CN101917087B - Magnetic suspension flywheel energy storage device adopting suspension/energy storage integrated flywheel - Google Patents

Abstract

A magnetic suspension flywheel energy storage device adopting a suspension/energy storage integrated flywheel comprises a shell, a permanent magnet type radial magnetic suspension bearing A stator and a permanent magnet type radial magnetic suspension bearing B stator which are respectively positioned at the bottom and the top of the shell, an electromagnetic permanent magnet mixed type axial magnetic suspension bearing stator and an electric/power generator stator which are arranged on the inner wall of the shell, and a permanent magnet type radial magnetic suspension bearing B rotor, an electric/power generator rotor, a suspension/energy storage integrated flywheel A, a suspension/energy storage integrated flywheel B and a permanent magnet type radial magnetic suspension bearing A rotor which are arranged on a main shaft from top to bottom; the suspension/energy storage integrated flywheel B is positioned between the permanent magnet type radial magnetic suspension bearing A stator and the electromagnetic permanent magnet mixed type axial magnetic suspension bearing stator, and the suspension/energy storage integrated flywheel A is arranged between the motor/generator stator and the electromagnetic permanent magnet mixed type axial magnetic suspension bearing stator. The invention has compact structure, small volume, light weight, high efficiency and high energy density.

Description

A magnetic levitation flywheel energy storage device using a suspension/energy storage integrated flywheel

technical field

The invention relates to a flywheel energy storage technology in electric energy storage technology, in particular to a magnetic levitation flywheel energy storage device adopting a suspension/energy storage integrated flywheel.

Background technique

The storage of electric energy can be divided into four types according to specific methods: electrochemical energy storage, electromagnetic energy storage, phase change energy storage and physical energy storage. Among them, electrochemical energy storage includes lead-acid battery energy storage, nickel-hydrogen battery energy storage, nickel-cadmium battery energy storage, lithium-ion battery energy storage, sodium-sulfur battery energy storage and flow battery energy storage, electromagnetic energy storage includes superconducting energy storage and supercapacitor energy storage, phase change energy storage includes ice cold storage energy storage, etc., physical energy storage includes pumped water energy storage, compressed air energy storage and flywheel energy storage.

Electrochemical energy storage devices refer to a type of device that converts the chemical energy of positive and negative active materials into electrical energy through electrochemical reactions. Electrochemical energy storage devices are cheap and mature in technology, but they have serious pollution, low efficiency, short service life, and difficult to control electric energy during use.

The superconducting energy storage in the electromagnetic energy storage converts electrical energy into magnetic energy and stores it in the magnetic field of the superconducting coil. Since the resistance of the superconducting coil is zero, the superconducting energy storage efficiency is relatively high and the pollution to the environment is relatively small, but Compared with other energy storage methods, the price of the superconducting material itself is relatively expensive, and the energy consumed and the cost required to maintain the low temperature are also considerable. A supercapacitor refers to a capacitor with a storage capacity 20 to 1000 times that of an ordinary capacitor. It uses a porous electrolyte to increase the area of the bipolar plates, thereby improving the energy storage capacity. The supercapacitor has the advantages of high energy density, fast charge and discharge speed, and long life. The disadvantage is that if it is used improperly, it will cause electrolyte leakage. At the same time, compared with aluminum electrolytic capacitors, their internal resistance is relatively large, so they cannot be used in AC circuits.

Phase change energy storage is the performance of using phase change materials to store heat in the form of latent heat in itself or release it to the environment during the phase change process, and convert electrical energy into thermal energy for storage. Therefore, a relatively large disadvantage of phase change energy storage is the conversion The efficiency is relatively low.

The pumped energy storage in the physical energy storage uses the power of the power grid when the power grid is rich to pump water to the upstream reservoir for energy storage, and opens the gate to the downstream to generate power when the power is in short supply. The release time of the pumped energy storage can range from several hours to a few days, and the overall efficiency is 70%. ~85%. Compressed air energy storage refers to the storage of a large amount of renewable energy by compressing air under high pressure, and then storing it in large underground caverns, depleted wells or aquifers. When discharging, the compressed air is released and By driving a turbine to generate electricity, a strand of energy can be stored for hundreds of hours. The disadvantage of compressed air energy storage is that the energy density is low and it is limited by the storage conditions of compressed air. The principle of flywheel energy storage is to accelerate the rotation of the flywheel disc through the motor, so that the electrical energy is converted into the rotational kinetic energy of the flywheel. When the power is supplied externally, the motor works in the generator state, and the energy storage flywheel drives the generator rotor to rotate to convert mechanical energy into electrical energy.

