Photovoltaic hydrogen production power supply method and system

Abstract

The invention discloses a photovoltaic hydrogen production power supply method and system, and belongs to a photovoltaic hydrogen production power supply system. Comprising a photovoltaic power generation module, a photovoltaic controller, a control system power supply and a hydrogen production power supply. The photovoltaic power generation module absorbs solar energy and converts the solar energy into electric energy; the photovoltaic controller is in circuit connection with the photovoltaic power generation module and is suitable for tracking to obtain the maximum output power of the photovoltaic power generation module; the control system power supply is in signal circuit connection with the photovoltaic controller, receives a part of direct current generated by the photovoltaic power generation module and supplies power to the control system; and the hydrogen production power supply is in signal circuit connection with the photovoltaic controller, receives the other part of direct current generated by the photovoltaic power generation module and supplies power to the hydrogen production equipment. According to the photovoltaic hydrogen production power supply system, an inverter, a rectifier and other devices are omitted, the power supply efficiency is high, the loss is small, a storage battery for storing energy is omitted, the occupied space is reduced, and the product cost is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of hydrogen production systems, and in particular to a photovoltaic hydrogen production power supply method and system. Background Art

[0002] At present, the power supply of existing hydrogen generators gradually adopts photovoltaic panels to use solar energy to generate direct current, which is then converted into alternating current after inversion and stored in batteries, and then supplied to hydrogen production equipment. Currently, most large-scale hydrogen production equipment adopts this power supply method, and small and micro hydrogen production equipment mostly uses municipal electricity as the power supply end. For hydrogen production equipment, the power supply is generally divided into two parts: system power supply and hydrogen electrolysis power supply. The alternating current stored in the battery is converted into a constant voltage power supply by the system power supply and then supplied to the system, and the other is converted into a constant current power supply by the hydrogen electrolysis power supply and then supplied to the electrolyzer. The power supply power of the constant current source for water electrolysis is called a power supply.

[0003] However, the technology of using solar energy to directly supply power is mostly applied to large-scale hydrogen production equipment, and all of them need to be equipped with batteries and inverters, with complex internal structures, large space occupation, and extremely high equipment costs. For micro hydrogen production equipment, most of them directly use the mains as the power supply. There is no photovoltaic power supply solution suitable for micro hydrogen production equipment, especially to meet the actual needs of small equipment size, low transmission loss, and low production cost. Summary of the invention

[0004] In order to overcome the above technical defects, the present invention provides a photovoltaic hydrogen production and power supply method and system to solve the problems involved in the background technology.

[0005] In one aspect, the present invention provides a photovoltaic hydrogen production power supply method and system, comprising:

[0006] Photovoltaic power generation module absorbs solar energy and converts it into electrical energy;

[0007] A photovoltaic controller, connected to the photovoltaic power generation module circuit, suitable for tracking and obtaining the maximum output power of the photovoltaic power generation module;

[0008] A control system power supply is connected to the photovoltaic controller signal circuit, receives a portion of the direct current generated by the photovoltaic power generation module, and supplies power to the control system;

[0009] The hydrogen production power supply is connected to the photovoltaic controller signal circuit, receives another part of the direct current generated by the photovoltaic power generation module, and supplies power to the hydrogen production equipment.

[0010] Preferably or optionally, the control system power supply is a DC / DC regulated direct current power supply.

[0011] Preferably or optionally, the hydrogen production power supply uses direct current as a DC / CC constant current direct current power supply.

[0012] Preferably or optionally, the photovoltaic controller is an MPPT controller.

[0013] Preferably or optionally, the hydrogen production equipment adopts an electrolyzer hydrogen filling device.

[0014] On the other hand, a power supply method based on the photovoltaic hydrogen production power supply system is characterized in that the method further comprises the following steps:

[0015] Step 1: Obtain the output voltage of the photovoltaic controller;

[0016] Step 2: Dynamically adjust the energy distribution management of the control system power supply and the hydrogen production power supply according to the output voltage of the photovoltaic controller.

[0017] Preferably or optionally, the method further comprises the steps of:

[0018] Step 21, judging whether the output voltage is greater than a first threshold value, if so, maintaining the normal operation state of the control system power supply and the hydrogen production power supply; if not, starting the energy distribution management program and executing the next step;

[0019] Step 22, determine whether the output voltage is greater than a second threshold; if so, maintain the normal operation of the control system power supply and the hydrogen production power supply; if not, proceed to the next step;

[0020] Step 23, determine whether the output voltage is greater than the third threshold value; if so, reduce the amount of hydrogen production by limiting the current of the hydrogen production power supply, reduce the total power consumption load, increase the output voltage to the second threshold value, and execute the next step; if not, turn off the hydrogen production power supply and the hydrogen production equipment to stop hydrogen production, and control the system power supply and control system to start the energy-saving mode;

[0021] Step 24, determine whether the adjusted output voltage is not lower than the second threshold value, if so, maintain the current state; if not, turn off the hydrogen production power supply and hydrogen production equipment, and stop hydrogen production.

