Direct-current converter, direct-current conversion method, electric equipment and photovoltaic system

Abstract

The invention provides a direct current converter, a direct current conversion method, electric equipment and a photovoltaic system. The direct current converter comprises an inversion module, a transformation module and a rectification module, the inversion module is used for inverting direct current into alternating current, the inversion module comprises a first switching device, the rectification module is used for rectifying the alternating current into the direct current, and the rectification module comprises an inductor and a second switching device. The inductor and one second switching device correspond to the two first switching devices of one bridge arm in the inversion module respectively, and the other two second switching devices in the plurality of second switching devices correspond to the two first switching devices of the other bridge arm in the inversion module respectively, driving of the two first switching devices located on the same bridge arm in the inversion module is complementary, the second switching device and the corresponding first switching device are synchronously conducted, and the conduction duration is the same. According to the direct current converter, the conversion efficiency can be improved, and meanwhile the miniaturization design of the direct current converter is achieved.

Description

Technical Field

[0001] This application relates to the field of power electronics, and more particularly to a DC converter, a DC conversion method, an electrical device, and a photovoltaic system. Background Technology

[0002] Electrical equipment typically incorporates DC-DC converters to convert electrical energy supplied by an external power source into the DC power required by the equipment's load, ensuring normal operation. To meet the miniaturization and operational demands of electrical equipment, DC-DC converters often need to provide greater power output while minimizing their footprint. Therefore, improving the conversion efficiency of DC-DC converters is crucial. Summary of the Invention

[0003] This application provides a DC-DC converter, a DC-DC conversion method, an electrical device, and a photovoltaic system. The DC-DC converter of this application, through targeted optimization of its internal topology, can improve the conversion efficiency of the DC-DC converter, thereby increasing the power output of the DC-DC converter while meeting the requirements of miniaturization design. This application specifically includes the following technical solutions:

[0004] In a first aspect, this application provides a DC-DC converter, which includes an inverter module, a transformer module, and a rectifier module. The inverter module is used to invert a first DC power supply into a first AC power supply. The inverter module has a full-bridge structure and includes multiple first switching devices. The transformer module is used to convert the first AC power supply into a second AC power supply. The rectifier module is used to rectify the second AC power supply into a second DC power supply. The voltage of the second DC power supply is different from the voltage of the first DC power supply. The rectifier module includes an inductor and multiple second switching devices. The inductor and one second switching device correspond to two first switching devices in one bridge arm of the inverter module, respectively. The other two second switching devices correspond to two first switching devices in another bridge arm of the inverter module, respectively. The driving of the two first switching devices in the same bridge arm of the inverter module is complementary. The second switching device and its corresponding first switching device are synchronously turned on and have the same on-time.

[0005] This application's DC-DC converter achieves complementary driving of two first switching devices located on the same bridge arm, with the two first switching devices in the inverter module diagonally opposite each other conducting synchronously for the same duration. This allows the inverter module to convert the first DC power supplied by the external power source into first AC power, which is then supplied to the transformer module. By setting the second switching device to conduct synchronously with its corresponding first switching device for the same duration—that is, one or the other two first switching devices in the rectifier module conducting synchronously with their corresponding two first switching devices in the inverter module for the same duration—the rectifier module can unidirectionally and synchronously rectify the second AC power into the second DC power.

[0006] Furthermore, this DC-DC converter replaces a second switching device on any arm of the rectifier module with an inductor, shortening the current transmission path within the rectifier module. This improves current transmission efficiency and reduces current loss during transmission. Simultaneously, compared to a rectifier module entirely composed of second switching devices, replacing a second switching device on any arm of the rectifier module with an inductor effectively reduces the average current flowing through the transformer module and inductor, significantly decreasing the effective current loss in the transformer module's inductor. Furthermore, by reducing the current transmission path, lowering the average effective current value, and reducing losses, this DC-DC converter improves current transmission efficiency, thereby increasing the converter's conversion efficiency and enabling miniaturization. Moreover, increased conversion efficiency reduces heat generation, further miniaturizing the converter and lowering heat dissipation requirements.

[0007] In one implementation, during one operating cycle of the DC-DC converter, when the second AC current passes through an inductor and a second switching device, the DC-DC converter operates in the resonant half-cycle; when the second AC current passes through two second switching devices, the DC-DC converter operates in the voltage regulation half-cycle. The sum of the duration of the resonant half-cycle and the duration of the voltage regulation half-cycle equals the duration of one operating cycle.

[0008] In this implementation, when the second AC current flows through a second switching device connected in series with the inductor, the DC-DC converter can be understood as operating in the resonant half-cycle. When the second AC current flows through two second switching devices not connected in series with the inductor, the DC-DC converter can be understood as operating in the voltage regulation half-cycle. It is understandable that by setting the sum of the duration of the resonant half-cycle and the voltage regulation half-cycle to equal the duration of one operating cycle, the output voltage of the second DC current from the DC-DC converter can be stabilized by adjusting at least one of the durations of the voltage regulation half-cycle or the resonant half-cycle, thereby improving the accuracy and stability of the output voltage provided by the DC-DC converter to the load.

[0009] One implementation involves keeping the duration of one working cycle constant, and adjusting the ratio of the duration of the resonant half-cycle to the duration of the voltage regulation half-cycle by separately adjusting the duration of the resonant half-cycle and the duration of the voltage regulation half-cycle.

[0010] In this implementation, the duration of one duty cycle is fixed, which can also be understood as the operating frequency of the DC-DC converter remaining constant. In this case, by adjusting the durations of the resonant half-cycle and the voltage regulation half-cycle separately, the ratio between their durations can be adjusted, thereby enabling closed-loop regulation of the DC-DC converter's output voltage. In other words, in this embodiment, a control method that uses a fixed duty cycle and simultaneously adjusts the durations of the resonant half-cycle and the voltage regulation half-cycle can achieve closed-loop voltage regulation and stable output of the DC-DC converter, further improving its conversion efficiency.

[0011] One implementation method involves keeping the duration of the resonant half-cycle constant, and achieving closed-loop voltage regulation of the DC-DC converter by adjusting the duration of one working cycle and the duration of the voltage regulation half-cycle respectively.

[0012] In this implementation, when the duration of the DC-DC converter's resonant half-cycle is fixed, the closed-loop voltage regulation effect of the DC-DC converter can be achieved by adjusting the duration of its duty cycle and the duration of its voltage regulation half-cycle, thereby improving the stability of the output voltage provided to the load. In other words, in this embodiment, a control method that keeps the resonant half-cycle duration constant while simultaneously adjusting the duration of the duty cycle and the voltage regulation half-cycle can be used to achieve closed-loop voltage regulation and stable output of the DC-DC converter, further improving its conversion efficiency.

