High-power high-efficiency direct-current converter

Abstract

The invention discloses a high-power efficient direct current converter, and relates to the technical field of power electronics. The high-power and high-efficiency direct-current converter comprises an inverter circuit of which the input side is electrically connected with a direct-current input side and which is used for converting direct-current voltage input by the direct-current input side into alternating-current voltage to be output; the input side of any isolation transformation rectification circuit is electrically connected with the output side of the inversion circuit, and the isolation transformation rectification circuit comprises an isolation transformation module and a rectification circuit; the input side of the non-isolation adjusting circuit is used for being electrically connected with the second rectification output side of the corresponding isolation conversion rectification circuit, the output side of the non-isolation adjusting circuit is used for being electrically connected with a corresponding load, and the non-isolation adjusting circuit is used for adjusting the direct-current voltage provided by the second rectification output side and then outputting the direct-current voltage. According to the embodiment of the invention, DC voltage conversion can be effectively realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power electronics, and particularly relates to a high-power and high-efficiency direct current converter. BACKGROUND

[0002] Generally in the field of power electronics, hydrogen energy is the best way for large-scale and long-period storage of renewable energy. The cost of a hydrogen storage container is lower than that of a fixed energy storage battery, the midstream transportation mode is flexible, and the downstream application frequency is wide. The volatility of new energy brings great challenges to the stability of the power grid, and it is urgent to stabilize and periodically store and regulate to achieve cross-season and long-period power and electricity regulation. Off-grid hydrogen production is an effective means.

[0003] The photovoltaic solar panel outputs direct current, and the power supply requirement of the electrolytic cell is also direct current. Therefore, compared with an alternating current collection scheme, a direct current collection scheme for large-scale new energy can reduce the conversion link, improve power transmission efficiency, and reduce costs. In addition, compared with an alternating current hydrogen production scheme, a direct current hydrogen production system has higher power quality and better stability, fast and reliable power regulation, and low transmission loss, and is considered to be a more promising topology.

[0004] Under the above background, the large capacity of new energy generation makes the capacity of the direct current converter continue to increase, and a larger power level power device needs to be used or a plurality of low-voltage converters in parallel need to be used to meet the requirements of large power conversion. Among them, the use of a plurality of low-voltage direct current converters in parallel structure has flexible redundancy control characteristics, which can effectively improve the reliability of the system, but when the load is low, the efficiency is much lower than that under rated operating conditions, and a control strategy needs to be used to optimize and improve the overall efficiency of the parallel system. At present, the power of the plurality of low-voltage direct current converter parallel structure is generally low. Moreover, as the power increases, the low direct current bus voltage will cause the line loss to increase and the transmission distance to be short, and the operation efficiency of the hydrogen production system faces challenges, and the applicability of the low-voltage parallel scheme needs to be studied.

[0005] Therefore, the existing DC / DC (Direct Current to Direct Current) hydrogen production power supply product cannot meet the application requirements of high-power and high-efficiency direct current conversion for large-scale renewable energy direct current off-grid hydrogen production in the future. SUMMARY

[0006] The embodiment of the application provides a high-power and high-efficiency direct current converter, which can realize high-efficiency and high-power direct current conversion.

[0007] In a first aspect, the embodiment of the application provides a high-power and high-efficiency direct current converter, which comprises: The inverter circuit is electrically connected with the DC input side, and is configured to convert a DC voltage input by the DC input side into an AC voltage and output the AC voltage. The at least one isolated conversion rectifier circuit is electrically connected with the output side of the inverter circuit, and includes an isolated transformer module and a rectifier circuit. The isolated transformer module is configured to perform isolated transformation on the AC voltage and output the AC voltage after the isolated transformation to the rectifier circuit, and the rectifier circuit is configured to rectify the AC voltage output by the isolated transformer module and output corresponding DC voltages through a first rectifier output side and a second rectifier output side, respectively. The non-isolated regulating circuit is electrically connected with the corresponding second rectifier output side at the input side and is electrically connected with the corresponding load at the output side, and is configured to output a DC voltage provided by the second rectifier output side after voltage regulation. In the same isolated conversion rectifier circuit, the first rectifier output side and the output side of the non-isolated regulating circuit are connected to the same corresponding load in parallel.

[0008] In some possible embodiments, the isolated conversion rectifier circuit further includes: A resonance network is electrically connected with the output side of the inverter circuit at the input side and is electrically connected with the input side of the isolated transformer module at the output side.

[0009] In some possible embodiments, the resonance network includes: A resonance inductor is electrically connected with a first end of the output side of the inverter circuit at a first end thereof and is electrically connected with a first end of the input side of the isolated transformer module at a second end thereof. A resonance capacitor is electrically connected with a second end of the output side of the inverter circuit at a first end thereof and is electrically connected with a second end of the input side of the isolated transformer module at a second end thereof.

[0010] In some possible embodiments, the isolated transformer module includes a first isolated transformer and a second isolated transformer, and the rectifier circuit includes a first rectifier module and a second rectifier module. A primary winding of the first isolated transformer is connected in series with a primary winding of the second isolated transformer, a secondary winding of the first isolated transformer is electrically connected with the input side of the first rectifier module, and an output side of the first rectifier module is the first rectifier output side. A secondary winding of the second isolated transformer is electrically connected with the input side of the second rectifier module, and an output side of the second rectifier module is the second rectifier output side.

[0011] In some possible implementation manners, the first rectification module comprises a first rectification diode and a second rectification diode, and / or the second rectification module comprises a third rectification diode and a fourth rectification diode; The anode of the first rectification diode is electrically connected with a first end of a secondary winding of the first isolation transformer, and the anode of the second rectification diode is electrically connected with a second end of the secondary winding of the first isolation transformer; The cathode of the first rectification diode and the cathode of the second rectification diode are electrically connected to form a common terminal, which constitutes a first end of a first rectification output side, and a center tap of the first isolation transformer constitutes a second end of the first rectification output side; The anode of the third rectification diode is electrically connected with a first end of a secondary winding of the second isolation transformer, and the anode of the fourth rectification diode is electrically connected with a second end of the secondary winding of the second isolation transformer; The cathode of the third rectification diode and the cathode of the fourth rectification diode are electrically connected to form a common terminal, which constitutes a first end of a second rectification output side, and a center tap of the second isolation transformer constitutes a second end of the first rectification output side.

[0012] In some possible implementation manners, the first rectification module further comprises a first output capacitor, and / or the second rectification module further comprises a second output capacitor; The first output capacitor is arranged between the first end of the first rectification output side and the second end of the first rectification output side; The second output capacitor is arranged between the first end of the second rectification output side and the second end of the second rectification output side.

[0013] In some possible implementation manners, the high-power high-efficiency DC converter further comprises: A clamping circuit, an input side of the clamping circuit being configured to be electrically connected with the DC input side, and an output side of the clamping circuit being electrically connected with the inverter side of the inverter circuit; The clamping circuit is configured to limit a current change rate on a bridge arm switch tube in the inverter circuit and limit an AC voltage amplitude of the output side of the inverter circuit.

