Wide-voltage photovoltaic hydrogen production device and control method

Abstract

The invention relates to the technical field of photovoltaic hydrogen production converters, in particular to a wide-voltage photovoltaic hydrogen production device and a control method.The device comprises two inductors Li and Lb, diodes D1 and D2, two capacitors CL and CH, a three-port converter, N SM modules, a DC-DC converter, a hydrogen production device and a photovoltaic power generation unit PV, one port of the three-port converter is connected with the photovoltaic power generation unit, and the other port of the three-port converter is connected with the photovoltaic power generation unit; one port is connected with a high-voltage output capacitor to the ground, and the last port is connected with a hydrogen production device. Most of power is directly connected to the hydrogen production device through a path of the three-port converter, and a small part of power is used for processing part of current through the DC-DC converter to manage power flow between a photovoltaic power generation unit and the hydrogen production device and then is output to the hydrogen production device, so that power can be continuously supplied to the hydrogen production device while the power conversion stage number is reduced, and the power conversion efficiency is improved. The rated value of the DC-DC converter is reduced, so that the efficiency is improved; and the topological structure is simple, and the size and the cost are greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic hydrogen production converters, and in particular to a wide-voltage photovoltaic hydrogen production device and a control method. Background Art

[0002] Photovoltaic hydrogen production technology, as a cutting-edge application of renewable energy, has received widespread attention in recent years. Its core principle is to use photovoltaic systems to convert solar energy into electrical energy, and then generate hydrogen through the process of water electrolysis. This technology can not only effectively reduce dependence on fossil fuels, but also significantly reduce greenhouse gas emissions, providing strong support for achieving sustainable development goals.

[0003] With the improvement of photovoltaic module efficiency and the reduction of cost, the economic efficiency of photovoltaic power generation has gradually increased. However, traditional photovoltaic hydrogen production devices still face many challenges in power conversion and management. Traditional photovoltaic hydrogen production devices usually mainly use low-voltage output, and energy loss may occur during the transmission of electricity from photovoltaic modules to hydrogen production devices. The energy conversion efficiency is low, resulting in a large amount of light energy not being effectively utilized. The energy loss during the electrolysis of water further affects the hydrogen production and the efficiency of the overall system. In addition, photovoltaic power generation is affected by weather and light changes, and the output voltage and current fluctuate greatly. It is difficult for traditional systems to effectively adjust, resulting in instability in hydrogen production. The complexity and high cost of the system also increase the difficulty of maintenance, and the durability and reliability of the components are insufficient, which may lead to frequent failures and replacements. At the same time, traditional systems may produce high harmonic distortion, affecting the stability of the output voltage. These problems limit the efficiency, reliability and economy of traditional photovoltaic hydrogen production devices. Summary of the invention

[0004] The purpose of the present invention is to provide a wide voltage photovoltaic hydrogen production device and a control method, aiming to solve the technical problems of traditional photovoltaic hydrogen production devices, such as complex system integration, multiple power conversion stages, mainly low voltage output and low efficiency.

[0005] To achieve the above object, the present invention provides a wide voltage photovoltaic hydrogen production device, comprising an inductor L i , diodes D1, D2, two capacitors C L , C H , three-port converter, SM module, DC-DC converter, photovoltaic panel PV and hydrogen generator;

[0006] N SM modules are arranged in series as submodules, and the voltage across the two ends is V ac ;

[0007] The three-port converter is composed of N SM modules connected in series to form an upper bridge arm to bear high voltage, a switch tube S wL As the lower bridge arm, the high voltage end capacitor C HConnect the ground and the DC-DC converter, the low voltage capacitor C L Direct access to hydrogen generator;

[0008] The positive pole of the photovoltaic panel PV is connected to the inductor L i The negative pole of the photovoltaic panel PV is connected to the power ground, and the inductor L i The output end of the N SM modules is connected to the input end and the anode of the diode D1, and the output end of the N SM modules is connected to the anode of the diode D2 and the switch tube S wL The drain;

[0009] The input end of the three-port converter is connected in parallel to the photovoltaic panel PV, and the output end of the three-port converter is connected in series with the input end of the DC-DC converter and in parallel with the input end of the hydrogen generator;

[0010] The input end of the DC-DC converter is connected in series to the input end of the hydrogen generator.

