Self-powered direct current cooling device and flywheel energy storage system

Abstract

The invention discloses a self-power-taking type direct-current cooling device, which comprises a power taking module connected with a three-phase winding of a motor of a flywheel energy storage system and used for obtaining alternating current through the three-phase winding; the rectifying and voltage-stabilizing module is used for converting the alternating current into direct current and outputting direct current voltage; the control module generates a driving signal based on the DC voltage; the heat dissipation module is started when receiving the driving signal so as to carry out air cooling on a heating part of the flywheel energy storage device; the output end of the electricity taking module is connected with the input end of the rectifying and voltage stabilizing module, the output end of the rectifying and voltage stabilizing module is connected with the control module, and the control module is connected with the heat dissipation module. Heat dissipation of the flywheel energy storage system does not depend on an external power grid any more, self-sufficiency of the cooling device is achieved through energy of the flywheel, the flywheel energy storage system is particularly suitable for extreme working conditions such as power grid faults, the cooling power utilization function of the system can still be maintained, and therefore the reliability and independence of the flywheel energy storage system under the abnormal working condition are improved.

Description

Technical Field

[0001] This application relates to the field of power transmission and distribution technology, and in particular to a self-powered DC cooling device and a flywheel energy storage system. Background Technology

[0002] Existing flywheel energy storage devices all rely on grid power for cooling. However, during grid failures, such as power outages or voltage drops, the cooling system stops operating. This shutdown leads to continuous heat generation from the motor / generator (permanent magnet synchronous motor), magnetic bearings, and power converter as the flywheel continues to rotate. This can cause irreversible damage, including demagnetization of permanent magnets, carbonization of bearing lubricating oil, and burnout of the IGBT module in the converter. The braking resistor also consumes energy for heat dissipation. To mitigate the risk of power outages, some solutions incorporate UPS systems, but these require additional investment in batteries, charging modules, and monitoring devices, resulting in higher costs. Furthermore, UPS systems themselves suffer from short battery life and frequent maintenance. In addition, traditional cooling solutions have fixed power outputs and cannot dynamically adjust to flywheel speed (heat load). Additionally, insufficient heat dissipation may occur during high-speed flywheel operation, leading to continued grid power consumption during low-speed standby and wasted standby energy.

[0003] In summary, existing DC cooling devices suffer from unstable power supply and high cost. Summary of the Invention

[0004] This disclosure provides a self-powered DC cooling device and a flywheel energy storage system to at least solve the above-mentioned technical problems existing in the prior art.

[0005] According to a first aspect of this application, a self-powered DC cooling device is provided, comprising: The power acquisition module is connected to the three-phase windings of the motor in the flywheel energy storage system, and obtains AC power through the three-phase windings; A rectifier and voltage regulator module is used to convert the AC power into DC power and output DC voltage; The control module is used to generate a drive signal based on the DC voltage; The heat dissipation module is activated upon receiving a drive signal to cool the heat-generating components of the flywheel energy storage device using air cooling. The output terminal of the power supply module is connected to the input terminal of the rectifier and voltage regulator module, the output terminal of the rectifier and voltage regulator module is connected to the control module, and the control module is connected to the heat dissipation module.

[0006] In one possible implementation, the rectifier and voltage regulator module includes: A three-phase rectifier bridge receives AC power from the power supply module and converts the AC power into pulsating DC power. A DC / DC voltage regulator circuit is used to convert the pulsating DC power into a DC voltage with a preset voltage value. The input terminal of the three-phase rectifier bridge is connected to the output terminal of the power supply module, and the output terminal of the three-phase rectifier bridge is connected to the input terminal of the DC / DC voltage regulator circuit.

[0007] In one embodiment, an energy storage capacitor is connected in parallel to the DC output terminal of the three-phase rectifier bridge.

[0008] In one embodiment, the DC / DC regulator circuit includes: The system comprises a voltage divider resistor, a PWM control chip, a switching transistor, and a transformer; the voltage divider resistor is connected to the feedback terminal of the PWM control chip; the output terminal of the PWM control chip is connected to the gate of the switching transistor, and the collector of the switching transistor is connected to the input terminal of the transformer.

[0009] In one embodiment, the control module includes: a voltage detection circuit, a comparison circuit, and a logic circuit. The output terminal of the voltage detection circuit is connected to the first input terminal of the comparison circuit, the second input terminal of the comparison circuit is provided with a voltage threshold, and the output terminal of the comparison circuit is connected to the input terminal of the logic circuit. The voltage detection circuit is used to detect the DC voltage value output by the rectifier and voltage regulator module; The comparison circuit is used to compare the DC voltage value with a voltage threshold, and outputs a logic signal when the DC voltage value reaches the voltage threshold. A logic circuit for generating a drive signal based on the logic signal.

