A new type of underwater energy storage device support isolated power supply system

Abstract

The application relates to a novel isolated network power supply system supported by an underwater energy storage device, which comprises an underwater energy storage system, a photovoltaic power generation system, a wind power generation system, a load system and a control center system; the control center system is used for cooperatively controlling the underwater energy storage system, the photovoltaic power generation system and the wind power generation system according to load demand, and through direct power supply of the photovoltaic power generation system and the wind power generation system and switching of the charging and discharging mode of the underwater energy storage system, stable power supply of the load system is realized. The application provides a system for power supply under isolated network conditions supported by a novel underwater energy storage device, which can simultaneously generate power by a small wind turbine and photovoltaic power generation, and supply power for loads in the isolated network; when fluctuation occurs in the network, the energy storage system can play the roles of voltage stabilization and frequency regulation. Therefore, the application can be widely applied in the technical field of energy storage.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, specifically to a novel islanded power supply system supported by an underwater energy storage device. This islanded power supply system includes wind power, photovoltaic power, energy storage, and loads, and can be applied to renewable energy power supply scenarios where power is supplied independently under off-grid conditions. Background Technology

[0002] Offshore unmanned wellhead platforms have low power loads, but to maintain continuous production, it is necessary to ensure continuous and stable power supply for platform production, control, and communication. The conventional solution is to lay submarine cables to supply power from surrounding central platforms; however, laying submarine cables involves high investment and often affects project profitability. It can even lead to some marginal oil and gas fields being undevelopable due to low economic returns, resulting in low oilfield reserve utilization rates and difficulties in stabilizing and increasing production in oil and gas field clusters.

[0003] With advancements in offshore wind power, solar power, and energy storage technologies, a stable and continuous power supply can be achieved for a certain period by constructing an independent power supply system composed of wind, solar, and energy storage. This provides an independent power supply system for remote offshore wellhead platforms and onshore integrated industrial parks.

[0004] For underwater energy storage systems, heat dissipation is a major challenge that urgently needs to be addressed. Based on our independently developed underwater energy storage system, we have simplified the design of the external circulation cooling system for the battery cells by optimizing the thermal management system of conventional energy storage batteries and using external heat exchange pipes for indirect cooling. However, the external heat exchange pipes require an external water tank for cooling, and the large volume and space occupied by the tank limit the flexibility of the underwater energy storage system for use on offshore platforms and onshore industrial parks. Summary of the Invention

[0005] To address the heat dissipation problem of underwater energy storage systems, the present invention aims to provide an isolated grid power supply system supported by a compact and simple underwater energy storage device. By designing the structure of the underwater energy storage device and coordinating the control of wind, solar, and energy storage sources, this system can provide stable and long-term power supply in isolated grid scenarios, providing a new power supply mode for the development of onshore industrial parks and offshore low-load marginal oil fields.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A novel islanded power supply system supported by an underwater energy storage device includes: Underwater energy storage systems, photovoltaic power generation systems, wind power generation systems, load systems, and control center systems; The control center system is used to coordinate the control of the underwater energy storage system, photovoltaic power generation system, and wind power generation system according to the load demand. By directly supplying power to the photovoltaic power generation system and the wind power generation system, and switching the charging and discharging modes of the underwater energy storage system, the system can achieve a stable power supply to the load system.

[0008] Furthermore, the underwater energy storage system includes an underwater energy storage device, a through-cabin bundled cable, an open water tank, an annular water tank, a submersible pump, and an energy storage converter; The underwater energy storage device is installed in the open water tank and includes a steel pressure chamber, an energy storage device installed in the steel pressure chamber, and an annular wound heat exchange tube installed on the outer wall of the steel pressure chamber. The energy storage device is connected to the energy storage converter via a DC cable through a cabin bundle cable, and is connected to the control center system via a communication cable to realize charging and discharging control and status monitoring. The open water tank is connected to the annular water tank on both sides, and the water is continuously circulated by a submersible pump built into the annular water tank to ensure that the water can continuously provide a cold source. The energy storage device is cooled by the heat exchange tube.

[0009] Furthermore, a temperature sensor is installed inside the open water tank, and the temperature sensor is connected to the control center system via a communication cable to collect and upload the water temperature data of the open water tank.

[0010] Furthermore, the photovoltaic power generation system includes photovoltaic modules and a photovoltaic converter; The photovoltaic module is used to convert light energy into electrical energy; The photovoltaic converter is connected to the control center system via a communication cable and to the photovoltaic module via a DC cable. Under the control of the control center system, it converts the DC power output by the photovoltaic module into AC power to supply power to the load system.