[0011] Among them, one port of the three-port converter is connected to the two ends of the photovoltaic panel PV to input direct current, and one port is connected to the high-voltage end capacitor C H Two ends, one port is connected to the low voltage end capacitor C L Both ends.

[0012] The DC-DC converter is composed of two switch tubes S b1 , S b2 and an inductor L b Composition, switch tube S b1 The source is connected to the switch S b2 The drain and inductance L b The input end of the switch tube S b2 The source is connected to the power ground, the inductor L b The output end is connected to the hydrogen generator, namely V b The positive electrode of the hydrogen generator is connected to the power supply ground.

[0013] Wherein, the gates of the power switch tubes of the wide-voltage photovoltaic hydrogen production device are respectively connected to the controller.

[0014] The present invention also proposes a control method for a wide voltage photovoltaic hydrogen production device, using the wide voltage photovoltaic hydrogen production device, comprising the following steps:

[0015] Step 1: Perform MPPT control on the output power of the photovoltaic panel PV;

[0016] Step 2: Adjust the working mode according to the output voltage of the photovoltaic panel PV, which can be low voltage output mode or high voltage output mode;

[0017] Step 3: In low voltage output mode, bypass the SM module and only need to control the switch tube SwL The conduction or shutdown directly supplies power to the hydrogen generator;

[0018] Step 4: In high-voltage output mode, the output voltage of each SM module is added together in the series connection to form a higher total output voltage;

[0019] Step 5: Use a pair of complementary PWM waves to drive the DC-DC converter according to the current i H ,I bb and V o , control switch tube S b1 , S b2 The duty cycle is used to control the current to match the voltage required by the hydrogen generator.

[0020] Optional, high voltage output mode is divided into two working modes: when there is V in <V o When the voltage of the photovoltaic panel PV is less than the configured voltage of the hydrogen generator, it is the working mode 1; when there is V in ≥V o When the relationship is like this, that is, when the voltage of the photovoltaic panel PV is greater than the configured voltage of the hydrogen generator, it is the second working mode.

[0021] Optionally, in working mode 1 or working mode 2, the total output voltage V ac The waveform duty cycle is d SM With input voltage V in , output voltage V o 、V H All have the following relationship: V in =V o d SM +(1-d SM )(V H +V o ).

[0022] The present invention provides a wide voltage photovoltaic hydrogen production device and a control method, the device includes two inductors L i , L b , diodes D1, D2, two capacitors C L , C H , three-port converter, N SM modules, DC-DC converter, a hydrogen generator and photovoltaic power generation unit PV, one port of the three-port converter is connected to the photovoltaic power generation unit, one port is connected to the high-voltage output capacitor to the ground, and the last port is connected to the hydrogen generator. The present invention has two working modes: low voltage and high voltage. When the hydrogen generator needs low voltage, each SM is directly bypassed, and only the following S wLThe switching action powers the hydrogen generator. Through the processing of the three-port converter, most of the voltage is connected to the hydrogen generator through a direct path for continuous power supply. When the hydrogen generator requires high voltage output, multiple half-bridge sub-modules are connected in series to easily achieve high voltage output. Each module only needs to process a relatively low voltage, which reduces the voltage carrying requirements of a single module. Since the voltage is distributed to multiple modules, the voltage and current pressure faced by a single module is relatively small, thereby enhancing its reliability. At this time, the sub-module string SM is started, and this module string and the switch tube S wL Together, we can achieve boost output high voltage V H , to match the voltage requirement of hydrogen production, most of the power is directly connected to the hydrogen generator through a three-port converter, and a small part of the power will be processed by a DC-DC converter to manage the power flow between the photovoltaic power generation unit and the hydrogen generator, and then output to the hydrogen generator, reducing the number of power conversion levels while continuously powering the hydrogen generator, realizing the reduction of the rated value of the DC-DC converter, thereby improving efficiency; and the topology is simple, greatly reducing the size and cost; the high and low voltage working modes achieve wide voltage output to match the voltage requirement of hydrogen production; the SM module series bears high voltage relative to the traditional switch tube, enabling it to flexibly adjust the output within a wider voltage range, adapt to the changes in photovoltaic power generation, and achieve efficient energy conversion and reduce switching losses. Its low harmonic distortion characteristics improve the quality of the output voltage and ensure the stability of hydrogen production. The design of the SM module series allows the number of modules to be flexibly increased or decreased according to demand to adapt to different voltage and power requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a structural schematic diagram of a wide-voltage photovoltaic hydrogen production device of the present invention.

