Flywheel energy storage system with electromagnetic coupler

An electromagnetic coupling, flywheel energy storage technology, applied in the field of flywheel energy storage system, can solve the problem of increasing the unbalanced power impact of the system

Pending Publication Date: 2022-03-29

STATE POWER INVESTMENT CORP RES INST

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AI-Extracted Technical Summary

Problems solved by technology

The connection of a high proportion of power electronic devices will cause the power grid to remain at a low inertia level for a long time, in...

Method used

Between the flywheel rotor 20 and the electromagnetic coupler 30, a fixed speed ratio speed change device 61 is set, the rotating speed of the generator rotor can be better adapted to the scope of application of the rotating speed of the electromagnetic coupler 30, and the burden of the electromagnetic coupler 30 is alleviated, That is, the setting of the speed change device can make the output speed of the flywheel rotor 20 change to the ideal range of the input speed of the electromagnetic coupler 30 (the mechanical speed of the inner rotor 32), so that the electromagnetic coupler 30 can better output a stable speed through rotor compensation. current.

By setting the variable speed ratio adjustable device 62 between the flywheel rotor 20 and the electromagnetic coupler 30, and adaptively adjusting the variable speed ratio of the variable speed ratio adjustable device 62 according to the current speed of the flywheel rotor 20, the flywheel rotor 20 can be The output speed of the electromagnetic coupler 30 is better transformed into the ideal range of the input speed of the electromagnetic coupler 30, further reducing the current regulation burden of the electromagnetic coupler 30, improving the applicability of the electromagnetic coupler 30, and expanding the speed range of the flywheel rotor 20.

Optionally, the flywheel energy storage system 1 can be connected with the power grid so as to participate in the grid inertia response, store the overflowed energy in the flywheel rotor 20 according to the overflow ratio or draw energy from the flywheel rotor 20 to supplement the power grid according to the missing ratio, and reduce the grid frequency fluctuation.

Optionally, the ideal interval of the input rotational speed of electromagnetic coupler 30 is (3000 ± 1000) rpm, by setting the speed change device with suitable gear ratio, the output rotational speed of flywheel rotor 20 can be changed to that of electromagnetic coupler 30 Enter the ideal range of the speed. When the input rotational speed of the electromagnetic coupler 30 (the rotational speed of the generator rotor) is in the range of (3000±1000) rpm, the electromagnetic coupler 30 can respond more quickly to the change of the mechanical rotational speed of the inner rotor 32 to keep the outer rotor 31 The mechanical speed is constant.

That is to say, speed change device is used to carry out speed regulation to the rotating speed of flywheel rotor 2...

Abstract

The invention provides a flywheel energy storage system with an electromagnetic coupler, which comprises a motor, a flywheel rotor, the electromagnetic coupler, a frequency converter and a generator, and is characterized in that the motor is connected with the flywheel rotor to drive the flywheel rotor to rotate, the electromagnetic coupler comprises an outer rotor and an inner rotor, and the outer rotor sleeves the inner rotor and is spaced from the inner rotor; the flywheel rotor is in transmission connection with the inner rotor, the inner rotor generates a rotating magnetic field to drive the outer rotor to rotate, and the frequency converter is connected with the outer rotor to change the current frequency of the outer rotor so as to change the magnetic field rotating speed matched with the current, so that the mechanical rotating speed of the outer rotor is kept constant. The generator generates power, accesses the power grid and inputs electric energy with stable frequency into the power grid, the requirement of power transmission to the power grid is met, power electronic devices are not needed, rotational inertia in the power grid can be improved, necessary voltage and frequency support is provided for the power grid, and the capacity of the power grid for efficiently accepting new energy is improved.

Application Domain

Electrical storage systemAc network load balancing +3

Technology Topic

Flywheel energy storage systemElectric generator +11

Image

Examples

Experimental program(3)

Example Embodiment

[0076] Example 1:

[0077] Such as figure 1 and figure 2 As shown, the flywheel energy storage system 1 of the present embodiment includes an electric motor 10, a flywheel 20, an electromagnetic coupler 30, a frequency converter 40, a generator 50, a first transfer shaft 71, a second drive shaft 72. The electromagnetic coupler 30 includes an inner rotor 32 and the outer rotor 31, and the inner rotor 32 is an input end of the electromagnetic coupler 30, and the outer rotor 31 is connected to the input end of the generator 50.

[0078] The motor 10 is located on one side of the flywheel rotor 20, and the first transport shaft 71 passes through the flywheel rotor 20 and transmits the flywheel rotor 20, and the transmission shaft 30 is transmitted to the output end of the motor 10. Connect, the other end of the first drive shaft 71 is connected to the inner rotor 32. One end of the second drive shaft 72 is connected to the outer rotor 31, and the other end of the second drive shaft 72 is connected to the input of the generator 50.