[0013] In one implementation, the duration of the resonant half-cycle is equal to half the duration of the resonant period of the transformer module. The duration of the resonant period of the transformer module is: 2π√LrCr, where Lr is the inductance of the resonant inductor in the transformer module and Cr is the capacitance of the resonant capacitor in the transformer module.

[0014] In this implementation, by setting the duration of the resonant half-cycle to be determined by the duration of the resonant period of the transformer module, the duration of the DC converter operating in the resonant half-cycle can be fixed. Furthermore, by adjusting the duration of the operating period and the duration of the voltage regulation half-cycle, the DC converter can achieve closed-loop voltage regulation and stable output, thereby further improving the conversion efficiency of the DC converter.

[0015] In one implementation, the transformer module includes a primary winding and a secondary winding. The primary winding is coupled to an inverter module, and the secondary winding is coupled to a rectifier module. Multiple second switching devices include a first diode, a second diode, and a third diode. The cathode of the first diode is coupled to one end of an inductor, the anode of the first diode is coupled to the cathode of the second diode, the anode of the second diode is coupled to the anode of the third diode, and the cathode of the third diode is coupled to the other end of the inductor. One end of the secondary winding of the transformer module is coupled between the inductor and the third diode, and the other end of the secondary winding of the transformer module is coupled between the first diode and the second diode.

[0016] In this implementation, by coupling the primary winding to the inverter module, the first AC current generated by the inverter module is transmitted to the transformer module. By coupling the secondary winding to the rectifier module, the transformer module transmits the second AC current, after voltage adjustment, to the rectifier module, enabling the rectifier module to perform unidirectional rectification output of the second AC current. Furthermore, by using three diodes as the multiple second switching devices in the rectifier module, the rectifier module of the DC-DC converter is passively controlled, eliminating the need for an additional control module to separately control and adjust the unidirectional rectification effect. This simplifies the internal topology of the DC-DC converter and further enables its miniaturization.

[0017] In one implementation, a plurality of first switching devices include a plurality of sub-switches, each of which includes a first pole, a second pole, and a control pole. The control pole is used to control the conduction duration between the first pole and the second pole. The plurality of sub-switches include a first sub-switch, a second sub-switch, a third sub-switch, and a fourth sub-switch. The first poles of the first sub-switches and the first poles of the third sub-switches are coupled together. The second poles of the first sub-switches and the first poles of the second sub-switches are coupled together. The first poles of the fourth sub-switches and the second poles of the third sub-switches are coupled together. One end of the primary coil is coupled between the third sub-switches and the fourth sub-switches, and the other end of the primary coil is coupled between the first sub-switches and the second sub-switches.

[0018] In this implementation, by setting multiple first switching devices in the inverter module as four sub-switches, each sub-switches in the inverter module can be actively controlled, thereby ensuring the inverter module's ability to convert DC to AC, thus guaranteeing the normal operation of the DC-DC converter. Simultaneously, by actively controlling each sub-switches in the inverter module, at least one of the following can be adjusted based on different voltage regulation requirements: the duration of the DC-DC converter operating in the resonant half-cycle, the duration of the voltage regulation half-cycle, or the duration of the entire operating cycle. This satisfies different voltage output requirements of the DC-DC converter, expanding its applicability and application range.

[0019] In one implementation, the second terminals of the second sub-switch and the fourth sub-switch are simultaneously coupled to at least one of the cathode of the first diode and one end of the inductor.

[0020] In this implementation, by setting the internal topology of the DC-DC converter to a non-isolated closed-loop connection and by replacing a second switching device in the full-bridge rectifier module with an inductor, the internal impedance of the DC-DC converter can be reduced, thereby improving the conversion efficiency and power density of the DC-DC converter and further realizing the miniaturization design of the DC-DC converter.

[0021] In one implementation, the DC-DC converter further includes a control module coupled to the control electrode of each sub-switch, which is used to adjust the on-time of each sub-switch.

[0022] In this implementation, by coupling the control module to the control electrode of each sub-switch, the control module can actively control each sub-switch, thereby ensuring the inverter module's ability to convert DC to AC and guaranteeing the normal functioning of the DC-DC converter. Simultaneously, by controlling each sub-switch, the control module can adjust at least one of the following durations: the duration of the DC-DC converter's resonant half-cycle, the duration of its voltage regulation half-cycle, or the duration of its entire operating cycle. This allows for different voltage outputs from the DC-DC converter, expanding its applicability and application range.

[0023] In one implementation, the plurality of sub-switches include at least one of a relay, a wide bandgap device, a metal-oxide-semiconductor field-effect transistor, a bipolar junction transistor, an insulated-gate bipolar transistor, a gallium nitride switching device, and a silicon carbide (SiC) switching device.

[0024] In one implementation, the DC-DC converter includes two capacitors: one capacitor is connected in series with the primary winding, and the other capacitor is connected in series with the secondary winding.

[0025] In this implementation, by connecting one capacitor in series with the primary winding, a DC-DC isolation effect is achieved between the inverter module and the transformer module. Simultaneously, by replacing the second switching device in either bridge arm of the DC-DC converter's rectifier module with an inductor, an asymmetrical topology is formed within the DC-DC converter. By connecting a capacitor in series with both the primary and secondary windings of the transformer module, voltage balance between the high-voltage and low-voltage sides of the transformer module can be ensured. Furthermore, connecting a capacitor in series with both the primary and secondary windings of the transformer module results in different operating states for the transformer module during the resonant half-cycle and the voltage regulation half-cycle of the DC-DC converter. This allows the transformer module to deliver current from the input side of the DC-DC converter to both the DC-DC converter and its output side throughout the entire operating cycle.

[0026] Secondly, this application provides a DC-DC conversion method applied to a DC-DC converter, the DC-DC converter including: an inverter module, a transformer module, and a rectifier module, the DC-DC conversion method including:

[0027] The inverter module receives the input first DC power and inverts the first DC power into first AC power. The inverter module has a full-bridge structure and includes multiple first switching devices.

[0028] The transformer module converts the first AC power into the second AC power.

[0029] The rectifier module rectifies the second AC power into a second DC power, which is then supplied to the load. The rectifier module includes an inductor and a plurality of second switching devices, and the inductor and one second switching device correspond to two first switching devices in one of the bridge arms of the inverter module, respectively.

[0030] The control system ensures that the second switching device, which has a corresponding relationship, is synchronously turned on with the first switching device and that the on-time is the same.

