CN105811738B - A kind of full superconduction primary field excitation linear generator of direct-drive type wave-activated power generation - Google Patents

Abstract

The invention discloses a full superconducting primary excitation linear generator for direct-drive wave power generation, which is composed of a primary stator and a secondary mover. The opening formed by two primary iron cores faces the U-shaped iron core of the secondary mover, the primary armature winding arranged in the primary iron core, the primary excitation winding arranged in the U-shaped iron core, and the secondary mover It is an iron core with a slotted structure without windings, and the primary iron core is provided with a corresponding slotted structure. In the present invention, the arc-shaped excitation winding is set outside the primary iron core, and the cooling system does not move, which reduces the complexity. The secondary of the multi-tooth structure can increase the magnetic field conversion rate and terminal voltage, and make up for the shortcoming of low voltage at low speed; the unequal-spaced teeth can reduce the tooth pitch at the end, and increase the frequency and amplitude of the voltage emitted when moving to the end.

Description

A fully superconducting primary excitation linear generator for direct drive wave power generation

technical field

The invention belongs to the field of linear generators, and relates to a primary excitation linear generator applied to a direct-drive wave power generation system.

Background technique

Ocean energy is widely distributed on the earth's surface, and wave energy is a kind of ocean energy with wide distribution, high energy density, highest grade and easiest direct utilization. Wave power generation does not make any noise, and there is no risk of oil spills. Wave power generation will open a new era of pure energy. Wave energy power generation technology can be directly applied to power supply systems for marine observation instruments, power supply systems for military and civilian test buoys, power supply systems for Dokdo, power supply systems for operating platforms, and large-scale grid-connected ocean energy power generation systems. The direct drive reciprocating wave power generation device adopts the direct combination of energy harvesting device and linear generator, which changes the traditional power generation method of converting linear motion into rotary motion through other mechanical devices and drives the rotary generator, and directly collects the energy of linear motion. The intermediate energy transmission link is omitted, and the power generation efficiency of the system can be increased by more than 20%. At the same time, the complexity of the system is reduced, the volume is reduced, and the stability is improved. In addition, the direct-drive wave power generation system has simple structure, low cost, and wide application area, which is suitable for large-scale application. Therefore, direct drive reciprocating wave energy generation has broad prospects. However, due to the characteristics of low-speed direct drive of wave power generation, the primary energy conversion has the characteristics of large thrust and low speed, and the air gap of the motor is much larger than that of the rotating motor, so that the linear generators with traditional permanent magnet structure and electric excitation structure are bulky. , The disadvantage of low power density.

Contents of the invention

Technical problem: The present invention provides a direct-drive wave power generation with full superconducting primary excitation linear power generation with high power density and efficiency, using the primary excitation to simplify the cooling system structure, and operating the secondary segment design to optimize the output power quality of the motor machine.

Technical solution: The full superconducting primary excitation linear generator for direct-drive wave power generation of the present invention is composed of a primary stator and a secondary mover. The primary stator is composed of multiple sets of stator units arranged in a straight line. Each of the stators The unit includes a U-shaped iron core with an opening facing the secondary mover formed by two primary iron cores, a primary armature winding arranged in the primary iron core, and a primary excitation winding arranged in the U-shaped iron core, The secondary mover is an iron core with a cogged structure without windings, and the primary iron core is provided with a corresponding cogged structure. The tooth width of the secondary mover alveolar structure is the same, and the secondary mover is divided into a first secondary section with a tooth pitch of 2τ, two second secondary sections with a tooth pitch of 1.25τ, and two tooth pitches is the third sub-section of τ, the first sub-section is located in the middle of the secondary mover, the two third sub-sections are respectively located at both ends of the sub-mover, and the second sub-section (14) is located in the first Between the sub-segment and the third sub-segment. The primary excitation winding is divided into two parts, one part is arranged on the outside where the two primary iron cores are adjacent, and the other part is arranged on the excitation winding support arranged along the outside of the U-shaped iron core, the primary excitation winding and the primary electric current The pivot windings are all superconducting windings.

Further, in the present invention, the superconducting winding is composed of a pie-shaped MgB ₂ superconducting wire material, and the primary stator is provided with an armature winding cooling Dewar and an excitation winding cooling Dewar.

