Wide-voltage photovoltaic hydrogen production device

Abstract

The utility model relates to the technical field of photovoltaic hydrogen production converters, in particular to a wide-voltage photovoltaic hydrogen production device which 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 is connected with a high-voltage output capacitor to the ground, and the last port is connected with a hydrogen production device. According to the utility model, 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 subjected to partial current treatment through the DC-DC converter to manage power flow between the photovoltaic power generation unit and the hydrogen production device, and then is output to the hydrogen production device; power can be continuously supplied to the hydrogen production device while the power conversion stage number is reduced, and 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 utility model relates to photovoltaic hydrogen production converter technical field, concretely relates to a wide voltage photovoltaic hydrogen production device. BACKGROUND

[0002] As a frontier application of renewable energy, photovoltaic hydrogen production technology has received widespread attention in recent years. Its core principle is to convert solar energy into electrical energy using a photovoltaic system, and then generate hydrogen gas through the process of water electrolysis. This technology not only effectively reduces dependence on fossil fuels, but also significantly reduces 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 economy of photovoltaic power generation gradually increases. However, traditional photovoltaic hydrogen production devices still face many challenges in power conversion and management. Traditional photovoltaic hydrogen production devices are usually low-voltage output-based, and energy loss may occur during the transmission of electrical energy from photovoltaic modules to hydrogen production devices, resulting in low energy conversion efficiency. A large amount of light energy is not effectively utilized, and energy loss in the water electrolysis process further affects hydrogen production, affecting the overall system efficiency. In addition, photovoltaic power generation is affected by weather and light changes, with large fluctuations in output voltage and current. Traditional systems are difficult to effectively regulate, causing instability in hydrogen production. The complexity of the system and high cost increase the difficulty of maintenance, and the durability and reliability of the components are insufficient, which may cause frequent failures and replacement. At the same time, the traditional system may generate 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

[0004] The utility model aims at providing a wide voltage photovoltaic hydrogen production device and control method, aiming at solving the technical problems of traditional photovoltaic hydrogen production devices, such as complex system integration, multiple power conversion stages, low-voltage output-based and low efficiency.

[0005] To achieve the above-mentioned purpose, the utility model provides a wide voltage photovoltaic hydrogen production device, which comprises an inductor L i , diodes D1, D2, two capacitors C L , C H , a three-port converter, an SM module, a DC-DC converter, a photovoltaic panel PV and a hydrogen generator.

[0006] N said SM module is arranged in series as a sub-module, and the voltage at both ends is V ac .

[0007] The three-port converter is respectively composed of N SM modules in series, and the upper bridge arm bears high voltage. One switch tube S wL acts as the lower bridge arm, and the high-voltage capacitor CH a low-voltage capacitor C L directly connected to a hydrogen generator;

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

[0009] an input end of the three-port converter is connected in parallel to the photovoltaic panel PV, an output end of the three-port converter is connected in series to an input end of the DC-DC converter and in parallel to an 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] wherein one port of the three-port converter is connected to input direct current between two ends of the photovoltaic panel PV, one port is connected to two ends of a high-voltage capacitor C H , and one port is connected to two ends of a low-voltage capacitor C L .

[0012] wherein the DC-DC converter is respectively composed of two switch tubes S b1 , S b2 and an inductor L b , a source of the switch tube S b1 is connected to a drain of the switch tube S b2 and an input end of the inductor L b , a source of the switch tube S b2 is connected to a power supply ground, and an output end of the inductor L b is connected to the hydrogen generator, i.e., a positive electrode of V b , and a negative electrode of the hydrogen generator is connected to the power supply ground.

[0013] wherein the gate of the power switch tube of the wide-voltage photovoltaic hydrogen production device is respectively connected to a controller.

