A photovoltaic-pem integrated system for hydrogen production by electrolysis of water

Abstract

The utility model relates to photovoltaic power generation and hydrogen energy equipment technical field, concretely disclose a kind of photovoltaic-PEM water electrolysis hydrogen integrated system, including photovoltaic module array, PEM electrolytic cell, energy storage battery, controller, sensor and hydrogen production and safety component, the photovoltaic module array includes confluence and protection, coupling switching module, DC / DC converter, direct current bus and current limiting module, the energy storage battery is provided with bidirectional DC / DC.The photovoltaic-PEM water electrolysis hydrogen integrated system, can be switched in three kinds of topologies between direct connection, DC / DC+MPPT direct connection and energy storage indirect in this system, to flexibly match different weather and load condition, direct connection topology is used to reduce intermediate conversion loss in fine weather, DC / DC+MPPT direct connection topology is used to lock electrolytic cell high-efficiency work area when light fluctuation or low irradiation, rely on energy storage indirect topology to maintain hydrogen production at night or in rain, solve the problem of low efficiency of traditional single topology.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic power generation and hydrogen energy equipment technology, specifically a photovoltaic-PEM electrolysis water production hydrogen production integrated system. Background Technology

[0002] The photovoltaic-PEM electrolysis water production hydrogen integrated system refers to a new type of comprehensive energy utilization system that integrates photovoltaic power generation units and PEM electrolysis water production units. Through modular integration of hardware equipment and coordinated optimization of software control strategies, it realizes the efficient conversion of photovoltaic clean energy into green hydrogen.

[0003] Photovoltaic output has significant nonlinear and fluctuating characteristics. Its IV curve is difficult to match stably with the VI working curve of the PEM electrolyzer in the long term. Simple direct connection is prone to overcurrent or deviation from the efficient working range when there are drastic changes in irradiance. Efficiency can be improved by relying on a single DC / DC converter, but it is difficult to maintain continuous hydrogen production at night or in rainy weather. Although energy storage can buffer fluctuations, it increases the cost and control complexity. Utility Model Content

[0004] The purpose of this invention is to provide an integrated photovoltaic-PEM water electrolysis hydrogen production system. This system solves the problems mentioned in the background art by switching between three topologies—direct connection, DC / DC+MPPT direct connection, and energy storage indirect connection—according to operating conditions.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a photovoltaic-PEM electrolysis water production hydrogen production integrated system, comprising a photovoltaic module array, a PEM electrolyzer, an energy storage battery, a controller, sensors, and hydrogen production and safety components. The hydrogen production and safety components include one or more of the following: gas-liquid separation, drying and purification, buffering and back pressure, pressure relief, safety cut-off, unidirectional and flame arrestor, and purging and emission units. The photovoltaic module array includes a current collector and protection module, a coupling switching module, a DC / DC converter, a DC bus, and a current limiting module. The energy storage battery is equipped with a bidirectional DC / DC converter. The coupling switching module in the photovoltaic module array is connected to the controller. The controller is connected to the sensors, the controller is connected to the PEM electrolyzer, the controller is connected to the energy storage battery, and the PEM electrolyzer is connected to the hydrogen production and safety components. The controller and the coupling switching module cooperate to enable the system to switch between three topologies: direct connection, DC / DC+MPPT direct connection, and indirect connection to the energy storage battery. The current limiting module provides hardware-level overcurrent protection.

[0006] Preferably, the coupling switching module is composed of a DC contactor array. The coupling switching module has mechanical interlock and electrical interlock, allowing only one topology to be closed, and pre-charging the bus through a pre-charging resistor during switching to suppress inrush current.

[0007] By adopting the above technical solution, mechanical and electrical interlocks are used to prevent topology malfunctions and ensure that only one topology operates.

[0008] Preferably, the current limiting module includes a Hall current sensor, a high-speed comparator, and a power semiconductor driver, and a backup fuse is electrically connected in series at the output of the current limiting module.

[0009] By adopting the above technical solution, a backup fuse provides dual protection to prevent overcurrent damage to the system.