[0079] The flywheel energy storage system 1 of the present embodiment has a storage state, a release energy state, and a standby state, i.e., the working process of the flywheel energy storage system 1 has the energy storage phase, the release stage, and the standby phase.

[0080] In the storage phase, the generator 50 is idling, the motor 10 draws electric energy from the grid, and the output of the motor 10 drives the rotational speed of the flywheel rotor 20 by the first transport shaft 71, and the speed of the flywheel rotor 20 rises, that is, the electrical energy conversion to The kinetic energy is stored in the flywheel rotor 20. The speed of the flywheel rotor 20 rises until the set speed is reached. It will be appreciated that there is no energy output in the flywheel energy storage system 1 in the energy storage phase.

[0081] In the release stage, the motor 10 is standby, that is, the motor 10 does not input energy to the flywheel rotor 20, the flywheel rotor 20 releases the moving energy, and the flywheel rotor 20 drives the inner rotor 32 rotation, the outer rotor 31 rotates and passes through the second transmission. The shaft 72 drives the generator 50 to generate electricity, and the generator 50 inputs electric energy having a stable frequency through the transformer, and does not require the decoupling, rectification, frequency modulation, regulation of power electronics, and improve the rotation inertia in the grid. The voltage and frequency support reduces the risk of large frequency deviations in the grid, so that the power system can operate safely, and improve the power of the grid to efficiently accept new energy.

[0082] As an example, in the release stage, the generator 50 is connected to the network, its output current is 50 Hz. According to the difference between the rotational speed of the flywheel 20 and the ideal mechanical speed of the outer rotor 31, the current frequency transmitted to the outer rotor 31 is changed, and the magnetic field speed matching the outer rotor 31 current is adjusted. , Ultimately the mechanical speed R of the outer rotor 31 1 An ideal mechanical speed equal to the outer rotor 31. The mechanical speed of the outer rotor 31 is not maintained constant by the effect of the rotational speed of the rotor rotor 20, so that the generator 50 can transmit the power supply to the grid to achieve synchronous power generation.

[0083] In the standby phase, the motor 10 is standby, the generator 50 is idling. The flywheel rotor 20 loss is small for mechanical energy to maintain system no-load consumption.

Example Embodiment

[0084] Example 2:

[0085] Below image 3 Taking the flywheel energy storage system 1 of the present embodiment, the flywheel energy storage system 1 of the present embodiment includes an electric motor 10, a flywheel 20, an electromagnetic coupler 30, a frequency converter 40, a generator 50, and a speed ratio shifting device 61. The first transfer shaft 71, the second drive shaft 72, and the third transmitting shaft 73. The flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to the embodiment, and the difference portions are not described herein.

[0086] Such as image 3 As shown, the first transport shaft 31 passes through the flywheel rotor 20 and transmits one end of the flywheel shaft 31 and the output end of the motor 10, and the other end of the first drive shaft 3 and the fixed speed ratio shift speed. The input end of the device 61 is driven. One end of the second drive shaft 32 is connected to the output terminal of the fixed speed ratio shifting device 61, and the other end is connected to the inner rotor 32. The third drive shaft 73 is connected to the outer rotor 31 and the other end is connected to the input segment of the generator 50. The speed ratio fixed to the speed ratio shifting device 61 is fixed, which is the ratio of the input end speed and the output terminal rotation speed.

[0087] In the present embodiment, the rotational speed of the flywheel rotor 20 is equal to the rotational speed of the input end of the transmission ratio shifting device 61, and the rotational speed of the transmission ratio shifting device 61 is equal to the rotational speed of the inner rotor 32.

[0088] At the energy storage phase, the generator stator is disconnected from the grid. The electromagnetic coupler 30 is idling, and the motor 10 draws electric energy from the grid. The output of the motor 10 drives the rotational speed of the flywheel rotor 20 by the first drive shaft 31, and the flywheel rotor 20 The speed of the speed increased storage kinetic energy, that is, the electrical energy conversion into kinetic energy storage in the flywheel rotor 20. The speed of the flywheel rotor 20 rises until the set speed is reached. It will be appreciated that there is no energy output in the flywheel energy storage system 1 in the energy storage phase.