Further, in the present invention, in the primary stator, the distance between two adjacent stator units is (5N+1+2/3)τ-D, where D is the length of the stator units in the linear arrangement direction, N is an odd number, the distance between two primary iron cores in the same stator unit is (M±1/2)τ-d, where d is the length of the primary iron core in the direction of linear arrangement, and M is an integer.

Further, in the present invention, in the primary stator, the distance between two adjacent stator units is (6+2/3)τ-D, the tooth width of the secondary mover is equal to that of the primary stator, and the first secondary section The cogging ratio, that is, the ratio of the tooth width to the slot width is 1:3, the cogging ratio of the second sub-stage is 1:1.5, and the cogging ratio of the third sub-stage is 1:1.

The invention is mainly composed of a primary and a secondary. The primary of the motor is composed of a casing, a primary iron core, an armature winding, an excitation winding and a cooling Dewar, and the secondary mainly includes a permeable core with a cogged structure and slot filling. Among them, the primary is fixed on the casing, and the secondary is that the moving part is directly connected with the wave energy collection device (pontoon). Both the superconducting armature winding and the superconducting excitation winding are located on a fixed primary, which simplifies the superconducting cooling mechanism. The secondary is an iron core with alveolar structure, without any winding, and has a simple structure.

In one solution of the present invention, the motor has a cylindrical structure, the outer cylinder is the primary (stator) of the motor, and the inner cylinder is the secondary (mover) of the motor. The excitation winding and the armature winding are made of MgB ₂ superconducting wire. In order to realize the insulation between the wires, the MgB ₂ superconducting wire is covered with a non-conductive material (high temperature resistant glass fiber). The excitation winding support is made of titanium alloy or aluminum alloy. The mover is a magnetically conductive metal body or an alloy magnetically conductive body with a cog structure, and the slots are filled with non-magnetically conductive materials.

In the preferred solution of the present invention, the excitation winding adopts a sleeve-type cooling Dewar structure, and is installed between the primary iron core and the casing, and an isolation container or an integral container is used between phases, and the cooling gas inlet is located at the upper end, and the outlet is located at the lower end. The excitation winding adopts an arc design and is supported by a non-magnetic titanium alloy bracket.

In the preferred solution, the armature winding adopts a sleeve-type cooling Dewar, which is installed in the primary tank, and the primary armature winding is wrapped in an annular tubular Dewar tube, and the tubes are connected by a connecting tube, and the cooling gas inlet is located at the uppermost Dewar tube On one side, the outlet is located on the other side of the bottom Dewar tube.

In a preferred solution, liquid hydrogen can be used as the refrigerant. The primary iron core and the secondary iron core are iron-cobalt alloy materials with a high saturation point. The secondary tooth pitch adopts a variable tooth pitch structure that gradually decreases from the middle to the end along with the secondary position.

In the present invention, the arc-shaped excitation winding is set outside the primary iron core, and the cooling system does not move, which reduces the complexity. Superconducting excitation can increase the air gap magnetic density, increase the power density, and realize the adjustment of the magnetic field. The superconducting armature can eliminate armature loss, increase power generation efficiency, reduce slot width, and increase effective magnetic flux area between primary and secondary. The primary and secondary iron core structure of _MgB2 superconducting material and iron-cobalt alloy can make full use of the field strength of _MgB2 and the high saturation point of iron-cobalt alloy. The secondary of the multi-tooth structure can increase the magnetic field conversion rate and terminal voltage, and make up for the shortcoming of low voltage at low speed; the unequal-spaced teeth can reduce the tooth pitch at the end, and increase the frequency and amplitude of the voltage emitted when moving to the end. Modular structure, complete mechanical structure and independent cooling unit, which reduces the difficulty of cooling.

