Wide-range input direct-current power supply for photovoltaic water electrolysis hydrogen production and control method

Abstract

The invention belongs to the technical field of water electrolysis hydrogen production control, and particularly relates to a wide-range input direct-current power supply for photovoltaic water electrolysis hydrogen production and a control method, the wide-range input direct-current power supply comprises a DC / DC power supply system, and the DC / DC power supply system comprises an electric energy input module, a direct-current bus, a dual-output module, a hybrid energy storage module and a control module; the electric energy input module supports 500V-1500V wide voltage input, and photovoltaic energy collection is maximized in combination with an MPPT algorithm and a high-frequency switch conversion technology; the double output modules are differentially adapted to the stable operation of the alkaline electrolysis system and the quick response requirement of the PEM electrolysis system; the hybrid energy storage module adopts a hybrid energy storage architecture, and cooperates with the control module to realize power buffering and energy optimization distribution based on a dynamic threshold value of an operation database and weather forecast and a three-level scheduling mechanism. According to the invention, wide-range efficient utilization of photovoltaic energy is realized, stable operation of two hydrogen production systems is guaranteed, hydrogen production continuity and economy are considered, and overall efficiency and reliability of photovoltaic hydrogen production are improved.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production control technology through water electrolysis, specifically relating to a wide-range input DC power supply and control method for photovoltaic water electrolysis hydrogen production. Background Technology

[0002] Direct green electricity connection has accelerated the development of off-grid hydrogen production in the hydrogen energy industry. However, traditional alkaline water electrolysis hydrogen production technology, due to its slow response and poor resistance to fluctuations, is difficult to adapt to the randomness and volatility of renewable energy. In contrast, PEM hydrogen production technology, although more expensive, has the outstanding advantage of rapid response, enabling it to quickly respond to changes in operating conditions and thus achieve rapid hydrogen production. Based on the rapid response of PEM hydrogen production technology and the low cost and mature technology of alkaline water electrolysis hydrogen production technology, the alkaline-PEM hybrid hydrogen production combination is gradually becoming a development trend.

[0003] As the core energy conversion unit of a photovoltaic water electrolysis hydrogen production system, the DC / DC power supply undertakes key functions such as voltage stabilization, current stabilization, and power regulation of the photovoltaic output power. Its performance directly determines the photovoltaic power utilization rate, water electrolysis hydrogen production efficiency, and system operational stability. However, existing DC / DC power supplies for photovoltaic water electrolysis hydrogen production generally suffer from a narrow input adaptation range, making it difficult to match the wide fluctuation characteristics of photovoltaic power generation. Furthermore, in the context of alkaline-PEM mixed hydrogen production, the DC / DC power supply is required to take into account the differences between the two electrolyzers and dynamically adjust the output power to maximize hydrogen production efficiency while ensuring system lifespan. Summary of the Invention

[0004] To address the aforementioned shortcomings in the existing technology, this invention provides a wide-range input DC power supply and control method for photovoltaic water electrolysis hydrogen production, thereby solving the problems mentioned in the background technology.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A wide-range input DC power supply for photovoltaic water electrolysis to produce hydrogen, characterized in that the DC / DC power supply system specifically includes: The power input module has its input terminal connected to the photovoltaic power generation array; DC bus; The first output module has its output terminal used to connect to the alkaline water electrolysis hydrogen production system; The second output module has its output terminal used to connect to the PEM water electrolysis hydrogen production system. A hybrid energy storage module includes a first energy storage unit and a second energy storage unit; Control module; The output terminal of the power input module, the input terminals of the first output module and the second output module, and the hybrid energy storage module are all connected to the DC bus. The control module is communicatively connected to the power input module, the first output module, the second output module, and the hybrid energy storage module. The control module also includes a hierarchical energy scheduling mechanism, which dynamically executes hierarchical energy scheduling based on preset thresholds by monitoring the power status of the DC bus.

[0006] Furthermore, the power input module includes a first input filter circuit, a first power conversion circuit, and a first output filter circuit connected in sequence; wherein the input terminal of the first input filter circuit is connected to the photovoltaic power generation array, and the output terminal of the first output filter circuit is connected to the DC bus. The power input module further includes a first control component, the first control component comprising: The first sampling unit has its input terminal connected between the photovoltaic power generation array and the first input filter circuit, and is used to collect the voltage and current parameters output by the photovoltaic power generation array. The first DSP controller has its input terminal connected to the output terminal of the first sampling unit, and its internal MPPT control algorithm is integrated. The first PWM drive unit has its input terminal connected to the output terminal of the first DSP controller, and its output terminal connected to the control terminal of the first power conversion circuit.