[0014] In some possible implementation manners, the clamping circuit comprises anode reactance, at least one clamping diode, a clamping resistor and a clamping capacitor; A first end of the anode reactance is electrically connected with a first end of the DC input side and a first end of the clamping resistor, a first end of the clamping capacitor is electrically connected with a second end of the clamping resistor, and a second end of the clamping capacitor is electrically connected with a second end of the DC input side; The at least one clamping diode is arranged in series between a second end of the anode reactance and the second end of the clamping resistor, and a current flow direction from anode to cathode of any clamping diode is same as a current flow direction from the second end of the anode reactance to the second end of the clamping resistor.

[0015] In some possible implementations, the clamping circuit further includes at least one first voltage equalizing capacitor and / or at least one first voltage equalizing resistor; Any first voltage equalizing capacitor is connected in parallel across the corresponding clamping diode, and any first voltage equalizing resistor is connected in parallel across the corresponding clamping diode.

[0016] In some possible implementations, the inverter circuit includes a first bridge arm switch group, a second bridge arm switch group, a third bridge arm switch group, and a fourth bridge arm switch group; The first end of the first bridge arm switch group is electrically connected to the first end of the DC input side, the second end of the first bridge arm switch group is electrically connected to the first end of the second bridge arm switch group at the first node, and the second end of the second bridge arm switch group is electrically connected to the second end of the DC input side. The first end of the third bridge arm switch group is electrically connected to the first end of the DC input side, the second end of the third bridge arm switch group is electrically connected to the first end of the fourth bridge arm switch group at the second node, and the second end of the fourth bridge arm switch group is electrically connected to the second end of the DC input side. The first node is the first terminal on the output side of the inverter circuit, and the second node is the second terminal on the output side of the inverter circuit. The first bridge arm switch group, the second bridge arm switch group, the third bridge arm switch group, and the fourth bridge arm switch group each include: at least one switch unit connected in series, the switch unit including a bridge arm switch transistor and anti-parallel diodes disposed across the bridge arm switch transistor.

[0017] In some possible implementations, any switching unit may further include a second voltage-equalizing capacitor, a current-limiting resistor, and a second voltage-equalizing resistor; The second voltage equalizing capacitor and the current limiting resistor are connected in series to form a series branch, and the series branch is set in parallel at both ends of the bridge arm switch tube. The second equalizing resistor is connected in parallel across the two ends of the bridge arm switching transistor.

[0018] In some possible implementations, the non-isolated regulation circuit is implemented using a flying capacitor buck converter or a two-level interleaved buck converter.

[0019] In some possible implementations, the DC input side is connected to a photovoltaic solar panel, which is used to convert solar energy into DC power. The load includes an electrolyzer used for electrolytic hydrogen production under DC power.

[0020] Based on the same inventive concept, in a second aspect, embodiments of this application provide a DC power supply system, which includes a photovoltaic solar panel, an electrolytic cell, and a high-power, high-efficiency DC converter as provided in any of the embodiments of the first aspect of this application; the high-power, high-efficiency DC converter is electrically connected between the photovoltaic solar panel and the electrolytic cell. Photovoltaic solar panels are used to convert solar energy into DC power, and the DC power is input to a high-power, high-efficiency DC converter for DC conversion. Electrolyzers are used to electrolyze hydrogen under the DC power supply of the high-power, high-efficiency DC converter.

[0021] As described above, the high-power, high-efficiency DC-DC converter provided in this application, on the one hand, achieves efficient utilization of the AC voltage output by the inverter circuit by setting at least one isolated conversion rectifier circuit, with the input sides of different isolated conversion rectifier circuits connected in parallel to the output side of the inverter circuit. This enables high-power and high-efficiency voltage level conversion from the medium-voltage DC bus to the low-voltage bus. Furthermore, different isolated conversion rectifier circuits can provide different output ports, thus enabling the DC-DC converter of this application to have distributed multi-port output capability. The output ports corresponding to different isolated conversion rectifier circuits can be connected in parallel, independently, or partially in parallel, with a large power adjustment range, thereby simultaneously meeting the requirements of different load capacities and voltage levels, and thus supporting mixed access of different loads.

[0022] On the other hand, in the embodiments of this application, since the isolated converter rectifier circuit outputs DC voltage through the first rectifier output side and the second rectifier output side respectively in the same isolated converter rectifier circuit, and the DC voltage provided by the second rectifier output side is regulated by the non-isolated regulating circuit and then output to the corresponding load, the output port of the first rectifier output side and the output side of the non-isolated regulating circuit connected in parallel is connected to the same load. For the first rectifier output side not connected to the non-isolated regulating circuit, its output rectified voltage conversion loss is low. For the second rectifier output side connected to the non-isolated regulating circuit, its output voltage can be further controlled and regulated by the non-isolated regulating circuit. Therefore, in actual operation, the high-power and high-efficiency DC converter of this application can quickly achieve closed-loop control of the voltage / current of each output port by adjusting the duty cycle of the non-isolated regulating circuit. At the same time, it can also avoid the low system conversion efficiency caused by the non-isolated regulating circuit being used to regulate the rectified output voltage. Therefore, this DC converter can have the characteristics of high output voltage / current flexibility, high adjustability, and relatively high system conversion efficiency. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in one embodiment of this application; Figure 2This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 3 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 4 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 6 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 7 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter provided in another embodiment of this application; Figure 8 This is a schematic diagram of the structure of a DC power supply system provided in an embodiment of this application; Figure 9 This is a schematic diagram of the structure of a DC power supply system provided in another embodiment of this application. Detailed Implementation

[0025] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0027] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0028] It should be noted that the transistors in the embodiments of this application can be either N-type or P-type transistors. For N-type transistors, the on-state level is high and the off-state level is low. That is, when the gate of an N-type transistor is high, its first and second terminals are connected; when the gate of an N-type transistor is low, its first and second terminals are off. For P-type transistors, the on-state level is low and the off-state level is high. That is, when the control terminal of a P-type transistor is low, its first and second terminals are connected; when the control terminal of a P-type transistor is high, its first and second terminals are off. In specific implementations, the gate of each transistor is used as its control terminal. Furthermore, depending on the signal and type of the gate of each transistor, its first terminal can be used as the source and its second terminal as the drain, or vice versa. No distinction is made here. Additionally, the on-state and off-state levels in the embodiments of this invention are general terms. The on-state level refers to any level that enables the transistor to conduct, and the off-state level refers to any level that enables the transistor to turn off / become off.

[0029] In the embodiments of this application, the term "electrical connection" can refer to a direct electrical connection between two components, or it can refer to an electrical connection between two components via one or more other components.

[0030] In the embodiments of this application, the first node, the second node, and the third node are defined only for the convenience of describing the circuit structure, and the first node, the second node, and the third node are not actual circuit units.

[0031] Various modifications and variations can be made to this application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, this application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation methods provided in the embodiments of this application can be combined with each other without contradiction.

[0032] Before describing the technical solutions provided in the embodiments of this application, in order to facilitate understanding of the embodiments of this application, this application first specifically explains the problems existing in the related technologies: As mentioned above, the inventors of this application have discovered that existing DC / DC hydrogen production power supply products are suitable for low-voltage applications and cannot meet the application requirements of large-scale renewable energy medium-voltage DC off-grid hydrogen production in the future.