Beneficial effect: compared with the prior art, the present invention has the following advantages:

The invention is a primary excitation full superconducting linear generator. Both the excitation winding and the armature winding are located at the primary stage of the stator. The complex cooling dewar, refrigerator and related joints do not need to move, and the complexity is greatly reduced. The choice of MgB ₂ superconducting material can be refrigerated by liquid hydrogen, which reduces the requirements of the refrigerator and avoids the complexity of mixing multiple superconducting materials, which is conducive to realization. The use of superconducting excitation windings instead of conventional copper wire windings increases the air gap magnetic flux density and increases the power density. At the same time, the magnetic field adjustment can be realized by changing the current of the excitation windings, reducing the voltage of external circuit switching devices formed by large wave changes. Working pressure, increase the power adjustment range. The armature winding adopts superconducting wire, which can eliminate the armature loss and increase the power generation efficiency, and because the current carrying capacity of the superconducting winding is much higher than that of the through winding, the width of the slot can be reduced and the effective magnetic flux area between the primary and secondary can be increased , At the same time, due to the use of superconducting windings with fewer turns, the reactance of the armature winding can be reduced and the power factor can be improved. The primary and secondary iron core structure with core iron-cobalt alloy is adopted. Due to the high saturation point of the iron-cobalt alloy, the advantages of the strong working magnetic field of the MgB ₂ superconducting material and the matching of the saturation point of the iron-cobalt alloy can be fully utilized. The primary adopts a multi-tooth structure, which can increase the magnetic field conversion rate, thereby increasing the effective voltage, and making up for the shortcoming of low output voltage at low speed of the wave direct drive; the teeth are arranged at unequal intervals, and the distance between the teeth at the secondary end is smaller than the distance between the secondary middle teeth , the linear motor is driven by waves, and its movement speed at the end decreases. Therefore, by reducing the tooth pitch at the end, the rate of change of the magnetic field when moving to the end can be increased, thereby increasing the frequency and amplitude of the voltage emitted by the motor. By adopting the ratio of 1:3 (the first secondary stage), 1:1.5 (the second secondary stage) and 1:1 (the third secondary stage), the phase angle difference of the three-phase voltage of the motor output voltage can be 120°. The modular structure is completely adopted, and the complete mechanical structure and cooling unit between the modules are independent. They can be cooled independently, which reduces the difficulty of cooling and facilitates installation and transportation.

Description of drawings

Fig. 1 is a cross-sectional view of a primary excitation full superconducting linear generator.

Fig. 2 is a schematic diagram of a single module of a primary excitation full superconducting linear generator.

Fig. 3 is the primary armature cooling Dewar diagram of the primary excitation full superconducting linear generator.

Fig. 4 is a secondary structure diagram of the primary excitation full superconducting linear generator.

In the figure: 1. Primary core, 2. Secondary core, 3. Armature winding cooling Dewar, 4. Field winding cooling Dewar, 5. Primary field winding, 6. Primary armature winding, 7. Field winding Bracket, 8. Dewar air-conditioning input tube for excitation winding, 9. Dewar air-conditioning output tube for excitation winding, 10. Dewar air-conditioning input port for armature winding, 11. Dewar air-conditioning output port for armature winding, 12. Armature winding Dewar air-conditioning output port Air-conditioning transmission pipe between tiles, 13. the first secondary section, 14. the second secondary section, 15. the third secondary section.

Detailed ways

The present invention will be further described below in conjunction with embodiment and accompanying drawing.

This embodiment will be described below with reference to FIGS. 1-4 . This embodiment includes primary and secondary. The primary is composed of primary iron core 1 , primary field winding 5 , primary armature winding 6 , field winding cooling Dewar 4 , armature winding cooling Dewar 5 and field winding support 7 . The secondary is composed of secondary sections 13, 14 and 15 with different tooth-tooth ratios, and epoxy resin is filled in the secondary grooves to realize secondary movement. The primary and secondary iron cores use iron-cobalt alloys to increase the magnetic saturation point of the motor core. The excitation winding is supported by the excitation winding bracket 7, and the excitation winding outside the bracket and the excitation winding 5 inside the bracket adopt a pie-shaped winding structure, and the current in the winding is a direct current in the opposite direction to form an arc-shaped closed magnetic circuit. The primary under the same excitation winding bracket is an independent primary module (as shown in Figure 2). The field winding Dewar 4 inputs refrigerant through the field winding Dewar cold air input port 8 , and performs cooling cycle through the field winding Dewar cold air output pipe 9 . The armature winding is enclosed in the armature winding cooling Dewar 3, through the armature winding Dewar cold air input port 10, the armature winding intermediate transition tube 12, the armature winding Dewar cold air output port 11 and the armature winding cooling Dewar Watt 3 realizes the refrigeration cycle of the armature winding.