[0010] Preferably, the DC bus is composed of a copper busbar and a capacitor array, and the DC bus is connected in parallel with a TVS and an RC absorber to suppress surges.

[0011] By adopting the above technical solution, stable power transmission of the DC bus can be ensured through copper busbars and capacitor arrays.

[0012] Preferably, the energy storage battery is a vanadium redox flow battery. The energy storage battery is connected to the DC bus via a bidirectional DC / DC converter to achieve voltage matching and energy return. The energy storage battery is connected to a controller, and the controller performs power distribution of the energy storage battery based on the SOC threshold.

[0013] By adopting the above technical solution, bidirectional energy flow can be achieved by adapting the vanadium redox flow battery to the bus via a bidirectional DC / DC converter.

[0014] Preferably, the sensors include an irradiance sensor, a temperature sensor, a bus voltage and current sensor, a hydrogen production flow and differential pressure sensor, and a hydrogen leakage sensor. When the hydrogen leakage sensor detects that the leakage threshold has reached a set value, it triggers ventilation, an alarm, and a total power outage.

[0015] By adopting the above technical solution, key parameters of the system are monitored in real time through multiple types of sensors, providing data support for control.

[0016] Preferably, the controller includes an MPPT module, a power distribution module, and a safety and current limiting module. The controller is equipped with an execution interface to drive the DC / DC converter, a coupling switching module, and a cabinet heat dissipation unit. The cabinet heat dissipation unit has a cabinet protection rating of ≥IP54. The cabinet heat dissipation unit is installed using modular slide rails and positioning pins to form a bottom-in, top-out air duct and is equipped with a replaceable filter. A leakage probe and an exhaust fan are arranged at the top of the cabinet heat dissipation unit.

[0017] By adopting the above technical solution, the controller's multiple modules can work together to achieve MPPT, power distribution and safety control, and drive the operation of core components.

[0018] Preferably, the bus and protection includes a fuse, a surge protector, and a reverse protection diode, and the bus and protection is provided with hot-swappable terminals.

[0019] By adopting the above technical solution, overcurrent protection, surge protection and reverse connection protection are achieved through fuses, surge protectors and reverse connection protection diodes, respectively, to ensure power safety.

[0020] Preferably, in the direct-connect topology, the maximum power point voltage of the photovoltaic module array is matched with the operating voltage of the electrolyzer; in the DC / DC+MPPT direct-connect topology, the operating point is limited to the linear segment VI of the electrolyzer; and in the energy storage indirect topology, a power allocation strategy is configured according to the energy storage capacity and the SOC threshold.

[0021] By adopting the above technical solution, conversion losses can be reduced through a direct connection topology.

[0022] Compared with the prior art, the beneficial effects of this utility model are: This photovoltaic-PEM electrolysis water production hydrogen integrated system: 1. This system can flexibly switch between three topologies: direct connection, DC / DC+MPPT direct connection, and energy storage indirect connection, thereby flexibly matching different weather and load conditions. In good weather, the direct connection topology is used to reduce intermediate conversion losses. When there are fluctuations in light or low radiation, the DC / DC+MPPT direct connection topology is used to lock the high-efficiency working area of ​​the electrolyzer. At night or during cloudy or rainy weather, the energy storage indirect topology is used to maintain hydrogen production, solving the problem of low efficiency of traditional single topology. 2. In this system, the current limiting module quickly responds to overcurrent faults, the coupling switching module prevents topology malfunctions through mechanical and electrical interlocks, and the pre-charge suppresses inrush current. The vanadium redox flow battery is connected to the bus via bidirectional DC / DC, and combined with the SOC threshold, energy storage regulation is achieved to buffer photovoltaic fluctuations, avoid equipment damage due to fluctuations, and extend service life. 3. This system uses modular sliding rail installation, which facilitates outdoor deployment and maintenance. At the same time, the system supports multi-unit parallel connection and upper-level monitoring docking, which can meet the needs of remote areas for off-grid, scientific research and teaching, and emergency hydrogen production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall system structure of this utility model; Figure 2 This is a schematic diagram of the direct matching coupling topology of this utility model; Figure 3 This is a schematic diagram of the DC / DC+MPPT coupled topology of this utility model; Figure 4 This is a schematic diagram of the indirect coupling topology of the energy storage (vanadium liquid flow) of this utility model; Figure 5 This is a schematic diagram of the functional block structure of the controller of this utility model.