[0033] Specifically, existing conventional hydrogen production power supplies are mostly designed and considered based on grid-connected systems, with AC power input. Hydrogen production power supplies used in off-grid DC hydrogen production for renewable energy applications have low input voltage levels and low capacity, which cannot meet the application requirements of medium-voltage DC for large-scale off-grid renewable energy hydrogen production in the future. Therefore, a higher-power, more efficient DC-DC conversion solution is lacking in related technologies.

[0034] To address the aforementioned technical problems, embodiments of this application provide a high-power, high-efficiency DC-DC converter. The high-power, high-efficiency DC-DC converter provided in these embodiments is described below.

[0035] Figure 1 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in one embodiment of this application.

[0036] like Figure 1 As shown, this application provides a high-power, high-efficiency DC-DC converter 100, such as... Figure 1 As shown, the high-power, high-efficiency DC-DC converter 100 of this application embodiment includes: Inverter circuit 10, the input side of inverter circuit 10 is electrically connected to DC input side Vin through clamping circuit 40, and is used to convert the DC voltage input to DC input side Vin into AC voltage output; At least one isolation converter rectifier circuit 20, the input side of any isolation converter rectifier circuit 20 is electrically connected to the output side of the inverter circuit 10, and the isolation converter rectifier circuit 20 includes an isolation transformer module 21 and a rectifier circuit 22; The isolation transformer module 21 is used to isolate and transform the AC voltage, and output the AC voltage after isolation and transformation to the rectifier circuit 22. The rectifier circuit 22 is used to rectify the AC voltage output by the isolation transformer module 21, and output the corresponding DC voltage through the first rectifier output side and the second rectifier output side respectively. The first rectifier output side is used to be electrically connected to the corresponding load. The non-isolated regulating circuit 30 has an input side that is electrically connected to the corresponding second rectifier output side and an output side that is electrically connected to the corresponding load. The non-isolated regulating circuit 30 is used to regulate and output the DC voltage provided by the second rectifier output side. In the same isolation converter rectifier circuit 20, the first rectifier output side and the output side of the non-isolated regulation circuit 30 are connected in parallel and then connected to the same corresponding load; different isolation converter rectifier circuits 20 may correspond to the same or different loads.

[0037] In this application, in some renewable energy utilization scenarios, the aforementioned DC input side Vin can be connected to a photovoltaic solar panel, which is used to convert solar energy into DC power output. In one example, the DC input side Vin can provide a medium-voltage DC voltage.

[0038] The inverter circuit 10 described above may include multiple bridge arm switches. In actual inverter operation, by controlling the different bridge arm switches to turn on or off, the DC voltage input to the DC input side Vin is converted into an AC voltage output.

[0039] The aforementioned isolation converter rectifier circuit 20 can convert high-frequency AC power into stable DC power and achieve electrical isolation. The isolation converter rectifier circuit 20 includes an isolation transformer module 21 and a rectifier circuit 22. The isolation transformer module 21 is used to isolate and transform the AC voltage, and outputs the isolated and transformed AC voltage to the rectifier circuit 22. The isolation transformer module 21 can be implemented using an isolation transformer.

[0040] The rectifier circuit 22 is used to rectify the AC voltage output by the isolation transformer module 21, and outputs corresponding DC voltages through the first rectifier output side and the second rectifier output side, respectively. The rectifier circuit 22 can adopt a bridge rectifier circuit or a full-wave rectifier circuit, etc.

[0041] In this application, the aforementioned first rectifier output side can be used for electrical connection to a corresponding load. The load may be, for example, an electrolytic cell or other DC electrical equipment. The load can be a low-voltage DC electrical device.

[0042] The DC voltage provided by the second rectifier output side can be regulated by the non-isolated regulating circuit 30 and output to the corresponding load. The non-isolated regulating circuit 30 can be, for example, a flying capacitor buck converter or a two-level interleaved buck converter. In actual operation, the DC converter 100 can achieve closed-loop control of the voltage / current of each output port Vout by adjusting the duty cycle of the non-isolated regulating circuit 30.

[0043] In the same isolated converter rectifier circuit 20, the output port Vout of the first rectifier output side and the output side of the non-isolated regulation circuit 30 are connected in parallel and then connected to the same load.

[0044] The output ports Vout of different isolation converter rectifier circuits 20 can be connected in parallel, independently, or partially in parallel to meet the requirements of different load capacities and voltage levels. The magnitude and sign of the DC voltage output from the output ports Vout of different isolation converter rectifier circuits 20 can be flexibly adjusted according to specific power consumption scenarios.

[0045] Different isolation converter rectifier circuits 20 may correspond to the same or different loads. For example...Figure 1 As shown, the output ports Vout of different isolation converter rectifier circuits 20 can be connected in parallel, and the loads corresponding to different isolation converter rectifier circuits 20 are the same. By connecting the output ports in parallel to form Vout1, the current of the load can be superimposed and output.

[0046] Please see again. Figure 2 The output ports Vout of different isolation converter rectifier circuits 20 can take their own independent forms (Vout1, ..., Voutn), and the loads corresponding to different isolation converter rectifier circuits 20 are different.

[0047] In some other possible embodiments, the output ports Vout of the different isolation converter rectifier circuits 20 may be partially connected in parallel. In other words, among the multiple isolation converter rectifier circuits 20, some isolation converter rectifier circuits 20 have the same load, and some isolation converter rectifier circuits 20 have different loads.

[0048] This application provides a DC-DC converter 100, including as follows: Figure 1 The single-output configuration shown is for a single load, or includes, for example, a single-output configuration. Figure 2 The diagram shows a multi-output configuration for multiple loads. This DC-DC converter 100, by incorporating an inverter circuit 10, at least one isolated conversion rectifier circuit 20, and a non-isolated regulation circuit 30, enables high-power and high-efficiency voltage level conversion from a medium-voltage DC bus to a low-voltage bus.

[0049] This application provides a high-power, high-efficiency DC-DC converter 100. On one hand, by setting at least one isolated conversion rectifier circuit 20, the input sides of different isolated conversion rectifier circuits 20 are connected in parallel to the output side of the inverter circuit 10, thereby achieving efficient utilization of the AC voltage output by the inverter circuit 10. This enables high-power and high-efficiency voltage level conversion from a medium-voltage DC bus to a low-voltage bus. Furthermore, different isolated conversion rectifier circuits 20 can provide different output ports Vout, thus enabling the DC-DC converter 100 of this application to have distributed multi-port output capability. The output ports Vout corresponding to different isolated conversion rectifier circuits 20 can be connected in parallel, independently, or partially in parallel, with a large power adjustment range, thereby simultaneously meeting the requirements of different load capacities and voltage levels, and thus supporting mixed access of different loads.

