700V direct current bus-based grid-connected and off-grid wind-light hydrogen storage coupling hydrogen production power supply system

Abstract

The utility model discloses a 700V direct current bus-based grid-connected and off-grid wind-light hydrogen storage coupling hydrogen production power supply system. The system comprises a photovoltaic power generation module, a wind power generation module, a hybrid energy storage module, a grid-connected module and a water electrolysis hydrogen production module. The photovoltaic power generation module and the wind power generation module are respectively connected to a 700V direct current bus through a DC / DC converter and an AC / DC rectifier, and power switch tubes in the DC / DC converter and the AC / DC rectifier all adopt SiC MOSFETs. When a power grid operates normally, if the electric energy supplied to the water electrolysis hydrogen production module by the wind and light power generation module is redundant, the redundant electric energy is stored in the hybrid energy storage module; and if the generating capacity of the wind power generation module and the photovoltaic power generation module is insufficient, the electric energy stored by the hybrid energy storage module is released to the water electrolysis hydrogen production module, so that efficient and stable operation of the water electrolysis hydrogen production module is ensured. When a power grid breaks down, the system operates in an off-network mode, and the wind and light power generation module and the hybrid energy storage module jointly provide electric energy needed by operation of the water electrolysis hydrogen production module.

Description

Technical Field

[0001] This utility model relates to the fields of new energy and water electrolysis for hydrogen production, specifically to a coupled wind-solar-hydrogen storage power supply system based on a 700V DC bus. Background Technology

[0002] Wind power, solar power, and other new energy power generation methods are gradually replacing traditional power generation methods. However, the disadvantages of new energy power generation are its intermittency and volatility, making it impossible to provide a continuous and stable power supply, leading to wind and solar power curtailment. Increasing energy storage capacity is one way to solve the problem of local consumption of new energy. Curtailed new energy power can be used to power water electrolysis hydrogen production plants. This measure can effectively improve the utilization rate of new energy, reduce the impact of new energy volatility on the power system, and facilitate the construction of a new power system.

[0003] Existing electrolyzers are classified into three categories based on the electrolyte used: PEM electrolyzers, solid oxide electrolyzers, and alkaline electrolyzers. The electrolyzer is a key component of the water electrolysis hydrogen production system and must be connected to a DC power supply. The power supply comes from photovoltaic power generation modules, transmitting DC power to the water electrolysis hydrogen production system. In this case, the coupling method is generally indirect coupling using a converter. Taking photovoltaic hydrogen production as an example, a DC / DC converter is used to provide power to the electrolysis equipment; if the power is provided by a wind turbine, an AC / DC converter is also needed to convert it to DC power.

[0004] However, existing wind-solar-hydrogen storage coupled hydrogen production power systems have the following drawbacks:

[0005] (1) AC bus is mostly used. Electrolysis hydrogen production modules and photovoltaic power generation modules output DC, and their coupling with AC bus is relatively complex, which reduces efficiency and increases cost.

[0006] (2) Most are off-grid systems. Off-grid systems are not directly connected to the power grid. Curtailed wind and solar power need to be converted into hydrogen energy and then into electricity by thermal power plants, resulting in low utilization rates of curtailed wind and solar power.

[0007] (3) Most of them use lithium batteries as energy storage components, which is a single form. Energy storage modules that only use lithium batteries have problems such as high upstream lithium prices and the cost will increase exponentially as the capacity of lithium batteries increases, and they cannot effectively compensate for instantaneous power fluctuations. Utility Model Content

[0008] The technical problem to be solved by this utility model is to provide a multi-condition off-grid hydrogen production power supply system based on a DC bus.

[0009] The specific technical solution adopted in this utility model is as follows:

[0010] A grid-connected and off-grid wind-solar-hydrogen-storage coupled hydrogen production power system based on a 700V DC bus includes a photovoltaic power generation module, a wind power generation module, a hybrid energy storage module, a water electrolysis hydrogen production module, a first DC / DC converter, a second DC / DC converter, a third DC / DC converter, an AC / DC rectifier, a grid-connected module, and a 700V DC bus.

[0011] The photovoltaic power generation module is unidirectionally connected to the 700V DC bus via the first DC / DC converter, the wind power generation module is unidirectionally connected to the 700V DC bus via the AC / DC rectifier, the hybrid energy storage module is bidirectionally connected to the 700V DC bus via the second DC / DC converter, the water electrolysis hydrogen production module is unidirectionally connected to the 700V DC bus via the third DC / DC converter, and the 700V DC bus is connected to the public power grid via the grid connection module.