[0014] The utility model provides a kind of wide-voltage photovoltaic hydrogen production device, including two inductors L i , L b , diode D1, D2, two capacitors C L , C H, three-port converter, N SM modules, DC-DC converter, a hydrogen generator and a photovoltaic power unit PV, one of the three-port converter ports is connected to the photovoltaic power unit, one is connected to the high-voltage output capacitor to the ground, and the last port is connected to the hydrogen generator. The utility model discloses two working modes of low pressure and high pressure, when the hydrogen generator needs low pressure, each SM is bypassed directly, only the following S wL Switching action supplies power to the hydrogen generator, and most of the voltage is connected to the hydrogen generator through the direct path of the three-port converter for continuous power supply. When the hydrogen generator needs high-voltage output, multiple half-bridge sub-modules can easily realize high-voltage output. Each module only needs to handle relatively low voltage, reducing the voltage bearing requirement of a single module. Since the voltage is distributed to multiple modules, the voltage and current pressure faced by a single module is small, thereby enhancing its reliability. At this time, the sub-module string SM is started. The module string and the switch tube S wL Together realize boost output high voltage V H To match the hydrogen voltage demand, most of the power is connected to the hydrogen generator through the direct path of the three-port converter, and a small part of the power is processed by the DC-DC converter to manage the power flow between the photovoltaic power unit and the hydrogen generator, and then output to the hydrogen generator. Reducing the number of power conversion stages while also continuously supplying power to the hydrogen generator, realizing the reduction of the rated value of the DC-DC converter, thereby improving the efficiency. The topology structure is simple, greatly reducing the size and cost. The high and low voltage working mode realizes wide voltage output to match the hydrogen voltage demand. The SM module string bears high voltage relative to the traditional switch tube, enabling it to flexibly adjust the output within a wide voltage range, adapting to changes in photovoltaic power generation while achieving efficient energy conversion and reducing switching loss. Its low harmonic distortion characteristic improves the quality of the output voltage, ensuring the stability of hydrogen production. The design of the SM module string 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 DRAWINGS

[0015] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0016] Figure 1 It is a structure diagram of a wide voltage photovoltaic hydrogen production device of the present application.

[0017] Figure 2 It is a switch tube S wLConducting operation device schematic diagram.

[0018] Figure 3 Is the low voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, switch tube S wL Off operation schematic diagram.

[0019] Figure 4 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, DC-DC converter is not enabled, SM working mode is input mode, switch tube S wL Conducting operation schematic diagram.

[0020] Figure 5 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, DC-DC converter is not enabled, SM working mode is bypass mode, switch tube S wL Conducting operation schematic diagram.

[0021] Figure 6 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, DC-DC converter is not enabled, SM working mode is input mode, switch tube S wL Off operation schematic diagram.

[0022] Figure 7 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, DC-DC converter is not enabled, SM working mode is bypass mode, switch tube S wL Off operation schematic diagram.

[0023] Figure 8 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, SM working mode is input mode, switch tube S wL , S b1 Off, switch tube S b2 Conducting operation schematic diagram.

[0024] Figure 9 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, SM working mode is bypass mode, switch tube S b2 Conducting, switch tube S wL , S b1 Off operation schematic diagram.

[0025] Figure 10 Is the high voltage working mode of the wide voltage photovoltaic hydrogen generator of the application, SM is not enabled, switch tube S b1 Conducting, S b2 , S wL Off operation schematic diagram.

[0026] Figure 11SM is not enabled, and the switch tube S b2 is turned on, and the switch tube S b1 is turned off. wL The running schematic diagram when the switch tube S

[0027] Figure 12 SM is enabled, and the switch tube S wL is turned on, and the switch tube S b2 is turned off. b1 The running schematic diagram when the switch tube S

[0028] Figure 13 SM is enabled, and the switch tube S wL is turned on, and the switch tube S b1 is turned off. b2 The running schematic diagram when the switch tube S DETAILED DESCRIPTION

[0029] Embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0030] Referring to Figure 1 , the present application provides a wide voltage photovoltaic hydrogen production device, which comprises an inductor L i , diodes D1 and D2, two capacitors C L , C H , a three-port converter, an SM module, a DC-DC converter, a photovoltaic panel PV and a hydrogen generator.

[0031] N SM modules are arranged in series as sub-modules, and the voltage between two ends is V ac .

[0032] The three-port converter is respectively composed of N SM modules in series, the upper bridge arm bears high voltage, one switch tube S wL serves as the lower bridge arm, the high-voltage end capacitor C H is connected to the ground and the DC-DC converter, and the low-voltage end capacitor C L is directly connected to the hydrogen generator.

[0033] The positive electrode of the photovoltaic panel PV is connected to the input end of the inductor L i , and the negative electrode of the photovoltaic panel PV is connected to the power supply ground, and the inductor L iThe output end of the controller is connected to the input end of the N SM modules, the anode of the diode D1, the output end of the N SM modules is connected to the anode of the diode D2, the drain of the switch tube S wL ;

[0034] The input end of the three-port converter is connected in parallel to the photovoltaic panel PV, the output end of the three-port converter is connected in series to the input end of the DC-DC converter and in parallel to the input end of the hydrogen generator;

[0035] The input end of the DC-DC converter is connected in series to the input end of the hydrogen generator.