[0022] Step 25, determine whether the output voltage after adjustment to stop hydrogen production is greater than the first threshold value, if so, restart the hydrogen production power supply, and the current limit value of the hydrogen production power supply will increase step by step to supply power to the electrolyzer.

[0023] Preferably or optionally, the method for increasing the current limiting value in steps further comprises the following steps:

[0024] Step 251, increasing the current of the hydrogen production power supply, the current increase amount being a predetermined proportion of the full load current of the hydrogen production equipment;

[0025] Step 252, determine whether the output voltage is greater than the second threshold stable time is greater than a predetermined time; if so, execute the next step; if not, reduce the current of the hydrogen production power supply to the previous state;

[0026] Step 253, repeat the above steps 251 to 252 until the hydrogen production equipment is fully loaded.

[0027] Preferably or optionally, the first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

[0028] Preferably or optionally, the method further comprises the steps of:

[0029] Obtain whether the output power of the photovoltaic power generation module is lower than the preset power threshold. If so, shut down the external power supply and connect to the dummy load detection system;

[0030] If the current and voltage of the dummy load detection system are higher than the preset power threshold and are stable within a predetermined time, the system starts to output power to the outside.

[0031] The present invention relates to a photovoltaic hydrogen production power supply method and system, which has the following beneficial effects compared to the prior art: the photovoltaic hydrogen production power supply system of this embodiment does not need to invert the collected direct current into alternating current, and can directly use the direct current generated by the solar photovoltaic panel to power hydrogen production and the system, which not only eliminates the need for inverters, rectifiers and other devices, but also has high power supply efficiency and low loss. In addition, the direct current generated by the photovoltaic power generation device is used to power the hydrogen production equipment and control system, eliminating the need for batteries for energy storage, reducing space occupied, and reducing product costs. Its power supply method uses dynamic intelligent adjustment of the hydrogen production rate, which achieves hydrogen production with surplus electricity while ensuring the stability of the system power supply, thereby enhancing the stability of the photovoltaic hydrogen production power supply system and solving the volatility characteristics of photovoltaic hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a block diagram of the power supply system in Example 1 of the present invention.

[0033] Figure 2 It is a structural block diagram of the power distribution management design of the power supply system in Example 1 of the present invention.

[0034] Figure 3 It is a structural block diagram of power management when the MPPT controller is started and stopped in Example 1 of the present invention.

[0035] Figure 4 It is a flowchart of the power supply method in Embodiment 2 of the present invention.

[0036] Figure 5 It is a flowchart of energy distribution management in Example 2 of the present invention. DETAILED DESCRIPTION

[0037] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0038] Example 1

[0039] See attached Figures 1 to 3 , a photovoltaic hydrogen production power supply system, including: a photovoltaic power generation module, a photovoltaic controller, a control system power supply and a hydrogen production power supply.

[0040] Wherein, the photovoltaic power generation module is a photoelectric conversion device that can absorb solar radiation to generate direct current. The photovoltaic controller is preferably an MPPT controller, which is connected to the photovoltaic power generation module circuit, suitable for real-time detection of the power generation voltage of the solar panel, and tracking the maximum output power of the photovoltaic power generation module. Through maximum power tracking, more electricity can be output, thereby improving the hydrogen production efficiency of the hydrogen production equipment. The control system power supply is connected to the photovoltaic controller signal circuit, receives a part of the direct current generated by the photovoltaic power generation module, and supplies power to the control system. The control system includes a control system of the photovoltaic part, a hydrogen production equipment, and a control and detection unit on the hydrogen filling equipment. The control system includes but is not limited to functional units such as an MPPT controller, a hydrogen production control unit, an environmental safety monitoring unit, a hydrogen production power supply work management unit, a hydrogen production condition detection unit, and a hydrogen production purity detection unit. The hydrogen production power supply is connected to the photovoltaic controller signal circuit, receives another part of the direct current generated by the photovoltaic power generation module, and supplies power to the hydrogen production equipment. The hydrogen production equipment adopts an electrolyzer hydrogen production and filling integrated machine or a hydrogen production and filling integrated exchange cabinet, which has relatively excellent adaptability to wide power fluctuations in hydrogen production. The electrolyzer is the main equipment used to produce hydrogen by electrolyzing water. PEM electrolyzer is the preferred choice for photovoltaic hydrogen production because its rapid response capability is more adaptable to the volatility of green electricity and the hydrogen purity is higher.