[0007] Furthermore, the first output module includes a second input filter circuit, a second power conversion circuit, and a second output filter circuit connected in sequence; wherein the input terminal of the second input filter circuit is connected to the DC bus, and the output terminal of the second output filter circuit is connected to the alkaline water electrolysis hydrogen production system. The first output module further includes a second control component, the second control component including: The second sampling unit, with its input terminal connected to the output terminal of the second output filter circuit, is used to collect the output voltage and output current flowing into the alkaline water electrolysis hydrogen production system. The second DSP controller has its input terminal connected to the output terminal of the second sampling unit; The second PWM drive unit has its input terminal connected to the output terminal of the second DSP controller, and its output terminal connected to the control terminal of the second power conversion circuit.

[0008] Furthermore, the second output module includes a third input filter circuit, a third power conversion circuit, and a third output filter circuit connected in sequence; wherein the input terminal of the third input filter circuit is connected to the DC bus, and the output terminal of the third output filter circuit is connected to the PEM water electrolysis hydrogen production system. The second output module further includes a third control component, the third control component comprising: The third sampling unit, with its input terminal connected to the output terminal of the third output filter circuit, is used to collect the output voltage and output current flowing to the PEM water electrolysis hydrogen production system. The third DSP controller has its input terminal connected to the output terminal of the third sampling unit; The third PWM drive unit has its input terminal connected to the output terminal of the third DSP controller, and its output terminal connected to the control terminal of the third power conversion circuit.

[0009] Furthermore, the first energy storage unit is used to provide continuous energy output to the DC bus when the photovoltaic power generation is lower than the load demand; the second energy storage unit is used to buffer the instantaneous power fluctuations of the DC bus.

[0010] Furthermore, the control module collects and stores the operating status data of the photovoltaic power generation array, the alkaline water electrolysis hydrogen production system, the PEM water electrolysis hydrogen production system, and the hybrid energy storage module to build an operating database, and sets a first preset threshold and a second preset threshold based on the operating database.

[0011] Furthermore, the control module also combines weather forecast information to predict future lighting conditions, and dynamically adjusts the first and second preset thresholds based on the operating database and weather forecast results.

[0012] Furthermore, the tiered energy dispatch mechanism is divided into three levels based on a first preset threshold and a second preset threshold, specifically: The first level is the low power mode: when the available power of the DC bus is lower than the first preset threshold, the control module controls the first energy storage unit to output energy to the DC bus, and provides the alkaline water electrolysis hydrogen production system with electrical energy to maintain the hot standby state through the first output module. The PEM water electrolysis hydrogen production system stops running, and the second energy storage unit maintains a high power to buffer the power disturbance of the DC bus. The second level is the steady-state mode: when the available power of the DC bus is between the first preset threshold and the second preset threshold, the control module controls the power input module to supply the power to the alkaline water electrolysis hydrogen production system through the first output module. The excess power is used to charge the second energy storage unit first. After the second energy storage unit is fully charged, the excess power is used to charge the first energy storage unit. The third-level hybrid hydrogen production mode: When the available power of the DC bus is higher than the second preset threshold, the control module controls the alkaline water electrolysis hydrogen production system to operate at full load, and at the same time controls the second output module to start the PEM water electrolysis hydrogen production system, and the second energy storage unit buffers the instantaneous power fluctuation of the DC bus.

[0013] Furthermore, the first preset threshold is the sum of the standby power consumption of the alkaline water electrolysis hydrogen production system and the system's basic losses; the second preset threshold is the sum of the rated power of the alkaline water electrolysis hydrogen production system and the maximum charging power of the first energy storage unit.

[0014] This invention also discloses a control method for a wide-range input DC power supply used in photovoltaic water electrolysis for hydrogen production, applied to the aforementioned wide-range input DC power supply, comprising the following steps: Step A: The control module collects the operating status data of the photovoltaic power generation array, the alkaline water electrolysis hydrogen production system, the PEM water electrolysis hydrogen production system, and the hybrid energy storage module, and builds and updates the operating database; Step B: The control module combines weather forecast information to predict future sunshine conditions, sets a first preset threshold and a second preset threshold based on the operating database, and dynamically adjusts the first preset threshold and the second preset threshold according to the prediction results. Step C: The power input module collects the voltage and current parameters of the photovoltaic power generation array through the first sampling unit. The first DSP controller tracks the maximum power point of the photovoltaic power generation array based on the MPPT control algorithm and drives the first power conversion circuit to transmit power to the DC bus. Step D: The control module monitors the available power of the DC bus in real time and performs hierarchical scheduling based on the relationship between the available power and the first preset threshold and the second preset threshold; Step E: The first output module and the second output module respectively collect output parameters through their corresponding sampling units, and the output state of the power conversion circuit is adjusted by the DSP controller to adapt to the operating requirements of the corresponding water electrolysis hydrogen production system.