[0025] Figure 2 The switch tube S of the wide voltage photovoltaic hydrogen production device of the present invention is used in the low voltage working mode. wL Schematic diagram of the operating device in conduction mode.

[0026] Figure 3 The switch tube S of the wide voltage photovoltaic hydrogen production device of the present invention is used in the low voltage working mode. wL Schematic diagram of shutdown operation.

[0027] Figure 4The high voltage working mode of the wide voltage photovoltaic hydrogen production device of the present invention is that the DC-DC converter is not enabled, the SM working mode is the input mode, and the switch tube S wL Schematic diagram of conduction operation.

[0028] Figure 5 The high voltage working mode of the wide voltage photovoltaic hydrogen production device of the present invention is that the DC-DC converter is not enabled, the SM working mode is the bypass mode, and the switch tube S wL Schematic diagram of conduction operation.

[0029] Figure 6 The high voltage working mode of the wide voltage photovoltaic hydrogen production device of the present invention is that the DC-DC converter is not enabled, the SM working mode is the input mode, and the switch tube S wL Shutdown operation diagram.

[0030] Figure 7 The high voltage working mode of the wide voltage photovoltaic hydrogen production device of the present invention is that the DC-DC converter is not enabled, the SM working mode is the bypass mode, and the switch tube S wL Shutdown operation diagram.

[0031] Figure 8 The high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention is the SM working mode, and the switch tube S wL , S b1 Turn off, switch S b2 Schematic diagram of conduction operation.

[0032] Fig. 9 In the high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention, the SM working mode is the bypass mode, and the switch tube S b2 The switch tube S is turned on. wL , S b1 Shutdown operation diagram.

[0033] Fig.10 In the high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention, SM is not enabled, and the switch tube S b1 On, S b2 , S wL Schematic diagram of operation during shutdown.

[0034] Fig.11 In the high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention, SM is not enabled, and the switch tube S b2 On, S b1 , S wL Shutdown operation diagram.

[0035] Fig.12The high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention is that the SM working mode is the input mode, and the switch tube S wL , S b2 The switch tube S is turned on. b1 Schematic diagram of operation during shutdown.

[0036] Fig.13 The high-voltage working mode 2 of the wide-voltage photovoltaic hydrogen production device of the present invention is that the SM working mode is the input mode, and the switch tube S wL , S b1 The switch tube S is turned on. b2 Schematic diagram of the device operating when shut down.