[0041] Among them, the photovoltaic controller is connected to the control system power supply and the hydrogen production power supply circuit respectively. Simply put, one of the circuits is used to power the control system (including sensor detection device, display screen, hydrogen filling device solenoid valve, hydrogen exchange compartment door control device, etc.) in the micro hydrogen production and charging integrated machine or hydrogen production and charging integrated exchange cabinet (control system power supply), and the other circuit is used to power the PEM electrolyzer separately (hydrogen production power supply). Based on this, the photovoltaic controller transmits the output DC power to the control system power supply, and then the control system power supply powers the control system. The control system power supply can be a DC / DC DC power supply. The DC / DC circuit in the MPPT controller plays a buck-boost role and tracks the maximum power point of the MPPT controller. Another circuit transmits the output DC power to the hydrogen production power supply, and then the hydrogen production power supply powers the electrolyzer. The hydrogen production power supply uses DC power for DC / CC constant current power supply, that is, the DC / CC circuit is a DC voltage to constant current source output, which is used to convert the front-end voltage output source into a current source output, and use the current source to drive the PEM electrolyzer to electrolyze water. The DC / CC circuit is an adjustable constant current source circuit or an adjustable LC current limiting source circuit; refer to the attached Figure 2 , R1 and A1 form a current detection amplifier circuit to measure the current value, and R2 and R3 voltage divider detection circuit detect the output voltage VCC voltage value. VCC is the voltage of the output single control system power supply and hydrogen production power supply. When dynamically adjusted, the control system detects the voltage value of VCC and compares it with the threshold value, and outputs PWM / DAC or other types of signals to control and adjust the output value of the constant current source of the hydrogen production power supply. When the load current changes, the current value of the constant current circuit will automatically adjust.

[0042] Compared with the existing technicians, the photovoltaic hydrogen production power supply system in this embodiment has the following advantages: the photovoltaic hydrogen production power supply system in this embodiment does not need to invert the collected DC power into AC power, and can directly use the DC power generated by the solar photovoltaic panel to power hydrogen production and the system, which not only saves the inverter, rectifier and other devices, but also has high power supply efficiency and low loss. In addition, the DC power generated by the photovoltaic power generation device is used to power the hydrogen production equipment and the control system, eliminating the need for batteries for energy storage, reducing the occupied space and reducing product costs.

[0043] Example 2

[0044] On the one hand, the photovoltaic power generation module is greatly affected by factors such as weather, season, dust, fallen leaves and equipment operation conditions, which will cause the energy generated by the photovoltaic power generation module to have strong volatility. The existing technology uses storage batteries as intermediate units to overcome the above problems, but for small and micro hydrogen production and filling equipment, the solution of using storage batteries as intermediate units is not applicable. On the other hand, for large hydrogen production and filling systems, the required power of the control system is not large, but for small and micro hydrogen production and filling equipment, since the power generation power of the photovoltaic power generation module is small and the hydrogen production requirements are small, the proportion of power required by the control system power supply is relatively large; especially when the front-end photovoltaic power supply is insufficient, the proportion of power required by the control system power supply is more prominent. Therefore, while keeping the entire photovoltaic hydrogen production system small, it becomes particularly important to maximize the use of photovoltaic hydrogen production.

[0045] Based on the photovoltaic hydrogen production power supply system in Example 1, this embodiment proposes a photovoltaic hydrogen production power supply method. Figure 4 , the method also includes the following steps: obtaining the output voltage of the photovoltaic controller; then dynamically adjusting the energy allocation management of the control system power supply and the hydrogen production power supply according to the output voltage of the photovoltaic controller, and the power supply priority of the control system power supply is higher than the power supply of the hydrogen production electrolyzer. In other words, on the basis of ensuring the normal operation of the system power supply, the use of the surplus power hydrogen production power supply is considered to enhance the power supply stability of the photovoltaic hydrogen production power supply system.

[0046] The photovoltaic power generation module plays a buck-boost role through the DC / DC circuit built into the MPPT controller, tracking the maximum power point of the MPPT controller, and can output more electricity, thereby improving the hydrogen production efficiency of the hydrogen production equipment.

