CN106849573B - Double-rotor double-winding cylindrical linear generator based on magnetic field modulation principle - Google Patents

Abstract

The invention discloses a double-rotor double-winding cylindrical linear generator based on a magnetic field modulation principle, belongs to the field of linear generators for wave power generation, and aims to solve the problem that the conventional direct-drive wave power generation system is poor in power generation quality. The invention comprises a casing, a double-winding stator, a permanent magnet rotor, a modulation rotor, a permanent magnet rotor output shaft and a modulation rotor output shaft; the double-winding stator is fixed on the inner circular surface of the shell, and the modulation rotor and the permanent magnet rotor are sequentially arranged inside the double-winding stator from outside to inside; the permanent magnet rotor is fixed on the output shaft of the permanent magnet rotor, the modulation rotor is positioned between the double-winding stator and the permanent magnet rotor, two ends of the modulation rotor respectively extend out of end covers at two sides of the shell, the extending part at the left side serves as the output shaft of the modulation rotor, and the axes of the output shaft of the modulation rotor and the output shaft of the permanent magnet rotor are overlapped.

Description

Double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation

technical field

The invention belongs to the field of linear generators for wave power generation.

Background technique

Ocean wave energy is a clean power generation energy, which can meet the needs of ocean observation instruments, military and civilian test buoys, Dokdo, and operating platforms through wave energy generation. At present, the traditional wave energy power generation method usually uses a mechanical device to convert the vertical linear motion of the wave into a rotary motion, and drives the rotary generator to generate electricity. In contrast, the direct-drive power generation method uses the energy recovery device and the linear motor to directly combine the power generation, which saves the complex mechanical transmission link in the middle, improves the power generation efficiency of the system, and improves the integration and stability of the power generation system. improved. Therefore, direct-drive wave power generation has broad application prospects. However, in the current direct-drive power generation system, due to the large thrust, low speed and inconstancy of the linear motion converted by the energy recovery device, the parameters such as the amplitude and frequency of the power generation voltage of the linear motor change greatly, resulting in poor power generation quality of the system. There may even be problems such as system instability.

SUMMARY OF THE INVENTION

The purpose of the invention is to solve the problem of poor power generation quality of the existing direct-drive wave power generation system, and to provide a double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation.

The double-mover double-winding cylindrical linear generator based on the magnetic field modulation principle of the present invention includes a casing 4, a double-winding stator 5, a permanent magnet mover 7, a modulation mover 6, a permanent magnet mover output shaft 10 and a modulation mover output shaft 1;

The double-winding stator 5 is fixed on the inner circular surface of the casing 4, and the inside of the double-winding stator 5 is sequentially provided with a modulation mover 6 and a permanent magnet mover 7 from the outside to the inside; the permanent magnet mover 7 is fixed on the output shaft of the permanent magnet mover 10, the left end of the permanent magnet mover output shaft 10 is slidably connected to the modulation mover 6 through the second bearing 3, and the right end of the permanent magnet mover output shaft 10 protrudes from the right end cover of the casing 4, and passes through the third The bearing 8 is also slidably connected with the modulation mover 6;

The modulating mover 6 is located between the double-winding stator 5 and the permanent magnet mover 7, and both ends of the modulating mover 6 protrude from the end covers on both sides of the housing 4 respectively, and the right protruding part passes through the third bearing 8 and the The fourth bearing 9 is slidably connected with the permanent magnet mover 7 and the right end cover of the casing 4; the left extension part is used as the modulation mover output shaft 1, and the modulation mover output shaft 1 passes through the first bearing 2 and The second bearing 3 is respectively slidably connected with the left end cover of the casing 4 and the permanent magnet mover 7;

There is a radial air gap L1 between the modulation mover 6 and the double-winding stator 5; there is a radial air gap L2 between the modulation mover 6 and the permanent magnet mover 7; the modulation mover output shaft 1 and the permanent magnet mover output shaft The axes of 10 coincide.

Preferably, the double-winding stator 5 is composed of a stator core 5-3, a first stator winding 5-1 and a second stator winding 5-2; the first stator winding 5-1 is an m ₁ phase stator winding, when the first stator winding 5-1 When the stator winding 5-1 is connected with m ₁ -phase alternating current, it will form a p _s1 pole pair armature magnetic field moving along the axis direction, m1, p _s1 are positive integers; the second stator winding 5-2 is an m2 Phase stator winding, when the second stator winding 5-2 has m2-phase alternating current, an armature magnetic field with _ps2 pole pairs moving along the axis direction will be formed, and m2 and _ps2 are positive integers.