[0015] Compared with the prior art, the present invention has the following beneficial effects: To address the differentiated requirements of "long-term stable operation" for alkaline water electrolysis hydrogen production systems and "rapid response and flexible start-stop" for PEM water electrolysis hydrogen production systems, a first output module and a second output module are designed respectively. Through the collaborative logic of target parameters issued by the control module and real-time adjustment by the DSP controller, precise adaptation of output power is achieved. A hybrid energy storage architecture is adopted, combined with a dynamic threshold adjustment mechanism based on the operating database and weather forecast, and a three-level energy dispatch strategy. The first energy storage unit ensures the hot standby and continuous operation of the alkaline electrolysis system during periods of no light / low light, while the second energy storage unit buffers instantaneous power fluctuations. The control module dynamically optimizes the dispatch logic, which not only solves the problem of hydrogen production interruption caused by insufficient photovoltaic power, but also achieves efficient absorption of photovoltaic peak power, while reducing the redundancy configuration cost of the energy storage system, thus achieving a dual optimization of hydrogen production continuity and economy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a wide-range input DC power supply for photovoltaic water electrolysis hydrogen production according to the present invention; Figure 2 This is a schematic diagram of the power input module of the present invention; Figure 3 This is a schematic diagram of the structure of the first output module of the present invention; Figure 4 This is a schematic diagram of the structure of the second output module of the present invention; The reference numerals in the accompanying drawings include: 1. Photovoltaic power generation array; 2. DC / DC power supply system; 21. Power input module; 221. First input filter circuit; 222. First power conversion circuit; 223. First output filter circuit; 224. First sampling unit; 225. First DSP controller; 226. First PWM drive unit; 22. DC bus; 23. First output module; 231. Second input filter circuit; 232. Second power conversion circuit; 233. Second output filter circuit; 234. Second sampling unit; 35. Second DSP controller; 236. Second PWM drive unit; 24. Second output module; 241. Third input filter circuit; 242. Third power conversion circuit; 243. Third output filter circuit; 244. Third sampling unit; 245. Third DSP controller; 246. Third PWM drive unit; 25. Hybrid energy storage module; 251. First energy storage unit; 252. Second energy storage unit; 26. Control module; 3. Alkaline water electrolysis hydrogen production system; 4. PEM water electrolysis hydrogen production system. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images. They should not be construed as limiting the scope of this application. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0019] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0021] Example 1:

[0022] like Figure 1-4 As shown, this invention provides a wide-range input DC power supply and control method for photovoltaic water electrolysis hydrogen production. Through a modular architecture and intelligent energy dispatch strategy, it resolves the contradiction between the intermittency and volatility of photovoltaic power generation and the stable operation requirements of the water electrolysis hydrogen production system. At the same time, it adapts to the different power consumption characteristics of alkaline water electrolysis hydrogen production systems and PEM water electrolysis hydrogen production systems, thereby maximizing the utilization of photovoltaic energy and achieving continuous and efficient operation of the hydrogen production process.

[0023] Specifically, a wide-range input DC power supply, i.e., a DC / DC power system 2, for photovoltaic water electrolysis to produce hydrogen includes an energy input module 21, a DC bus 22, a first output module 23, a second output module 24, a hybrid energy storage module 25, and a control module 26. Each module forms an energy system adapted to wide-range photovoltaic fluctuations through specific electrical connections and communication logic. The input terminal of the power input module 21 is directly connected to the photovoltaic power generation array 1. Its core feature is that it supports a wide range of inputs and can adapt to the voltage fluctuations of the photovoltaic power generation array under different light intensities. Multiple sets can be set to connect to the photovoltaic power generation array 1 respectively. The DC bus 22 serves as the core of energy collection and distribution, receiving a wide range of power from the power input module 21 and transmitting it to subsequent modules. The first output module 23 and the second output module 24 are adapted to electrolysis systems of different power levels to cover a wide range of load requirements. The hybrid energy storage module 25 is directly connected to the DC bus 22 and achieves energy buffering and backup protection through two internally differentiated energy storage units. The control module 26 establishes communication connections with the power input module 21, the first output module 23, the second output module 24 and the hybrid energy storage module 25 respectively. As the control core of the system, it coordinates the operating status of each module and realizes intelligent energy distribution and scheduling.