[0050] On the other hand, in the same isolated converter rectifier circuit 20, the isolated converter rectifier circuit 20 outputs DC voltage through the first rectifier output side and the second rectifier output side respectively. The DC voltage provided by the second rectifier output side is regulated by the non-isolated regulating circuit 30 and then output to the corresponding load. The output port Vout of the first rectifier output side and the output side of the non-isolated regulating circuit 30, which are connected in parallel, is connected to the same load. For the first rectifier output side not connected to the non-isolated regulating circuit 30, its output rectified voltage conversion loss is low. For the second rectifier output side connected to the non-isolated regulating circuit 30, its output voltage can be further controlled and regulated by the non-isolated regulating circuit 30. Therefore, in actual operation, the DC converter 100 can quickly achieve closed-loop control of the voltage / current of each output port Vout by adjusting the duty cycle of the non-isolated regulating circuit 30. At the same time, it can also avoid the low system conversion efficiency caused by the non-isolated regulating circuit 30 being used to regulate the rectified output voltage. Therefore, the DC converter 100 can have the characteristics of high output voltage / current flexibility, high adjustability, and relatively high system conversion efficiency.

[0051] Please see below. Figure 3 , Figure 3 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in another embodiment of this application. According to some feasible embodiments of this application, optionally, such as... Figure 3 As shown, the isolation converter rectifier circuit 20 also includes: The input side of the resonant network 23 is electrically connected to the output side of the inverter circuit 10, and the output side of the resonant network 23 is electrically connected to the input side of the isolation transformer module 21.

[0052] In this embodiment, a resonant network 23 is provided between the inverter circuit 10 and the isolation transformer module 21. The resonant network 23 can realize efficient energy conversion and transmission in the DC-DC converter 100 by utilizing the resonant characteristics of inductors and capacitors.

[0053] The resonant network 23 can be implemented using a series resonant converter, a parallel resonant converter, or an LLC resonant converter, etc. This application does not impose strict limitations here, and the specific implementation can be determined according to the actual application requirements.

[0054] Please see below. Figure 4 or Figure 5 , Figure 4 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in another embodiment of this application. According to some feasible embodiments of this application, optionally, such as... Figure 4 The high-power, high-efficiency DC-DC converter 100 shown also includes: Clamping circuit 40, the input side of clamping circuit 40 is electrically connected to DC input side Vin, and the output side of clamping circuit 40 is electrically connected to inverter side of inverter circuit 10. The clamping circuit 40 is used to limit the rate of change of current on the bridge arm switching transistors in the inverter circuit 10, and to limit the amplitude of the AC voltage on the output side of the inverter circuit 10.

[0055] In this application, such as Figure 4 or Figure 5 As shown, by providing a clamping circuit 40 at the input terminal of the DC-DC converter 100, the downstream circuits can be protected. Specifically, the clamping circuit 40 can be used to limit the rate of change of current flowing through the bridge arm switch in the inverter circuit 10 when the bridge arm switch is turned on. Furthermore, the clamping circuit 40 can also limit the amplitude of the AC voltage on the output side of the inverter circuit 10, thereby preventing excessive AC voltage oscillation amplitude from damaging circuit components.

[0056] In practical applications, the clamping circuit 40 described above can typically be composed of components such as diodes, capacitors, and resistors. Its working principle is based on the unidirectional conductivity of diodes and the energy storage characteristics of capacitors. This application does not impose strict restrictions on the specific circuit topology of the clamping circuit 40.

[0057] Please see below. Figure 6 or Figure 7 , Figure 6 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in another embodiment of this application. Figure 7 This is a schematic diagram of the structure of a high-power, high-efficiency DC-DC converter 100 provided in another embodiment of this application. Optionally, according to some feasible embodiments of this application, the resonant network 23 includes: Resonant inductor L r2 Resonant inductor L r2 The first terminal is electrically connected to the first terminal of the output side of the inverter circuit 10, and the resonant inductor L r2 The second terminal is electrically connected to the first terminal on the input side of the isolation transformer module 21; Resonant capacitor C r2 Resonant capacitor C r2 The first terminal is electrically connected to the second terminal of the output side of the inverter circuit 10, and the resonant capacitor C r2 The second terminal is electrically connected to the second terminal of the input side of the isolation transformer module 21.

[0058] In this embodiment, the resonant inductor L is specifically configured as described above. r2 and resonant capacitor C r2 These components together form a resonant circuit. At the resonant frequency, the impedances of the relevant capacitors and inductors cancel each other out, thus achieving efficient energy transfer. Figure 6 orFigure 7 In the middle, the resonant inductor L r1 and resonant capacitor C r1 For the resonant inductor and resonant capacitor in another isolated converter rectifier circuit 20.

[0059] In practical applications, the aforementioned resonant inductor L r2 It can be externally supplied. Alternatively, the leakage inductance of the isolation transformer in the isolation transformer module 21 can be used as a substitute, thereby reducing the overall cost and size of the DC converter 100.

[0060] It should be added that, when the isolation transformer module 21 is implemented using an isolation transformer, the aforementioned resonant capacitor C... r2 It can also be placed on the secondary side of an isolation transformer; there are no strict restrictions on this.

[0061] Optionally, in some embodiments, when the isolation transformer module 21 is implemented using an isolation transformer, a magnetizing inductor L connected in parallel with the primary winding of the isolation transformer can also be provided. m1 L m2 This is to store energy to prevent sudden current changes and maintain stable circuit operation.

[0062] In this case, the magnetizing inductor L m1 L m2 With the aforementioned resonant inductor L r2 and resonant capacitor C r2 This can form an LLC resonant network 23, thus enabling the input power to be transferred to the secondary side of the isolation transformer.

[0063] In practical applications, the aforementioned magnetizing inductor L m1 L m2 It can be externally supplied. Alternatively, the aforementioned magnetizing inductor L m1 L m2 Alternatively, the magnetizing inductance of the isolation transformer itself can be used, thereby reducing the overall cost and size of the DC-DC converter 100.

[0064] According to some feasible embodiments of this application, optionally, the isolation transformer module 21 includes a first isolation transformer T. r1 Second isolation transformer T r2 The rectifier circuit 22 includes a first rectifier module and a second rectifier module; First isolation transformer T r1 The primary winding and the second isolation transformer T r2 The primary windings are connected in series, and the first isolation transformer T r1 The secondary winding is electrically connected to the input side of the first rectifier module, and the output side of the first rectifier module is the first rectifier output side; Second isolation transformer T r2The secondary winding is electrically connected to the input side of the second rectifier module, and the output side of the second rectifier module is the second rectifier output side.

[0065] In this embodiment, by setting the isolation transformer module 21 to consist of two transformers connected in series and parallel, the turns ratio of the actual transformer can be effectively reduced. Furthermore, by using two isolation transformers to achieve isolation transformers between the inverter circuit 10 and the rectifier circuit 22, the overall output efficiency of the DC converter can also be effectively improved.

[0066] In specific operations, the aforementioned first isolation transformer T r1 Second isolation transformer T r2 Through electromagnetic induction, the AC voltage of the primary winding is transformed into the AC voltage of the secondary winding. Simultaneously, the aforementioned first isolation transformer T... r1 Second isolation transformer T r2 It can achieve electrical isolation to prevent electrical interference between different parts of the primary and secondary circuits, thereby improving the overall safety and reliability of the converter.

[0067] In practical applications, the first isolation transformer T is configured and adjusted. r1 Second isolation transformer T r2 The turns ratio of the isolation transformer allows for regulation of the port output voltage. The step-down AC transformers in each isolation converter rectifier circuit 20 can employ different turns ratios and capacities to meet the voltage level requirements of different loads.