[0012] The grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus has two working modes: grid-connected mode and off-grid mode.

[0013] The hybrid energy storage module has three operating modes: power transmission mode, power supply mode, and energy storage mode. The three operating modes switch according to the working conditions of the two operating modes.

[0014] Preferably, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is a power deficit in the public power grid, the photovoltaic power generation module is controlled to transmit first electrical energy to the 700V DC bus through the first DC / DC converter, and the wind power generation module is controlled to transmit second electrical energy to the 700V DC bus through the AC / DC rectifier. After the first electrical energy and the second electrical energy are combined on the 700V DC bus, they are sent to the public power grid through the grid-connected module.

[0015] Preferably, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is a power deficit in the public power grid, and the first and second electrical energy transmitted by the photovoltaic power generation module and the wind power generation module to the public power grid are still insufficient to meet the power deficit of the public power grid, then the hybrid energy storage module is switched to the power transmission mode, and power is transmitted to the public power grid through the hybrid energy storage module via the second DC / DC converter, the 700V DC bus, and the grid-connected module.

[0016] Preferably, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid, the photovoltaic power generation module is controlled to transmit a third electrical energy to the 700V DC bus through the first DC / DC converter, and the wind power generation module is controlled to transmit a fourth electrical energy to the 700V DC bus through the AC / DC rectifier. After the third and fourth electrical energy are combined on the 700V DC bus, they are used to supply power to the water electrolysis hydrogen production module through the third DC / DC converter.

[0017] Preferably, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid and the water electrolysis hydrogen production module is already operating at full power, the hybrid energy storage module is switched to the energy storage mode, and the remaining energy in the third and fourth electrical energy is transmitted to the hybrid energy storage module through the 700V DC bus and the second DC / DC converter.

[0018] Preferably, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid and the third and fourth electrical energy sources are insufficient to enable the water electrolysis hydrogen production module to operate at full power, then the hybrid energy storage module is switched to the power supply mode, and power is supplied to the water electrolysis hydrogen production module through the hybrid energy storage module via the second DC / DC converter, the 700V DC bus, and the third DC / DC converter.

[0019] Preferably, when the grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in off-grid mode, the grid-connected module is controlled to disconnect the connection between the 700V DC bus and the public power grid, and the hybrid energy storage module is switched to the power supply mode. On the one hand, it provides voltage support for the 700V DC bus, and on the other hand, it works with the photovoltaic power generation module and the wind power generation module to provide the power required for the operation of the water electrolysis hydrogen production module.

[0020] Preferably, the photovoltaic power generation module includes a photovoltaic panel, an equipment monitoring and protection device, an MPPT circuit, and a combiner device; the wind power generation module includes a wind turbine and an equipment monitoring and protection device.

[0021] Preferably, the hybrid energy storage module includes a liquid-cooled lithium iron phosphate battery cell, a supercapacitor, an energy management device, and an equipment monitoring and protection device.

[0022] Preferably, the water electrolysis hydrogen production module includes a water electrolysis hydrogen production device, a hydrogen purification device, and an equipment monitoring and protection device. The hydrogen produced by the water electrolysis hydrogen production module is collected, processed by the purification device, and then transported to the hydrogen storage device.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) The present invention provides a grid-connected or off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus, which can switch between grid-connected and off-grid working modes to achieve efficient hydrogen production under various working conditions.

[0025] (2) The 700V DC bus used in this system can reduce the energy conversion links of photovoltaic, hydrogen production and hybrid energy storage modules compared with the AC bus, thereby improving the energy utilization efficiency of the system.

[0026] (3) The hybrid energy storage module used in this system employs both liquid-cooled lithium iron phosphate batteries and supercapacitors. The lithium iron phosphate batteries can provide power continuously and stably, while the supercapacitors can compensate for instantaneous power fluctuations. This not only utilizes redundant power to ensure reliable system operation but also improves power quality and the system's surge protection capability.

[0027] (4) When there is a redundancy in the electrical energy supplied by the photovoltaic power generation module and the wind power generation module to the water electrolysis hydrogen production module, the redundant electrical energy is stored in the hybrid energy storage module. When the supply from the wind and solar power generation equipment is insufficient, the electrical energy stored in the hybrid energy storage module is released to the water electrolysis hydrogen production module to ensure the efficient and stable operation of the water electrolysis hydrogen production module.