[0024] The power input module 21 is the core unit for achieving wide-range input adaptation. Its input voltage range covers DC 500V to 1500V, enabling it to adapt to the output voltage fluctuations of the photovoltaic power generation array 1 under different lighting conditions such as weak light and strong light, thus matching the intermittent and fluctuating characteristics of photovoltaic power generation. Figure 2As shown, the internal circuit architecture adopts a "filter-conversion-re-filter" structure, specifically including a first input filter circuit 221, a first power conversion circuit 222, and a first output filter circuit 223 connected in sequence.

[0025] The specific structure of the first input filter circuit 221 is not limited in this embodiment; for example, an LC passive filter topology can be used. The input terminal of the first input filter circuit 221 is connected to the photovoltaic power generation array 1. Its core function is to filter out harmonic interference, voltage spikes, and instantaneous fluctuations in the output power of the photovoltaic power generation array 1, while suppressing the reverse conduction of interference generated by subsequent circuits to the photovoltaic power generation array 1, avoiding the impact of unstable power under wide voltage fluctuations on subsequent circuits, and ensuring the stability of the power conversion process. The first power conversion circuit 222 employs a wide-range adaptable high-frequency switching conversion technology. It achieves efficient energy conversion by controlling the high-frequency switching of the switching devices. Specifically, based on the target DC bus voltage range issued by the control module 26 and combined with the MPPT tracking results of the first DSP controller 225, it adjusts the duty cycle and phase shift angle of the switching devices to achieve precise conversion from a wide input voltage (500V-1500V) to the target voltage of the DC bus 22. It also possesses power regulation capabilities, dynamically adjusting the output power according to system load requirements to ensure that the electrical parameters (voltage and current) output to the DC bus 22 remain stable within a wide fluctuation range of 5%-150% of photovoltaic power. Compared to traditional power frequency conversion technology, high-frequency switching conversion technology not only significantly reduces circuit size and weight but also improves energy conversion efficiency. The first output filter circuit 223 can also adopt an LC filter structure to further filter out switching noise and interference generated during the operation of the first power conversion circuit 222, making the final input electrical energy to the DC bus 22 purer and improving the overall system reliability.

[0026] To maximize the harvesting of photovoltaic energy, the power input module 21 is also equipped with a first control component, which includes a first sampling unit 224, a first DSP controller 225, and a first PWM drive unit 226. The input terminal of the first sampling unit 224 is connected between the photovoltaic power generation array 1 and the first input filter circuit 221, and can collect the voltage and current parameters output by the photovoltaic power generation array 1 in real time, and transmit the collected parameter signals to the first DSP controller 225. The first DSP controller 225 integrates an MPPT control algorithm, which is adapted to a wide input voltage range of 500V-1500V. Based on the voltage and current parameters transmitted by the first sampling unit 224, it can calculate the maximum power point of the photovoltaic power generation array 1 in real time and generate the corresponding control signal. The input terminal of the first PWM drive unit 226 is connected to the output terminal of the first DSP controller 225, and can convert the control signal output by the first DSP controller 225 into a drive signal to control the switching device of the first power conversion circuit 222, so that the power input module 21 always operates near the maximum power point of the photovoltaic power generation array 1, maximizing the photovoltaic energy harvesting efficiency. The control module 26 establishes communication with the first DSP controller 225 and sends it the target voltage range of the DC bus 22. The first DSP controller 225 combines the MPPT tracking results and adjusts the power conversion parameters within this voltage range to ensure the voltage stability of the DC bus 22 under a wide range of photovoltaic input.

[0027] The first output module 23 is specifically designed to adapt to the operational requirements of the alkaline water electrolysis hydrogen production system 3, such as... Figure 3 As shown, the internal circuit also adopts a "filter-conversion-re-filter" structure, including a second input filter circuit 231, a second power conversion circuit 232, and a second output filter circuit 233 connected in sequence. The specific topology of the second input filter circuit 231 is not limited in this embodiment. For example, an LC passive filter structure can be used, with its input terminal connected to the DC bus 22, to filter out voltage fluctuations and noise on the DC bus 22, providing stable input power for subsequent power conversion.

[0028] The second power conversion circuit 232 adopts full-bridge DC / DC conversion technology. Based on the rated voltage and current parameters of the alkaline water electrolysis hydrogen production system 3, it regulates the voltage and current of the DC bus 22 to ensure that the output power meets the stable operation requirements of the alkaline water electrolysis hydrogen production system 3. The second output filter circuit 233 can adopt an LC low-pass filter topology, which consists of a high-frequency filter inductor and an electrolytic capacitor with low equivalent series resistance. Its core function is to further filter out the high-frequency noise and voltage ripple generated by the second power conversion circuit 232 during the switching operation, so that the waveform of the power output to the alkaline water electrolysis hydrogen production system 3 is smoother and purer, effectively reducing the interference of ripple on the electrode reaction of the electrolyzer, extending the service life of the electrolyzer, and improving the purity and efficiency of the hydrogen production process.