[0011] Furthermore, the wind power generation system includes a wind turbine converter, a wind turbine, and a wind turbine controller; The wind turbine is used to convert wind energy into electrical energy; The fan controller is connected to the fan via an AC cable and is used to rectify and invert the AC power generated by the fan into DC power. The wind turbine converter is connected to the wind turbine controller via a DC cable and is used to invert the DC power output by the wind turbine controller into AC power to supply power to the load system. The wind turbine controller and wind turbine converter are connected to the control center system via communication cables.

[0012] Furthermore, the load system includes a power distribution cabinet, a lighting system, a communication system, and power equipment; One side of the distribution cabinet is connected to the energy storage system, photovoltaic power generation system, and wind power generation system via AC cables, and the other side is connected to the lighting system, communication system, and power equipment via AC cables, respectively, for supplying power to the lighting system, communication system, and power equipment.

[0013] Furthermore, the control center system includes an operator station and a switch; The operating station is connected to the switch via a communication cable. The switch is connected to the photovoltaic power generation system, the wind power generation system, and the underwater energy storage system via communication cables. The operating station controls the photovoltaic power generation, wind power generation, and energy storage charging and discharging processes, and monitors the status of the underwater energy storage system in real time.

[0014] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention achieves stable power supply to the load system by coordinating the control of the underwater energy storage system, photovoltaic power generation system, and wind power generation system, enabling direct power supply from the photovoltaic power generation system and wind power generation system, and switching of the charging and discharging modes of the underwater energy storage system. It can provide stable and continuous power supply to the load directly without relying on the power grid.

[0015] 2. This invention simplifies the heat exchange unit of conventional energy storage systems, allowing the energy storage system to be located in a water-protected environment, providing abundant natural cold sources and simplifying the system's internal cooling system.

[0016] 3. This invention couples an underwater energy storage system with wind and solar power generation, and enables the controlled charging and discharging of the energy storage system through a control station. When the energy storage system's charge drops to a certain limit, it can be automatically charged. When the system voltage and current decrease, it can be discharged to the outside at any time through the control station, ensuring that the isolated grid power supply system can continuously and stably supply power to the outside world.

[0017] Therefore, this invention can be widely applied in the field of energy storage technology. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a schematic diagram of an islanded power supply system supported by a novel underwater energy storage device provided in an embodiment of the present invention; The labels for the attached figures are as follows: 1. Underwater energy storage device; 2. Through-cabin bundled cable; 3. Open pool; 4. Circular water tank; 5. Submersible pump; 6. Temperature sensor; 7. Communication cable; 8. DC cable; 9. Energy storage converter; 10. Wind turbine converter; 11. Photovoltaic converter; 12. Photovoltaic module; 13. Small wind turbine; 14. Wind turbine controller; 15. Switch; 16. Operator station; 17. Distribution cabinet; 18. Lighting system; 19. Communication system; 20. Power equipment. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0020] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0021] In some embodiments of the present invention, a novel islanded power supply system supported by an underwater energy storage device is provided. This system includes: an energy storage system consisting of an underwater energy storage system, a ring-shaped water tank, an open water tank, a submersible pump, and an energy storage converter; a photovoltaic power generation system consisting of photovoltaic modules and a photovoltaic converter; a wind power generation system consisting of a small wind turbine, a wind turbine controller, and a wind turbine converter; a load system consisting of a distribution cabinet, a lighting system, a communication system, and power equipment; and a control center system consisting of a switch and an operator station. The present invention provides a system supported by a novel underwater energy storage device that can supply power under islanded conditions. It can simultaneously generate power from small wind turbines and photovoltaics to supply power to loads within the islanded grid. Furthermore, when power fluctuations occur within the grid, the energy storage system can play a role in voltage stabilization and frequency regulation.

[0022] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0023] Example 1 like Figure 1 As shown in the figure, this embodiment provides a novel islanded power supply system supported by an underwater energy storage device, which includes: an underwater energy storage system, a photovoltaic power generation system, a wind power generation system, a load system, and a control center system. The control center system is used to coordinate the control of the energy storage system, the photovoltaic power generation system, and the wind power generation system according to the power demand of the offshore platform. Stable power supply to the load system is achieved through direct power supply from the photovoltaic and wind power generation systems and switching of the charging and discharging modes of the energy storage system.