[0031] One implementation involves an inverter module receiving a first direct current input and converting it into a first alternating current, comprising:

[0032] The two first switching devices located diagonally opposite each other are controlled to conduct synchronously for the same duration.

[0033] In one implementation, the rectifier module rectifies the second AC power into a second DC power, comprising:

[0034] During the period when the second alternating current flows through the inductor and a second switching device, the two first switching devices corresponding to the inductor and the second switching device are controlled to be turned on.

[0035] In one implementation, the rectifier module rectifies the second AC power into a second DC power, comprising:

[0036] During the period when the second alternating current passes through two other second switching devices among a plurality of second switching devices, the two first switching devices corresponding to the other two second switching devices are controlled to turn on.

[0037] Thirdly, this application provides an electrical device including a load and a DC-DC converter as provided in any of the above implementations, the DC-DC converter being used to convert a first DC power supplied by an external power source into a second DC power and supply it to the load.

[0038] The electrical equipment of this application, by configuring a DC-DC converter coupled to the load, enables the DC-DC converter to convert the first DC power supplied by the external power source into a second DC power required for the normal operation of the load, thereby meeting the voltage requirements of the load. Furthermore, because the electrical equipment of this application uses the DC-DC converter provided by any of the above-described implementations, the electrical equipment of this application possesses all the beneficial effects that the DC-DC converter provided by any of the above-described implementations may have.

[0039] Fourthly, this application provides a photovoltaic system, which includes a photovoltaic device, an energy storage device, and a DC-DC converter as provided in any of the above implementations. The DC-DC converter is coupled between the photovoltaic device and the energy storage device. The photovoltaic device is used to provide a first DC power to the DC-DC converter, and the DC-DC converter is used to convert the first DC power into a second DC power and provide it to the energy storage device. The energy storage device is used to store electrical energy.

[0040] The photovoltaic system of this application, by coupling a DC-DC converter between the photovoltaic device and the energy storage device, can convert the first DC power provided by the photovoltaic device into a second DC power and supply it to the energy storage device, which can store electrical energy. Furthermore, because the photovoltaic system of this application uses the DC-DC converter provided by any of the above-described implementations, the photovoltaic system of this application possesses all the beneficial effects that the DC-DC converter provided by any of the above-described implementations may have. Attached Figure Description

[0041] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the working scenario of the electrical equipment provided in the embodiments of this application;

[0043] Figure 2 This is a schematic diagram of the planar structure of the electrical equipment provided in the embodiments of this application;

[0044] Figure 3 This is a schematic diagram of the planar structure of the electrical equipment provided in the embodiments of this application;

[0045] Figure 4 This is a schematic diagram of the planar structure of the photovoltaic system provided in the embodiments of this application;

[0046] Figure 5 This is a schematic diagram of the planar structure of the DC-DC converter provided in the embodiments of this application;

[0047] Figure 6 This is a schematic diagram of the internal topology of a DC-DC converter provided in an embodiment of this application;

[0048] Figure 7 This is a schematic diagram of the internal topology of a DC-DC converter provided in an embodiment of this application;

[0049] Figure 8 This is a schematic diagram of the planar structure of the rectifier module of the DC-DC converter provided in the embodiments of this application;

[0050] Figure 9 This is a control timing diagram of the control module in a DC-DC converter provided in an embodiment of this application;

[0051] Figure 10 This is a schematic diagram of the planar structure of the DC-DC converter provided in the embodiments of this application;

[0052] Figure 11 This is a schematic diagram illustrating the workflow of the DC-DC conversion method provided in the embodiments of this application. Detailed Implementation

[0053] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are merely some, and not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection claimed in this application.

[0054] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the working scenario of the electrical equipment 1000 provided in an embodiment of this application. Figure 1 In the illustrated embodiment, the electrical device 1000 includes a DC-DC converter 100 and a load 1001. The DC-DC converter 100 converts a first DC power supplied by an external power source into a second DC power source and supplies it to the load 1001 to meet the power requirements for normal operation of the load 1001. The voltage of the first DC power source can be greater than or less than the voltage of the second DC power source. In other words, the DC-DC converter 100 performs power conversion on the electrical energy supplied by the external power source, converting it into the electrical energy required by the load 1001 and supplying it to the load 1001, thereby meeting the normal operation requirements of the load 1001.

[0055] Please see Figure 2 , Figure 2 This is a schematic plan view of the electrical equipment 1000 provided in an embodiment of this application. Figure 2In the illustrated embodiment, the electrical device 1000 can be an electric vehicle 1000a, and the load 1001 can be the motor 1001a of the electric vehicle 1000a. The electric vehicle 1000a includes a power battery 1002a, a motor 1001a, wheels 1003a, and a vehicle body 1004a. The wheels 1003a are fixed relative to the vehicle body 1004a and can rotate about their own axis relative to the vehicle body 1004a. The power battery 1002a, the motor 1001a, and the DC-DC converter 100 are all fixed inside the vehicle body 1004a, which provides protection for the power battery 1002a, the motor 1001a, and the DC-DC converter 100.

[0056] The power battery 1002a is used to store electrical energy and provide power to the motor 1001a. The motor 1001a is connected to the wheel 1003a for transmission. The motor 1001a is used to drive the wheel 1003a to rotate around its own axis so as to realize the function of driving the electric vehicle 1000a.

[0057] For example, when the power battery 1002a has insufficient power or needs to be charged, it can be done, but is not limited to, through an external power source, such as... Figure 2 The charging station 1005 shown charges the power battery 1002a of the electric vehicle 1000a. Specifically, when the electric vehicle 1000a is charging, a DC-DC converter 100 is coupled between the charging station 1005 and the power battery 1002a. The DC-DC converter 100 is used to convert the electrical energy provided by the charging station 1005 into the voltage required by the power battery 1002a and deliver it to the power battery 1002a for charging.

[0058] It should be noted that, in Figure 2 In the illustrated embodiments, the DC-DC converter 100 is described exemplarily only as being located inside the electric vehicle 1000a, but it is not limited to the DC-DC converter 100 provided in this application embodiment being only located inside the electric vehicle 1000a. In other embodiments of this application, the DC-DC converter 100 may also be, but is not limited to, being located in the charging pile 1005 or the charging gun of the charging pile 1005 (not shown in the figure), to achieve the effect of current-voltage conversion when charging the power battery 1002a of the electric vehicle 1000a. This application embodiment does not specifically limit this.