[0068] In one example, the first isolation transformer T r1 Second isolation transformer T r2 It can be used as a step-down isolation transformer.

[0069] In this embodiment, the first rectifier module is used to rectify the first isolation transformer T. r1 The output AC voltage is rectified, and the rectified DC voltage is output to the corresponding load through the first rectifier output side. The aforementioned second rectifier module can be used to rectify the second isolation transformer T. r2 The output AC voltage is rectified, and the rectified DC voltage is output to the subsequent non-isolated regulation circuit 30 through the second rectifier output side.

[0070] The first and second rectifier modules described above can employ bridge rectifier circuits to effectively reduce the voltage stress on the rectifier diodes. Alternatively, the first and second rectifier modules can also be implemented using full-wave rectifier circuits to effectively reduce the current stress on the isolation transformer windings.

[0071] In one application example, inverter circuit 10 outputs an AC square wave voltage, which is injected into isolation converter rectifier circuit 20. Isolation converter rectifier circuit 20 is configured with C... r2 Resonant capacitor, resonant inductor L r2 and magnetizing inductor L m1 L m2 The LLC resonant network 23 enables the transfer of input power to the first isolation transformer T. r1 and the second isolation transformer T r2 Secondary side. Next, since the isolation transformer secondary side is equipped with a first rectifier module and a second rectifier module, the AC voltage can be rectified into a DC voltage, thereby realizing the conversion of the AC voltage of the inverter circuit 10 into a low-voltage DC output, so as to provide a stable DC voltage for subsequent circuits or loads.

[0072] According to some feasible embodiments of this application, optionally, the first rectifier module includes a first rectifier diode D. s1 Second rectifier diode D s2 And / or, the second rectifier module includes a third rectifier diode D. s3 and the fourth rectifier diode D s4 ; First rectifier diode D s1 The anode and the first isolation transformer T r1 The first terminal of the secondary winding is electrically connected to the second rectifier diode D. s2 The anode is electrically connected to the second terminal of the secondary winding of the first isolation transformer; First rectifier diode D s1 The cathode and the second rectifier diode D s2 The common terminal formed by the cathode electrical connection constitutes the first terminal of the first rectifier output side, and the first isolation transformer T r1 The center tap forms the second end of the first rectifier output side; Third rectifier diode D s3 The anode and the second isolation transformer T r2 The first terminal of the secondary winding is electrically connected to the fourth rectifier diode D. s4 The anode and the second isolation transformer T r2 The second end of the secondary winding is electrically connected; Third rectifier diode D s3 The cathode and the fourth rectifier diode D s4 The common terminal formed by the cathode electrical connection constitutes the first terminal of the second rectifier output side, and the second isolation transformer T r2 The center tap forms the second end of the first rectifier output side.

[0073] The aforementioned first isolation transformer T r1 Second isolation transformer Tr2 The center tap of the secondary winding can divide the secondary winding into two symmetrical parts, thereby providing positive and negative symmetrical voltage output.

[0074] In this embodiment, the first rectifier module uses the first rectifier diode D. s1 Second rectifier diode D s2 During the positive and negative half-cycles of the alternating current, the first isolation transformer T... r1 The AC power at the secondary winding is rectified into DC power to provide a stable DC voltage to the corresponding load through the first rectified output side.

[0075] The second rectifier module uses the third rectifier diode D s3 and the fourth rectifier diode D s4 During the positive and negative half-cycles of the alternating current, the second isolation transformer T... r2 The AC power at the secondary winding is rectified into DC power to provide a stable DC voltage to the subsequent non-isolated regulation circuit 30 through the second rectifier output side.

[0076] According to some feasible embodiments of this application, optionally, the first rectifier module further includes a first output capacitor C. s1 And / or, the second rectifier module also includes a second output capacitor C. s2 ; First output capacitor C s1 It is positioned between the first end of the first rectifier output side and the second end of the first rectifier output side; Second output capacitor C s2 It is positioned between the first end of the second rectifier output side and the second end of the second rectifier output side.

[0077] The aforementioned first output capacitor C s1 It can effectively smooth the rectified DC voltage output from the first rectifier output side, reduce ripple, and maintain the stability of the output voltage from the first rectifier output side.

[0078] The aforementioned second output capacitor C s2 It can effectively smooth the rectified DC voltage output from the second rectifier output side, reduce ripple, and maintain the stability of the output voltage from the second rectifier output side.

[0079] According to some feasible embodiments of this application, optionally, the clamping circuit 40 includes an anode reactance L buf At least one clamping diode D buf Clamping resistor R buf and clamping capacitor C buf ; Anode reactance L buf The first terminal is connected to the first terminal of the DC input side Vin and the clamping resistor R. bufThe first terminal is electrically connected to the clamping capacitor C. buf The first terminal is connected to the clamping resistor R buf The second terminal is electrically connected to the clamping capacitor C. buf The second terminal is electrically connected to the second terminal of the DC input side Vin. At least one clamping diode D buf Series-connected anode reactance L buf The second terminal is connected to the clamping resistor R buf Between the second terminals, any clamping diode D buf The current flow direction from the anode to the cathode is the same as that of the anode reactance L. buf The second terminal to the clamping resistor R buf The direction of current flow at the second end.

[0080] It should be noted that at least one clamping diode D mentioned above buf The specific quantity can be selected according to the actual voltage level of the DC input side Vin, and this application does not impose strict limitations on it.

[0081] In this embodiment, one implementation structure of the clamping circuit 40 described above is provided. For example... Figure 6 or Figure 7 As shown, the clamping circuit 40 includes an anode reactance L buf At least one clamping diode D buf Clamping resistor R buf and clamping capacitor C buf The above-mentioned anodic reactance L buf The current change rate di / dt used to suppress the turn-on of the bridge arm switches and the turn-off of the diodes in inverter circuit 10 is related to the clamping diode D. buf Clamping resistor R buf and clamping capacitor C buf The clamping circuit 40, which together form a clamping circuit, can also effectively suppress voltage spikes caused by anode reactance and loop stray inductance when the bridge arm switch in the inverter circuit 10 is turned off.

[0082] Thus, the clamping circuit 40, by setting the aforementioned anode reactance L, buf At least one clamping diode D buf Clamping resistor R buf and clamping capacitor C buf On the one hand, it can limit the rate of change of current when the bridge arm switch in the inverter circuit 10 is turned on; on the other hand, it can limit the oscillation amplitude of the AC voltage on the output side of the inverter circuit 10, thereby effectively realizing the clamping protection of the circuit elements.

[0083] According to some feasible embodiments of this application, the clamping circuit 40 may optionally further include at least one first voltage equalization capacitor C. band / or at least one first voltage equalizing resistor R bs ; Any first equalizing capacitor C b Parallel to the corresponding clamping diode D buf At both ends, any first equalizing resistor R bs Parallel to the corresponding clamping diode D buf The two ends.

[0084] In one example, such as Figure 6 or Figure 7 As shown, to ensure that multiple clamping diodes can withstand voltage evenly when used in series, this can be achieved by adjusting the voltage across each clamping diode's D... buf The first voltage equalizing capacitor C is connected in parallel across both ends. b and / or the first equalizing resistor R bs To achieve voltage equalization protection, ensuring the clamping diode D is properly positioned. buf It can operate safely and reliably when used in series.