[0010] In one embodiment, the DC / DC regulator circuit further includes: An isolation circuit is provided, wherein the input terminal of the isolation circuit is connected to the output terminal of the PWM control chip, and the output terminal of the isolation circuit is connected to the input terminal of the transformer.

[0011] In one embodiment, the DC / DC regulator circuit is any one of a Buck voltage converter, a Boost voltage converter, or a Buck-Boost voltage converter.

[0012] In one embodiment, the heat dissipation module uses a DC cooling fan.

[0013] In one embodiment, the heating element includes any one or more of the following components: Electric motors / generators, magnetic bearings, power converters, and braking resistors.

[0014] According to a second aspect of this application, a flywheel energy storage system is provided, comprising: the self-powered DC cooling device described in any of the above embodiments.

[0015] The technical solution of this application enables the flywheel energy storage system to no longer rely on the external power grid for heat dissipation. It can achieve self-sufficiency of the cooling device by utilizing the flywheel's own energy, which is especially suitable for extreme conditions such as grid failures. It can still maintain the system's cooling power consumption function, thereby improving the reliability and independence of the flywheel energy storage system under abnormal conditions.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this application, nor is it intended to limit the scope of this application. Other features of this application will become readily apparent from the following description. Attached Figure Description

[0017] The above and other objects, features, and advantages of exemplary embodiments of this application will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of this application are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0018] Figure 1 A schematic diagram of the structure of the self-powered DC cooling device in an embodiment of this application is shown; Figure 2 A schematic diagram of the structure of an existing flywheel energy storage system is shown in an embodiment of this application; Figure 3 A block diagram illustrating the implementation of the rectifier and voltage regulator module in an embodiment of this application is shown. Detailed Implementation

[0019] To make the objectives, features, and advantages of this application more apparent and understandable, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the following description, the terms "first" and "second" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0022] The self-powered DC cooling device and flywheel energy storage system provided in this application are described below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, this application provides a self-powered DC cooling device, comprising: The power acquisition module is connected to the three-phase windings of the motor in the flywheel energy storage system, and obtains AC power through the three-phase windings; A rectifier and voltage regulator module is used to convert the AC power into DC power and output DC voltage; The control module is used to generate a drive signal based on the DC voltage; The heat dissipation module is activated upon receiving a drive signal to cool the heat-generating components of the flywheel energy storage device using air cooling. The output terminal of the power supply module is connected to the input terminal of the rectifier and voltage regulator module, the output terminal of the rectifier and voltage regulator module is connected to the control module, and the control module is connected to the heat dissipation module.

[0024] In this application, such as Figure 2 The diagram shows an existing method of powering the cooling devices of a flywheel system via the power grid. In this application, however, power is drawn from the motor of the energy storage flywheel, bypassing the power grid. The motor of the energy storage flywheel can be an electric motor or a generator. The power extraction module can directly draw power from the three-phase windings of the motor / generator of the flywheel energy storage unit. A rectifier and voltage regulator module is connected to the power extraction port to convert the AC power generated by the motor into stable DC power. The control module can generate a drive signal based on the DC voltage. The heat dissipation module, acting as a load, can be a DC cooling fan, with its input connected to the DC output of the rectifier and voltage regulator module. The heat-generating components can be the electric motor / generator, magnetic bearings, power converters, and braking resistors. In this application, the airflow of the DC cooling fan is directed to the components requiring cooling, such as the flywheel motor / generator, magnetic bearings, power converters, and braking resistors.

[0025] The self-powered DC cooling device provided in this application can still maintain the system's cooling power supply function under extreme conditions such as power grid failures. Utilizing the kinetic energy stored in the flywheel to generate electricity for self-use reduces the auxiliary power drawn from the grid, lowers system operating costs, and achieves green energy saving. It eliminates the need for a complex UPS to power the cooling system, reducing system complexity and cost. Furthermore, this application, through efficient rectification and voltage regulation design, ensures that the self-powered DC cooling device receives stable power throughout the entire speed range from flywheel start-up to maximum speed.

[0026] In some embodiments, the rectifier and voltage regulator module includes: A three-phase rectifier bridge receives AC power from the power supply module and converts the AC power into pulsating DC power. A DC / DC voltage regulator circuit is used to convert the pulsating DC power into a DC voltage with a preset voltage value. The input terminal of the three-phase rectifier bridge is connected to the output terminal of the power supply module, and the output terminal of the three-phase rectifier bridge is connected to the input terminal of the DC / DC voltage regulator circuit.

[0027] In this application, the three-phase rectifier bridge converts AC power into pulsating DC power, and then the DC / DC voltage regulator circuit processes the unstable "pulsating DC power" from the previous stage into a stable DC voltage with a preset voltage value.

[0028] The DC / DC voltage regulator circuit is any one of a Buck voltage converter, a Boost voltage converter, or a Buck-Boost voltage converter.