Preferably, the number of pole pairs of the permanent magnet _mover 7 is p _PM , and p _PM is a positive integer _; The permanent magnet units 7-1 are evenly distributed and arranged along the axis direction. The 2p _PM permanent magnet units 7-1 are fixed on the outer surface of the permanent magnet mover core 7-2. The magnetic directions are opposite; the magnetization direction of the permanent magnet unit 7-1 is radial magnetization.

Preferably, the modulation _mover 6 is composed of pm magnetic conductive blocks 6-1, _pm non-magnetic conductive blocks 6-2 and a mover bracket _6-3 , where pm is a positive integer; The magnetic conductive block 6-1 and the non-magnetic conductive block 6-2 are arranged alternately in the axial direction;

The conditions p _s1 =|kp _PM +jp _m | and p _s2 =kp _PM are satisfied at the same time, where k is a positive integer and j is an integer.

Preferably, the magnetic conductive block 6-1 is selected from soft magnetic composite material, silicon steel sheet, solid iron or soft ferrite.

Advantages of the present invention: The double-mover double-winding cylindrical linear generator based on the magnetic field modulation principle of the present invention has two independent movers, and the thrust and speed of the two movers are completely independent. Therefore, in the actual wave power generation system, no matter how one mover moves with the waves, through the effective control of the other mover, the voltage amplitude and frequency emitted by the generator can be kept constant, thereby improving the power generation quality of the power generation system. and system stability.

Description of drawings

1 is a schematic structural diagram of the double-mover double-winding cylindrical linear generator based on the magnetic field modulation principle;

Fig. 2 is the enlarged view of A place of Fig. 1;

3 is a schematic diagram of the winding arrangement of the first stator winding;

FIG. 4 is a schematic diagram of the winding arrangement of the second stator winding.

Detailed ways

The present invention will be further described below with reference to FIGS. 1 to 4 . FIG. 1 is a schematic structural diagram of an embodiment of a double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation.

The double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation includes a casing 4, a double-winding stator 5, a permanent magnet mover 7, a modulation mover 6, a permanent magnet mover output shaft 10 and a modulation mover output shaft 1;

The double-winding stator 5 is fixed on the inner circular surface of the casing 4, and the inside of the double-winding stator 5 is sequentially provided with a modulation mover 6 and a permanent magnet mover 7 from the outside to the inside; the permanent magnet mover 7 is fixed on the output shaft of the permanent magnet mover 10, the left end of the permanent magnet mover output shaft 10 is slidably connected to the modulation mover 6 through the second bearing 3, and the right end of the permanent magnet mover output shaft 10 protrudes from the right end cover of the casing 4, and passes through the third The bearing 8 is also slidably connected with the modulation mover 6;

The modulating mover 6 is located between the double-winding stator 5 and the permanent magnet mover 7, and both ends of the modulating mover 6 protrude from the end covers on both sides of the housing 4 respectively, and the right protruding part passes through the third bearing 8 and the The fourth bearing 9 is slidably connected with the permanent magnet mover 7 and the right end cover of the casing 4; the left extension part is used as the modulation mover output shaft 1, and the modulation mover output shaft 1 passes through the first bearing 2 and The second bearing 3 is slidably connected with the left end cover of the casing 4 and the permanent magnet mover 7;

There is a radial air gap L1 between the modulation mover 6 and the double-winding stator 5; there is a radial air gap L2 between the modulation mover 6 and the permanent magnet mover 7; the modulation mover output shaft 1 and the permanent magnet mover output shaft The axes of 10 coincide.

The double-winding stator 5 is composed of a stator core 5-3, a first stator winding 5-1 and a second stator winding 5-2; the first stator winding 5-1 is an m ₁ phase stator winding, when the first stator winding 5-1 When the winding 5-1 has m ₁ -phase alternating current, it will form a p _s1 pole pair armature magnetic field moving along the axis direction, m ₁ and p _s1 are positive integers; the second stator winding 5-2 is an m ₂ phase The stator winding, when the second stator winding 5-2 is supplied with m ₂ phase alternating current, will form an armature magnetic field with ps ₂ pole pairs moving along the axis direction, where m ₂ and ps ₂ are positive integers.