[0029] The first output module 23 is also equipped with a second control component for closed-loop regulation of the output power. This component includes a second sampling unit 234, a second DSP controller 235, and a second PWM drive unit 236. The input terminal of the second sampling unit 234 is connected to the output terminal of the second output filter circuit 233, and can collect the output voltage and output current parameters flowing to the alkaline water electrolysis hydrogen production system 3 in real time, and feed the parameter signals back to the second DSP controller 235. The control module 26 sends the target operating parameters (such as rated voltage and rated current) of the alkaline water electrolysis hydrogen production system 3 to the second DSP controller 235. After receiving the parameter signals fed back by the second sampling unit 234, the second DSP controller 235 compares them with the target parameters sent by the control module 26, calculates the deviation, and generates the corresponding adjustment control signal. The second PWM drive unit 236 converts the adjustment control signal output by the second DSP controller 235 into a drive signal to control the switching action of the second power conversion circuit 232, thereby achieving precise closed-loop regulation of the output voltage and current and ensuring a stable power supply for the alkaline water electrolysis hydrogen production system 3.

[0030] The second output module 24 is designed for the rapid response and flexible start-stop operation characteristics of the PEM water electrolysis hydrogen production system 4, such as... Figure 4 As shown, its internal structure is similar to that of the first output module 23, including a third input filter circuit 241, a third power conversion circuit 242 and a third output filter circuit 243 connected in sequence.

[0031] The third input filter circuit 241 can adopt an LC filter topology. Its input terminal is connected to the DC bus 22, responsible for filtering out power fluctuations in the DC bus 22 and providing a stable input for the third power conversion circuit 242. The third power conversion circuit 242 is the core unit adapted to the fast response characteristics of PEM. It adopts high-speed response switching devices and control architecture, such as the half-bridge LLC resonant converter technology of SiC MOSFET. The switching devices are selected with high voltage resistance, fast switching speed and low conduction loss SiC MOSFET. The switching frequency is set to 100kHz to 200kHz, which can quickly respond to control commands and realize rapid adjustment of output power to meet the dynamic operation requirements of PEM water electrolysis hydrogen production system 4. The third output filter circuit 243 can adopt an LC low-pass filter structure to filter out noise and ripple generated by the third power conversion circuit 242, ensuring that the power output to PEM water electrolysis hydrogen production system 4 is pure and stable.

[0032] The third control component of the second output module 24 includes a third sampling unit 244, a third DSP controller 245, and a third PWM drive unit 246. The input terminal of the third sampling unit 244 is connected to the output terminal of the third output filter circuit 243, and it collects the output voltage and output current parameters flowing to the PEM electrolysis water hydrogen production system 4 in real time and feeds them back to the third DSP controller 245. The control module 26 sends the start / stop command and target operating parameters of the PEM electrolysis water hydrogen production system 4 to the third DSP controller 245 according to the scheduling requirements of the mixed hydrogen production mode. The third DSP controller 245 compares and analyzes the target parameters with the feedback parameters of the third sampling unit 244 and generates an adjustment control signal. The third PWM drive unit 246 converts the control signal into a drive signal to control the operating state of the third power conversion circuit 242, realizes precise adjustment of the output power, and ensures the stability of the power during the start-up, shutdown and load adjustment process of the PEM electrolysis water hydrogen production system 4.

[0033] The hybrid energy storage module 25 serves as the system's energy buffer and backup unit, comprising a functionally differentiated first energy storage unit 251 and a second energy storage unit 252. These two units work together to achieve peak shaving and valley filling of energy and ensure continuous system operation. The first energy storage unit 251 is a backup energy storage unit, employing high-capacity energy storage devices such as lithium battery packs. Its core function is to provide continuous energy output to the DC bus 22 when the photovoltaic power generation is lower than the load demand, ensuring that the alkaline water electrolysis hydrogen production system 3 does not shut down due to insufficient photovoltaic energy. The second energy storage unit 252 is a buffer transition unit, employing high-power-density, fast-response energy storage devices, such as supercapacitor modules. It is mainly used to buffer instantaneous power fluctuations on the DC bus 22. When the photovoltaic output power changes abruptly or the electrolysis system load is adjusted, the second energy storage unit 252 can quickly absorb or release energy, suppressing voltage fluctuations on the DC bus 22, maintaining system power balance, and ensuring stable operation of all modules.