[0036] One port of the three-port converter is connected to input direct current between the photovoltaic panel PV, one port is connected to the high-voltage end capacitor C H , and one port is connected to the low-voltage end capacitor C L .

[0037] The DC-DC converter is respectively composed of two switch tubes S b1 , S b2 and an inductor L b , the source of the switch tube S b1 is connected to the drain of the switch tube S b2 and the input end of the inductor L b , the source of the switch tube S b2 is connected to the power supply ground, and the output end of the inductor L b is connected to the hydrogen generator, i.e. the anode of V b , and the negative electrode of the hydrogen generator is connected to the power supply ground.

[0038] The gate of the power switch tube of the wide-voltage photovoltaic hydrogen generation device is respectively connected to the controller.

[0039] Specifically, the working mode of the wide-voltage photovoltaic hydrogen generation device is divided into two kinds: low-voltage output mode and high-voltage output mode; and the high-voltage output mode is divided into two working modes: when there is a relationship of V in < V o in the circuit, i.e. the voltage of the photovoltaic power generation unit PV is less than the configured voltage of the hydrogen generator, it is working mode one; when there is a relationship of V in ≥ V o in the circuit, i.e. the voltage of the photovoltaic power generation unit PV is greater than the configured voltage of the hydrogen generator, it is working mode two.

[0040] Please refer to Figures 2 to 13 for specific description:

[0041] Low-voltage working mode: D1 is cut off, the voltage of the capacitor C H is unchanged, the controller controls the SM bypass, i.e. controls the switch tubes S 1_1 , S 2_1、to S n_1 Shutdown, S 1_2 S 2_2 To S n_2 Conduction, 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 S b1 S b2 Turn off, capacitors C1, C2 to C n With constant voltage, inductance L b Voltage remains constant; such as Figure 2 As shown, D2 is cut off, and the inductor L... i Charging, the controller controls the switching transistor S wL On, capacitor C L Discharge supplies power to the hydrogen generator;

[0042] like Figure 3 As shown, inductor L i Discharge occurs, D2 conducts, and the controller controls the switching transistor S. wL Turn off, capacitor C L Charge;

[0043] High-voltage operation mode: The SM module is started to bear the high voltage, and the switching transistor S within it... 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 state to enter either the input or bypass mode, making it compatible with the switching transistor S. wL The switch action coordinates with the power supply to the hydrogen generator; when V in <V o When the voltage of the photovoltaic power generation unit PV is less than the voltage configured for the hydrogen generator, it is in high-voltage operating mode one. In this mode, diodes D1 and D2 are both in the off state, and the SM module remains in the conducting state. That is, the controller controls the series sub-modules to be in the input mode or bypass mode, so that diode D1 is reverse biased.

[0044] In high-voltage operating mode one, in the first switching state, inductor L i Charging, because of the N SM modules connected in series and the switching transistor S wL Both are in the on state. When the SM operating mode is the input mode, diode D... 1_1 D 2_1 To D n_1 Forward bias, diode D 1_2 D 2_2 Dn_2 Reverse biased, capacitor C1, C2 to C n Voltage increasing, inductor L i Start to pass through N SM modules and switch S in series wL Store energy, capacitor C L Directly power to the hydrogen generator by single stage conversion.

[0045] When SM working mode is bypass mode, diode D 1_1 , D 1_2 , D 2_1 , D 2_2 to D n_1 , D n_2 Reverse biased, capacitor C1, C2 to C n Voltage unchanged, inductor L i Start to pass through N SM modules and switch S in series wL Store energy, capacitor C L Directly power to the hydrogen generator by single stage conversion.

[0046] Similarly, in the second switch state, switch S wL is off, while N SM modules in series are still on, diode D2 is forward biased. When SM working mode is put-in mode, diode D 1_1 , D 2_1 to D n_1 Forward biased, diode D 1_2 , D 2_2 , D n_2 Reverse biased, capacitor C1, C2 to C n Voltage increasing, inductor L i Start to pass through diode D2 and capacitor C L Release stored energy.