[0028] (5) When a grid fault occurs, the connection with the grid can be cut off by the grid-connected module, and the voltage support of the DC bus can be provided by the hybrid energy storage module, which improves the power supply reliability of the entire system. Attached Figure Description

[0029] Figure 1 This is a general framework diagram of a 700V DC bus-based on-grid wind-solar-hydrogen-storage coupled hydrogen production power system.

[0030] The components include: 1. Photovoltaic power generation module; 2. Wind power generation module; 3. Hybrid energy storage module; 4. Electrolysis water hydrogen production module; 5. First DC / DC converter; 6. Second DC / DC converter; 7. Third DC / DC converter; 8. AC / DC rectifier; 9. Grid connection module. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description. It should be understood that terms such as "having," "comprising," and "including" as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0032] The techniques described below can be modified in various ways and have multiple embodiments, which are described in detail below with reference to the accompanying drawings. However, this does not mean that the techniques described below are limited to the specific embodiments. It should be understood that this utility model includes all similar modifications, equivalents, and substitutions without departing from the spirit and scope of the techniques described below.

[0033] This utility model provides a grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus, including a photovoltaic power generation module 1, a wind power generation module 2, a hybrid energy storage module 3, a water electrolysis hydrogen production module 4, a first DC / DC converter 5, a second DC / DC converter 6, a third DC / DC converter 7, an AC / DC rectifier 8, a grid-connected module 9, and a 700V DC bus;

[0034] The photovoltaic power generation module 1 is unidirectionally connected to the 700V DC bus via the first DC / DC converter 5; the wind power generation module 2 is unidirectionally connected to the 700V DC bus via the AC / DC rectifier 8; the hybrid energy storage module 3 is bidirectionally connected to the 700V DC bus via the second DC / DC converter 6; the water electrolysis hydrogen production module 4 is unidirectionally connected to the 700V DC bus via the third DC / DC converter 7; and the 700V DC bus is connected to the public power grid via the grid connection module 9.

[0035] The grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus has two working modes: grid-connected mode and off-grid mode.

[0036] The hybrid energy storage module 3 has three operating modes: power transmission mode, power supply mode, and energy storage mode, and the three operating modes switch according to the working status of the two working modes.

[0037] In this system, the photovoltaic DC / DC converter 5, the wind power AC / DC rectifier 8, the energy storage DC / DC converter 6, and the hydrogen production module DC / DC converter 7 all use SiC MOSFETs as power switching transistors, which have the characteristics of lower switching losses and higher switching frequencies. This can reduce the size of heat dissipation devices and inductors and capacitors in the converter and improve the power density of the power electronic converter.

[0038] When the public power grid is operating normally, the system can switch to grid-connected mode.

[0039] Specifically, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is a power deficit in the public power grid, the photovoltaic power generation module 1 is controlled to transmit first electrical energy to the 700V DC bus through the first DC / DC converter 5, and the wind power generation module 2 is controlled to transmit second electrical energy to the 700V DC bus through the AC / DC rectifier 8. After the first electrical energy and the second electrical energy are combined on the 700V DC bus, they are sent to the public power grid through the grid-connected module 9.

[0040] Furthermore, when the grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is a power deficit in the public power grid, and the first and second electrical energy transmitted by the photovoltaic power generation module 1 and the wind power generation module 2 to the public power grid are still insufficient to meet the power deficit of the public power grid, then the hybrid energy storage module 3 is switched to the power transmission mode, and power is transmitted to the public power grid through the hybrid energy storage module 3 via the second DC / DC converter 6, the 700V DC bus, and the grid-connected module 9.

[0041] Furthermore, when the grid-connected wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid, the photovoltaic power generation module 1 is controlled to transmit third electrical energy to the 700V DC bus through the first DC / DC converter 5, and the wind power generation module 2 is controlled to transmit fourth electrical energy to the 700V DC bus through the AC / DC rectifier 8. After the third and fourth electrical energy are combined on the 700V DC bus, they are used to supply power to the water electrolysis hydrogen production module 4 through the third DC / DC converter 7.