[0047] See attached Figure 5, the energy distribution management method also includes the following steps: Step 21, determine whether the output voltage is greater than the first threshold value, if so, keep the control system power supply and hydrogen production power supply in normal operation; if not, start the energy distribution management program and execute the next step; Step 22, determine whether the output voltage is greater than the second threshold value; if so, keep the control system power supply and hydrogen production power supply in normal operation; if not, execute the next step; Step 23, determine whether the output voltage is greater than the third threshold value; if so, increase the output voltage to greater than the second threshold value by current limiting processing of the hydrogen production power supply, and execute the next step; if not, turn off the hydrogen production power supply and the hydrogen production equipment to stop hydrogen production, and at the same time control the system power supply and the control system to start the energy-saving mode; Step 24, determine whether the adjusted output voltage is greater than the second threshold value, if so, maintain the current state; if not, turn off the hydrogen production power supply and the hydrogen production equipment to stop hydrogen production; Step 25, determine whether the adjusted output voltage is greater than the first threshold value, if so, start the hydrogen production power supply, and the current limit value of the hydrogen production power supply will step up to power the electrolyzer.

[0048] Among them, the first threshold is greater than the second threshold, and the second threshold is greater than the third threshold. The first threshold is the warning voltage to which the output voltage of the photovoltaic controller drops. In the power sufficient state, the output voltage of the photovoltaic controller is a fixed voltage value V, which is greater than the first threshold. When the output voltage is higher than the first threshold, and is within the voltage input range of the control system power supply and the hydrogen production power supply, the hydrogen production device is operating normally. The second threshold is the voltage required for the control system power supply to maintain the operation of the control system. In actual operation, the second threshold is not a fixed value, and changes relatively with the change of the control system load. The third threshold is at least the voltage required for the control system power supply to maintain the control system in an energy-saving state. It can be understood that the third threshold is greater than or equal to the output power supply of the control system power supply to maintain the standby voltage required by the control system.

[0049] That is to say, the method in which the hydrogen production current value will step up also includes the following steps: step 251, increase the current of the hydrogen production power supply, and the current increase amount is a predetermined proportion of the full-load current of the hydrogen production equipment; step 252, determine whether the output current is greater than the second threshold stabilization time is greater than the predetermined time; if so, execute the next step; if not, reduce the current of the hydrogen production power supply to the previous state; step 253, repeat the above steps 251 to 252 until the hydrogen production equipment can be fully loaded. Because the voltage value at this time is the output voltage adjusted by reducing the output power of the photovoltaic controller. At this time, the control system cannot accurately obtain the power output of the photovoltaic controller. The step-up is the process of trying to load. For example, first add 1 / 10 of the full-load hydrogen production current, monitor whether the output voltage of the MPPT controller can be restored to the target second threshold and above, monitor for a period of time, and after stabilization, add to 2 / 10, detect the output voltage of the MPPT controller, and so on, perform gradient loading, if the photovoltaic end power is sufficient, it can be added to full load. When the output voltage of the monitored MPPT controller is adjusted less than the target second threshold, stop loading. By dynamically adjusting the second threshold value and the third threshold value, the hydrogen production power supply and the hydrogen production device are restored to a normal operating state.

[0050] In order to solve the problem that solar energy is not enough to supply power to the system for stable standby, the following scheme is adopted to protect the photovoltaic hydrogen production system. The method also includes the following steps: obtaining whether the output power of the photovoltaic power generation module is lower than the preset power threshold, if so, shutting down the external power supply and connecting to the dummy load detection system; detecting that the current and voltage of the dummy load detection system are higher than the preset power threshold and stable within a certain period of time, then starting to output power to the outside.

[0051] In other words, the input end of the MPPT controller will detect whether the output power of the photovoltaic power generation module is lower than the preset power threshold. If it is lower than the preset power threshold, the external power supply will be shut down. During this process, a dummy load system will be connected. When it is detected that the current and voltage are higher than the preset power threshold and are stable for a certain period of time, the external power supply will be started to protect the hydrogen production equipment.

[0052] See attached Figure 3, R4 and A2 are current detection amplifiers, converted into voltage signals, and compared by a comparator at A3. Vref is the reference power supply at one end of the comparator, which is set according to the actual situation. When the current detected is greater than the set comparison threshold, the output of A3 will reverse. One end of A3 is connected to the switch tube P1 of the dummy load RL, and A4 is an inverter, that is, when the front end of A4 is high level, the back end is low level, and the output of A4 is connected to the switch tube control end P2, so that when the load end RL is connected, the external output VCC is disconnected. This circuit can be derived with a hysteresis circuit and a delayed opening switch control end, etc., to prevent the back end from oscillating and starting, and play a role in protecting the hydrogen production equipment.