[0029] In some embodiments, an energy storage capacitor is connected in parallel to the DC output terminal of the three-phase rectifier bridge.

[0030] In this application, a large-capacity capacitor is connected in parallel at the DC output terminal of the rectifier and voltage regulator module to smooth the voltage and provide short-term power support when the flywheel speed is extremely low.

[0031] In some embodiments, the DC / DC regulator circuit includes: The system comprises a voltage divider resistor, a PWM control chip, a switching transistor, and a transformer; the voltage divider resistor is connected to the feedback terminal of the PWM control chip; the output terminal of the PWM control chip is connected to the gate of the switching transistor, and the collector of the switching transistor is connected to the input terminal of the transformer.

[0032] In this application, the voltage divider resistor samples the output DC voltage and feeds it back to the PWM control chip. The PWM control chip adjusts the duty cycle of its output pulse based on the feedback voltage. The PWM signal drives the gate of the switching transistor, enabling it to turn on and off at high speed. The switching transistor chops the DC current into high-frequency AC current, which is then converted and isolated for transmission via a transformer. In this embodiment, the switching transistor is an insulated-gate bipolar transistor (IGBT), with its gate connected to the output terminal of the PWM control chip and its collector connected to one end of the primary winding of the transformer.

[0033] In some embodiments, the DC / DC regulator circuit further includes: An isolation circuit is provided, wherein the input terminal of the isolation circuit is connected to the output terminal of the PWM control chip, and the output terminal of the isolation circuit is connected to the input terminal of the transformer.

[0034] The isolation circuit in this application can provide electrical isolation, achieving electrical isolation between the PWM control chip and the transformer, and avoiding interference or common-mode noise between high and low voltage circuits.

[0035] In some embodiments, the control module includes: a voltage detection circuit, a comparison circuit, and a logic circuit. The output terminal of the voltage detection circuit is connected to the first input terminal of the comparison circuit, the second input terminal of the comparison circuit is provided with a voltage threshold, and the output terminal of the comparison circuit is connected to the input terminal of the logic circuit. The voltage detection circuit is used to detect the DC voltage value output by the rectifier and voltage regulator module; The comparison circuit is used to compare the DC voltage value with a voltage threshold, and outputs a logic signal when the DC voltage value reaches the voltage threshold. A logic circuit for generating a drive signal based on the logic signal.

[0036] In this application, a voltage detection circuit is used to detect the DC voltage output by the rectifier and voltage regulator module to obtain the DC voltage value. The voltage detection circuit can be constructed from a high-precision resistor divider network. The inverting input of the voltage comparator is connected to the output voltage of the voltage detection circuit, and the non-inverting input of the voltage comparator is connected to a reference voltage source to provide the voltage threshold. This reference voltage can be generated by a precision Zener diode circuit or a dedicated reference voltage chip. When the output voltage is less than the reference voltage, it indicates that the DC voltage has not met the startup requirements, and the comparator outputs a low level; when the output voltage is greater than or equal to the reference voltage, it indicates that the DC voltage is sufficient, and the comparator output flips to a high level. The logic circuit generates a drive signal with sufficient driving capability and conforming to the interface requirements of the heat dissipation module based on the logic signal output by the comparator circuit.

[0037] In this application, the logic circuit can be a MOSFET driver or a simple transistor switching circuit. When the comparator output signal is high, the driver is activated, outputting a high-current drive signal to the heat dissipation module (such as a DC fan), and the fan starts. It is understood that, to eliminate frequent start-stop cycles caused by voltage fluctuations, the logic circuit can also integrate a simple hysteresis function, or add a delayed start circuit after the drive signal.

[0038] In one specific implementation, when the flywheel begins to rotate and the DC output voltage reaches the voltage threshold, the rectifier bridge outputs a voltage sufficient to start the DC / DC module. The self-powered DC cooling device then operates, outputting a stable 220V DC voltage to drive the fan and ensure its normal operation. When the flywheel decelerates and its speed falls below the operating voltage range of the DC-DC power module, the DC / DC module shuts down due to low input voltage, and the fan stops. At this point, since the heat generated by the flywheel has also been significantly reduced, forced air cooling is no longer necessary.

[0039] This application provides a flywheel energy storage system, including the self-powered DC cooling device described in any of the above embodiments.

[0040] The self-powered DC cooling device provided in this application can maintain the system's cooling power supply during power grid failures, achieving self-sufficiency in the heat dissipation system. The technical solution provided in this application offers advantages in four dimensions: reliability, economy, system optimization, and energy conservation. This application ensures that the flywheel body (especially key heat-generating components such as the motor, magnetic bearings, and braking resistors) will not be damaged due to overheating. For example, it prevents permanent magnet motor demagnetization, avoids bearing lubricant carbonization, brake resistor overheating damage, and fire, thus ensuring that the flywheel can be immediately put into operation after power grid restoration, greatly extending the system's lifespan.