[0042] Furthermore, when the grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid and the water electrolysis hydrogen production module 4 has reached full power operation, then the hybrid energy storage module 3 is switched to the energy storage mode, and the remaining energy in the third and fourth electrical energy is transmitted to the hybrid energy storage module 3 through the 700V DC bus and the second DC / DC converter 6.

[0043] Furthermore, when the grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in grid-connected mode, if there is no power deficit in the public power grid, and the third and fourth electrical energy sources are insufficient to enable the water electrolysis hydrogen production module 4 to operate at full power, then the hybrid energy storage module 3 is switched to the power supply mode, and power is supplied to the water electrolysis hydrogen production module 4 through the hybrid energy storage module 3 via the second DC / DC converter 6, the 700V DC bus, and the third DC / DC converter 7.

[0044] When the photovoltaic power generation module 1 and the wind power generation module 2 supply power to the water electrolysis hydrogen production module 4 and the hybrid energy storage module 3 respectively, one approach is to supply power to the water electrolysis hydrogen production module 4 at the first moment and to supply power to the hybrid energy storage module 3 at the second moment. Alternatively, one of the photovoltaic power generation module 1 or the wind power generation module 2 supplies power to the water electrolysis hydrogen production module 4, while the other supplies power to the hybrid energy storage module 3.

[0045] When a fault occurs in the public power grid, the system can switch to off-grid mode.

[0046] Specifically, when the grid-connected and off-grid wind-solar-hydrogen storage coupled hydrogen production power system based on a 700V DC bus is in off-grid mode, the grid-connected module 9 is controlled to disconnect the 700V DC bus from the public power grid, and the hybrid energy storage module 3 is switched to the power supply mode. On the one hand, it provides voltage support for the 700V DC bus, and on the other hand, together with the photovoltaic power generation module 1 and the wind power generation module 2, it provides the power required for the operation of the water electrolysis hydrogen production module 4.

[0047] The photovoltaic power generation module 1 includes a photovoltaic panel, an equipment monitoring and protection device, an MPPT circuit, and a combiner device; the wind power generation module 2 includes a wind turbine and an equipment monitoring and protection device.

[0048] The photovoltaic panel includes a first photovoltaic array and a second photovoltaic array arranged adjacent to each other. The first photovoltaic array forms a first angle with the horizon, and the second photovoltaic array forms a second angle with the horizon. The first angle is different from the second angle. This arrangement maximizes the capture of solar energy at different locations, and the angled area between the first and second photovoltaic arrays can further reflect sunlight for full utilization.

[0049] The wind turbine generator set includes a telescopic main mast, a swivel joint, and turbine blades. The telescopic main mast comprises a first mast body and a second mast body. The first end of the first mast body is fixed to the ground, and the second mast body is slidably connected to the second end of the first mast body. The swivel joint is slidably mounted on the end of the second mast body furthest from the ground, and the swivel joint is fixedly connected to the turbine blades. This configuration allows for real-time adjustment of the turbine blade height and angle, resulting in better utilization of wind energy.

[0050] The grid-connected module 9 includes a first switch and a second switch. The first switch controls the connection between the grid-connected module 9 and the public power grid, and the second switch controls the connection between the grid-connected module 9 and the 700V DC bus. The grid-connected module 9 further includes a power sensor for detecting whether there is a power deficit in the public power grid. The hybrid energy storage module 3 includes a liquid-cooled lithium iron phosphate battery unit, a supercapacitor, an energy management device, and an equipment monitoring and protection device.

[0051] The water electrolysis hydrogen production module 4 includes a water electrolysis hydrogen production device, a hydrogen purification device, and an equipment monitoring and protection device. The hydrogen produced by the water electrolysis hydrogen production module 4 is collected, processed by the purification device, and then transported to the hydrogen storage device.

[0052] The photovoltaic power generation module 1, the wind power generation module 2, the hybrid energy storage module 3, the water electrolysis hydrogen production module 4, and the grid-connected module 9 are all equipped with Bluetooth communication units to realize wireless transmission of information between the photovoltaic power generation module 1, the wind power generation module 2, the hybrid energy storage module 3, the water electrolysis hydrogen production module 4, and the grid-connected module 9.