[0089] In the release stage, the motor 10 is standby, that is, the motor 10 does not input energy to the flywheel rotor 20, and the flywheel rotor 20 releases the moving energy, the flywheel rotor 20 drives the change speed ratio shifting device 61 to rotate, rotation inertia The output end of the shift ratio shifting device 61 is output, and the speed ratio of the transmission ratio of the transmission ratio shifting device 61 is related to the input end speed of the speed ratio shifting device 61 and the speed ratio shift ratio of the speed ratio shifting device 61. The output of 61 drives the inner rotor 32 by the second drive shaft 32, and the inner rotor 32 rotates the outer rotor 31 to rotate, and the outer rotor 31 drives the generator 50 to generate electricity through the third drive shaft 72.

[0090] A fixed speed ratio shifting device 61 is provided between the flywheel 20 and the electromagnetic coupler 30, and the rotational speed of the generator rotor can better accommodate the scope of the speed of the electromagnetic coupler 30, the burden of the electromagnetic coupler 30, that is, the transmission device The settings can make the output speed of the flywheel rotor 20 to the ideal area of the input rotational speed (the mechanical speed of the inner rotor 32) of the electromagnetic coupler 30, thereby making the electromagnetic coupler 30 better through the rotor to compensatest the output stable current.

[0091] Optionally, the ideal interval of the input speed of the electromagnetic coupler 30 is (3000 ± 1000) RPM, by providing a transmission device having a suitable variable speed, the output speed of the flywheel 20 can be changed to the input speed of the electromagnetic coupler 30. This ideal interval. When the input speed of the electromagnetic coupler 30 (the rotation speed of the generator rotor) is within the (3000 ± 1000) RPM range, the electromagnetic coupler 30 can respond faster to the mechanical rotational speed of the inner rotor 32 to maintain the outer rotor 31. The mechanical speed is constant.

[0092] Alternatively, the variable speed ratio of the transmission ratio shifting device 61 is 0.03-333.

[0093] Alternatively, the speed ratio shifting device 61 is a gear transmission, a liquid torque converter, a magnetic solenoid, a permanent magnet transmission, or a magnetic coupler transmission device having a shifting function.

Example Embodiment

[0094] Example 3:

[0095] Below Figure 4 Taking the flywheel energy storage system 1 of the present embodiment, the flywheel energy storage system 1 of the present embodiment includes an electric motor 10, a flywheel 20, an electromagnetic coupler 30, a frequency converter 40, a generator 50, a speed ratio adjustable device 62, The first transfer shaft 71, the second drive shaft 72, and the third transmitting shaft 73. The flywheel rotor 20, the motor 10, and the electromagnetic coupler 30 are similar to the embodiment, and the difference portions are not described herein.

[0096] Such as Figure 4 As shown, the first transport shaft 31 passes through the flywheel rotor 20 and transmits from the flywheel rotor 20, and one end of the first drive shaft 31 is connected to the output of the motor 10, and the other end of the first drive shaft 31 is adjustable. The input end of the device 62 is connected. One end of the second drive shaft 32 is connected to the output terminal of the shift ratio adjustment device 62, and the other end is connected to the inner rotor 32. The third drive shaft 73 is connected to the outer rotor 31 and the other end is connected to the input segment of the generator 50. The shift ratio of the shift ratio adjustable device 62 is adjustable, and the shift ratio of the shift ratio tunnel 62 is the ratio of the input end speed and the output terminal rotation speed.

[0097] Alternatively, the variable speed ratio adjustable device 62 can be a multi-stage transmission, i.e., the shift ratio tunnel 62 has a plurality of shift ratios, and can be switched according to the rotational speed of the flywheel 20. Alternatively, the variable speed ratio adjustment device 62 can be a stepless transmission, i.e., the shift ratio tunnel 62 can continuously adjust its variable speed ratio within a certain range.

[0098]Alternatively, the shift ratio tunnel 62 is a gear transmission, a liquid torque converter, a magnetic solenoid, a permanent magnet transmission, or a magnetic resolution device having a multi-stage or stepless shift function.

[0099] By providing a shift ratio tuning device 62 between the flywheel 20 and the electromagnetic coupler 30, the speed ratio adjustment device 62 is adapted according to the current speed of the flywheel 20, and the output speed of the flywheel rotor 20 can be made. Better transition to the ideal area of the input speed of the electromagnetic coupler 30, further reducing the current adjustment burden of the electromagnetic coupler 30, increasing the applicability of the electromagnetic coupler 30, and can also expand the rotational speed section of the flywheel rotor 20.

[0100] When the speed of the flywheel rotor 20 increases, the shift ratio of the shift ratio adjustment device 62 can increase, and when the rotational speed of the flywheel rotor 20 drops, the shift ratio of the speed ratio adjustment device 62 is reduced to make the shift ratio. The output of the adjustable device 62 holds within an ideal area of the input speed of the electromagnetic coupler 30, and the electromagnetic coupler 30 is quickly adjusted to output a constant frequency current to the grid.

PUM

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