In summary, compared with other energy storage methods, the main advantages of flywheel energy storage are: (1) high energy storage density and high instantaneous power; (2) short charging time; (3) long service life; (4) High energy conversion efficiency, up to 85-95% per strand; (5) Insensitive to temperature, very friendly to the environment. Therefore, flywheel energy storage technology is considered to be the most promising and competitive energy storage technology at present, and has very broad application prospects.

In order to reduce mechanical friction, a magnetic suspension bearing is used in the flywheel energy storage device to suspend the rotor. According to whether the levitation force is controllable, magnetic suspension bearings can be divided into two types: passive type and active type. Passive magnetic bearings mainly use the inherent repulsion or attraction between magnetic materials (such as between permanent magnetic materials, between permanent magnetic materials and soft magnetic materials) to achieve the suspension of the rotating shaft. It has a simple structure and less power loss. The active magnetic suspension bearing mainly realizes the stable suspension of the rotating shaft by actively controlling the magnetic field force between the stator and the rotor. A complete active magnetic suspension bearing system usually consists of a magnetic suspension bearing body, a displacement sensor, a controller and a power amplifier. According to According to the different ways of establishing the bias magnetic field, the active magnetic bearing can be divided into the full electromagnetic type and the electromagnetic permanent magnetic hybrid type. Both the bias magnetic field and the control magnetic field of the all-electromagnetic magnetic suspension bearing are generated by electromagnets; the electromagnetic permanent magnetic hybrid magnetic suspension bearing uses permanent magnetic materials to establish the bias magnetic field, which can greatly reduce the power loss of the magnetic suspension bearing.

Generally speaking, the flywheel in the existing magnetic levitation flywheel energy storage device is only used to store electric energy, and the structure of the magnetic levitation bearing system is relatively complicated, and the energy loss and use cost are relatively high.

Contents of the invention

The object of the present invention is to provide a magnetic levitation flywheel energy storage device with compact structure, small volume, light weight, high efficiency and high energy density.

The magnetic levitation flywheel energy storage device of the present invention comprises a shell, a permanent magnet type radial magnetic levitation bearing A stator, a permanent magnet type radial magnetic levitation bearing B stator respectively located at the bottom and top of the shell, and an electromagnetic permanent magnetic hybrid type mounted on the inner wall of the shell Axial magnetic bearing stator and motor/generator stator, and permanent magnet type radial magnetic bearing B rotor, motor/generator rotor, suspension/energy storage integrated flywheel A, suspension/storage The flywheel B and the permanent magnet radial magnetic bearing A rotor can be integrated, and the two ends of the main shaft protrude from the casing respectively; the permanent magnet radial magnetic bearing A rotor is located in the permanent magnet radial magnetic bearing A stator, and the motor/generator The rotor is located in the stator of the motor/generator, the permanent magnet radial magnetic suspension bearing B rotor is located in the permanent magnetic radial magnetic suspension bearing B stator; the suspension/energy storage integrated flywheel B is located in the permanent magnetic radial magnetic suspension bearing A stator and the electromagnetic Between the permanent magnet hybrid axial magnetic suspension bearing stators, the suspension/energy storage integrated flywheel A is arranged between the motor/generator stator and the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing stator.

Between the outer end surface of the permanent magnet type radial magnetic suspension bearing A rotor and the inner end surface of the permanent magnet type radial magnetic suspension bearing A stator, the upper end surface of the suspension/energy storage integrated flywheel B and the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing under the stator Between the end faces, between the lower end face of the suspension/energy storage integrated flywheel A and the upper end face of the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator, between the outer end face of the motor/generator rotor and the inner end face of the motor/generator stator, permanent magnet There is an air gap between the outer end surface of the B-type radial magnetic bearing B rotor and the inner end surface of the permanent magnet radial magnetic bearing B stator as a storage medium for magnetic field energy, and the width of the air gap is preferably between 0.3 and 1.5 mm.