[0085] By using each clamping diode D buf The first voltage equalizing capacitor C is connected in parallel across both ends. b First equalizing capacitor C b This is a dynamic voltage equalization capacitor. The first voltage equalization capacitor C... b It can effectively utilize the charging and discharging characteristics of a capacitor when the voltage in the circuit changes rapidly, thereby achieving the clamping of diode D under dynamic conditions. buf Dynamic voltage equalization at both ends effectively suppresses the clamping diode D. buf Transient overvoltage, avoid clamping diode D buf It has been subjected to pressure and broken down.

[0086] By clamping diode D buf The first voltage equalizing resistor R is connected in parallel across both ends. bs The first equalizing resistor R bs This is a static voltage equalization resistor. The first voltage equalization resistor R... bs The shunt clamping diode D buf The reverse leakage current, thus affecting the clamping diode D buf When the reverse leakage current is large, it can effectively reduce the clamping diode D. buf Voltage drop on top, to avoid clamping diode D buf The leakage current was too large, and the voltage was too high, which caused the breakdown.

[0087] According to some feasible embodiments of this application, optionally, such as Figure 6 or Figure 7 As shown, the inverter circuit 10 includes a first bridge arm switch group, a second bridge arm switch group, a third bridge arm switch group, and a fourth bridge arm switch group. The first end of the first bridge arm switch group is electrically connected to the first end of the output side of the clamping circuit 40, the second end of the first bridge arm switch group is electrically connected to the first end of the second bridge arm switch group at the first node N1, and the second end of the second bridge arm switch group is electrically connected to the second end of the output side of the clamping circuit 40. The first end of the third bridge arm switch group is electrically connected to the first end of the output side of the clamping circuit 40, the second end of the third bridge arm switch group is electrically connected to the first end of the fourth bridge arm switch group at the second node N2, and the second end of the fourth bridge arm switch group is electrically connected to the second end of the output side of the clamping circuit 40. The first node N1 is the first terminal of the output side of the inverter circuit 10, and the second node N2 is the second terminal of the output side of the inverter circuit 10. The first bridge arm switch group, the second bridge arm switch group, the third bridge arm switch group, and the fourth bridge arm switch group each include: at least one switch unit connected in series, the switch unit including a bridge arm switch transistor and anti-parallel diodes disposed across the bridge arm switch transistor.

[0088] like Figure 6 or Figure 7 As shown, the bridge arm switching transistors include, for example, transistor T1 in the first bridge arm switching group, transistor T2 in the second bridge arm switching group, transistor T3 in the third bridge arm switching group, or transistor T4 in the fourth bridge arm switching group. The anti-parallel diodes include, for example, diode D1 in the first bridge arm switching group, diode D2 in the second bridge arm switching group, diode D3 in the third bridge arm switching group, or diode D4 in the fourth bridge arm switching group.

[0089] In this embodiment, an inverter full-bridge structure is formed by configuring the above four bridge arm switch groups. Each of the above bridge arm switch groups includes: at least one switch unit connected in series, and the switch unit includes a bridge arm switch transistor and anti-parallel diodes disposed across the bridge arm switch transistor. Figure 6 or Figure 7 Only two sets of switch units connected in series are shown in this illustration. However, in some other embodiments, there may be one or more switch units in each bridge arm switch group. This is not a strict limitation.

[0090] In actual inverter operation, the DC voltage is modulated into AC voltage and output from the first node N1 and the second node N2 by controlling the switching transistors in different bridge arm switch groups to conduct or turn off; the anti-parallel diodes provide reverse freewheeling function during the inverter process. The AC voltage output by inverter circuit 10 is, for example, an AC square wave voltage.

[0091] The aforementioned bridge arm switching transistors can be, for example, gate turn-off thyristors (GTOs), power bipolar junction transistors (BJTs), power MOSFETs (Power Metal-Oxide-Semiconductor Field-Effect Transistors), or insulated gate bipolar transistors (IGBTs), and are not strictly limited here.

[0092] It should be noted that in some feasible embodiments, when the above-mentioned bridge arm switching transistors are power MOSFETs or insulated gate bipolar transistors, these devices have high voltage withstand capability and fast switching characteristics, which can replace the function of clamping circuit 40 to a certain extent. Therefore, in this case, clamping circuit 40 can be removed to reduce the overall circuit cost and complexity of the DC converter.

[0093] Please continue reading Figure 6 or Figure 7 According to some feasible embodiments of this application, optionally, any switching unit further includes a second voltage-equalizing capacitor, a current-limiting resistor, and a second voltage-equalizing resistor; The second voltage equalizing capacitor and the current limiting resistor are connected in series to form a series branch, and the series branch is set in parallel at both ends of the bridge arm switch tube. The second equalizing resistor is connected in parallel across the two ends of the bridge arm switching transistor.

[0094] like Figure 8 or Figure 8 As shown, the aforementioned second voltage-equalizing capacitor is, for example, the second voltage-equalizing capacitor C in the first bridge arm switch group. d1 The second equalizing capacitor C in the second bridge arm switch group d2 The second equalizing capacitor C in the third bridge arm switch group d3 Or the second equalizing capacitor C in the fourth bridge arm switch group d4 A current-limiting resistor, such as the current-limiting resistor R in the first bridge arm switch group. d1 The current-limiting resistor R in the second bridge arm switch group d2 The current-limiting resistor R in the third bridge arm switch group d3 Or the current-limiting resistor R in the fourth bridge arm switch group d4 The second voltage equalizing resistor is, for example, the second voltage equalizing resistor R in the first bridge arm switch group. s1 The second equalizing resistor R in the second bridge arm switch group s1 The second equalizing resistor R in the third bridge arm switch group s3 and the second equalizing resistor in the fourth bridge arm switch groupds4 .

[0095] In one example, to ensure that multiple bridge arm switches can withstand voltage evenly when used in series, voltage equalization protection is achieved by connecting a series branch formed by a second voltage equalization capacitor and a current-limiting resistor connected in series in parallel across each bridge arm switch, and / or by connecting a second voltage equalization resistor in parallel, so as to ensure that the bridge arm switches can operate safely and reliably when used in series.

[0096] By connecting a second voltage-equalizing capacitor in parallel across the bridge arm switch and a current-limiting resistor in series to form a series branch, the second voltage-equalizing capacitor can effectively utilize the charging and discharging characteristics of a capacitor when the voltage in the circuit changes rapidly, thereby achieving dynamic voltage equalization of the bridge arm switch during the switching process under dynamic conditions. Simultaneously, the current-limiting resistor provides current-limiting protection during the charging and discharging process of the second voltage-equalizing capacitor.

[0097] A second voltage-equalizing resistor, which is a static voltage-equalizing resistor, is connected in parallel across the bridge arm switching transistors. This static voltage-equalizing resistor, connected in parallel across the bridge arm switching transistors, can be used to ensure static voltage equalization of the series-connected bridge arm switching transistors.

[0098] According to some feasible embodiments of this application, the above-mentioned non-isolated regulation circuit 30 may optionally be implemented using a flying capacitor buck circuit or a two-level interleaved buck circuit.

