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CN-122000853-A - Off-grid and grid-connected dual-purpose hydrogen-electricity hybrid energy storage system

CN122000853ACN 122000853 ACN122000853 ACN 122000853ACN-122000853-A

Abstract

The invention relates to the technical field of new energy, in particular to a hydrogen-electricity hybrid energy storage system for off-grid and grid connection, which comprises a DC-DC power supply controller, an electrolytic hydrogen production device, a lithium battery device, a logic control circuit and a renewable energy-based power generation device, wherein the DC-DC power supply controller is electrically connected with the power generation device through a direct current bus, the logic control circuit is electrically connected with the DC-DC power supply controller, the lithium battery device and the electrolytic hydrogen production device are connected with the logic control circuit, the lithium battery device is integrated with the energy storage and the electrolytic hydrogen production device, various switchable working modes are formed through the logic control circuit, a multi-path self-adaptive solution is provided for the fluctuation renewable energy, the problem of independent setting of the energy storage and the hydrogen production in the traditional scheme is solved, and the energy utilization degree of freedom and the efficiency of the off-grid system can be improved by adopting a serial coupling mode.

Inventors

  • TANG PENG
  • LIU YUQUN

Assignees

  • 奥科津创(苏州)氢能源科技有限公司

Dates

Publication Date
20260508
Application Date
20260209

Claims (10)

  1. 1. The off-grid and grid-connected dual-purpose hydrogen-electricity hybrid energy storage system is characterized by comprising a DC-DC power supply controller (600), an electrolytic hydrogen production device (200), a lithium battery device (300), a logic control circuit and a renewable energy source-based power generation device (100); The logic control circuit is electrically connected with the DC-DC power supply controller (600), and the lithium battery device (300) and the electrolytic hydrogen production device (200) are connected into the logic control circuit; The logic control circuit is configured to control the lithium battery device (300) to be electrically connected with the direct current bus via the DC-DC power controller (600) for charging or discharging based on the output power characteristic of the power generation device (100), or control the electrolytic hydrogen production device (200) to be electrically connected with the direct current bus via the DC-DC power controller (600) for electrolytic hydrogen production, or control the lithium battery device (300) and the electrolytic hydrogen production device (200) to be electrically connected with the direct current bus via the DC-DC power controller (600) in series after being commonly connected with each other.
  2. 2. The system according to claim 1, characterized in that the power generation device (100) is a distributed photovoltaic power generation device or the power generation device (100) is a wind power generation device.
  3. 3. The system of claim 1, wherein the logic control circuit comprises a first switching control mechanism (410) disposed between the lithium battery device (300) and the DC-DC power controller (600), a second switching control mechanism (420) disposed between the electrolytic hydrogen production device (200) and the DC-DC power controller (600), and a third switching control mechanism disposed between the lithium battery device (300) and the electrolytic hydrogen production device (200).
  4. 4. The system of claim 2, wherein the power generation device (100) is a distributed photovoltaic power generation device; the logic control circuit is configured to: when in a strong light level or a medium light level, and the light intensity is stable: Controlling the lithium battery device (300) to be connected in series with the electrolytic hydrogen production device (200) in the start-stop stage of the system, and being electrically connected with the direct current bus through the DC-DC power supply controller (600); After the system is started and stopped, controlling the lithium battery device (300) to be electrically connected with the direct current bus through the DC-DC power supply controller (600) to charge the lithium battery device (300), simultaneously releasing the series connection of the lithium battery device (300) and the electrolytic hydrogen production device (200), and releasing the electrical connection of the electrolytic hydrogen production device (200) and the DC-DC power supply controller; After the electric quantity of the lithium battery device (300) reaches a first preset electric quantity, controlling the lithium battery device (300) and the electrolytic hydrogen production device (200) to be connected in series, and jointly electrically connecting with the direct current bus through the DC-DC power supply controller (600); when the light intensity is in a strong light level and the fluctuation of the light intensity is large: Controlling the lithium battery device (300) to be connected in series with the electrolytic hydrogen production device (200) and electrically connected with the direct current bus through the DC-DC power supply controller (600); after the lithium battery device (300) reaches a second preset electric quantity, releasing the series connection between the lithium battery device (300) and the electrolytic hydrogen production device (200), and releasing the electric connection between the lithium battery device (300) and the DC-DC power supply controller (600), and simultaneously controlling the electrolytic hydrogen production device (200) to be electrically connected with the direct current bus through the DC-DC power supply controller (600) so as to produce hydrogen by electrolysis; when at a medium light level and the light intensity fluctuates downwards, or when the lithium battery device (300) is in a full state: only controlling the electrolytic hydrogen production device (200) to be electrically connected with the direct current bus through the DC-DC power controller (600) so as to carry out electrolytic hydrogen production; at low light level and at steady light intensity: -controlling only the lithium battery device (300) to be electrically connected with the direct current bus via the DC-DC power controller (600) to charge the lithium battery device (300); The real-time light intensity reaches 80% or more of the preset rated light intensity, the real-time light intensity reaches 50% to 80% of the preset rated light intensity, the real-time light intensity is defined as a medium light level, the real-time light intensity is lower than 50% of the preset rated light intensity, the light intensity is stably defined as that the change of current per second is not more than 5% of the current of the last second, the current is determined as light intensity fluctuation when any change of current per second exceeds 5% of the last time within thirty seconds of arbitrary work, and the current exceeding 1% is determined as light intensity fluctuation downwards.
  5. 5. The system of claim 4, wherein the logic control circuit further comprises a light intensity sensor for monitoring the intensity of the illumination.
  6. 6. The system of claim 4, wherein the first predetermined amount of power is 90% of the rated capacity of the lithium battery device (300).
  7. 7. The system of claim 4, wherein the second predetermined amount of power is 100% of the rated capacity of the lithium battery device (300).
  8. 8. The system of claim 1, further comprising a housing (500), wherein the DC-DC power controller (600), the lithium battery device (300), and the logic control circuit are disposed within the housing (500).
  9. 9. The system of claim 8, wherein the electrolytic hydrogen production device is fixedly disposed on an outer sidewall of the tank (500).
  10. 10. The system according to claim 8, characterized in that the front panel of the box (500) is provided with an openable and closable door.