[0037] Fig.14 is the high voltage working mode 1 and 2 of the wide voltage photovoltaic hydrogen production device of the present invention. ac 、V ab Output voltage waveform and control switch tube S wL PWM pulse waveform diagram. DETAILED DESCRIPTION

[0038] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0039] See also Figure 1 The present invention provides a wide voltage photovoltaic hydrogen production device, comprising an inductor L i , diodes D1, D2, two capacitors C L , C H , three-port converter, SM module, DC-DC converter, photovoltaic panel PV and hydrogen generator;

[0040] N SM modules are arranged in series as submodules, and the voltage across the two ends is V ac ;

[0041] The three-port converter is composed of N SM modules connected in series to form an upper bridge arm to bear high voltage, a switch tube S wL As the lower bridge arm, the high voltage end capacitor C H Connect the ground and the DC-DC converter, the low voltage capacitor C L Direct access to hydrogen generator;

[0042] The positive pole of the photovoltaic panel PV is connected to the inductor L i The negative pole of the photovoltaic panel PV is connected to the power ground, and the inductor L iThe output end of the N SM modules is connected to the input end and the anode of the diode D1, and the output end of the N SM modules is connected to the anode of the diode D2 and the switch tube S wL The drain;

[0043] The input end of the three-port converter is connected in parallel to the photovoltaic panel PV, and the output end of the three-port converter is connected in series with the input end of the DC-DC converter and in parallel with the input end of the hydrogen generator;

[0044] The input end of the DC-DC converter is connected in series to the input end of the hydrogen generator.

[0045] One port of the three-port converter is connected to the two ends of the photovoltaic panel PV to input direct current, and one port is connected to the high-voltage capacitor C H Two ends, one port is connected to the low voltage end capacitor C L Both ends.

[0046] The DC-DC converter consists of two switching tubes S b1 , S b2 and an inductor L b Composition, switch tube S b1 The source is connected to the switch S b2 The drain and inductance L b The input end of the switch tube S b2 The source is connected to the power ground, the inductor L b The output end is connected to the hydrogen generator, namely V b The positive electrode of the hydrogen generator is connected to the power supply ground.

[0047] The gates of the power switch tubes of the wide-voltage photovoltaic hydrogen production device are respectively connected to the controller.

[0048] Specifically, the wide voltage photovoltaic hydrogen production device has two working modes: low voltage output mode and high voltage output mode; and the high voltage output mode is further divided into two working modes: when there is V in <V o When the voltage of the photovoltaic power generation unit PV is less than the configured voltage of the hydrogen generator, it is the working mode 1; when there is V in ≥V o When the relationship is like this, that is, the voltage of the photovoltaic power generation unit PV is greater than the configured voltage of the hydrogen generator, it is the second working mode;

[0049] See also Figures 2 to 13 , the following is a detailed description:

[0050] Low voltage working mode: D1 is cut off, capacitor C H The voltage remains unchanged, and the controller controls the SM bypass, that is, controls the switch tube S 1_1 , S 2_1, to S n_1 Shutdown, S 1_2 , S 2_2 To S n_2 Conducting, diode D 1_1 , D 1_2 , D 2_1 , D 2_2 To D n_1 , D n_2 Cut off, the controller controls the switch tube S b1 , S b2 Shutdown, capacitors C1, C2 to C n The voltage remains unchanged, the inductance L b The voltage remains unchanged; Figure 2 As shown, D2 is cut off, inductor L i Charging, the controller controls the switch tube S wL conduction, capacitor C L Discharging to supply power to the hydrogen generator;

[0051] like Figure 3 As shown, the inductor L i Discharge, D2 is turned on, and the controller controls the switch tube S wL Turn off, capacitor C L Charge;

[0052] High-voltage working mode: Start the SM module to bear the high voltage, and the switch tube S 1_1 , S 2_1 , to S n_1 With S 1_2 , S 2_2 To S n_2 The controller controls its on / off to enter the input mode or bypass mode, so that it is connected to the switch tube S wL The switch action cooperates to supply power to the hydrogen generator; when V in <V o When the voltage of the photovoltaic power generation unit PV is less than the configured voltage of the hydrogen generator, it is the high-voltage working mode 1. In this mode, diodes D1 and D2 are both in the cut-off state, and the SM module remains in the on state, that is, the controller controls the series-connected sub-modules to be in the input mode or the bypass mode, so that the diode D1 is in the reverse bias.