[0059] Please see Figure 3 , Figure 3 This is a schematic plan view of the electrical equipment 1000 provided in an embodiment of this application. Figure 3In the embodiments shown, the electrical device 1000 can also be a communication device 1000b, and the load 1001 can be, but is not limited to, a device such as a chip 1001b within the communication device 1000b. The chip 1001b can be used to receive or transmit signals and can be used to supply power to the chip 1001b within the communication device 1000b.

[0060] Specifically, the DC-DC converter 100 is coupled between the DC bus 1006 and the internal chip 1001b of the communication device 1000b. The DC-DC converter 100 converts the current and voltage provided by the DC bus 1006 into the current and voltage required for the operation of the chip 1001b. For example, the DC voltage input to the DC-DC converter 100 from the DC bus 1006 can be 48V. The DC-DC converter 100 accepts the DC voltage input from the DC bus 1006 and can convert the 48V DC voltage into a 12V DC voltage, which is then delivered to the chip 1001b to meet the operating requirements of the chip 1001b.

[0061] For example, the communication device 1000b may be, but is not limited to, a wired communication device 1000b, such as a server, router, or switch. The communication device 1000b may also be, but is not limited to, a wireless communication device 1000b, such as a terminal device, access network device, or core network device. When the communication device 1000b is a wireless communication device 1000b, it may further include functional components such as a baseband module and a radio frequency module.

[0062] For example, when the DC-DC converter 100 is applied within the communication device 1000b, the DC-DC converter 100, acting as the board mount power (BMP) of the communication device 1000b, converts the DC voltage provided by the DC bus 1006 into the DC voltage required by the various functional devices within the communication device 1000b. The DC-DC converter 100 can also be used to provide isolated and closed-loop regulated output conditions.

[0063] It should be noted that, in Figure 3 In the illustrated embodiment, the DC converter 100 converts the DC voltage provided by the DC bus 1006 to 12V as an example for illustrative purposes only. However, it is not limited to the DC voltage value required by each functional device in the communication device 1000b, nor is it limited to the DC converter 100 being able to step down the DC voltage provided by the DC bus 1006.

[0064] That is, different functional components within the communication equipment 1000b require different DC voltages. When the DC converter 100 supplies power to different functional components within the communication equipment 1000b, it can convert the DC voltage provided by the DC bus 1006 into different magnitudes to meet the power supply requirements of these components. The DC converter 100 can either step down or step up the DC voltage provided by the DC bus 1006; this embodiment does not specifically limit the specific application in this regard.

[0065] At the same time, Figure 3 In the illustrated embodiment, the example of supplying DC power to the DC converter 100 via the DC bus 1006 is provided as an example only, but it is not limited to the DC converter 100 being supplied with input current only via the DC bus 1006. In other embodiments of this application, DC power can also be supplied to the DC converter 100 via a DC power supply or other means.

[0066] Please see Figure 4 , Figure 4 This is a schematic diagram of the planar structure of the photovoltaic system 2000 provided in an embodiment of this application. Figure 4 In the illustrated embodiment, the DC-DC converter 100 can also be applied to the photovoltaic system 2000. Specifically, the photovoltaic system 2000 includes a photovoltaic device 2001, a DC-DC converter 100, and an energy storage device 2002. The DC-DC converter 100 is coupled between the photovoltaic device 2001 and the energy storage device 2002. The photovoltaic device 2001 provides a first DC power to the DC-DC converter 100, and the DC-DC converter 100 converts the first DC power into a second DC power and provides it to the energy storage device 2002. The energy storage device 2002 stores electrical energy.

[0067] In other words, the DC-DC converter 100 is coupled between the photovoltaic device 2001 and the energy storage device 2002. The photovoltaic device 2001 can be used to convert light energy into electrical energy, which is then processed by the DC-DC converter 100 and supplied to the energy storage device 2002. The energy storage device 2002 is used to store electrical energy. The energy storage device 2002 can be, but is not limited to, a lithium battery.

[0068] For example, the photovoltaic system 2000 may also include an inverter 2003 and a power grid 2004. Figure 4 In the embodiment shown, the energy storage device 2002 is coupled to the power grid 2004 via an inverter 2003. The inverter 2003 can be used to convert the DC power stored in the energy storage device 2002 into AC power and supply it to the power grid 2004.

[0069] It should be noted that, in Figure 4The embodiments shown are merely examples of one possible embodiment of the photovoltaic system 2000, but are not limited to the functional devices in the photovoltaic system 2000 provided in this application embodiment, nor are they limited to the relative positional relationship and connection relationship of each functional device. In other embodiments of this application, the functions, positional relationship and connection relationship of the functional devices in the photovoltaic system 2000 can be adjusted according to actual design requirements and application scenarios, and this application embodiment does not make specific limitations in this regard.

[0070] In this application specification, the DC-DC converter 100 is described exemplarily as being applied within a communication device 1000b. In other embodiments of this application, the DC-DC converter 100 may also be applied, but is not necessarily applied, in a wireless base station, data center, XPU computing board, or other possible power-consuming device 1000.

[0071] This application provides a DC-DC converter, which includes an inverter module, a transformer module, and a rectifier module. The inverter module inverts a first DC current into a first AC current. The inverter module has a full-bridge structure and includes multiple first switching devices. The transformer module converts the first AC current into a second AC current. The rectifier module rectifies the second AC current into a second DC current and provides the second DC current to a load. The rectifier module includes an inductor and multiple second switching devices. The inductor and one second switching device correspond to two first switching devices in one bridge arm of the inverter module, and the other two second switching devices correspond to two first switching devices in another bridge arm of the inverter module. The driving of two first switching devices in the same bridge arm of the inverter module is complementary, and the second switching device and its corresponding first switching device conduct synchronously for the same duration. This DC-DC converter, through targeted optimization of its internal topology, can improve the conversion efficiency and reduce heat generation, thereby increasing the power output of the DC-DC converter while meeting the requirements of miniaturization design.

[0072] Please refer to the following for details. Figure 5 , Figure 5 This is a schematic planar structure diagram of the DC-DC converter 100 provided in an embodiment of this application. Figure 5 In the illustrated embodiment, the DC-DC converter 100 includes an inverter module 10, a transformer module 20, and a rectifier module 30. The inverter module 10 is coupled to the DC bus 1006, the rectifier module 30 is coupled to the load 1001, and the transformer module 20 is coupled between the inverter module 10 and the rectifier module 30.

[0073] For example, inverter module 10 converts the first DC power input to DC converter 100 via DC bus 1006 into first AC power, and transmits the generated first AC power to transformer module 20. Transformer module 20 converts the first AC power transmitted by inverter module 10 into second AC power, and transmits the second AC power to rectifier module 30. Rectifier module 30 rectifies the second AC power provided by transformer module 20, that is, rectifier module 30 converts the second AC power into second DC power and transmits it to load 1001.