[0024] In a preferred embodiment, the underwater energy storage system includes an underwater energy storage device 1, a through-tank cable 2, an open water tank 3, an annular water tank 4, a submersible pump 5, a communication cable 7, a DC cable 8, and an energy storage converter 9. The underwater energy storage device 1 is housed within the open water tank 3 and includes a steel pressure chamber, an energy storage device housed within the steel pressure chamber, and an annular wound heat exchange tube mounted on the outer wall of the steel pressure chamber. The energy storage device is connected to the energy storage converter and the control center system via the through-tank cable 2, DC cable 8, and communication cable 7, respectively, to achieve charging / discharging control and status monitoring. The open water tank 3 is connected to the annular water tank 4 on both sides, and the submersible pump 5, built into the annular water tank 4, ensures continuous water circulation within the tank, guaranteeing a continuous supply of cooling water. The heat exchange tube cools the energy storage device.

[0025] In this embodiment, the heat dissipation of the battery cells and PCS system inside the energy storage device is entirely accomplished by the heat exchange pipes on the outer wall of the steel pressure chamber and external cooling water.

[0026] In a preferred embodiment, a temperature sensor 6 is installed inside the open water tank 3. The temperature sensor 6 is connected to the control center system via a communication cable and is used to collect and upload the water temperature data of the open water tank 3.

[0027] In a preferred embodiment, the photovoltaic power generation system includes a photovoltaic module 12 and a photovoltaic converter 11. The photovoltaic module 12 is installed at a predetermined location on the offshore platform and is used to convert light energy into electrical energy. The photovoltaic converter 11 is connected to the control center system and the photovoltaic module 12 via a communication cable 7 and a DC cable 8, respectively, and is used to convert the DC power output by the photovoltaic module 12 into AC power to supply power to the load system under the control of the control center system.

[0028] In a preferred embodiment, the wind power generation system includes a wind turbine converter 10, a small wind turbine 13, and a wind turbine controller 14. The small wind turbine 13 is installed at a predetermined location on the offshore platform and is used to convert wind energy into electrical energy. The wind turbine controller 14 is connected to the small wind turbine 13 via an AC cable and is used to rectify and invert the AC power generated by the small wind turbine 13 into DC power. The wind turbine converter 10 is connected to the wind turbine controller 14 via a DC cable 8 and is used to invert the DC power output by the wind turbine controller into AC power to supply power to the load system. The wind turbine controller 14 and the wind turbine converter 10 are connected to a control center system via a communication cable.

[0029] In a preferred embodiment, the load system includes a power distribution cabinet 17, a lighting system 18, a communication system 19, and a power equipment 20. The power distribution cabinet 17 is connected on one side to an energy storage system, a photovoltaic power generation system, and a wind power generation system via AC cables, and on the other side to the lighting system 18, the communication system 19, and the power equipment 20 via AC cables, supplying power to these systems.

[0030] In a preferred embodiment, the control center system includes an operator station 16 and a switch 15. The operator station 15 is connected to the switch 15 via a communication cable 7. The switch 15 is connected to the photovoltaic converter 11, the wind turbine converter 10, the energy storage converter 9, and the underwater energy storage device 1 via the communication cable 7. The operator station 16 regulates the photovoltaic power generation, wind power generation, and energy storage charging and discharging processes, and simultaneously monitors the status of the underwater energy storage device 1 in real time.

[0031] The workflow of this invention is as follows: The AC power generated by the small fan 13 is first rectified and inverted into DC power by the fan controller 14, and then inverted into AC power by the fan converter 10 to power the load system; the DC power generated by the photovoltaic module 12 can be directly powered to the load system through the distribution cabinet 17 after passing through the photovoltaic converter 11. When the power generation of photovoltaic module 12 and / or small wind turbine 13 exceeds the load demand of distribution cabinet 17, lighting system 18 and communication system 19, the underwater energy storage device 1 can be automatically charged through the monitoring and control of operation station 16. When the photovoltaic module 12 and the small wind turbine 13 are not generating electricity or the power generation is too small to meet the load demand, the operation station 16 can automatically discharge the underwater energy storage device 1 to supplement the power supply capacity of the grid by feedback of voltage and current signals.