[0099] In one example, due to the low voltage stress and high efficiency of the flying capacitor buck converter, the non-isolated regulation circuit 30 is specifically implemented using a flying capacitor buck converter. The specific topology of the flying capacitor buck converter is as follows: Figure 9 or Figure 9 As shown. This flying capacitor buck converter circuit includes: a switching device Q. b1 Q b2 D b1 D b2 Inductor L b1 Output capacitor C o1 And flying capacitors, whose specific working principle will not be described in detail here.

[0100] In this example, the flying capacitor buck converter reduces the voltage stress on the switching devices to half that of the conventional two-level topology by introducing a flying capacitor, which can significantly reduce the voltage stress and ripple current of the switching devices.

[0101] In actual operation of the flying capacitor buck converter circuit, the output voltage at the port can be dynamically adjusted by changing the duty cycle of the flying capacitor buck converter circuit. Based on this, in actual operation, the DC-DC converter 100 can ultimately achieve closed-loop control of the voltage / current of each output port Vout by adjusting the duty cycle of the non-isolated regulation circuit 30.

[0102] In some other embodiments, the structure of the two-level interleaved buck circuit is relatively simple and the control strategy is relatively easy to implement. Therefore, in the scenario where the input side of the non-isolated regulation circuit 30 is a low voltage input, the two-level interleaved buck circuit can also be used to realize the non-isolated voltage regulation function of the non-isolated regulation circuit 30.

[0103] It should be added that, in some other embodiments, other non-isolated voltage regulation topologies can also be used to implement the non-isolated regulation circuit 30 of this application. This application does not strictly limit the implementation topology of the non-isolated regulation circuit 30, and the specific topology can be selected and set according to the actual needs of the DC-DC converter 100. For example, the actual non-isolated voltage regulation topology is selected based on the input voltage magnitude on the input side of the actual non-isolated regulation circuit 30.

[0104] According to some feasible embodiments of this application, optionally, the DC input side Vin is connected to a photovoltaic solar panel, which is used to convert solar energy into DC power. The load includes an electrolyzer used for electrolytic hydrogen production under DC power.

[0105] In this embodiment, the DC input side Vin is connected to the photovoltaic solar panel to achieve effective utilization of photovoltaic power generation. The DC-DC converter 100 is positioned between the photovoltaic solar panel and the electrolyzer. The step-down AC transformers in each isolated conversion rectifier circuit 20 can employ different turns ratios and capacities to meet the voltage levels of different electrolyzers, thus supporting power conversion from medium-voltage DC to low-voltage for various types of electrolyzers. Furthermore, the DC-DC converter 100 features a modular AC transformer and resonant cavity structure and distributed multi-port output capability, avoiding the manufacturing difficulties of large-capacity AC transformers, significantly increasing the capacity of the hydrogen production power system, and improving the renewable energy utilization rate.

[0106] Overall, considering the application requirements of off-grid hydrogen production systems for renewable energy, such as a wide power adjustment range, fast response speed, and adaptability to the volatility and intermittency of renewable energy, the medium-voltage DC converter 100 topology and control proposed in this application can be used for mixed access of various types of electrolyzers, realizing the efficient, low-cost, and large-scale development of hydrogen production from renewable energy.

[0107] Furthermore, the DC transformer proposed in this application can be connected to various types of electrolyzers, thus adapting to the volatility and intermittency of renewable energy. For example, the various types of electrolyzers can include alkaline electrolyzers and PEM (Proton Exchange Membrane) electrolyzers. Alkaline electrolyzers are characterized by large capacity and good economic efficiency, but slow start-up and shutdown; PEM electrolyzers are characterized by small capacity and high cost, but rapid start-up, making them suitable for new energy scenarios. By combining the characteristics of different electrolyzers, it is possible to flexibly adapt to the energy fluctuation and intermittency scenarios of renewable energy.

[0108] It is understood that the above are all examples and do not serve as a substantial limitation on the high-power, high-efficiency DC-DC converter 100 protected in this application.

[0109] Based on the same inventive concept, this application also provides a DC power supply system. Please refer to the following... Figure 8 , Figure 9 This is a schematic diagram of a DC power supply system provided in one embodiment of this application. The DC power supply system 1000 includes a photovoltaic solar panel 200, at least one electrolytic cell, and a high-power, high-efficiency DC converter 100 as provided in any of the foregoing embodiments of this application.

[0110] The aforementioned high-power, high-efficiency DC-DC converter 100 is electrically connected between the photovoltaic solar panel 200 and the electrolytic cell; The photovoltaic solar panel 200 is used to convert solar energy into DC power and input the DC power to the high-power, high-efficiency DC converter 100 for DC conversion. The electrolyzer is used to produce hydrogen by electrolysis under the DC power supply of the high-power, high-efficiency DC converter 100.

[0111] In other embodiments, see also [link to relevant documentation]. ​ , ​ This is a schematic diagram of the structure of a DC power supply system 1000 provided in another embodiment of this application. An embodiment of this application provides a DC power supply system 1000, including as follows: ​ The single-output configuration shown is for a single electrolytic cell, or includes, for example, a single-output configuration for a single electrolytic cell. ​ The diagram shows a multi-output configuration for n electrolytic cells.

[0112] In practical applications, in response to the application requirements of off-grid hydrogen production systems for renewable energy, such as a wide power adjustment range, fast response speed, and adaptability to the volatility and intermittency of renewable energy, the DC power supply system 1000 provided in this application embodiment can be used for the mixed access of various types of electrolyzers to realize the efficient, low-cost, and large-scale hydrogen production development of renewable energy.

[0113] It should be understood that the DC power supply system 1000 provided in this application embodiment has the beneficial effects of the high power and high efficiency DC converter 100 provided in this application embodiment. For details, please refer to the specific description of the high power and high efficiency DC converter 100 in the above embodiments. This embodiment will not repeat the description here.

[0114] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0115] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0116] It should be clarified that the various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. According to the embodiments described above, these embodiments do not exhaustively describe all details, nor do they limit this application to only the specific embodiments described. Obviously, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to make good use of this application and modifications based on it. This application is limited only by the claims and their full scope and equivalents.

[0117] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on a study of the drawings, specification, and claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other structures; the quantity refers to "one" but does not exclude multiple; the terms "first" and "second" are used to identify names and not to indicate any particular order. Any reference numerals in the claims should not be construed as limiting the scope of protection. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

[0118] This document uses specific examples to illustrate the principles and implementation methods of this application. The examples are merely for the purpose of helping to understand the method and core ideas of this application. The above are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, and the existence of an infinite number of specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the concept and technical solution of this application to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A high-power, high-efficiency DC-DC converter, characterized in that, The high-power, high-efficiency DC-DC converter includes: An inverter circuit, wherein the input side of the inverter circuit is electrically connected to the DC input side, is used to convert the DC voltage input to the DC input side into an AC voltage output; At least one isolation converter rectifier circuit, wherein the input side of any one of the isolation converter rectifier circuits is electrically connected to the output side of the inverter circuit, and the isolation converter rectifier circuit includes an isolation transformer module and a rectifier circuit; The isolation transformer module is used to isolate and transform the AC voltage, and output the isolated and transformed AC voltage to the rectifier circuit. The rectifier circuit is used to rectify the AC voltage output by the isolation transformer module, and output corresponding DC voltages through the first rectifier output side and the second rectifier output side respectively. The first rectifier output side is used to be electrically connected to the corresponding load. A non-isolated regulating circuit, wherein the input side of the non-isolated regulating circuit is electrically connected to the corresponding second rectifier output side, the output side of the non-isolated regulating circuit is electrically connected to the corresponding load, and the non-isolated regulating circuit is used to regulate and output the DC voltage provided by the second rectifier output side; In the same isolated converter rectifier circuit, the first rectifier output side and the output side of the non-isolated regulating circuit are connected in parallel and then connected to the same corresponding load; different isolated converter rectifier circuits may correspond to the same or different loads.