[0053] Compared with the existing technical personnel, the photovoltaic hydrogen production power supply system and method in this embodiment have the following advantages: the photovoltaic hydrogen production power supply system in this embodiment does not need to invert the collected DC power into AC power, and can directly use the DC power generated by the solar photovoltaic panel to power hydrogen production and the system, which not only eliminates the need for inverters, rectifiers and other devices, but also has high power supply efficiency and low loss. In addition, the DC power generated by the photovoltaic power generation device is used to power the hydrogen production equipment and control system, eliminating the need for batteries for energy storage, reducing space occupied, and reducing product costs. Its power supply method uses dynamic intelligent adjustment of the hydrogen production rate, which achieves hydrogen production with surplus power while ensuring the stability of the system power supply, thereby enhancing the stability of the photovoltaic hydrogen production power supply system.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A photovoltaic hydrogen production power supply system, characterized in that: include: Photovoltaic power generation module absorbs solar energy and converts it into electrical energy; A photovoltaic controller, connected to the photovoltaic power generation module circuit, suitable for tracking and obtaining the maximum output power of the photovoltaic power generation module; A control system power supply is connected to the photovoltaic controller signal circuit, receives a portion of the direct current generated by the photovoltaic power generation module, and supplies power to the control system; The hydrogen production power supply is connected to the photovoltaic controller signal circuit, receives another part of the direct current generated by the photovoltaic power generation module, and supplies power to the hydrogen production equipment.

2. The photovoltaic hydrogen production power supply system according to claim 1, characterized in that: The control system power supply is a DC / DC regulated direct current power supply.

3. The photovoltaic hydrogen production power supply system according to claim 1, characterized in that: The hydrogen production power supply uses direct current as a DC / CC constant current direct current power supply.

4. The photovoltaic hydrogen production power supply system according to claim 1, characterized in that: The photovoltaic controller is an MPPT controller.

5. The photovoltaic hydrogen production power supply system according to claim 1, characterized in that: The hydrogen production equipment adopts an electrolytic cell to produce hydrogen filling device.

6. A power supply method based on the photovoltaic hydrogen production power supply system according to any one of claims 1 to 5, characterized in that: The method further comprises the steps of: Step 1: Obtain the output voltage of the photovoltaic controller; Step 2: Dynamically adjust the energy distribution management of the control system power supply and the hydrogen production power supply according to the output voltage of the photovoltaic controller.

7. The photovoltaic hydrogen production and power supply method according to claim 6, characterized in that: The method further comprises the steps of: Step 21, judging whether the output voltage is greater than a first threshold value, if so, maintaining the normal operation state of the control system power supply and the hydrogen production power supply; if not, starting the energy distribution management program and executing the next step; Step 22, determine whether the output voltage is greater than a second threshold; if so, maintain the normal operation of the control system power supply and the hydrogen production power supply; if not, proceed to the next step; Step 23, determine whether the output voltage is greater than the third threshold value; if so, reduce the amount of hydrogen production by limiting the current of the hydrogen production power supply, reduce the total power consumption load, increase the output voltage to the second threshold value, and execute the next step; if not, turn off the hydrogen production power supply and the hydrogen production equipment to stop hydrogen production, and control the system power supply and control system to start the energy-saving mode; Step 24, determine whether the adjusted output voltage is not lower than the second threshold value, if so, maintain the current state; if not, turn off the hydrogen production power supply and hydrogen production equipment, and stop hydrogen production. Step 25, determine whether the output voltage after adjustment to stop hydrogen production is greater than the first threshold value, if so, restart the hydrogen production power supply, and the current limit value of the hydrogen production power supply will increase step by step to supply power to the electrolyzer.

8. The photovoltaic hydrogen production and power supply method according to claim 7, characterized in that: The method for increasing the current limit value in steps also includes the following steps: Step 251, increasing the current of the hydrogen production power supply, the current increase amount being a predetermined proportion of the full load current of the hydrogen production equipment; Step 252, determining whether the output voltage is greater than the second threshold and the stable time is greater than a predetermined time; If yes, proceed to the next step; if no, reduce the current of the hydrogen production power supply to the previous state; Step 253, repeat the above steps 251 to 252 until the hydrogen production equipment is fully loaded.

9. The photovoltaic hydrogen production and power supply method according to claim 7, characterized in that: The first threshold is greater than the second threshold, and the second threshold is greater than the third threshold.

10. The photovoltaic hydrogen production and power supply method according to claim 6, characterized in that: The method further comprises the steps of: Obtain whether the output power of the photovoltaic power generation module is lower than the preset power threshold. If so, shut down the external power supply and connect to the dummy load detection system; If the current and voltage of the dummy load detection system are higher than the preset power threshold and are stable within a predetermined time, the system starts to output power to the outside.

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