[0053] In high voltage operation mode 1, in the first switching state, the inductor L i Charging, because the N SM modules and switch tube S in series wL are both in the on state. When the SM working mode is the input mode, the diode D 1_1 , D 2_1 To D n_1 Forward biased, diode D 1_2 , D 2_2 , Dn_2 Reverse bias, capacitors C1, C2 to C n The voltage increases, the inductor L i Start by connecting N SM modules and switch tube S in series. wL Storage energy, capacitor C L Single-stage conversion is used to directly supply power to the hydrogen generator.

[0054] When the SM works in bypass mode, the diode D 1_1 , D 1_2 , D 2_1 , D 2_2 To D n_1 , D n_2 Reverse bias, capacitors C1, C2 to C n The voltage remains unchanged, the inductor L i Start by connecting N SM modules and switch tube S in series. wL Storage energy, capacitor C L Single-stage conversion is used to directly supply power to the hydrogen generator.

[0055] Similarly, in the second switching state, the switch tube S wL When the SM working mode is the input mode, the diode D 1_1 , D 2_1 To D n_1 Forward biased, diode D 1_2 , D 2_2 , D n_2 Reverse bias, capacitors C1, C2 to C n The voltage increases, the inductance L i Start with diode D2 and capacitor C L Release stored energy.

[0056] When the SM works in bypass mode, the diode D 1_1 , D 1_2 , D 2_1 , D 2_2 To D n_1 , D n_2 Reverse bias, capacitors C1, C2 to C n The voltage remains unchanged, the inductance L i Start with diode D2 and capacitor C L During this period, most of the output power also passes through the lower port capacitor C L Therefore, in high-voltage operation mode 1, power is directly output from the three-port converter to the hydrogen generator.

[0057] When V in ≥V oWhen the voltage of the photovoltaic power generation unit PV is greater than the configured voltage of the hydrogen generator, it is the high voltage working mode 2. In this mode, the switch S wL In both switching states, it is in a completely off state. The working mode of the N SM modules connected in series is used to control whether the hydrogen generator is powered after partial power processing by the DC-DC converter, or whether the voltage at the output end of the three-port converter is directly output to the hydrogen generator without being processed by the DC-DC converter.

[0058] In the first switching state, the N SM modules in series are in bypass or input mode, diode D1 is reverse biased, and diode D2 is turned on. The inductor starts to store energy through the series SM and diode D2, and the voltage difference is V in -V o The power of the hydrogen generator is passed through the lower capacitor C L supply.

[0059] In the second switching state, the N SM modules in series are turned off and disabled, while the switch S wL The diode D1 is now conducting. i With input voltage V in Together, a DC-DC converter is used to provide the required voltage for the hydrogen generator using two-stage power conversion.

[0060] When V ac When the voltage across the two ends is large enough, the bridge arm current i SM In the reverse direction, with the current i L Flows to capacitor C with lower potential H , capacitors C1, C2 to C n The voltage decreases, such as Fig.12 As shown, the switch tube S in the DC-DC converter b1 Turn off, switch tube S b2 The capacitor C H The voltage increases;

[0061] like Fig.13 As shown, the switch tube S in the DC-DC converter b1 Conducting, switching tube S b2 Turn off, at this time the capacitor C H The voltage decreases, the inductance L b The voltage increases.