[0041] In addition, this application transfers the power supply of the cooling system from the vulnerable external power grid to its own robust mechanical rotating system, removing a critical single point of failure and thus significantly improving the mean time between failures (MTBF) of the entire flywheel energy storage system.

[0042] The technical solution provided in this application eliminates the need for a separate uninterruptible power supply or redundant control power supply for the cooling fan. This saves on hardware costs such as UPS, batteries, and additional AC / DC power modules, and simplifies electrical wiring, thereby reducing system construction and hardware costs. Furthermore, in the flywheel standby state (keeping rotating to respond at any time), traditional solutions draw power from the grid, resulting in continuous standby losses. This solution, however, consumes the flywheel's own stored power, achieving "zero-cost" standby cooling and reducing the user's electricity expenses. This further reduces operating energy consumption and standby losses.

[0043] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit devices, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0044] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0045] In the context of this application, a machine-readable medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media can be, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0046] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device for displaying information to the user (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor); and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the computer. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0047] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as a data server), or computing systems that include middleware components (e.g., an application server), or computing systems that include frontend components (e.g., a user computer with a graphical user interface or web browser through which a user can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., a communication network). Examples of communication networks include local area networks (LANs), wide area networks (WANs), and the Internet.

[0048] Computer systems can include clients and servers. Clients and servers are generally located far apart and typically interact via communication networks. Client-server relationships are created by computer programs running on the respective computers and having a client-server relationship with each other. Servers can be cloud servers, servers in distributed systems, or servers incorporating blockchain technology.

[0049] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A self-powered DC cooling device, characterized by, The self-powered DC cooling device comprises: a power taking module connected to the three-phase winding of the motor of the flywheel energy storage system, and configured to obtain AC power through the three-phase winding; a rectification and voltage stabilization module configured to convert the AC power into DC power and output a DC voltage; a control module configured to generate a driving signal based on the DC voltage; a heat dissipation module configured to be started when receiving the driving signal, and configured to perform air cooling on the heat generating components of the flywheel energy storage device; an output end of the power taking module is connected to an input end of the rectification and voltage stabilization module, an output end of the rectification and voltage stabilization module is connected to the control module, and the control module is connected to the heat dissipation module.

2. The self-powered DC cooling device of claim 1, wherein, Therefore, the rectification and voltage stabilization module comprises: a three-phase rectification bridge configured to receive the AC power sent by the power taking module, and configured to convert the AC power into pulsating DC power; a DC / DC voltage stabilization circuit configured to convert the pulsating DC power into DC power with a preset voltage value; wherein, the input end of the three-phase rectification bridge is connected to the output end of the power taking module, and the output end of the three-phase rectification bridge is connected to the input end of the DC / DC voltage stabilization circuit.

3. The self-powered DC cooling device according to claim 2, wherein a DC output end of the three-phase rectification bridge is connected in parallel with an energy storage capacitor.

4. The self-powered DC cooling device of claim 2, wherein, The DC / DC voltage stabilization circuit comprises: a voltage dividing resistor, a PWM control chip, a switching tube and a transformer; the voltage dividing resistor is connected to the feedback end of the PWM control chip; the output end of the PWM control chip is connected to the gate of the switching tube, and the collector of the switching tube is connected to the input end of the transformer.

5. The self-powered DC cooling device of claim 1, wherein, The control module comprises: a voltage detection circuit, a comparison circuit and a logic circuit, the output end of the voltage detection circuit is connected to the first input end of the comparison circuit, the second input end of the comparison circuit is provided with a voltage threshold, and the output end of the comparison circuit is connected to the input end of the logic circuit; the voltage detection circuit is configured to detect the DC voltage value output by the rectification and voltage stabilization module; the comparison circuit is configured to compare the DC voltage value with the voltage threshold, and output a logic signal when the DC voltage value reaches the voltage threshold; the logic circuit is configured to generate a driving signal based on the logic signal.

6. The self-powered DC cooling device of claim 4, wherein, The DC / DC voltage stabilization circuit further comprises: an isolation circuit, the input end of the isolation circuit is connected to the output end of the PWM control chip, and the output end of the isolation circuit is connected to the input end of the transformer.

7. The self-powered DC cooling device according to claim 1, wherein the DC / DC voltage stabilization circuit is any one of a Buck type voltage converter, a Boost type voltage converter or a Buck-Boost type voltage converter.

8. The self-powered DC cooling device according to claim 1, wherein the heat dissipation module adopts a DC cooling fan.

9. The self-powered DC cooling device of claim 2, wherein, The heat generating components include any one or more of the following components: a motor / generator, a magnetic bearing, a power converter and a braking resistor.

10. A flywheel energy storage system characterized by, The self-powered DC cooling device according to any one of claims 1-9.

Images