[0074] Among them, Figure 5 In the illustrated embodiment, the DC bus 1006 serves as a DC input power source, providing DC power to the DC converter 100. The DC power provided by the DC bus 1006 to the DC converter 100 is schematically referred to as the first DC power, and the voltage of the first DC power is schematically referred to as the input voltage Vin. The DC power provided by the DC converter 100 to the load 1001 is schematically referred to as the second DC power, and the voltage of the second DC power is schematically referred to as the output voltage Vout.

[0075] For example, the output voltage Vout of the second DC power supply satisfies the condition: Vin / N ≤ Vout ≤ Vin / 2N. Here, N can be understood as the turns ratio of the transformer module 20, that is, the ratio between the number of turns of the secondary coil 22 of the transformer module 20 and the number of turns of the primary coil 21 of the transformer module 20.

[0076] For example, the DC converter 100 also includes a control module 40, which is electrically connected to at least one of the inverter module 10 or the rectifier module 30. The control module 40 is used to generate a control module 40 signal and provide it to at least one of the inverter module 10 or the rectifier module 30 to control the cooperation between the inverter module 10 and the rectifier module 30 so that the output voltage Vout of the second DC power supplied by the DC converter 100 to the load 1001 meets the power demand of the load 1001.

[0077] It should be noted that when the DC converter 100 is applied to different application scenarios, the input voltage Vin of the first DC power supplied to the DC converter 100 by the second DC bus 1006 and the output voltage Vout of the second DC power supplied to the load 1001 by the DC converter 100 can be adjusted according to the power demand of the load 1001. In this embodiment, the input voltage Vin of the first DC power and the output voltage Vout of the second DC power are not limited to being fixed.

[0078] The DC-DC converter 100 of this application improves the conversion efficiency and reduces the heat generation of the DC-DC converter 100 by specifically optimizing its internal topology, thereby improving the power output of the DC-DC converter 100 while meeting the miniaturization design requirements.

[0079] Next, this application specification will further describe the technical solution of this application in conjunction with the following drawings and embodiments.

[0080] Please refer to the following: Figure 6 , Figure 6 This is a schematic diagram of the internal topology of the DC-DC converter 100 provided in an embodiment of this application. Figure 6 In the illustrated embodiment, the DC-DC converter 100 includes an inverter module 10, a transformer module 20, and a rectifier module 30. The inverter module 10 is used to invert a first DC power supply into a first AC power supply. The inverter module 10 has a full-bridge structure and includes multiple first switching devices. The transformer module 20 is used to convert the first AC power supply into a second AC power supply. The rectifier module 30 is used to rectify the second AC power supply into a second DC power supply.

[0081] Specifically, such as Figure 6 As shown, the inverter module 10 may include multiple first switching devices, and the multiple first switching devices include multiple sub-switching transistors. Figure 6 The diagram illustrates multiple sub-switches Q. Each sub-switches Q may include a first electrode, a second electrode, and a control electrode. The control electrode is used to control the on or off state of the first switching device and to control the conduction duration between the first electrode and the second electrode.

[0082] When the sub-switch Q is turned on, current can flow between its first and second terminals. When the sub-switch Q is turned off, no current can flow between its first and second terminals. Figure 6 In the illustrated embodiment, the first electrode of each first switching device is shown to be the first electrode T1, the second electrode to be the second electrode T2, and the control electrode to be the control electrode T3.

[0083] For example, when the sub-switch Q is a MOSFET, the control electrode of the sub-switch Q can be understood as the gate. The first electrode of the sub-switch Q can be the source of the sub-switch Q, and the second electrode can be the drain of the sub-switch Q. Alternatively, the first electrode can be the drain of the sub-switch Q, and the second electrode can be the source of the sub-switch Q. In the embodiments of this application, the sub-switch Q can be in a conducting state driven by a signal of a first level, and in a non-circuited state driven by a signal of a second level. The first level can be greater than the second level, or the first level can be less than the second level.

[0084] In this application specification, an example is given of multiple sub-switches Q in the inverter module 10, including four sub-switches Q, which are respectively the first sub-switches Q1, the second sub-switches Q2, the third sub-switches Q3, and the fourth sub-switches Q4.

[0085] For example, the inverter module 10 has a full-bridge structure, which includes two bridge arms. It can be understood that two first switching devices sequentially coupled from a plurality of first switching devices constitute one bridge arm, for example... Figure 6 The first sub-switch Q1 and the second sub-switch Q2 shown in the diagram form one bridge arm, and the third sub-switch Q3 and the fourth sub-switch Q4 form another bridge arm.

[0086] Specifically, such as Figure 6 As shown, the control terminals T3 of the first sub-switch Q1, the second sub-switch Q2, the third sub-switch Q3, and the fourth sub-switch Q4 are all coupled to the control module 40. That is, the control module 40 is coupled to the control terminal T3 of each sub-switch Q, and the control module 40 is used to adjust the conduction time of each sub-switch Q.

[0087] Understandably, the control module 40 can adjust the magnitude of the second DC voltage supplied by the DC converter 100 to the load 1001 by adjusting the duty cycle of at least one of the first sub-switch Q1, the second sub-switch Q2, the third sub-switch Q3, or the fourth sub-switch Q4.

[0088] Meanwhile, by coupling the control module 40 to the control electrode T3 of each sub-switch Q, the control module 40 can actively control each sub-switch Q, thereby ensuring the inverter module 10's effect of converting DC to AC, and guaranteeing the normal functioning of the DC-DC converter 100. Furthermore, by controlling each sub-switch Q, the control module 40 can adjust at least one of the following durations: the duration of the DC-DC converter 100's operation during the resonant half-cycle, the duration of its voltage regulation half-cycle, or the duration of its entire operating cycle. This allows for different voltage outputs from the DC-DC converter 100, expanding its applicability and scope of use.

[0089] For example, the control module 40 may be, but is not limited to, any one of a microcontroller unit (MCU), a general-purpose central processing unit (CPU), a general-purpose processor, a digital signal processing unit (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA), or any combination of other programmable logic devices, transistor logic devices, and hardware components.

[0090] For example, the first terminal T1 of the first sub-switch Q1 is coupled to the first terminal T1 of the third sub-switch Q3, and the second terminal T2 of the first switch Q1 is coupled to the first terminal T1 of the second sub-switch Q2. The second terminal T2 of the second sub-switch Q2 is coupled to the second terminal T2 of the fourth sub-switch Q4, and the second terminal T2 of the third sub-switch Q3 is coupled to the first terminal T1 of the fourth sub-switch Q4.