The number of pole pairs of the permanent magnet mover 7 is p _PM , and p _PM is a positive integer; the permanent magnet mover 7 is composed of a permanent magnet mover iron core 7-2 and 2p _PM permanent magnet units 7-1, and 2p _PM permanent magnet units 7-1 is evenly distributed and arranged along the axis direction, 2p _PM permanent magnet units 7-1 are fixed on the outer surface of the permanent magnet mover core 7-2, and the magnetization directions of the two adjacent permanent magnet units 7-1 are opposite ; The magnetization direction of the permanent magnet unit 7-1 is radial magnetization.

The modulation mover 6 is composed of pm magnetic conductive blocks 6-1, _pm non-magnetic conductive blocks 6-2 and a mover support 6-3, where _{p m is} a positive integer; the mover supports 6-3 are staggered along the axis direction Set the magnetic conductive block 6-1 and the non-magnetic conductive block 6-2;

The conditions p _s1 =|kp _PM +jp _m | and p _s2 =kp _PM are satisfied at the same time, where k is a positive integer and j is an integer.

The magnetic conductive block 6-1 is made of soft magnetic composite material, silicon steel sheet, solid iron or soft ferrite.

In order to illustrate the working principle of the present invention, the following description is made with reference to FIGS. 1 to 4 .

Assuming that the number of pole pairs of the permanent magnet mover is p _PM , the speed is V _PM , and the initial phase angle is θ _PM , the permanent magnet magnetomotive force F _PM (θ, t) formed by the permanent magnet mover moving along the axis direction can be expressed as for

In the formula, F _k ——the magnitude of each harmonic magnetomotive force;

k——harmonic number of permanent magnet magnetomotive force;

θ——Mechanical angle;

t - time.

Assuming that the number of permeable blocks of the modulating mover is p _m , the velocity is V _m , and the initial phase angle is θ _m , the space ratio permeance λ(θ, t) that changes with time under the action of the modulating mover can be expressed as

where λ ₀ , λ _i ——the permeance amplitude of each harmonic ratio;

i——The number of harmonic permeance ratio.

The permanent magnet magnetic field moving along the axis direction generated by the magnetomotive force of the permanent magnet under the action of the modulating mover can be expressed as

where B _k is the amplitude of the natural harmonic magnetic field, and B _k = F _k λ ₀ ;

B _k,i — the modulated harmonic magnetic field amplitude, and B _k,i =F _k λ _i .

It can be seen from formula (3) that two types of magnetic fields will be generated under the joint action of the permanent magnet mover and the modulation mover. The first type is the natural harmonic magnetic field. The characteristic of this type of magnetic field is that its number of pole pairs and velocity are the same as those of the magnetomotive force of the permanent magnet mover, and the magnitude of this type of magnetic field is B _k . The second type is the modulation harmonic magnetic field. The characteristic of this type of magnetic field is that the number of pole pairs of the magnetic field is related to the number of pole pairs of the permanent magnet mover and the number of permeable blocks in the modulation mover, and its magnetic field speed is also related to the permanent magnet mover. is related to the velocity of both the modulating mover, and the magnitude of this type of magnetic field is B _k,i , as follows:

p _k,j =|kp _PM +jp _m | (4)

j=0,±1,±2,... (6)

where p _k,j and V _k,j are the number of pole pairs and synchronizing velocity of the modulated harmonic magnetic field.

According to the principle of electromechanical energy conversion, only when the pole pairs and speeds of the two magnetic fields are the same, a constant thrust can be generated, thereby realizing electromechanical energy conversion. Therefore, the first stator winding 5-1 is designed to generate an armature magnetic field with the same number of pole pairs and speed as the modulated harmonic magnetic field through the winding arrangement. Then, the first stator winding 5-1, the modulation mover and the permanent magnet mover constitute a magnetic field modulation type double mover linear motor. In this case, the electromagnetic thrust acting on the modulating mover is equal to the sum of the electromagnetic thrusts acting on the stator and the permanent magnet mover, and their electromagnetic thrusts are in opposite directions. At the same time, the thrust relationship between the modulating mover and the permanent magnet mover and between the modulating mover and the first stator winding 5-1 is always proportional. In addition, the speed of the armature magnetic field generated by the first stator winding 5-1 is equal to the speed of the modulated harmonic magnetic field, therefore, the speed can be adjusted with reference to formula (5). Therefore, due to the interaction between the first stator winding 5-1, the modulation mover and the permanent magnet mover, the modulation mover and the permanent magnet mover can only achieve speed decoupling, but the thrust between them is still coupled. In practical applications, if only one set of windings (the first stator winding 5-1) is used, the voltage emitted by the windings will be extremely unstable due to the uncertainty of the wave motion.