[0024] In the diagram: 10. Photovoltaic module array; 11. Busbar and protection; 12. Coupling switching module; 13. DC / DC converter; 14. DC bus; 15. Current limiting module; 20. PEM electrolyzer; 30. Energy storage battery; 31. Bidirectional DC / DC converter; 40. Controller; 50. Sensor; 60. Hydrogen production and safety components. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] Please see Figures 1-5 This utility model provides a technical solution: a photovoltaic-PEM electrolysis water production hydrogen production integrated system, including a photovoltaic module array 10, a current combiner and protection 11, a coupling switching module 12, a DC / DC converter 13, a DC bus 14, a current limiting module 15, a PEM electrolyzer 20, an energy storage battery 30, a bidirectional DC / DC converter 31, a controller 40, a sensor 50, and hydrogen production and safety components 60.

[0027] The photovoltaic module array 10 includes a current collector and protection module 11, a coupling switching module 12, a DC / DC converter 13, a DC bus 14, and a current limiting module 15. The energy storage battery 30 is equipped with a bidirectional DC / DC converter 31. The coupling switching module 12 in the photovoltaic module array 10 is connected to a controller 40, which is connected to a sensor 50 and a PEM electrolyzer 20. The PEM electrolyzer 20 is connected to a hydrogen production and safety component 60. The controller 40 works in conjunction with the coupling switching module 12 to enable the system to be connected in three topologies: direct connection, DC / DC + MPPT direct connection, and indirect connection with energy storage. The switching mechanism includes a current limiting module 15 providing hardware-level overcurrent protection. The coupling switching module 12 consists of a DC contactor array, featuring both mechanical and electrical interlocks, allowing only one topology to close at a time. During switching, a pre-charge resistor is used to pre-charge the bus to suppress inrush current. The current limiting module 15 includes a Hall current sensor, a high-speed comparator, and a power semiconductor driver. A backup fuse is electrically connected in series at the output of the current limiting module 15. The DC bus 14 consists of a copper busbar and a capacitor array, with a TVS and RC absorption connected in parallel to suppress surges. The energy storage battery 30 is a vanadium redox flow battery, connected via a bidirectional DC / DC converter. DC31 is connected to DC bus 14 to achieve voltage matching and energy return. Energy storage battery 30 is connected to controller 40. Controller 40 distributes power to energy storage battery 30 based on SOC threshold. Sensor 50 includes an irradiance sensor, a temperature sensor, a bus voltage and current sensor, a hydrogen production flow and differential pressure sensor, and a hydrogen leakage sensor. When the hydrogen leakage sensor detects a leakage threshold reaching a set value, it triggers ventilation, an alarm, and a total power outage. Controller 40 includes an MPPT module, a power distribution module, and a safety and current limiting module. Controller 40 is equipped with an execution interface to drive DC / DC converter 13, a coupling switching module 12, and the enclosure. The heat dissipation unit is in operation. The enclosure protection level of the heat dissipation unit is ≥IP54. The enclosure heat dissipation unit is installed using modular slide rails and positioning pins to form a bottom-in and top-out air duct and is equipped with a replaceable filter. The upper part of the enclosure heat dissipation unit is equipped with a leakage probe and an exhaust fan. The busbar and protection 11 includes fuses, surge protectors and anti-reverse diodes. The busbar and protection 11 is equipped with hot-swappable terminals. The maximum power point voltage of the photovoltaic module array 10 in the direct connection topology is matched with the working voltage of the electrolytic cell. Under the DC / DC+MPPT direct connection topology, the working point is limited to the linear segment VI of the electrolytic cell. Under the indirect energy storage topology, the power allocation strategy is configured according to the energy storage capacity and SOC threshold. Example 1: As Figure 1 and Figure 2As shown, the photovoltaic module array 10 directly drives the PEM electrolyzer 20 after passing through the "current combiner and protection 11". The module series and parallel configuration is selected according to the principle of "photovoltaic MPP voltage ≈ PEM electrolyzer 20 linear operating voltage". The inlet is equipped with a DC contactor and a pre-charge resistor, and is equipped with fuse / reverse protection and SPD. The controller 40 is responsible for monitoring and interlocking. Once an overcurrent, voltage deviation from the linear range, or leakage alarm occurs, it will immediately disconnect or switch to the DC / DC mode. The debugging is carried out by gradually increasing the irradiance from low to medium to high, and confirming that the operating point is in the linear range. This embodiment has the simplest structure and the lowest cost, and is suitable for sunny and relatively stable load scenarios.

