CN113991933B - A compact flywheel energy storage battery - Google Patents

Abstract

The invention discloses a compact flywheel energy storage battery, belonging to the technical field of electric energy storage, comprising: an energy storage flywheel formed by stacking at least one hollow flywheel disk on a flywheel shaft; The upper end cover and the lower end cover on both sides; the casing is fixed between the upper end cover and the lower end cover, forming a vacuum chamber with the upper end cover and the lower end cover; the high-speed motor is arranged between the upper end cover and the energy storage flywheel, or the energy storage flywheel Between the lower end cover; mechanical bearings and permanent magnetic bearings; high-speed motors are fixed on the stepped rotating shaft, and an annular water channel is provided. The invention reduces the axial length of the flywheel energy storage battery, has a compact structure, is simple and reliable, and reduces material consumption. In the same vacuum chamber, a larger-capacity flywheel energy storage battery can be formed by stacking more hollow flywheel discs; different flywheel energy storage batteries can also form larger capacity and larger Power flywheel energy storage battery pack.

Description

A compact flywheel energy storage battery

technical field

The invention belongs to the technical field of electric energy storage, and more specifically relates to a compact flywheel energy storage battery.

Background technique

With the continuous development and development of new energy technologies, energy storage technology has received extensive attention. Among the existing energy storage technologies, the flywheel energy storage device has the advantages of good dynamic performance and no secondary pollution, which has attracted more and more attention. The flywheel energy storage device includes the flywheel rotor, generator, permanent magnetic bearing, mechanical bearing and motor casing. In the limited space of the vacuum machine cavity, how to improve the heat dissipation efficiency and how to choose the structure and installation method of each component make the vacuum machine The full and reasonable use of cavity space has become a concern of the public.

In addition, after the design of the flywheel energy storage device is completed, its energy storage capacity and motor power can only change within a small range, which cannot be applied to occasions with larger capacity and higher power, and a larger volume of flywheel energy storage battery is required , will cause problems such as increased floor space and difficulty in handling. Therefore, how to improve the universality of the application of flywheel energy storage batteries is also worthy of attention.

Contents of the invention

In view of the defects and improvement needs of the prior art, the present invention provides a compact flywheel energy storage battery to reduce the axial length of the flywheel energy storage battery shaft, improve the first-order critical speed and rotor stiffness, and make the overall structure of the flywheel battery It is compact and reduces the amount of materials used. There is an annular water channel at the annular winding motor to increase the heat dissipation efficiency. At the same time, the capacity of the energy storage battery can be changed by increasing or decreasing the number of hollow flywheel discs at the stepped shaft. In addition, the upper and lower end covers of the designed motor are flat, and multiple flywheel batteries can be axially stacked through flanges to form a flywheel energy storage battery with larger capacity and power, which improves the flexibility and universality of flywheel battery applications. At the same time, There is also the advantage of saving cost and floor space.

To achieve the above object, in the first aspect, the present invention provides a compact flywheel energy storage battery, comprising:

An energy storage flywheel, the energy storage flywheel is formed by stacking N hollow flywheel discs on the flywheel shaft, N≥1;

An upper end cover and a lower end cover respectively arranged on the upper and lower sides of the energy storage flywheel;

The casing is fixed between the upper end cover and the lower end cover, and forms a vacuum chamber with the upper end cover and the lower end cover;

The high-speed motor is arranged between the upper end cover and the energy storage flywheel, or between the energy storage flywheel and the lower end cover; the high-speed motor includes a motor stator fixing ring, a motor stator and a motor rotor arranged from outside to inside, and a The armature winding of the motor, the rotor permanent magnet attached or embedded in the motor rotor, and the motor rotor is fixed on the flywheel shaft, and the motor stator is fixed on the casing through the motor stator fixing ring;

Mechanical bearings for connecting the upper end cover, the flywheel shaft and the lower end cover;

The permanent magnetic bearing is placed between the upper end cover and the energy storage flywheel, installed on the upper end cover, and forms an air gap with the upper surface of the energy storage flywheel.

Further, the armature winding is a ring winding; the motor stator is slotted inside and outside, and the area of the outside slot is greater than or equal to the area of the inside slot, so that the armature winding can wrap around the motor stator.