[0091] For example, one end 21a of the primary coil 21 of the transformer module 20 is coupled between the third sub-switch Q3 and the fourth sub-switch Q4, and the other end 21b of the primary coil 21 of the transformer module 20 is coupled between the first sub-switch Q1 and the second sub-switch Q2. Specifically, one end 21a of the primary coil 21 of the transformer module 20 corresponds to one end 22a of the secondary coil 22, and the other end 21b of the primary coil 21 corresponds to one end 22b of the secondary coil 22.

[0092] Understandably, by setting multiple first switching devices in the inverter module 10 as four sub-switches Q, each sub-switches Q in the inverter module 10 can be actively controlled, thereby ensuring the inverter module 10's effect of converting DC power to AC power, thus guaranteeing the normal operation of the DC-DC converter 100. Simultaneously, by actively controlling each sub-switches Q in the inverter module 10, at least one of the following can be adjusted based on different voltage regulation requirements: the duration of the DC-DC converter 100 operating in the resonant half-cycle, the duration of the voltage regulation half-cycle, or the duration of the entire operating cycle. This satisfies the different voltage output requirements of the DC-DC converter 100, expanding its applicability and scope of use.

[0093] It should be noted that, in Figure 6 In the illustrated embodiments, only MOS transistors are used as an example of multiple first switching devices in the inverter module 10 for illustrative purposes. However, this does not limit the first switching devices in the inverter module 10 provided in this application embodiment to be limited to MOS transistors. In other embodiments of this application, the type and model of the first switching devices of the inverter module 10, and other technical features, can be adjusted according to the actual application scenario of the DC-DC converter 100. This application embodiment does not specifically limit these aspects.

[0094] For example, but not limited to, in one possible embodiment, the plurality of first switching devices in the inverter module 10 may be, but are not limited to, one or more of the following types: relay, wide bandgap device, metal oxide semiconductor field effect transistor (MOSFET), bipolar junction transistor (BJT), insulated gate bipolar transistor (IGBT), gallium nitride switching device, silicon carbide switching device, etc.

[0095] For example, the rectifier module 30 includes an inductor L and a plurality of second switching devices, in Figure 6 The illustrated embodiment uses one inductor L as an example, but the number of inductors L shown in this application embodiment is not limited to this. The inductor L and one second switching device correspond to two first switching devices in one arm of the inverter module 10, respectively. The other two second switching devices in the plurality of second switching devices correspond to two first switching devices in another arm of the inverter module 10, respectively. The driving of the two first switching devices located in the same arm of the inverter module 10 is complementary; the second switching device and its corresponding first switching device are synchronously turned on and have the same on-time.

[0096] Specifically, in Figure 6 In the illustrated embodiment, the rectifier module 30 includes multiple second switching devices, each comprising three diodes D. Figure 6 The diodes are shown as D1, D2, and D3. Each diode D includes an anode (positive terminal) and a cathode (negative terminal). When current flows from the anode to the cathode, the diode D is turned on; otherwise, it is turned off.

[0097] like Figure 6As shown, the anode of the first diode D1 and the cathode of the second diode D2 are coupled together. The cathode of the first diode D1 is coupled to one end L1 of the inductor L. The anode of the second diode D2 is coupled to the anode of the third diode D3, and the cathode of the third diode D3 is coupled to the other end L2 of the inductor L. One end 22a of the secondary coil 22 of the transformer module 20 is coupled between the cathode of the third diode D3 and the other end L2 of the inductor L, and one end 22b of the secondary coil 22 of the transformer module 20 is coupled between the anode of the first diode D1 and the cathode of the second diode D2. By setting the secondary coil 22 to be coupled to the rectifier module 30, the transformer module 20 transmits the second AC current formed after adjusting the voltage to the rectifier module 30, so that the rectifier module 30 can unidirectionally rectify and output the second AC current.

[0098] The cathode of the first diode D1 and one end L1 of the inductor L are both coupled to one end of the load 1001, and the anodes of the second diode D2 and the third diode D3 are both coupled to the other end of the load 1001.

[0099] Understandably, when the multiple switching transistors in the rectifier module 30 are configured as multiple diodes D, the control state of the multiple diodes D in the rectifier module 30 is passive control. That is, the control module 40 is coupled to the control electrode T3 of the multiple sub-switches Q in the inverter module 10 to control the conduction or cutoff state of the sub-switches Q in the inverter module 10. At this time, the conduction or cutoff state of the multiple diodes D in the rectifier module 30 is controlled by the current flow in the rectifier module 30, and does not need to be controlled by the additional control module 40.

[0100] In other words, by setting multiple second switching devices in the rectifier module 30 as three diodes D, the rectifier module 30 of the DC converter 100 can be passively controlled without the need for an additional control module to separately control and adjust the rectifier module 30 to achieve unidirectional rectification. This simplifies the internal topology of the DC converter 100 and further realizes the miniaturization design of the DC converter 100.

[0101] It should be noted that, in Figure 6 In the illustrated embodiment, only diodes D are used as an example of multiple second switching devices in the rectifier module 30 for illustrative purposes. However, this application does not limit the second switching devices in the rectifier module 30 provided in this embodiment to be only diodes D. In other embodiments of this application, the types and models of multiple second switching devices in the rectifier module 30, and other technical features, can be adjusted according to the actual application scenario of the DC-DC converter 100. This application does not specifically limit these features.

[0102] For example, but not limited to, in one possible embodiment, the plurality of second switching devices in the rectifier module 30 may also be, but not limited to, one or more of the following types: relay, wide bandgap device, metal oxide semiconductor field effect transistor (MOSFET), bipolar junction transistor (BJT), insulated gate bipolar transistor (IGBT), gallium nitride switching device, silicon carbide switching device, etc.

[0103] For example, the multiple second switching devices in the rectifier module 30 can also be configured as multiple switching transistors such as field-effect transistors. In this case, the control electrode T3 of the multiple second switching devices in the rectifier module 30 can be coupled to, but is not limited to, the control module 40, so that the control module 40 can realize the on or off state of each second switching device in the rectifier module 30, thereby achieving the rectification effect of the rectifier module 30. The control module 40 used to control the second switching devices of the rectifier module 30 can be integrated with the control module 40 used to control the first switching devices in the inverter module 10, or it can be a different control module 40. This application embodiment does not specifically limit this.

