 3. An axially distributed double salient pole brushless DC motor according to claim 1, characterized in that: the excitation element (6) is a permanent magnet, and the permanent magnet is installed between the stator poles of each phase On the yoke, the motor works in a single-phase energization mode or a two-phase energization mode of a permanent magnet doubly salient motor. 4. An axially distributed double-salient pole brushless DC motor according to claim 1, characterized in that: the excitation element (6) includes an excitation winding and a permanent magnet, and the winding directions of adjacent excitation windings are opposite, each The winding direction of the armature winding of the phase stator pole is consistent with the winding direction of the excitation winding on the stator pole; the permanent magnet is installed on the yoke between the stator poles of each phase; the motor uses a hybrid excitation double salient pole motor single Phase energization mode or two-phase energization mode operation.