The distance between two adjacent stator units is (5N+1+2/3)τ-D, where D is the length of the stator units in the direction of linear arrangement, and N is an odd number. Preferably, this distance is (6+ 2/3) τ-D, the first module and the fourth primary module together form a phase winding, and the directions of the excitation windings between adjacent primary modules are opposite, that is, the current direction of the excitation armature outside the bracket is the same as that of the excitation armature inside the adjacent winding bracket The current direction is the same. The distance between two primary iron cores 1 in the same stator unit is (M±1/2)τ-d, where d is the length of the primary iron cores 1 in the direction of linear arrangement, and M is an integer. The same primary U-shaped iron core armature winding direction is opposite.

In a preferred embodiment of the present invention, the secondary is composed of different secondary sections, the tooth widths of different sections are the same, and the tooth width is equal to the primary tooth width. The cogging ratio of the first secondary section 13, that is, the ratio of the tooth width to the slot width is 1:3, the cogging ratio of the second secondary section 14 is 1:1.5, and the cogging ratio of the third secondary section 15 is 1:1. The voltage when moving to both ends is increased by changing the pitch of the teeth at the side ends. At this time, the three-stage voltage ratio at the same speed can be obtained as 1:1.6:2. The phase difference of each phase voltage is 120°, realizing three-phase symmetry. It can improve the phenomenon that the voltage at both ends of the motor drops sharply when it is driven by actual waves, and the output performance of the motor can be improved.

The above implementation method is applicable to a double-sided flat linear motor or a single-sided flat linear motor.

The foregoing embodiments are only preferred implementations of the present invention. It should be pointed out that those skilled in the art can make several improvements and equivalent replacements without departing from the principle of the present invention. Technical solutions requiring improvement and equivalent replacement all fall within the protection scope of the present invention.

Claims (3)

1. A full superconducting primary excitation linear generator for direct-drive wave power generation, characterized in that the linear generator is made up of a primary stator and a secondary mover, and the primary stator is made up of multiple groups of stator units arranged in a straight line , each of the stator units includes two primary iron cores (1), a U-shaped iron core with an opening facing the secondary mover, and a primary armature winding (6) arranged in the primary iron core (1). . The primary excitation winding (5) arranged in the U-shaped iron core, the secondary mover is an iron core with a cogged structure without winding, and the primary iron core (1) is provided with corresponding alveolar structure; The tooth widths of the tooth slot structures of the secondary movers are the same, and the secondary movers are divided into a first secondary section (13) with a tooth pitch of 2τ, and two second secondary sections (14) with a tooth pitch of 1.25τ ) and two third sub-sections (15) with a tooth pitch of τ, the first sub-section (13) is located in the middle of the secondary mover, and the two third sub-sections (15) are respectively located in the secondary mover Sub-two ends, the second sub-section (14) is located between the first sub-section (13) and the third sub-section (15); The primary field winding (5) is divided into two parts, one part is arranged on the outside where the two primary iron cores (1) are adjacent, and the other part is arranged on the field winding support (7) arranged along the outside of the U-shaped iron core , the primary field winding (5) and the primary armature winding (6) are superconducting windings; In the primary stator, the distance between two adjacent stator units is (5N+1+2/3)τ-D, where D is the length of the stator units in the direction of linear arrangement, N is an odd number, and the same stator unit The distance between the two primary iron cores (1) is (M±1/2)τ-d, where d is the length of the primary iron cores (1) in the direction of linear arrangement, and M is an integer. 2. direct drive type wave power generation according to claim 1 uses full superconducting primary excitation linear generator, it is characterized in that, described superconducting winding is made up of the MgB of pie structure ₂ superconducting wire material, in described primary stator An armature winding cooling Dewar (3) and an excitation winding cooling Dewar (4) are provided. 3. according to claim 1 or 2 described direct-drive type wave power generation with full superconducting primary excitation linear generator, it is characterized in that: in the described primary stator, the spacing of two adjacent stator units is (6+2/ 3) τ-D, the tooth width of the secondary mover and the primary stator are equal, the tooth-to-slot ratio of the first secondary section (13), that is, the ratio of the tooth width to the slot width is 1:3, and the second secondary The tooth space ratio of the segment (14) is 1:1.5, the tooth space ratio of the third sub-section (15) is 1:1.