[0104] To meet the miniaturization requirements of electrical equipment, DC-DC converters typically need to reduce their footprint while providing greater power output. However, this smaller footprint and higher power output demand places increasingly higher demands on the heat dissipation of DC-DC converters, making it crucial to improve their conversion efficiency.

[0105] The DC-DC converter 100 of this application achieves complementary driving of two first switching devices located on the same bridge arm, and the two first switching devices in the inverter module 10 located diagonally opposite each other are synchronously turned on with the same conduction duration. This allows the inverter module 10 to convert the first DC power supplied by the external power source into first AC power and provide it to the transformer module 20. By setting the second switching device to be synchronously turned on with its corresponding first switching device with the same conduction duration, that is, by setting one or the other two first switching devices in the rectifier module 30 to be synchronously turned on with the corresponding two first switching devices in the inverter module 10 with the same conduction duration, the rectifier module 30 can unidirectionally and synchronously rectify the second AC power into the second DC power.

[0106] The DC-DC converter 100 of this application replaces a second switching device on any bridge arm of the rectifier module 30 with an inductor L. By shortening the current transmission path within the rectifier module 30, it improves the current transmission efficiency within the rectifier module 30 while reducing current losses during transmission. Furthermore, compared to a rectifier module 30 entirely composed of second switching devices, replacing a second switching device on any bridge arm of the rectifier module 30 with an inductor L effectively reduces the average current flowing through the transformer module 20 and the inductor L within the DC-DC converter 100, and significantly reduces the effective current loss in the inductor L of the transformer module 20. Moreover, by reducing the current transmission path, lowering the average effective current value, and reducing losses, the DC-DC converter 100 improves current transmission efficiency, thereby increasing the conversion efficiency of the DC-DC converter 100 and achieving a miniaturized design. Furthermore, as the conversion efficiency of the DC-DC converter 100 is improved, the heat generated by the DC-DC converter 100 can be reduced, thereby reducing the heat dissipation requirements while realizing the miniaturization design of the DC-DC converter 100.

[0107] Because the electrical equipment 1000 of this application uses the DC converter 100 provided in any of the above embodiments, the electrical equipment 1000 of this application has all the possible beneficial effects of the DC converter 100 provided in any of the above embodiments.

[0108] Because the photovoltaic system 2000 of this application uses the DC converter 100 provided in any of the above embodiments, the photovoltaic system 2000 of this application possesses all the possible beneficial effects of the DC converter 100 provided in any of the above embodiments.

[0109] It should be noted that, in Figure 6 In the embodiments shown, only one possible arrangement of the inductor L in the rectifier module 30 is described as an example, but it is not limited to the arrangement of the inductor L provided in the embodiments of this application. In other embodiments of this application, the position of the inductor L in the rectifier module 30 can be adjusted according to actual design requirements, and the embodiments of this application do not make specific limitations in this regard.

[0110] For example, in one possible embodiment, please refer to Figure 8 , Figure 8 This is a planar structural schematic diagram of the rectifier module 30 of the DC-DC converter 100 provided in this embodiment. The inductor L can be connected to... Figure 6 In the illustrated embodiment, any one of the three diodes D can be swapped. Figure 8 In the embodiment shown in (a), the inductor L can be swapped with the third diode D3. Figure 8In the embodiment shown in (b), the inductor L can be swapped with the first diode D1. Figure 8 In the embodiment shown in (c), the inductor L can be swapped with the second diode D2.

[0111] In this application specification, Figure 6 The position of the inductor L shown in the embodiment is used as an example for illustrative description.

[0112] For example, such as Figure 6 As shown, the DC-DC converter 100 also includes at least two capacitors C. One of the capacitors C is connected in series with the primary winding 21, and the other capacitor C is connected in series with the secondary winding 22. Specifically, the at least two capacitors C include a first capacitor C1 and a second capacitor C2. The first capacitor C1 is connected in series with the primary winding 21 and coupled between the transformer module 20 and the inverter module 10. The second capacitor C2 is connected in series with the secondary winding 22 and coupled between the transformer module 20 and the rectifier module 30.

[0113] Specifically, such as Figure 6 As shown, the other end 21b of the primary winding 21 of the transformer module 20 is coupled between the first sub-switch Q1 and the second sub-switch Q2 through the first capacitor C1. One end 22a of the secondary winding 22 of the transformer module 20 is coupled between the third diode D3 and the other end L2 of the inductor L through the second capacitor C2.

[0114] Understandable, Figure 6 In the illustrated embodiment, by connecting a first capacitor C1 in series with the primary winding 21, the first capacitor C1 can achieve DC blocking. The rectifier module 30 of the DC-DC converter 100 replaces the switching transistor in any of the bridge arms with an inductor L, forming an asymmetrical topology inside the DC-DC converter 100. At this time, by connecting a capacitor C in series with both the primary winding 21 and the secondary winding 22 of the transformer module 20, voltage balance between the high-voltage and low-voltage sides of the transformer module 20 can be ensured.

[0115] Meanwhile, a capacitor C is connected in series with the primary coil 21 and the secondary coil 22 of the transformer module 20, so that the operating state of the transformer module 20 is different during the resonant half-cycle and the voltage regulation half-cycle of the DC converter 100. This enables the transformer module 20 to deliver the current from the input side of the DC converter 100 to the DC and output sides of the converter throughout the entire operating cycle.

[0116] Please see Figure 7 and Figure 9 , Figure 7 This is a schematic diagram of the internal topology of the DC-DC converter 100 provided in the embodiments of this application. Figure 9This is a control timing diagram of the control module 40 in the DC-DC converter 100 provided in an embodiment of this application. Figure 7 The DC-DC converter 100 and shown in the embodiment are provided Figure 6 The difference between the DC-DC converters 100 provided in the illustrated embodiments lies in the different positions of the first switching device turned on in the inverter module 10. During one operating cycle t of the DC-DC converter 100, when the second AC current flows through one of the second switching devices and an inductor L, the DC-DC converter 100 operates in the resonant half-cycle. When the second AC current flows through both second switching devices, the DC-DC converter operates in the voltage regulation half-cycle.

[0117] Among them, the sum of the durations of the two resonant half-cycles is equal to the duration of one working cycle t.

[0118] Understandably, by setting the duration of the resonant half-cycle to be equal to the sum of the durations of the resonant half-cycles, it is possible to stabilize the output voltage Vout of the second DC power supply provided by the DC converter 100 by adjusting at least one of the durations of the voltage regulation half-cycle or the resonant half-cycle, thereby improving the accuracy and stability of the output voltage Vout provided by the DC converter 100 to the load.