The permanent magnet type radial magnetic suspension bearing A stator and the permanent magnet type radial magnetic suspension bearing B stator are respectively embedded in the bottom and top of the casing, and their outer end surfaces are respectively located on the same plane as the bottom outer end surface and the top outer end surface of the casing. Correspondingly, the outer end surfaces of the permanent magnet type radial magnetic suspension bearing A rotor (11) and the permanent magnet type radial magnetic suspension bearing B rotor (6) are respectively located on the same plane as the bottom outer end surface and the top outer end surface of the casing (1) superior.

Based on the above structure, the magnetic levitation flywheel energy storage device of the present invention has the following advantages:

1. Use two permanent magnet type radial magnetic suspension bearings to realize the suspension of the rotor in four radial degrees of freedom, and use an electromagnetic permanent magnetic hybrid axial magnetic suspension bearing to realize the suspension of the rotor in the axial degree of freedom, which not only realizes the suspension of the rotor It also simplifies the structure of the magnetic suspension bearing system in the flywheel energy storage device, reduces the energy loss of the magnetic suspension bearing system, and improves the energy conversion efficiency of the flywheel energy storage device.

2. Using two suspension/energy storage integrated flywheels, the displacement control of the rotor and the storage of electric energy are combined into one, so that the structure of the flywheel energy storage device is simplified, the weight is reduced, the volume is reduced, and the energy density is increased.

Description of drawings

Figure 1 is a schematic plan view of the structure of a magnetic levitation flywheel energy storage device.

Label name in Fig. 1: 1, shell. 2. Permanent magnet type radial magnetic suspension bearing A stator. 3. Electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator. 4. Motor/generator stator. 5. Permanent magnet type radial magnetic suspension bearing B stator. 6. Permanent magnet type radial magnetic suspension bearing B rotor. 7. Spindle. 8. Motor/generator rotor. 9. Suspension/energy storage integrated flywheel A. 10. Suspension/energy storage integrated flywheel B. 11. Permanent magnet type radial magnetic bearing A rotor.

Detailed ways

As shown in Figure 1, the permanent magnet type radial magnetic suspension bearing A stator 2 of the present invention, the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator 3, the motor/generator stator 4, and the permanent magnet type radial magnetic suspension bearing B stator 5 are all It is set inside the shell 1, and its outer end faces are all in contact with the inner end faces of the shell 1. Among them, the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator 3 is located between the permanent magnetic radial magnetic suspension bearing A stator 2 and the motor/generator stator 4, and the motor/generator stator 4 is located in the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing Between the stator 3 and the permanent magnet type radial magnetic suspension bearing B stator 5. Permanent magnet radial magnetic suspension bearing B rotor 6, motor/generator rotor 8, suspension/energy storage integrated flywheel A9, suspension/energy storage integrated flywheel B10 and permanent magnet radial magnetic suspension bearing A rotor 11 are all set on the main shaft 7 outside, its inner end faces are in contact with the outer end faces of the main shaft 7. Among them, the rotor 11 of the permanent magnet type radial magnetic suspension bearing A is located in the shaft hole formed on the inner end surface of the stator 2 of the permanent magnet type radial magnetic suspension bearing A, and the outer end surface of the permanent magnet type radial magnetic suspension bearing A rotor 11 is in contact with the permanent magnet type radial magnetic suspension bearing A. There is a small air gap between the inner end faces of the stator 2 of the magnetic suspension bearing A; the integrated flywheel B10 of suspension/energy storage is located between the stator 2 of the permanent magnetic radial magnetic suspension bearing A and the stator 3 of the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing, and the suspension There is a small air gap between the upper end surface of the integrated flywheel B10 and the lower end surface of the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator 3; the integrated suspension/energy storage flywheel A9 is located type axial magnetic suspension bearing stator 3, and there is a small air gap between the lower end surface of the suspension/energy storage integrated flywheel A9 and the upper end surface of the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing stator 3; the motor/generator rotor 8 is located in the motor In the shaft hole formed by the inner end face of the generator stator 4, there is a small air gap between the outer end face of the motor/generator rotor 8 and the inner end face of the motor/generator stator 4; In the shaft hole formed on the inner end surface of the stator 5 of the magnetic type radial magnetic suspension bearing B, there is a small air gap between the outer end surface of the rotor 6 of the permanent magnetic type radial magnetic suspension bearing B and the inner end surface of the stator 5 of the permanent magnetic type radial magnetic suspension bearing B.