[0028] Example 2: Figure 1 and Figure 3 As shown, a step-up / step-down DC / DC converter is added between the photovoltaic module array 10 and the PEM electrolyzer 20. The controller 40 executes MPPT, but the operating point is limited to the safe voltage and current window of the PEM electrolyzer 20, and hardware current limiting is prioritized. When encountering rapid fluctuations such as cloud shadows, the MPPT adopts a steady-state strategy of "small step size + hysteresis", first stabilizing the current and then optimizing to avoid oscillation. During debugging, the input voltage is scanned first and then the irradiation step is performed to confirm "rapid convergence and no abnormal fluctuations". This embodiment can generate hydrogen well even with low irradiation, with small fluctuations and more flexible module selection, but the cost and control complexity are slightly higher.

[0029] Example 3: As Figure 1 , Figure 4 and Figure 5 As shown, the photovoltaic cells are connected to the DC bus 14 via the DC / DC converter 13, and the PEM electrolyzer 20 and energy storage battery 30 are connected in parallel. The energy storage is matched to the DC bus 14 via the bidirectional DC / DC converter 31. The control is mainly based on the SOC threshold. During the day, the surplus electricity is used to produce hydrogen first and then recharge. When there is insufficient sunlight, the energy storage compensates. At night or during continuous cloudy or rainy weather, the energy storage provides the power. When the power approaches the low threshold, the derating is smoothly reduced or the system is shut down according to the rules. The DC bus 14 side maintains basic voltage stabilization and current limiting. The thermal management and leakage interlock are always open. This embodiment can achieve continuous operation in all weather conditions, is not sensitive to weather, and is suitable for scenarios with high stability requirements.

[0030] Working Principle: When using this photovoltaic-PEM electrolysis water production hydrogen integrated system, the system uses the photovoltaic module array 10 as the energy input. The electrical energy is first collected, surge protected, and reverse-connected by the current collector and protection unit 11. The controller 40, combined with data such as irradiance, temperature, bus voltage, and current collected by the sensor 50, drives the coupling switching module 12 to achieve three topology switching to adapt to different operating conditions. In good weather, it switches to a direct connection topology to match the maximum power point voltage of the photovoltaic cells with the operating voltage of the PEM electrolyzer 20, reducing conversion losses. During periods of fluctuating light or low irradiance, it switches to a DC / DC13+MPPT direct connection topology, and the MPPT module of the controller 40 locks the electrolyzer 20. In the VI linear zone, a backup fuse is electrically connected in series at the output of the current limiting module 15 to achieve final fault isolation in case of current limiting failure or short circuit, thus protecting the system's safety in real time. At night / dark / rainy weather, the energy storage indirect topology is activated, and the vanadium redox flow battery 30 is matched with the DC bus 14 through the bidirectional DC / DC 31. The controller 40 allocates power according to the SOC threshold. When the hydrogen leakage sensor in the sensor 50 exceeds the threshold, it triggers ventilation, alarm, and power-off. The controller 40 also drives the enclosure heat dissipation unit. The upper part of the enclosure heat dissipation unit is equipped with a leakage probe and an exhaust fan. The leakage probe is used to detect leaks of pure water, cooling water, and energy storage battery electrolyte, while the exhaust fan is used to force ventilation and dilute the equipment cavity when the hydrogen leakage sensor reaches the threshold. Together with the hydrogen production and safety components 60, this ensures the efficient and safe operation of the system and increases its overall practicality.