[0062] Furthermore, the present invention also proposes a control method for a wide voltage photovoltaic hydrogen production device, using the wide voltage photovoltaic hydrogen production device, comprising the following steps:

[0063] Step 1: Perform MPPT control on the output power of the photovoltaic panel PV;

[0064] Step 2: Adjust the working mode according to the output voltage of the photovoltaic panel PV, which can be low voltage output mode or high voltage output mode;

[0065] Step 3: In low voltage output mode, bypass the SM module and only need to control the switch tube S wL The conduction or shutdown directly supplies power to the hydrogen generator;

[0066] Step 4: In high-voltage output mode, the output voltage of each SM module is added together in the series connection to form a higher total output voltage;

[0067] Step 5: Use a pair of complementary PWM waves to drive the DC-DC converter according to the current i H ,I bb and V o , control switch tube S b1 , S b2 The duty cycle is used to control the current to match the voltage required by the hydrogen generator.

[0068] The following steps are explained in detail:

[0069] Step 1: First, perform MPPT control on the output power of the photovoltaic power generation unit PV to make the photovoltaic power generation unit output the ideal power size, and collect the voltage V in and current i L The reference value V of the maximum power point is calculated by the MPPT algorithm ref , the PI controller is based on V ref and the actual output voltage V in The error between them adjusts the PWM signal, thereby controlling the working state of the three-port converter. Through PWM control, the output voltage V in is regulated to the maximum power point V ref , achieving maximum power tracking.

[0070] Step 2: If the output voltage of the photovoltaic power generation unit is low due to outdoor light, temperature, etc., determine the input voltage V in The size is low voltage, at this time the working mode of the converter is low voltage output mode; if the output voltage V in is high voltage, and the converter works in high voltage output mode;

[0071] Step 3: In low voltage output mode, bypass SM and only need to control the switch tube S wL The conduction or shutdown directly supplies power to the hydrogen generator. According to the volt-second balance, the inductor L i Apply voltage, switch S wL The duty cycle is d WL , input voltage V in and V oThe relationship between V is as follows: in =V o (1-d WL ), so the controller adjusts the switching tube S wL The duty cycle of the PWM drive signal is WL , can output an adjustable low voltage within a certain range, and control the output waveform and switch tube S of the SM module through the controller wL The periods are the same as T. At this time, the three-port converter directly outputs power to the hydrogen generator;

[0072] Step 4: In high-voltage output mode, in the series connection, the output voltage of each SM is added together to form a higher total output voltage, so the entire SM series module bears the high voltage. Assume that the maximum output voltage of each half-bridge submodule is V SMN , there are N sub-modules connected in series, and the total output voltage of the entire SM module series is:

[0073] The high voltage output mode is divided into two working modes: When V in <V o When the voltage of the photovoltaic power generation unit PV is less than the configured voltage of the hydrogen generator, it is the working mode 1; when there is V in ≥V o When the relationship is like this, that is, the voltage of the photovoltaic power generation unit PV is greater than the configured voltage of the hydrogen generator, it is the second working mode;

[0074] In the high voltage output mode, regardless of working mode 1 or working mode 2, the total output voltage of the entire SM module in series is V ac The waveform duty cycle is d SM With input voltage V in , output voltage V o 、V H All have the following relationship: V in =V o d SM +(1-d SM )(V H +V o );

[0075] In working mode 1, the SM module is in the input mode or bypass mode in two switching states. At this time, its output voltage is always at a high level, so its duty cycle d SM =1, It can be concluded that within a period T, L i The current change at both ends is

[0076] In working mode 2, switch S wLIn both switching states, it is in a completely off state, so in working mode 2 d WL =0; From this we can conclude that within a period T, L i The current change at both ends is

[0077] The three-port converter corresponding to the SM module output voltage V is obtained through analysis. ac Waveform and Switching S wL Pulse V gwl Waveform Fig.14 During the high voltage operation mode 1, the SM module always outputs a high level, and the switch S wL In the presence of duty cycle d WL During high voltage operation mode 2, the SM module shapes the voltage V ac The waveform is determined by the duty cycle d SM The changing square wave, while the switch S wL remains off during the entire duration. Therefore, V ab The voltage output is a three-level voltage, which can have three different voltage changes due to the value of the photovoltaic output high voltage.