Further, the second stator winding 5-2 can be designed to generate an armature magnetic field with the same pole pair number and speed as the natural harmonic magnetic field. Then, the second stator winding 5-2 and the permanent magnet mover constitute a permanent magnet synchronous linear motor. At this time, the second stator winding 5-2 only acts with the permanent magnet mover to generate thrust, and does not generate thrust with the modulation mover. In addition, since the pole pairs of the armature magnetic field generated by the first stator winding 5-1 and the second stator winding 5-2 are different, no thrust is generated between them, in other words, there is no influence between them. Therefore, through the interaction between the second stator winding 5-2 and the permanent magnet mover, the thrust decoupling of the modulation mover and the permanent magnet mover can be realized.

It can be seen from the above analysis that the electromagnetic thrust on the modulating mover is only related to the first stator winding 5-1, and the speed of the modulating mover is related to the armature magnetic field of the first stator winding 5-1 and the speed of the permanent magnet mover; The electromagnetic thrust on the permanent magnet mover is not only related to the first stator winding 5-1, but also affected by the second stator winding 5-2. At the same time, the speed of the permanent magnet mover is only related to the electric power of the second stator winding 5-2. The pivot magnetic field velocity is the same. Therefore, for the double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation, the thrust and speed of the modulating mover are completely independent of the thrust and speed of the permanent magnet mover.

In practical application, the modulation mover is connected with the wave transmission device, so the movement of the modulation mover has great randomness. At this time, the thrust and speed of the permanent magnet rotor are effectively controlled by the second stator winding 5-2, so that the speed of the armature magnetic field of the first stator winding 5-1 is always kept constant, thereby enabling the double-acting based on the principle of magnetic field modulation. The voltage amplitude and frequency emitted by the sub-double-winding cylindrical linear generator are always kept constant, which significantly improves the power generation quality of the entire power generation system.

Specifically, the number of pole pairs of the permanent magnet mover in FIG. 1 is 6, and the number of magnetic conductive blocks in the modulation mover is 10. It can be known from equation (4) that a series of modulated harmonic magnetic fields will be generated in the air gap. Among these modulated harmonic magnetic fields, the amplitude of the corresponding modulated harmonic magnetic field is usually the largest when k=1, j=-1, that is to say, the amplitude of the four pairs of polar magnetic fields in the modulated harmonic magnetic field is the largest. Therefore, the first stator winding 5-1 can generate 4-pole armature magnetic fields through the winding arrangement design, as shown in FIG. 3 (the first stator winding 5-1 has annular windings in each slot, In the figure, each toroidal winding is replaced by a vertical line). And by controlling the speed of the armature magnetic field generated by the first stator winding 5-1 to be the same as the speed of the 4-pole modulated harmonic magnetic field, the first stator winding 5-1, the modulation mover and the permanent magnet mover can realize electromechanical energy conversion.

At this time, it can also be known from equation (3) that a series of natural harmonic magnetic fields will be generated in the air gap. Among these natural harmonic magnetic fields, when k=1, the corresponding natural harmonic magnetic field has the largest amplitude, that is to say, the permanent magnet magnetic field has the largest amplitude. The sub-generating 6 pairs of poles have the largest amplitude of the natural harmonic magnetic field. Therefore, the second stator winding 5-2 can generate 6-pole armature magnetic fields through the winding arrangement design, as shown in FIG. 4 (the second stator winding 5-2 has annular windings in each slot, in the figure Each toroidal winding is replaced by a vertical bar). And by controlling the second stator winding 5-2 to generate the armature magnetic field at the same speed as the 6 pairs of polar natural harmonic magnetic fields, the second stator winding 5-2 and the permanent magnet mover can realize electromechanical energy conversion.

In addition, since the pole pairs of the armature magnetic field generated by the first stator winding 5-1 and the second stator winding 5-2 are different (one is a 4-pole armature magnetic field, the other is a 6-pole armature magnetic field), according to Electromechanical energy conversion principle, no thrust is generated between them. In other words, they do not affect each other.