The present invention uses permanent magnet type radial magnetic suspension bearing A rotor 11 and permanent magnet type radial magnetic suspension bearing A stator 2, between permanent magnet type radial magnetic suspension bearing B rotor 6 and permanent magnet type radial magnetic suspension bearing B stator 5 The interaction of the rotor realizes the passive levitation of the rotor in the four degrees of freedom in the radial direction, using the electromagnetic permanent magnet hybrid axial magnetic bearing stator 3 and the suspension/energy storage integrated flywheel A9, and the suspension/energy storage integrated flywheel B10 The interaction realizes the active suspension of the axial degree of freedom of the rotor.

When charging, the present invention uses the interaction between the motor/generator stator 4 and the motor/generator rotor 8 to make the rotor rotate at a high speed, and converts the input electric energy into a suspension/energy storage integrated flywheel A9 and a suspension/energy storage integration Transform the rotational kinetic energy of the flywheel B10, and disconnect the external power supply after reaching the rated speed. When discharging, use the interaction between the motor/generator stator 4 and the motor/generator rotor 8 to convert the rotational kinetic energy of the suspension/energy storage integrated flywheel A9 and the suspension/energy storage integrated flywheel B10 into electrical energy for output to the external load .

Claims (4)

1. A magnetic levitation flywheel energy storage device using a suspension/energy storage integrated flywheel, characterized in that it includes a housing (1), permanent magnet radial magnetic bearing A stators (2) located at the bottom and top of the housing (1) respectively ), the permanent magnet type radial magnetic bearing B stator (5), the electromagnetic permanent magnetic hybrid axial magnetic bearing stator (3) and the motor/generator stator (4) installed on the inner wall of the shell (1), and the upper And the permanent magnet type radial magnetic suspension bearing B rotor (6), motor/generator rotor (8), suspension/energy storage integrated flywheel A (9), suspension/energy storage integration installed on the main shaft (7) The flywheel B (10) and the permanent magnet type radial magnetic suspension bearing A rotor (11), the two ends of the main shaft (7) protrude from the housing respectively; the permanent magnet type radial magnetic suspension bearing A rotor (11) is located in the permanent magnet type radial magnetic suspension In the bearing A stator (2), the motor/generator rotor (8) is located in the motor/generator stator (4), and the permanent magnet radial magnetic suspension bearing B rotor (6) is located in the permanent magnet radial magnetic suspension bearing B stator ( 5) inside; the suspension/energy storage integrated flywheel B (10) is located between the permanent magnet type radial magnetic suspension bearing A stator (2) and the electromagnetic permanent magnetic hybrid axial magnetic suspension bearing stator (3), and the suspension/energy storage is integrated The chemical flywheel A (9) is arranged between the motor/generator stator (4) and the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator (3). 2. The magnetic levitation flywheel energy storage device according to claim 1, characterized in that between the outer end surface of the permanent magnet radial magnetic levitation bearing A rotor (11) and the inner end surface of the permanent magnet radial magnetic levitation bearing A stator (2), Between the upper end surface of the suspension/energy storage integrated flywheel B (10) and the lower end surface of the electromagnetic permanent magnet hybrid axial magnetic suspension bearing stator (3), between the lower end surface of the suspension/energy storage integrated flywheel A (9) and the electromagnetic permanent magnet Between the upper end faces of the hybrid axial magnetic bearing stator (3), between the outer end face of the motor/generator rotor (8) and the inner end face of the motor/generator stator (4), permanent magnet radial magnetic bearing B rotor (6 ) There is an air gap between the outer end face of the permanent magnet type radial magnetic bearing B stator (5) and the inner end face. 3. The magnetic levitation flywheel energy storage device according to claim 2, characterized in that the width of the air gap is between 0.3 mm and 1.5 mm. 4. The magnetic levitation flywheel energy storage device according to claim 1, 2 or 3, characterized in that the permanent magnet radial magnetic levitation bearing A stator (2) and the permanent magnet radial magnetic levitation bearing B stator (5) are respectively embedded in the housing The bottom and top of (1), the outer end surfaces of which are respectively located on the same plane as the bottom outer end surface and the top outer end surface of the housing (1); The outer end surfaces of the rotor (6) of the radial magnetic suspension bearing B are also located on the same plane as the bottom outer end surface and the top outer end surface of the casing (1).

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