[0078] In the DC-DC converter, a pair of complementary PWM waves are used to drive the current i H ,I bb and V o , control switch tube S b1 , S b2 The duty cycle is used to control the current to match the voltage required by the hydrogen generator.

[0079] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A wide voltage photovoltaic hydrogen production device, characterized in that: Including inductor L i , diodes D1, D2, two capacitors C L , C H , three-port converter, SM module, DC-DC converter, photovoltaic panel PV and hydrogen generator; N SM modules are arranged in series as submodules, and the voltage across the two ends is V ac ; The three-port converter is composed of N SM modules connected in series to form an upper bridge arm to bear high voltage, a switch tube S wL As the lower bridge arm, the high voltage end capacitor C H Connect the ground and the DC-DC converter, the low voltage capacitor C L Direct access to hydrogen generator; The positive pole of the photovoltaic panel PV is connected to the inductor L i The negative pole of the photovoltaic panel PV is connected to the power ground, and the inductor L i The output end of the N SM modules is connected to the input end and the anode of the diode D1, and the output end of the N SM modules is connected to the anode of the diode D2 and the switch tube S wL The drain; The input end of the three-port converter is connected in parallel to the photovoltaic panel PV, and the output end of the three-port converter is connected in series with the input end of the DC-DC converter and in parallel with the input end of the hydrogen generator; The input end of the DC-DC converter is connected in series to the input end of the hydrogen generator.

2. The wide voltage photovoltaic hydrogen production device according to claim 1, characterized in that: One port of the three-port converter is connected to the two ends of the photovoltaic panel PV to input direct current, and one port is connected to the high-voltage capacitor C H Two ends, one port is connected to the low voltage end capacitor C L Both ends.

3. The wide voltage photovoltaic hydrogen production device according to claim 2, characterized in that: The DC-DC converter consists of two switching tubes S b1 , S b2 and an inductor L b Composition, switch tube S b1 The source is connected to the switch S b2 The drain and inductance L b The input end of the switch tube S b2 The source is connected to the power ground, the inductor L b The output end is connected to the hydrogen generator, namely V b The positive electrode of the hydrogen generator is connected to the power supply ground.

4. The wide voltage photovoltaic hydrogen production device according to claim 3, characterized in that: The gates of the power switch tubes of the wide-voltage photovoltaic hydrogen production device are respectively connected to the controller.

5. A control method for a wide voltage photovoltaic hydrogen production device, using the wide voltage photovoltaic hydrogen production device as described in any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: Perform MPPT control on the output power of the photovoltaic panel PV; Step 2: Adjust the working mode according to the output voltage of the photovoltaic panel PV, which can be low voltage output mode or high voltage output mode; Step 3: In low voltage output mode, bypass the SM module and only need to control the switch tube S wL The conduction or shutdown directly supplies power to the hydrogen generator; Step 4: In high-voltage output mode, the output voltage of each SM module is added together in the series connection to form a higher total output voltage; Step 5: Use a pair of complementary PWM waves to drive the DC-DC converter according to the current i H ,I bb and V o , control switch tube S b1 , S b2 The duty cycle is used to control the current to match the voltage required by the hydrogen generator.

6. The control method of the wide voltage photovoltaic hydrogen production device as claimed in claim 5, characterized in that: The high voltage output mode is divided into two working modes: When V in <V o When the voltage of the photovoltaic panel PV is less than the configured voltage of the hydrogen generator, it is the working mode 1; when there is V in ≥V o When the relationship is like this, that is, when the voltage of the photovoltaic panel PV is greater than the configured voltage of the hydrogen generator, it is the second working mode.

7. The control method of the wide voltage photovoltaic hydrogen production device as claimed in claim 6, characterized in that: In working mode 1 or working mode 2, the total output voltage V ac The waveform duty cycle is d SM With input voltage V in , output voltage V o 、V H All have the following relationship: V in =V o d SM +(1-d SM )(V H +V o ).

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