The final effect is equivalent to that the first stator winding 5-1, the modulation mover and the permanent magnet mover are a double mover motor; while the second stator winding 5-2 and the permanent magnet mover are equivalent to the traditional permanent magnet synchronous motor Linear Motor. In this way, through the control of the first stator winding 5-1, the speed decoupling of the modulating mover and the permanent magnet mover can be achieved, but the thrusts of the two are coupled (not independent); further through the second stator winding 5-2 The control can realize the thrust decoupling between the modulating mover and the permanent magnet mover. Therefore, in practical applications, the effective control of the permanent magnet mover is realized by the second stator winding 5-2, and the voltage amplitude emitted by the first stator winding 5-1 can be guaranteed even under the random variable speed movement of the modulating mover. , the frequency is constant, so that the power generation quality of the entire power generation system is improved, and the stability of the system operation is also improved.

Claims (2)

1. The double-mover double-winding cylindrical linear generator based on the principle of magnetic field modulation is characterized in that, comprising a casing (4), a double-winding stator (5), a permanent magnet mover (7), a modulation mover (6) ), the permanent magnet mover output shaft (10) and the modulation mover output shaft (1); The double-winding stator (5) is fixed on the inner surface of the casing (4), and the inside of the double-winding stator (5) is sequentially provided with a modulation mover (6) and a permanent magnet mover (7) from the outside to the inside; The sub (7) is fixed on the permanent magnet mover output shaft (10), the left end of the permanent magnet mover output shaft (10) is slidably connected with the modulation mover (6) through the second bearing (3), and the permanent magnet mover outputs The right end of the shaft (10) protrudes from the right end cover of the casing (4), and is also slidably connected with the modulation mover (6) through the third bearing (8); The modulation mover (6) is located between the double-winding stator (5) and the permanent magnet mover (7). The side protruding part is slidably connected with the permanent magnet mover (7) and the right end cover of the casing (4) through the third bearing (8) and the fourth bearing (9); the left protruding part is used as the modulation mover an output shaft (1), the modulation mover output shaft (1) is slidably connected to the left end cover of the casing (4) and the permanent magnet mover (7) through the first bearing 2 and the second bearing (3), respectively; A radial air gap L1 exists between the modulation mover (6) and the double-winding stator (5); a radial air gap L2 exists between the modulation mover (6) and the permanent magnet mover (7); the modulation mover output shaft (1) Coinciding with the axis of the permanent magnet mover output shaft (10); The double-winding stator (5) is composed of a stator core (5-3), a first stator winding (5-1) and a second stator winding (5-2); the first stator winding (5-1) is an m ₁ -phase stator winding, when the first stator winding (5-1) has m ₁ -phase alternating current, it will form a _ps1 pole pair armature magnetic field that moves along the axis direction, and m1 and _ps1 are positive _integers ; The second stator winding (5-2) is an m ₂ -phase stator winding. When the second stator winding (5-2) is supplied with an m ₂ -phase alternating current, it will form an electric current with the number of _ps2 pole pairs moving along the axis direction. Pivot magnetic field, m ₂ , p _s2 are positive integers; The number of pole pairs of the permanent magnet mover (7) is p _PM , and p _PM is a positive integer; the permanent magnet mover (7) consists of a permanent magnet mover iron core (7-2) and 2p _PM permanent magnet units (7-1) Composition, 2p _PM permanent magnet units (7-1) are evenly distributed and arranged along the axis direction, 2p _PM permanent magnet units (7-1) are fixed on the outer surface of the permanent magnet mover core (7-2), phase The magnetization directions of the two adjacent permanent magnet units (7-1) are opposite; the magnetization direction of the permanent magnet units (7-1) is radial magnetization; The modulation mover (6) is composed of pm magnetic permeable blocks (6-1), _pm non-magnetic permeable blocks (6-2) and a mover bracket (6-3), and _{p m is} a positive integer; the mover The support (6-3) is staggered along the axis direction to arrange the magnetic conductive block (6-1) and the non-magnetic conductive block (6-2); The conditions p _s1 =|kp _PM +jp _m | and p _s2 =kp _PM are satisfied at the same time, where k is a positive integer and j is an integer. 2. The double-mover double-winding cylindrical linear generator based on the magnetic field modulation principle according to claim 1, is characterized in that, the magnetic conductive block (6-1) selects soft magnetic composite material, silicon steel sheet, solid iron or soft magnetic material for use. ferrite.

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