Further, the flywheel shaft is stepped.

Further, an annular groove is formed on the surface of the hollow flywheel disc.

Further, the two ends of the flywheel rotating shaft are respectively connected to the upper end cover and the lower end cover through the mechanical bearings, and both ends of the flywheel rotating shaft and the mechanical bearings are embedded in the upper end cover and the lower end cover; the flywheel The rotating shaft and the motor rotor are connected by interference fit.

Further, the permanent magnetic bearing is "n" type, including: a permanent magnetic bearing iron yoke, an outer ferromagnetic ring, an inner ferromagnetic ring and a permanent magnetic ring; wherein, the permanent magnetic bearing iron yoke is installed on the upper end cover , the upper surface of the outer ferromagnetic ring is in contact with the iron yoke of the permanent magnetic bearing, the lower surface forms an air gap with the upper surface of the energy storage flywheel, and the upper surface of the inner ferromagnetic ring is in contact with the lower surface of the permanent magnetic ring , the lower surface forms an air gap with the upper surface of the energy storage flywheel, and the upper surface of the permanent magnet ring is in contact with the iron yoke of the permanent magnet bearing.

Further, an annular water channel is set in the motor stator fixing ring.

In the second aspect, the present invention also provides a compact flywheel energy storage battery pack, including several compact flywheel energy storage batteries as described in the first aspect; the upper end cover and the lower end cover of each compact flywheel energy storage battery Flanges are provided on the flat surface, elastic gaskets are placed between the flanges, and they are fixedly connected by connectors, so as to form the compact flywheel energy storage battery pack.

In the third aspect, the present invention also provides a compact flywheel energy storage battery, comprising:

One-piece flywheel rotor installed vertically;

an upper end cover and a lower end cover respectively arranged on the upper and lower sides of the flywheel rotor;

The casing is fixed between the upper end cover and the lower end cover, and forms a vacuum chamber with the upper end cover and the lower end cover;

The high-speed motor is arranged between the upper end cover and the flywheel rotor; the high-speed motor includes a motor stator and a motor rotor arranged from the outside to the inside, and an armature winding around the motor stator, and a permanent rotor attached to or embedded in the motor rotor. magnet, and the motor stator is fixed on the casing, and the motor rotor is fixed on the rotating shaft of the flywheel rotor;

mechanical bearings for connecting the upper end cover, the rotating shaft and the lower end cover;

The permanent magnetic bearing is placed between the upper end cover and the flywheel rotor, installed on the upper end cover, and forms an air gap with the upper surface of the flywheel rotor.

Further, the armature winding is a ring winding; the motor stator is slotted inside and outside, and the area of the outside slot is greater than or equal to the area of the inside slot, so that the armature winding can wrap around the motor stator.

Generally speaking, through the above technical solutions conceived by the present invention, the following beneficial effects can be obtained:

(1) The present invention reduces the overall axial length of the flywheel energy storage battery, especially the use of an annular winding motor, which greatly shortens the length of the end of the winding. For a 2-pole motor, the length of the end of the winding is greatly reduced, which can A motor with a lower number of poles is used to reduce the frequency of the motor, reduce loss, simplify control, and improve cooling efficiency. Then, through the reasonable selection and assembly of other components in the machine cavity, the overall axial length of the flywheel energy storage battery is further reduced, the first-order critical speed of the system and the stiffness of the rotor are improved, the overall structure of the flywheel energy storage battery is compact, and the material is reduced. usage.

(2) The flywheel rotor part of the flywheel energy storage battery designed by the present invention is formed by stacking at least one hollow flywheel disc on the stepped flywheel shaft, and is fixed by interference fit, which can be increased or decreased by increasing or decreasing the number of hollow flywheel discs To change the capacity of the flywheel energy storage battery, so that the capacity of a single flywheel energy storage battery can be changed flexibly.

(3) The flywheel energy storage battery designed by the present invention is provided with an annular water channel on the motor stator fixing ring, which can greatly improve the heat dissipation efficiency of the motor, solve the problem that the vacuum chamber is difficult to dissipate heat, and make the output power of the motor can be further improved. , The internal structure of the flywheel energy storage battery will not become complicated due to the addition of a circular water channel, and will not occupy the space of the machine cavity.