[0034] The control module 26 is the "brain" of the entire DC / DC power system 2. It communicates with each DSP controller via the CAN bus to realize the entire process control of data acquisition, parameter calculation, threshold adjustment, and energy dispatch. The control module 26 continuously collects the output data of the photovoltaic power generation array 1, the operating power consumption data of the alkaline water electrolysis hydrogen production system 3, the operating power consumption data of the PEM water electrolysis hydrogen production system 4, and the charging and discharging status data of the hybrid energy storage module 25. It classifies and stores this data to build an operating database, which provides data support for threshold setting and dispatch strategy optimization.

[0035] Based on the constructed operating database, the control module 26 calculates and sets a first preset threshold and a second preset threshold. The first preset threshold is the sum of the standby power consumption of the alkaline water electrolysis hydrogen production system 3 and the system's basic losses. This threshold is a key indicator for determining whether photovoltaic energy can support the minimum operating requirements of the alkaline electrolysis system. The second preset threshold is the sum of the rated power of the alkaline water electrolysis hydrogen production system 3 and the maximum charging power of the first energy storage unit 251. This threshold is used to determine whether photovoltaic energy is excessive and whether it is necessary to start the PEM water electrolysis hydrogen production system 4 to absorb the excess power.

[0036] To further enhance the adaptability of the scheduling strategy, the control module 26 will also combine weather forecast information to predict the sunshine conditions for the next 24 hours. Based on the operating database and weather forecast results, it will dynamically adjust the first and second preset thresholds. For example, if continuous rainy days are predicted, the second preset threshold will be appropriately increased to allow the system to start the PEM electrolysis water production system 4 earlier, reduce the charging amount of the first energy storage unit 251, and reserve more reserve energy to cope with subsequent periods without light. If continuous sunny days are predicted, the second preset threshold will be appropriately decreased to allow the system to start the PEM electrolysis water production system 4 more actively and maximize the daily hydrogen production.

[0037] The built-in hierarchical energy scheduling mechanism of the control module 26 divides the system operation into three levels based on the first preset threshold and the second preset threshold, and dynamically executes scheduling according to the available power status of the DC bus 22.

[0038] When the available power of DC bus 22 is lower than the first preset threshold, the system enters a low-power mode. At this time, the photovoltaic power is weak or there is no photovoltaic output. The control module 26 will control the first energy storage unit 251 to output energy to DC bus 22. The first output module 23 will provide the alkaline water electrolysis hydrogen production system 3 with electrical energy to maintain the hot standby state, ensuring that it maintains a safe temperature and avoiding energy consumption and equipment damage caused by cold start the next day. At the same time, the PEM water electrolysis hydrogen production system 4 stops running, and the second energy storage unit 252 keeps a high power (e.g., 80%) on standby, focusing on smoothing the small disturbances of DC bus 22 and providing protection for sudden power shortages.

[0039] When the available power of DC bus 22 is between the first preset threshold and the second preset threshold, the system enters steady-state mode. At this time, the photovoltaic power is sufficient to meet the optimal operating requirements of alkaline water electrolysis hydrogen production system 3. The control module 26 will control the power input module 21 to supply all the power to alkaline water electrolysis hydrogen production system 3 through the first output module 23, so that it can operate efficiently and stably. The excess power generated will be used to charge the second energy storage unit 252 first. After the second energy storage unit 252 is fully charged, the remaining power will be used to charge the first energy storage unit 251, so as to realize the rational storage of energy.

[0040] When the available power of DC bus 22 is higher than the second preset threshold, the system enters the hybrid hydrogen production mode. At this time, there is excess photovoltaic power. Even if the alkaline water electrolysis hydrogen production system 3 is running at full load and the first energy storage unit 251 is charging at maximum capacity, there is still excess power to be consumed. The control module 26 will control the alkaline water electrolysis hydrogen production system 3 to continue to run at full load, and at the same time control the second output module 24 to start the PEM water electrolysis hydrogen production system 4 to consume the peak power. The second energy storage unit 252 absorbs the most intense instantaneous power fluctuations in real time to ensure the power balance and stable operation of the entire system.

[0041] This embodiment also discloses a control method for a wide-range input DC power supply used in photovoltaic water electrolysis for hydrogen production, including the following steps: Step A: The control module 26 collects the operating status data of the photovoltaic power generation array 1, the alkaline water electrolysis hydrogen production system 3, the PEM water electrolysis hydrogen production system 4, and the hybrid energy storage module 25. After sorting, filtering and storing the data, the module builds and updates the operating database in real time to provide data support for subsequent threshold setting and scheduling control.