[0031] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic-PEM electrolysis water electrolysis hydrogen production integrated system, comprising a photovoltaic module array (10), a PEM electrolyzer (20), an energy storage battery (30), a controller (40), a sensor (50), and a hydrogen production and safety component (60), wherein the hydrogen production and safety component (60) includes one or more of the following: gas-liquid separation, drying and purification, buffering and back pressure, pressure relief, safety shut-off, one-way and flame arrestor, and purging and emission units, characterized in that: The photovoltaic module array (10) includes a current collector and protection (11), a coupling switching module (12), a DC / DC converter (13), a DC bus (14), and a current limiting module (15). The energy storage battery (30) is equipped with a bidirectional DC / DC converter (31). The coupling switching module (12) in the photovoltaic module array (10) is connected to a controller (40). The controller (40) is connected to a sensor (50). The controller (40) is connected to a PEM electrolyzer (20). The controller (40) is connected to the energy storage battery (30). The PEM electrolyzer (20) is connected to a hydrogen production and safety component (60). The controller (40) cooperates with the coupling switching module (12) to enable the system to switch between three topologies: direct connection, DC / DC+MPPT direct connection, and indirect connection to the energy storage. The current limiting module (15) provides hardware-level overcurrent protection.

2. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The coupling switching module (12) is composed of a DC contactor array. The coupling switching module (12) has mechanical interlock and electrical interlock, allowing only one topology to be closed, and pre-charging the bus through a pre-charging resistor during switching to suppress inrush current.

3. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The current limiting module (15) includes a Hall current sensor, a high-speed comparator and a power semiconductor driver, and a backup fuse is electrically connected in series at the output of the current limiting module (15).

4. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The DC bus (14) is composed of a copper busbar and a capacitor array. The DC bus (14) is connected in parallel with a TVS and an RC absorber to suppress surges.

5. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The energy storage battery (30) is a vanadium redox flow battery. The energy storage battery (30) is connected to the DC bus (14) via a bidirectional DC / DC converter (31) to achieve voltage matching and energy return. The energy storage battery (30) is connected to the controller (40). The controller (40) performs power distribution of the energy storage battery (30) based on the SOC threshold.

6. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The sensor (50) includes an irradiance sensor, a temperature sensor, a bus voltage and current sensor, a hydrogen production flow and differential pressure sensor, and a hydrogen leakage sensor. When the hydrogen leakage sensor detects that the leakage threshold has reached a set value, it will trigger ventilation, alarm, and power outage.

7. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The controller (40) includes an MPPT module, a power distribution module and a safety and current limiting module. The controller (40) is equipped with an execution interface to drive the DC / DC converter (13), the coupling switching module (12) and the enclosure heat dissipation unit to operate. The enclosure heat dissipation unit has an enclosure protection level ≥ IP54. The enclosure heat dissipation unit is installed using a module slide rail and positioning pin to form a bottom-inlet and top-outlet air duct and is equipped with a replaceable filter. A leakage probe and an exhaust fan are arranged on the upper part of the enclosure heat dissipation unit.

8. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The bus and protection (11) includes a fuse, a surge protector and a reverse protection diode, and the bus and protection (11) is provided with hot-swappable terminals.

9. The photovoltaic-PEM electrolysis water production hydrogen integrated system according to claim 1, characterized in that: The maximum power point voltage of the photovoltaic module array (10) in the direct-connect topology is matched with the working voltage of the electrolyzer. The working point of the DC / DC+MPPT direct-connect topology is limited to the VI linear segment of the electrolyzer. The power allocation strategy is configured according to the energy storage capacity and SOC threshold in the energy storage indirect topology.

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