(4) The upper and lower end covers of the flywheel energy storage battery designed in the present invention are flat, and flanges can be installed on the upper and lower end covers, so that different flywheel energy storage batteries can be stacked axially to form larger capacity and higher power The flywheel energy storage battery pack improves the flexibility and universality of the application of the flywheel energy storage battery and reduces the occupied area.

(5) The "n" type permanent magnet bearing designed by the present invention can effectively ensure that the permanent magnets are concentric and reduce the eddy current loss of the motor as a whole.

(6) During the energy storage standby period and the charge and discharge period, the flywheel rotor can be subjected to axial electromagnetic force, so only a pair of mechanical bearings are required for positioning. The overall structure of the motor is simple and compact, which saves cost and is convenient for processing.

Description of drawings

Fig. 1 is a half-sectional view of a compact flywheel energy storage battery provided by an embodiment of the present invention;

Figure 2 is an enlarged view of the half-section of the high-speed motor in Figure 1;

Fig. 3 is an enlarged view of the half-section of the permanent magnetic bearing in Fig. 1;

Fig. 4 is a half-sectional view of axial stacking of a plurality of flywheel energy storage batteries shown in Fig. 1;

Fig. 5 is a half-sectional view of another compact flywheel energy storage battery provided by an embodiment of the present invention;

Throughout the drawings, the same reference numerals are used to designate the same elements or structures, wherein:

1-vacuum chamber, 2-hollow flywheel disc, 3-flywheel shaft, 401-upper end cover, 402-lower end cover, 5-casing, 6-high-speed motor, 601-motor stator fixing ring, 602-motor stator, 603 -Armature winding, 604-Motor rotor, 605-Rotor permanent magnet, 606-Annular water channel, 7-Flange, 8-Mechanical bearing, 9-Permanent magnetic bearing, 901-Permanent magnetic bearing iron yoke, 902-External ferromagnetic Ring, 903-inner ferromagnetic ring, 904-permanent magnetic ring, 10-elastic gasket, 11-connector, 12-flywheel rotor.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute a conflict with each other.

Referring to FIG. 1 and referring to FIG. 2 to FIG. 4 , the compact flywheel energy storage battery and the battery pack in this embodiment will be described in detail.

As shown in Figure 1, the present invention provides a compact modular flywheel energy storage battery, which adopts a vertical installation method and includes: a vacuum chamber 1, an energy storage flywheel, a flywheel shaft 3, an upper end cover 401, a lower end cover 402, and a Shell 5, high-speed motor 6, mechanical bearing 8, permanent magnetic bearing 9.

Specifically, the flywheel shaft 3 passes through the energy storage flywheel, the energy storage flywheel and the casing 5 are installed between the upper end cover 401 and the lower end cover 402, the high-speed motor 6 is placed between the energy storage flywheel and the lower end cover 402, and is sleeved on the flywheel shaft 3 The lower end, the upper end cover 401 and the lower end cover 402 are equipped with flange 7, and the permanent magnetic bearing 9 is placed between the upper end cover 401 and the energy storage flywheel, installed on the upper end cover 401, and forms an air gap with the upper surface of the energy storage flywheel. Wherein, the energy storage flywheel is formed by stacking N hollow flywheel discs 2 on the flywheel shaft 3, N≥1.

Further, the upper end cover 401 is made of non-ferromagnetic material, which reduces magnetic flux leakage from mechanical bearings and reduces losses.

Furthermore, the number of hollow flywheel discs 2 is greater than or equal to 1, and the flywheel energy storage battery with a larger capacity is stacked through the stepped flywheel shaft, and fixed by interference fit, leaving a certain distance from the casing 5 . It should be noted that when N≧2, the diameters of inner holes of the N hollow flywheel discs 2 are different.

Further, both ends of the flywheel shaft 3 are respectively connected to the upper end cover 401 and the lower end cover 402 through mechanical bearings 8 , and both ends of the flywheel shaft 3 and the mechanical bearings 8 are embedded in the upper end cover 401 and the lower end cover 402 .