[0042] Step B: The control module 26 combines weather forecast information to predict future lighting conditions, calculates and sets a first preset threshold and a second preset threshold based on historical data stored in the operating database, and dynamically adjusts the two thresholds according to the lighting prediction results to ensure that the thresholds can adapt to different lighting conditions. Step C: The power input module 21 collects the voltage and current parameters of the photovoltaic power generation array 1 through the first sampling unit 224 and transmits the parameter signals to the first DSP controller 225. The first DSP controller 225 calculates the maximum power point of the photovoltaic power generation array 1 based on the internally integrated MPPT control algorithm, generates the corresponding control signal and transmits it to the first PWM drive unit 226. The first PWM drive unit 226 converts the control signal into a drive signal and controls the switching action of the first power conversion circuit 222, so that the power input module 21 always tracks the maximum power point of the photovoltaic power generation array 1 and transmits the maximum amount of photovoltaic power collected to the DC bus 22.

[0043] Step D: The control module 26 monitors the available power of the DC bus 22 in real time, compares it with the first preset threshold and the second preset threshold, and executes the corresponding hierarchical scheduling strategy: when the available power is lower than the first preset threshold, the low power mode is executed; when the available power is between the first preset threshold and the second preset threshold, the steady state mode is executed; when the available power is higher than the second preset threshold, the mixed hydrogen production mode is executed.

[0044] Step E: The second sampling unit 234 of the first output module 23 and the third sampling unit 244 of the second output module 24 respectively collect the output voltage and output current parameters flowing to the corresponding water electrolysis hydrogen production system, and feed the parameters back to their respective DSP controllers. The DSP controllers generate adjustment control signals based on the deviation between the feedback parameters and the target parameters, and control the operation of the power conversion circuit through the PWM drive unit to achieve precise adjustment of the output power and ensure that it meets the operation requirements of the corresponding water electrolysis hydrogen production system.

[0045] The above are merely embodiments of the present invention. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The scope of protection in this application does not involve improvements to the software and methods. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A wide range input DC power supply for photovoltaic water electrolysis hydrogen generation, characterized by, The DC / DC power supply system (2) specifically comprises: an electric energy input module (21) having an input end connected with the photovoltaic power generation array (1); a DC bus (22); a first output module (23) having an output end for connecting with the alkaline water electrolysis hydrogen production system (3); a second output module (24) having an output end for connecting with the PEM water electrolysis hydrogen production system (4); a hybrid energy storage module (25) comprising a first energy storage unit (251) and a second energy storage unit (252); a control module (26); wherein the output end of the electric energy input module (21), the input ends of the first output module (23) and the second output module (24), and the hybrid energy storage module (25) are all connected with the DC bus (22); the control module (26) is in communication connection with the electric energy input module (21), the first output module (23), the second output module (24), and the hybrid energy storage module (25) respectively; the control module (26) further comprises a hierarchical energy scheduling mechanism, which dynamically executes hierarchical energy scheduling based on a preset threshold by monitoring the power state of the DC bus (22).

2. A wide range input DC power supply for photovoltaic water electrolysis hydrogen generation as claimed in claim 1, wherein, The electric energy input module (21) comprises a first input filter circuit (221), a first power conversion circuit (222), and a first output filter circuit (223) connected in sequence; wherein the input end of the first input filter circuit (221) is connected with the photovoltaic power generation array (1), and the output end of the first output filter circuit (223) is connected with the DC bus (22); The electric energy input module (21) further comprises a first control assembly, which comprises: a first sampling unit (224) having an input end connected between the photovoltaic power generation array (1) and the first input filter circuit (221) and being used for collecting voltage and current parameters output by the photovoltaic power generation array (1); a first DSP controller (225) having an input end connected with the output end of the first sampling unit (224) and having an MPPT control algorithm integrated therein; a first PWM driving unit (226) having an input end connected with the output end of the first DSP controller (225) and having an output end connected with the control end of the first power conversion circuit (222).

3. A wide range input DC power supply for photovoltaic water electrolysis hydrogen generation as claimed in claim 1 characterized in that: The first output module (23) comprises a second input filter circuit (231), a second power conversion circuit (232), and a second output filter circuit (233) connected in sequence; wherein the input end of the second input filter circuit (231) is connected with the DC bus (22), and the output end of the second output filter circuit (233) is connected with the alkaline water electrolysis hydrogen production system (3); The first output module (23) further comprises a second control assembly, which comprises: a second sampling unit (234) having an input end connected with the output end of the second output filter circuit (233) and being used for collecting output voltage and output current flowing to the alkaline water electrolysis hydrogen production system (3); a second DSP controller (235) having an input end connected with the output end of the second sampling unit (234); A second PWM driving unit (236) has an input end connected with an output end of the second DSP controller (235) and an output end connected with a control end of the second power conversion circuit (232).

4. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 1 characterized in that: The second output module (24) comprises a third input filter circuit (241), a third power conversion circuit (242) and a third output filter circuit (243) connected in sequence; an input end of the third input filter circuit (241) is connected with the DC bus (22), and an output end of the third output filter circuit (243) is connected with the PEM water electrolysis hydrogen production system (4); The second output module (24) further comprises a third control assembly, and the third control assembly comprises: A third sampling unit (244) has an input end connected with an output end of the third output filter circuit (243) and is used for collecting output voltage and output current flowing to the PEM water electrolysis hydrogen production system (4); A third DSP controller (245) has an input end connected with an output end of the third sampling unit (244); A third PWM driving unit (246) has an input end connected with an output end of the third DSP controller (245) and an output end connected with a control end of the third power conversion circuit (242).

5. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 1 characterized in that: The first energy storage unit (251) is used for providing continuous energy output to the DC bus (22) when photovoltaic power generation power is lower than load demand; and the second energy storage unit (252) is used for buffering transient power fluctuation of the DC bus (22).

6. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 1 characterized in that: The control module (26) collects and stores running state data of the photovoltaic array (1), the alkaline water electrolysis hydrogen production system (3), the PEM water electrolysis hydrogen production system (4) and the hybrid energy storage module (25), constructs a running database, and sets a first preset threshold and a second preset threshold based on the running database.

7. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 6, characterized in that: The control module (26) further predicts future light conditions in combination with weather forecast information, and dynamically adjusts the first preset threshold and the second preset threshold based on the running database and the weather prediction result.

8. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 7 characterized in that: The hierarchical energy scheduling mechanism is divided into three levels according to the first preset threshold and the second preset threshold, and specifically: The first level is a low-power mode: when available power of the DC bus (22) is lower than the first preset threshold, the control module (26) controls the first energy storage unit (251) to output energy to the DC bus (22), and provides the alkaline water electrolysis hydrogen production system (3) with electric energy for maintaining a standby state through the first output module (23), the PEM water electrolysis hydrogen production system (4) stops running, and the second energy storage unit (252) keeps high power to buffer power disturbance of the DC bus (22); The second level is a steady-state mode: when available power of the DC bus (22) is between the first preset threshold and the second preset threshold, the control module (26) controls electric energy of the electric energy input module (21) to supply the alkaline water electrolysis hydrogen production system (3) through the first output module (23), and the second energy storage unit (252) is charged with excess electric energy first, and the first energy storage unit (251) is charged with excess electric energy after the second energy storage unit (252) is fully charged; The third hydrogen production mode: when the available power of the DC bus (22) is higher than the second preset threshold, the control module (26) controls the alkaline water electrolysis hydrogen production system (3) to run at full load, and controls the second output module (24) to start the PEM water electrolysis hydrogen production system (4), and the second energy storage unit (252) buffers the transient power fluctuation of the DC bus (22).

9. A wide range input DC power supply for photovoltaic water electrolysis for hydrogen production as claimed in claim 8, characterized in that: The first preset threshold is the sum of the thermal standby power consumption and the system basic loss of the alkaline water electrolysis hydrogen production system (3); and the second preset threshold is the sum of the rated power of the alkaline water electrolysis hydrogen production system (3) and the maximum charging power of the first energy storage unit (251).

10. A control method of a wide-range input DC power supply for hydrogen production by photovoltaic electrolysis of water, applied to the wide-range input DC power supply for hydrogen production by photovoltaic electrolysis of water according to claims 1-9, characterized in that, The method comprises the following steps: Step A: the control module (26) collects the operation state data of the photovoltaic power generation array (1), the alkaline water electrolysis hydrogen production system (3), the PEM water electrolysis hydrogen production system (4) and the hybrid energy storage module (25), constructs and updates the operation database; Step B: the control module (26) predicts the future light condition in combination with the weather forecast information, sets the first preset threshold and the second preset threshold based on the operation database, and dynamically adjusts the first preset threshold and the second preset threshold according to the prediction result; Step C: the electric energy input module (21) collects the voltage and current parameters of the photovoltaic power generation array (1) through the first sampling unit (224), and the first DSP controller (225) tracks the maximum power point of the photovoltaic power generation array (1) based on the MPPT control algorithm, and drives the first power conversion circuit (222) to transmit electric energy to the DC bus (22); Step D: the control module (26) monitors the available power of the DC bus (22) in real time, and performs hierarchical scheduling based on the relationship between the available power and the first preset threshold and the second preset threshold; Step E: the first output module (23) and the second output module (24) respectively collect the output parameters through the corresponding sampling units, and adjust the output state of the power conversion circuit through the DSP controller, so as to adapt to the operation requirement of the corresponding water electrolysis hydrogen production system.

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