2. The high-power, high-efficiency DC-DC converter according to claim 1, characterized in that, The isolation converter rectifier circuit further includes: A resonant network is provided, wherein the input side of the resonant network is electrically connected to the output side of the inverter circuit, and the output side of the resonant network is electrically connected to the input side of the isolation transformer module.

3. The high-power, high-efficiency DC-DC converter according to claim 2, characterized in that, The resonant network includes: A resonant inductor, wherein the first end of the resonant inductor is electrically connected to the first end of the output side of the inverter circuit, and the second end of the resonant inductor is electrically connected to the first end of the input side of the isolation transformer module; A resonant capacitor, the first end of which is electrically connected to the second end of the output side of the inverter circuit, and the second end of which is electrically connected to the second end of the input side of the isolation transformer module.

4. The high-power, high-efficiency DC-DC converter according to claim 1, characterized in that, The isolation transformer module includes a first isolation transformer and a second isolation transformer, and the rectifier circuit includes a first rectifier module and a second rectifier module; The primary winding of the first isolation transformer is connected in series with the primary winding of the second isolation transformer, the secondary winding of the first isolation transformer is electrically connected to the input side of the first rectifier module, and the output side of the first rectifier module is the first rectifier output side. The secondary winding of the second isolation transformer is electrically connected to the input side of the second rectifier module, and the output side of the second rectifier module is the second rectifier output side.

5. The high-power, high-efficiency DC-DC converter according to claim 4, characterized in that, The first rectifier module includes a first rectifier diode and a second rectifier diode, and / or the second rectifier module includes a third rectifier diode and a fourth rectifier diode; The anode of the first rectifier diode is electrically connected to the first terminal of the secondary winding of the first isolation transformer, and the anode of the second rectifier diode is electrically connected to the second terminal of the secondary winding of the first isolation transformer. The common terminal formed by the electrical connection of the cathodes of the first rectifier diode and the second rectifier diode constitutes the first terminal of the first rectifier output side, and the center tap of the first isolation transformer constitutes the second terminal of the first rectifier output side. The anode of the third rectifier diode is electrically connected to the first end of the secondary winding of the second isolation transformer, and the anode of the fourth rectifier diode is electrically connected to the second end of the secondary winding of the second isolation transformer. The common terminal formed by the electrical connection of the cathodes of the third rectifier diode and the fourth rectifier diode constitutes the first terminal of the second rectifier output side, and the center tap of the second isolation transformer constitutes the second terminal of the first rectifier output side.

6. The high-power, high-efficiency DC-DC converter according to claim 4, characterized in that, The first rectifier module further includes a first output capacitor, and / or the second rectifier module further includes a second output capacitor; The first output capacitor is disposed between the first end of the first rectifier output side and the second end of the first rectifier output side; The second output capacitor is disposed between the first end of the second rectifier output side and the second end of the second rectifier output side.

7. The high-power, high-efficiency DC-DC converter according to claim 1, characterized in that, The high-power, high-efficiency DC-DC converter also includes: A clamping circuit, wherein the input side of the clamping circuit is electrically connected to the DC input side, and the output side of the clamping circuit is electrically connected to the inverter side of the inverter circuit; The clamping circuit is used to limit the rate of change of current on the bridge arm switching transistors in the inverter circuit, and to limit the AC voltage amplitude on the output side of the inverter circuit.

8. The high-power, high-efficiency DC-DC converter according to claim 7, characterized in that, The clamping circuit includes an anode reactor, at least one clamping diode, a clamping resistor, and a clamping capacitor; The first end of the anode reactor is electrically connected to the first end of the DC input side and the first end of the clamping resistor; the first end of the clamping capacitor is electrically connected to the second end of the clamping resistor; and the second end of the clamping capacitor is electrically connected to the second end of the DC input side. The at least one clamping diode is connected in series between the second end of the anode reactance and the second end of the clamping resistor, and the current flow direction from the anode to the cathode of any clamping diode is the same as the current flow direction from the second end of the anode reactance to the second end of the clamping resistor.

9. The high-power, high-efficiency DC-DC converter according to claim 8, characterized in that, The clamping circuit further includes at least one first voltage equalizing capacitor and / or at least one first voltage equalizing resistor; Any of the first voltage equalizing capacitors is connected in parallel across the corresponding clamping diode, and any of the first voltage equalizing resistors is connected in parallel across the corresponding clamping diode.

10. The high-power, high-efficiency DC-DC converter according to claim 1, characterized in that, The inverter circuit includes a first bridge arm switch group, a second bridge arm switch group, a third bridge arm switch group, and a fourth bridge arm switch group; The first end of the first bridge arm switch group is electrically connected to the first end of the DC input side, the second end of the first bridge arm switch group is electrically connected to the first end of the second bridge arm switch group at the first node, and the second end of the second bridge arm switch group is electrically connected to the second end of the DC input side. The first end of the third bridge arm switch group is electrically connected to the first end of the DC input side, the second end of the third bridge arm switch group is electrically connected to the first end of the fourth bridge arm switch group at the second node, and the second end of the fourth bridge arm switch group is electrically connected to the second end of the DC input side. The first node is the first terminal on the output side of the inverter circuit, and the second node is the second terminal on the output side of the inverter circuit; The first bridge arm switch group, the second bridge arm switch group, the third bridge arm switch group, and the fourth bridge arm switch group each include: at least one switch unit connected in series, the switch unit including a bridge arm switch transistor and anti-parallel diodes disposed at both ends of the bridge arm switch transistor.

11. The high-power, high-efficiency DC-DC converter according to claim 10, characterized in that, Any of the aforementioned switching units further includes a second voltage-equalizing capacitor, a current-limiting resistor, and a second voltage-equalizing resistor; The second voltage equalizing capacitor and the current limiting resistor are connected in series to form a series branch, and the series branch is connected in parallel across the two ends of the bridge arm switch transistor; The second equalizing resistor is connected in parallel across the two ends of the bridge arm switch.

12. The high-power, high-efficiency DC-DC converter according to any one of claims 1-11, characterized in that, The non-isolated regulation circuit is implemented using a flying capacitor buck circuit or a two-level interleaved buck circuit.

13. The high-power, high-efficiency DC-DC converter according to any one of claims 1-11, characterized in that, The DC input side is connected to a photovoltaic solar panel, which is used to convert solar energy into DC power. The load includes an electrolyzer for producing hydrogen by electrolysis under DC power.

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