Further, the high-speed motor 6 is located between the energy storage flywheel and the lower end cover 402, and is mounted on a stepped rotating shaft. It should be noted that the high-speed motor 6 can also be located between the energy storage flywheel and the upper end cover 401, and in practical engineering applications, an appropriate choice can be made according to the situation.

As shown in Figure 2, the high-speed motor 6 adopted in the present invention is a ring winding permanent magnet synchronous motor, including a motor stator fixed ring 601, a motor stator 602, an armature winding 603, a motor rotor 604, a rotor permanent magnet 605 and an annular water channel 606.

Further, the armature winding 603 is in the form of a ring winding, the motor stator 602 is slotted inside and outside, and the area of the outer slot is greater than or equal to the area of the inner slot, and the rotor permanent magnet 605 is built into the motor rotor 604, and the fixed ring of the motor stator Open annular channel 606 on 601, motor rotor 604 is fixedly connected to flywheel rotating shaft 3, motor stator 602 is connected to motor stator fixing ring 601, and motor stator fixing ring 601 is connected to casing 5, and high-speed motor 6 is flat as a whole.

Furthermore, the motor stator fixing ring 601 is made of non-ferromagnetic material, which reduces the magnetic flux leakage caused by the grooves on the outside of the motor stator 602 and reduces the loss.

Further, the flywheel shaft 3 is connected with the motor rotor 604 by interference fit.

As shown in FIG. 3 , the permanent magnetic bearing used in the present invention includes a permanent magnetic bearing iron yoke 901 , an outer magnetic ring 902 , an inner magnetic ring 903 and a permanent magnetic ring 904 .

Further, the permanent magnetic bearing 9 is installed on the upper end cover 401 to form an air gap with the upper surface of the energy storage flywheel, and a positive magnetic force along the Z axis is generated on the upper surface of the energy storage flywheel to realize mass unloading between the energy storage flywheel and the motor rotor.

Further, the permanent magnetic bearing 9 is in the shape of "n", wherein the permanent magnetic bearing iron yoke 901 is installed on the upper end cover 401, the upper surface of the outer ferromagnetic ring 902 is in contact with the permanent magnetic bearing iron yoke 901, and the lower surface is in contact with the energy storage flywheel An air gap is formed on the upper surface, the upper surface of the inner ferromagnetic ring 903 is in contact with the lower surface of the permanent magnet ring 904, the lower surface forms an air gap with the upper surface of the energy storage flywheel, and the upper surface of the permanent magnet ring 904 is in contact with the iron yoke 901 of the permanent magnet bearing.

As shown in FIG. 4 , when multiple flywheel energy storage batteries are axially stacked, elastic gaskets 10 and connectors 11 are required.

Furthermore, both the upper end cover 401 and the lower end cover 402 are provided with flanges 7, elastic gaskets 10 are placed between the flanges 7 of multiple compact flywheel energy storage batteries, and different flywheel batteries are axially stacked through connectors 11 , connected as a whole to form a flywheel energy storage battery pack with greater power and capacity.

As shown in Figure 5, it is another compact flywheel energy storage battery, which is suitable for the occasion of large energy storage, including a vacuum chamber 1, an upper end cover 401, a lower end cover 402, a casing 5, a high-speed motor 6, and a mechanical bearing 8 , permanent magnetic bearing 9, flywheel rotor 12.

Specifically, the flywheel rotor 12 is integrated, connecting the upper end cover 401 and the lower end cover 402, the permanent magnetic bearing 9 is placed between the upper end cover 401 and the flywheel rotor 12, installed on the upper end cover 401, and formed with the upper surface of the flywheel rotor 12 air gap.

Further, the upper end cover 401 is made of non-ferromagnetic material, which reduces magnetic flux leakage from mechanical bearings and reduces losses.

Further, both ends of the flywheel rotor 12 are respectively connected to the upper end cover 401 and the lower end cover 402 through the mechanical bearings 8 , and both ends of the flywheel rotor 12 and the mechanical bearings 8 are embedded in the upper end cover 401 and the lower end cover 402 .