[0032] When the underwater energy storage device 1 is continuously charging or discharging, the submersible pump 5 can be started by the control command of the operation station 16 to form an annular flowing cooling water environment in the annular water tank 4 and the open water tank 3, providing a cold source for the external heat exchanger of the underwater energy storage device 1. When the operating station 16 identifies that the underwater energy storage device 1 has a low power level through the internal monitoring signal of the energy storage system, it can charge the energy storage system with the electricity generated by the photovoltaic module 12 and the small wind turbine 13. When the power level reaches the upper limit of the battery, the charging can be stopped. When the power consumption of the lighting system 18, communication system 19 and power equipment 20 fluctuates, causing the voltage and current of the isolated grid system to become unstable, the underwater energy storage device 1 can be activated at any time to regulate the voltage and frequency of the isolated grid system in a short period of time. When the temperature sensor 6 and the thermal management system inside the underwater energy storage device 1 detect a rapid rise in temperature or a high temperature, the circulation speed of the water in the annular water tank can be adjusted by the submersible pump 5 to improve the heat dissipation capacity of the energy storage system. If this operation still fails to lower the water temperature, external cold fluid can be introduced into the annular water tank through the external interface on the open water tank 3 to lower the water temperature in the tank.

[0033] When the power equipment 20 operates intermittently or starts and stops frequently, the underwater energy storage device 1 can be activated to discharge to the islanded grid, thereby enhancing the islanded grid system's adaptability to load fluctuations.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A novel islanded power supply system supported by an underwater energy storage device, characterized in that, include: Underwater energy storage systems, photovoltaic power generation systems, wind power generation systems, load systems, and control center systems; The control center system is used to coordinate the control of the underwater energy storage system, photovoltaic power generation system, and wind power generation system according to the load demand. By directly supplying power to the photovoltaic power generation system and the wind power generation system, and switching the charging and discharging modes of the underwater energy storage system, the system can achieve a stable power supply to the load system.

2. The islanded power supply system supported by a novel underwater energy storage device as described in claim 1, characterized in that, The underwater energy storage system includes an underwater energy storage device, a hull-through bundled cable, an open water tank, an annular water tank, a submersible pump, and an energy storage converter. The underwater energy storage device is installed in the open water tank and includes a steel pressure chamber, an energy storage device installed in the steel pressure chamber, and an annular wound heat exchange tube installed on the outer wall of the steel pressure chamber. The energy storage device is connected to the energy storage converter via a DC cable through a cabin bundle cable, and is connected to the control center system via a communication cable to realize charging and discharging control and status monitoring. The open water tank is connected to the annular water tank on both sides, and the water is continuously circulated by a submersible pump built into the annular water tank to ensure that the water can continuously provide a cold source. The energy storage device is cooled by the heat exchange tube.

3. The islanded power supply system supported by a novel underwater energy storage device as described in claim 2, characterized in that, A temperature sensor is installed inside the open water tank. The temperature sensor is connected to the control center system via a communication cable to collect and upload the water temperature data of the open water tank.

4. The islanded power supply system supported by a novel underwater energy storage device as described in claim 1, characterized in that, The photovoltaic power generation system includes photovoltaic modules and a photovoltaic converter; The photovoltaic module is used to convert light energy into electrical energy; The photovoltaic converter is connected to the control center system via a communication cable and to the photovoltaic module via a DC cable. Under the control of the control center system, it converts the DC power output by the photovoltaic module into AC power to supply power to the load system.

5. The islanded power supply system supported by a novel underwater energy storage device as described in claim 1, characterized in that, The wind power generation system includes a wind turbine converter, a wind turbine, and a wind turbine controller; The wind turbine is used to convert wind energy into electrical energy; The fan controller is connected to the fan via an AC cable and is used to rectify and invert the AC power generated by the fan into DC power. The wind turbine converter is connected to the wind turbine controller via a DC cable and is used to invert the DC power output by the wind turbine controller into AC power to supply power to the load system. The wind turbine controller and wind turbine converter are connected to the control center system via communication cables.

6. The islanded power supply system supported by a novel underwater energy storage device as described in claim 1, characterized in that, The load system includes a power distribution cabinet, a lighting system, a communication system, and power equipment; One side of the distribution cabinet is connected to the energy storage system, photovoltaic power generation system, and wind power generation system via AC cables, and the other side is connected to the lighting system, communication system, and power equipment via AC cables, respectively, for supplying power to the lighting system, communication system, and power equipment.

7. The islanded power supply system supported by a novel underwater energy storage device as described in claim 1, characterized in that, The control center system includes operator stations and switches; The operating station is connected to the switch via a communication cable. The switch is connected to the photovoltaic power generation system, the wind power generation system, and the underwater energy storage system via communication cables. The operating station controls the photovoltaic power generation, wind power generation, and energy storage charging and discharging processes, and monitors the status of the underwater energy storage system in real time.

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