[0053] This invention provides a grid-connected / off-grid coupled wind-solar-hydrogen-storage hydrogen production power system based on a 700V DC bus. This system can switch between grid-connected and off-grid operating modes to achieve efficient hydrogen production under various conditions. The 700V DC bus used in this system, compared to an AC bus, reduces the energy conversion steps between the photovoltaic, hydrogen production, and hybrid energy storage modules, thus improving the system's energy utilization efficiency. The hybrid energy storage module used in this system simultaneously employs liquid-cooled lithium iron phosphate batteries and supercapacitors. The lithium iron phosphate batteries can continuously and stably provide power, while the supercapacitors can compensate for instantaneous power fluctuations. This solution not only effectively utilizes redundant power to ensure reliable system operation but also improves power quality and the system's surge resistance.

[0054] Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it. The above description is only a preferred embodiment of the present invention and is not limited to the scope of the present invention. Other changes and modifications made by those skilled in the art without departing from the spirit and protection scope of the present invention are still included within the protection scope of the present invention.

Claims

1. A 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system, comprising a photovoltaic power generation module (1), a wind power generation module (2), a hybrid energy storage module (3), a water electrolysis hydrogen production module (4), a first DC / DC converter (5), a second DC / DC converter (6), a third DC / DC converter (7), an AC / DC rectifier (8), a grid-connected module (9), and a 700V DC bus; the photovoltaic power generation module (1) is unidirectionally connected to the 700V DC bus through the first DC / DC converter (5), the wind power generation module (2) is unidirectionally connected to the 700V DC bus through the AC / DC rectifier (8), the hybrid energy storage module (3) is bidirectionally connected to the 700V DC bus through the second DC / DC converter (6), the water electrolysis hydrogen production module (4) is unidirectionally connected to the 700V DC bus through the third DC / DC converter (7), and the 700V DC bus is connected to a public power grid through the grid-connected module (9); characterized in that the 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system has two working modes of grid-connected mode and off-grid mode; the hybrid energy storage module (3) has three operating modes of power transmission mode, power supply mode, and energy storage mode.

2. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, the photovoltaic power generation module (1) comprises a photovoltaic panel, a device monitoring and protection device, an MPPT circuit, and a current collection device; the wind power generation module (2) comprises a wind turbine generator and a device monitoring and protection device.

3. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 2, characterized in that, the photovoltaic panel comprises a first photovoltaic array and a second photovoltaic array arranged adjacent to each other, the first photovoltaic array forms a first angle with the horizon, the second photovoltaic array forms a second angle with the horizon, and the first angle is different from the second angle.

4. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 2, characterized in that, the wind turbine generator comprises a telescopic main rod, a universal ball head, and a turbine blade, the telescopic main rod comprises a first rod body and a second rod body, a first end of the first rod body is fixedly arranged on the ground, the second rod body is connected to a second end of the first rod body in a lifting manner, the universal ball head is arranged on an end of the second rod body away from the ground, and the universal ball head is fixedly connected to the turbine blade.

5. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, the grid-connected module (9) comprises a first switch and a second switch, the first switch is used to control the on-off between the grid-connected module (9) and the public power grid, and the second switch is used to control the on-off between the grid-connected module (9) and the 700V DC bus.

6. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 5, characterized in that, the grid-connected module (9) further comprises a power sensor for detecting whether there is a power shortage in the public power grid.

7. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, the photovoltaic power generation module (1), the wind power generation module (2), the hybrid energy storage module (3), the water electrolysis hydrogen production module (4), and the grid-connected module (9) all have a Bluetooth communication unit for realizing wireless transmission of information among the photovoltaic power generation module (1), the wind power generation module (2), the hybrid energy storage module (3), the water electrolysis hydrogen production module (4), and the grid-connected module (9).

8. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, The first DC / DC converter (5), the second DC / DC converter (6), the third DC / DC converter (7) and the AC / DC rectifier (8) all use SiC MOSFET as power switch tube.

9. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, The hybrid energy storage module (3) comprises liquid-cooled lithium iron phosphate battery cells, supercapacitors, energy management devices and equipment monitoring and protection devices.

10. The 700V DC bus-based off-grid wind-solar-hydrogen storage coupled hydrogen production power system according to claim 1, characterized in that, The water electrolysis hydrogen production module (4) comprises a water electrolysis hydrogen production device, a hydrogen purification device and an equipment monitoring and protection device. The hydrogen produced by the water electrolysis hydrogen production module (4) after electrolysis is combined and treated by the purification device, and then delivered to the hydrogen storage device.

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