Furthermore, the high-speed motor 6 is located between the flywheel rotor 12 and the upper end cover 401 . In one case, the high-speed motor 6 is similar in structure to the high-speed motor in FIG. The rotor permanent magnet 605 attached or embedded in the motor rotor 604 , and the motor rotor 604 is fixed on the rotating shaft of the flywheel rotor 12 , and the motor stator 602 is fixed on the casing 5 through the motor stator fixing ring 601 . In another case, when the outer diameter of the motor stator 602 is relatively large, the high-speed motor 6 may not need the motor stator fixing ring 601 , and the motor stator 602 may be directly installed on the casing 5 .

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, All should be included within the protection scope of the present invention.

Claims (5)

1. A compact flywheel energy storage battery, characterized in that it comprises: An energy storage flywheel, the energy storage flywheel is formed by stacking N hollow flywheel discs (2) on the flywheel shaft (3), N≥1; the surface of the hollow flywheel discs (2) is provided with an annular groove; An upper end cover (401) and a lower end cover (402) respectively arranged on the upper and lower sides of the energy storage flywheel; The casing (5) is fixed between the upper end cover (401) and the lower end cover (402), and forms a vacuum chamber with the upper end cover (401) and the lower end cover (402); The high-speed motor (6) is arranged between the upper end cover (401) and the energy storage flywheel, or between the energy storage flywheel and the lower end cover (402); the high-speed motor (6) includes a motor stator fixing ring arranged from outside to inside (601), the motor stator (602) and the motor rotor (604), and the armature winding (603) surrounding the motor stator (602), the rotor permanent magnet (605) that is attached or embedded in the motor rotor (604) , and the motor rotor (604) is fixed on the flywheel shaft (3), the motor stator (602) is fixed on the casing (5) through the motor stator fixing ring (601); the armature winding (603) is annular Windings; the inside and outside of the motor stator (602) are slotted, and the area of the outside slot is greater than or equal to the area of the inside slot, so that the armature winding (603) is wrapped around the motor stator (602); the motor The stator fixing ring (601) is made of non-ferromagnetic material, and an annular water channel (606) is set in the motor stator fixing ring (601); The mechanical bearing (8) is used to connect the upper end cover (401), the flywheel rotating shaft (3) and the lower end cover (402); The permanent magnetic bearing (9) is placed between the upper end cover (401) and the energy storage flywheel, installed on the upper end cover (401), and forms an air gap with the upper surface of the energy storage flywheel. 2. The compact flywheel energy storage battery according to claim 1, characterized in that, the flywheel shaft (3) is stepped. 3. The compact flywheel energy storage battery according to claim 2, characterized in that, the two ends of the flywheel shaft (3) are respectively connected to the upper end cover (401) and the lower end cover (402) through the mechanical bearing (8) connected, and both ends of the flywheel shaft (3) and the mechanical bearings (8) are embedded in the upper end cover (401) and the lower end cover (402); the flywheel shaft (3) and the motor rotor (604 ) are connected by interference fit. 4. The compact flywheel energy storage battery according to claim 1, characterized in that, the permanent magnetic bearing (9) is "n" type, comprising: a permanent magnetic bearing iron yoke (901), an outer ferromagnetic ring ( 902), inner ferromagnetic ring (903) and permanent magnetic ring (904); wherein, the permanent magnetic bearing iron yoke (901) is installed on the upper end cover (401), and the upper surface of the outer ferromagnetic ring (902) In contact with the permanent magnetic bearing iron yoke (901), the lower surface forms an air gap with the upper surface of the energy storage flywheel, and the upper surface of the inner ferromagnetic ring (903) contacts with the lower surface of the permanent magnetic ring (904) , the lower surface forms an air gap with the upper surface of the energy storage flywheel, and the upper surface of the permanent magnet ring (904) is in contact with the iron yoke of the permanent magnet bearing (901). 5. A compact flywheel energy storage battery pack is characterized in that it comprises several compact flywheel energy storage batteries as claimed in any one of claims 1 to 4; the upper end cover ( 401) and the lower end cover (402) are provided with flanges (7) on a flat surface, elastic gaskets (10) are placed between the flanges (7), and are fixedly connected by connectors (11), thereby forming the Compact flywheel energy storage battery pack.

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