[0047] When SM working mode is bypass mode, diode D 1_1 , D 1_2 , D 2_1 , D 2_2 to D n_1 , D n_2 Reverse biased, capacitor C1, C2 to C n Voltage unchanged, inductor L i Start to pass through diode D2 and capacitor C L Release stored energy. During this period, most of the output power is also provided by the lower port capacitor C L . Therefore, in the high voltage working mode, power is directly output to the hydrogen generator by the three-port converter.

[0048] When V in ≥ V oWhen the voltage of the photovoltaic power generation unit PV is greater than the voltage configured for the hydrogen generator, it operates in high-voltage mode two. In this mode, switch S... wL In both switching states, it is in a completely off state. The operating mode of the N SM modules connected in series controls whether the power is supplied to the hydrogen generator after partial power processing by the DC-DC converter, or whether the voltage at the output of the three-port converter is directly output to the hydrogen generator without being processed by the DC-DC converter.

[0049] In the first switching state, the N series-connected SM modules are either bypassed or in operation, diode D1 is reverse-biased, and diode D2 is conducting. The inductor begins to store energy through the series-connected SM modules and diode D2, with a voltage difference of V. in -V o The power of the hydrogen generator is supplied by the lower capacitor C. L supply.

[0050] In the second switching state, the N SM modules connected in series are turned off and not enabled, while switch S... wL Off. Diode D1 is now on. Inductor L i With input voltage V in Together, through a DC-DC converter, two stages of power conversion are used to provide the required voltage to the hydrogen generator.

[0051] When V ac When the voltage across the bridge terminals is sufficiently large, the bridge arm current i SM In the opposite direction, with current i L Flow to capacitor C with lower potential H Capacitors C1, C2 to C n Voltage decreases, such as Figure 12 As shown, the switching transistor S in the DC-DC converter b1 Turn-off, switching transistor S b2 When the circuit is turned on, capacitor C is in conduction mode. H Voltage increases;

[0052] like Figure 13 As shown, the switching transistor S in the DC-DC converter b1 On / off transistor S b2 When the capacitor C is turned off, the capacitor C is at this time. H As voltage decreases, inductance L b The voltage increases.

[0053] The above-disclosed embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of the present utility model. Those skilled in the art can understand that implementing all or part of the above-described embodiments and making equivalent changes in accordance with the claims of the present utility model are still within the scope of the utility model.

Claims

1. A wide voltage photovoltaic hydrogen generator, characterized in that, comprises an inductance L i , two diodes D1, D2, two capacitors C L , C H , a three-port converter, a SM module, a DC-DC converter, a photovoltaic panel PV and a hydrogen generator; N of the SM modules are arranged in series as a submodule string, and the voltage at both ends is V ac ; The three-port converter is composed of N SM modules in series respectively, the upper bridge arm bears high voltage, one switch tube S wL As the lower bridge arm, the high-voltage end capacitor C H Connecting the ground and the DC-DC converter, the low-voltage end capacitor C L Directly access the hydrogen generator; The positive pole of the photovoltaic panel PV is connected to the input of the inductance L i The negative pole of the photovoltaic panel PV is connected to the power supply ground, the output of the inductance L i The output of the inductance L is connected to the input of the N SM modules, the positive pole of the diode D1, the output of the N SM modules is connected to the positive pole of the diode D2, the drain of the switch tube S wL ​ the input of the three-port converter is connected in parallel to the photovoltaic panel (PV), the output of the three-port converter is connected in series to the input of the DC-DC converter, and in parallel to the input of the hydrogen generator; the input of the DC-DC converter is connected in series to the input of the hydrogen generator.

2. The wide voltage photovoltaic hydrogen generator according to claim 1, characterized in that, One port of the three-port converter is connected to input DC voltage from the photovoltaic panel PV, one port is connected to the high voltage capacitor C H Two ends, one port is connected to the low voltage capacitor C L Two ends.

3. The wide voltage photovoltaic hydrogen generator according to claim 2, characterized in that, The DC-DC converter is composed of two switching tubes S b1 b2 and an inductor L b , the source of the switching tube S b1 is connected to the drain of the switching tube S b2 and the input of the inductor L b , the source of the switching tube S b2 is connected to the power ground, and the output of the inductor L b is connected to the hydrogen generator, i.e. the positive electrode of V b , and the negative electrode of the hydrogen generator is connected to the power ground.​ 4. The wide voltage photovoltaic hydrogen generator according to claim 3, characterized in that, the gates of the power switch tubes of the wide voltage photovoltaic hydrogen generator are connected to the controller, respectively.

Images