Description

Off-grid and grid-connected dual-purpose hydrogen-electricity hybrid energy storage system Technical Field The invention relates to the technical field of new energy, in particular to a hydrogen-electricity hybrid energy storage system for off-grid and grid connection. Background With the promotion of the 'double carbon' target, distributed renewable energy sources represented by photovoltaic and wind power are widely applied. However, its power generation has significant intermittent, random and fluctuating characteristics. In off-grid or remote areas, the instability of these energy sources presents a serious challenge for reliable power supply. In the prior art, the common solution mainly comprises an off-grid lithium battery energy storage system and an independent water electrolysis hydrogen production system, but both have obvious technical limitations: First, off-grid lithium battery energy storage systems, although fast in response, are limited by cost and volumetric energy density, and typically provide only short-term energy storage in the order of several hours. Under the off-grid scene with severe photovoltaic fluctuation, the lithium battery needs to be charged and discharged frequently with high multiplying power to stabilize the power fluctuation, so that the capacity attenuation of the battery can be accelerated, the service life is shortened, and the safety risk of thermal runaway is high. Meanwhile, long-time energy storage can not be realized by simply relying on a lithium battery in a daytime and a season, so that a large amount of surplus photovoltaic power is wasted, and the overall energy utilization rate is low. Secondly, for an independent water electrolysis hydrogen production system, particularly a proton exchange membrane electrolytic tank with high response speed, the hydrogen production system is considered to be an effective way for absorbing surplus renewable energy sources and producing green hydrogen. However, proton exchange membrane cells have high requirements for stability of the input power. If the photovoltaic power supply with large fluctuation is directly coupled, the proton exchange membrane electrolytic cell can work under the power with severe fluctuation for a long time, even under the working conditions of frequent start and stop and low load. This can lead to repeated mechanical stress and thermal shock to the membrane electrode, accelerated aging, performance decay, and potential safety hazards of hydrogen-oxygen cross-channeling due to gas permeation exacerbation under low load. In addition, conventional hydrogen production schemes typically require a high pressure hydrogen storage tank and transportation facilities, with risk of hydrogen storage leakage and higher transportation costs in the user side or mobile application scenario. Furthermore, in the prior art, the scheme of simply and parallelly connecting or independently managing the photovoltaic battery, the lithium battery and the electrolytic tank is tried, and the problems of efficient energy flow cooperation and cooperative optimization of equipment service life are not fundamentally solved. If the fluctuating photovoltaic is firstly charged into the lithium battery through the rectifying equipment and then the lithium battery is discharged to drive the electrolytic tank, the efficiency loss of twice energy conversion exists. If the photovoltaic is directly connected to the cell, there is a lack of effective buffering of power fluctuations, compromising cell life. In summary, there is a need for an integrated energy solution that can achieve long-term energy storage, high energy density, ready-to-use, safe and reliable, and intelligent adaptation to renewable energy fluctuations, while taking into account the service lives of the energy storage element and the hydrogen production device. The prior art has not yet effectively integrated and addressed the above-mentioned multiple challenges. Therefore, the invention provides an innovative off-grid and grid-connected dual-purpose hydrogen-electricity hybrid energy storage system and a cooperative control strategy thereof. Disclosure of Invention The invention mainly aims to provide a hydrogen-electricity hybrid energy storage system for off-grid and grid connection, which can store energy for a long time, has high energy density, is instant in use, is safe and reliable, can intelligently adapt to renewable energy fluctuation, and simultaneously has the service lives of an energy storage element and hydrogen production equipment. In order to achieve the aim, the invention provides a hydrogen-electricity hybrid energy storage system, which comprises a DC-DC power supply controller, an electrolytic hydrogen production device, a lithium battery device, a logic control circuit and a power generation device based on renewable energy sources; The logic control circuit is electrically connected with the DC-DC power supply controller, and the lithium battery