[0119] Specifically, within one working cycle t, the control module 40 controls the sum of the duty cycles of the first sub-switch Q1 and the second sub-switch Q2 to be 1, and controls the sum of the duty cycles of the third sub-switch Q3 and the fourth sub-switch Q4 to be 1.

[0120] Within one working cycle t, the control module 40 controls the first sub-switch Q1 and the fourth sub-switch Q4 to have the same control state, that is, the first sub-switch Q1 and the fourth sub-switch Q4 are simultaneously turned on or simultaneously turned off. The control module 40 controls the second sub-switch Q2 and the third sub-switch Q3 to have the same control state, that is, the second sub-switch Q2 and the third sub-switch Q3 are simultaneously turned on or simultaneously turned off.

[0121] Specifically, within one working cycle t, the control module 40 controls the complementary driving of the first sub-switch Q1 and the second sub-switch Q2, and also controls the complementary driving of the third sub-switch Q3 and the fourth sub-switch Q4. This complementary driving can be understood as follows: within one working cycle t, when the first sub-switch Q1 is on, the second sub-switch Q2 is off; when the first sub-switch Q1 is off, the second sub-switch Q2 is on. When the third sub-switch Q3 is on, the fourth sub-switch Q4 is off; when the third sub-switch Q3 is off, the fourth sub-switch Q4 is on.

[0122] For example, such as Figure 6 and Figure 9As shown, the control module 40 can control the first sub-switch Q1 and the fourth sub-switch Q4 to turn off simultaneously, and control the second sub-switch Q2 and the third sub-switch Q3 to turn on simultaneously.

[0123] At this time, the working circuit of the DC converter 100 on the inverter module 10 side is: first DC current, third sub-switch Q3, primary coil 21 of transformer module 20 and second sub-switch Q2. The current flow in this working circuit (as shown by the solid arrow in the inverter module 10) is as follows: from the third sub-switch Q3 through one end 21a of the primary coil 21 of transformer module 20, from one end 21a of the primary coil 21 through the other end 21b of the primary coil 21, and then from the other end 21b of the primary coil 21 through the second sub-switch Q2.

[0124] When the first alternating current flows from one end 21a of the primary coil 21 to the other end 21b of the primary coil 21, the flow of the second alternating current in the secondary coil 22 of the transformer module 20 (as shown by the solid arrow in the rectifier module 30) is as follows: from one end 22b of the secondary coil 22 to one end 22a of the secondary coil 22, from one end 22a of the secondary coil 22 to the inductor L, and then from the inductor L to the load 1001. At this time, the current in the rectifier module 30 flows through the inductor L and then to the load 1001, the second diode D2 is turned on, and the first diode D1 and the third diode D3 are turned off.

[0125] Understandably, when the control module 40 controls the first sub-switch Q1 and the fourth sub-switch Q4 in the inverter module 10 to turn off simultaneously, and controls the second sub-switch Q2 and the third sub-switch Q3 to turn on simultaneously, the current generated in the rectifier module 30 flows through the second diode D2 and the inductor L. Within one operating cycle t, the DC-DC converter 100 can be understood to be operating in the voltage regulation half-cycle t1.

[0126] For example, such as Figure 7 and Figure 9 As shown, the control module 40 can control the first sub-switch Q1 and the fourth sub-switch Q4 to be turned on, and control the second sub-switch Q2 and the third sub-switch Q3 to be turned off. At this time, the working circuit of the DC converter 100 on the inverter module 10 side is: the first DC current, the first sub-switch Q1, the primary coil 21 of the transformer module 20 and the fourth sub-switch Q4. The current flow in this working circuit (as shown by the solid arrow in the inverter module 10) is: from the first sub-switch Q1 through the other end 21b of the primary coil 21, from the other end 21b of the primary coil 21 through one end 21a of the primary coil 21, and from one end 21a of the primary coil 21 through the fourth sub-switch Q4.

[0127] When the first alternating current flows from the other end 21b of the primary coil 21 through one end 21a of the primary coil 21, the flow of the second alternating current in the secondary coil 22 of the transformer module 20 (as shown by the solid arrow in the rectifier module 30) is as follows: the current flows from one end 22a of the secondary coil 22 through one end 22b of the secondary coil 22, and from one end 22b of the secondary coil 22 through the second diode D2. At this time, the first diode D1 and the third diode D3 are turned on, the second diode D2 is turned off, and no current flows through the inductor L, so as to achieve the effect of the DC converter 100 outputting the second DC power to the load 1001 through the rectifier module 30.

[0128] Understandably, when the control module 40 controls the first sub-switch Q1 and the fourth sub-switch Q4 in the inverter module 10 to conduct simultaneously, and controls the second sub-switch Q2 and the third sub-switch Q3 to turn off simultaneously, the first diode D1 and the third diode D3 in the rectifier module 30 conduct, and the second diode D2 turns off. The current generated in the rectifier module 30 flows through the first diode D1 and the third diode D3. At this time, within one operating cycle t, the DC-DC converter 100 can be understood as operating in the resonant half-cycle t2.

[0129] In other words, when the current in the DC-DC converter 100 flows through the inductor L, the DC-DC converter 100 operates in the voltage regulation half-cycle t1. When the current in the DC-DC converter 100 does not flow through the inductor L, the DC-DC converter 100 operates in the resonant half-cycle t2. The duration of the resonant half-cycle t2 can be determined by the inductor L and the second capacitor C2. The sum of the duration of the resonant half-cycle t2 and the duration of the voltage regulation half-cycle t1 equals the duration of one operating cycle t.

[0130] Understandable, Figure 6 , Figure 7 and Figure 9 In the illustrated embodiment, replacing a diode D on any arm of the rectifier module 30 in the full-bridge structure with an inductor L shortens the current transmission path within the rectifier module 30, thereby improving the rectification efficiency of the rectifier module 30 while reducing current loss. Furthermore, compared to the full-bridge rectifier module 30, by connecting at least one inductor L in series with any arm of the rectifier module 30 of the DC-DC converter 100 provided in this embodiment, the average current flowing through the transformer module 20 and inductor L within the DC-DC converter 100 can be effectively reduced by at least 35%, and the effective current loss of the transformer module 20 and inductor L can be reduced by at least 60%. Additionally, as... Figure 9 As shown, the current in the transformer module 20 of the DC converter 100 of this application can maintain continuous active current conduction, thereby enabling the transformer module 20 to achieve the longest current conduction time.

[0131] For example, the duration of a working cycle t is fixed. By adjusting the duration of the resonant half-cycle and the voltage regulation half-cycle respectively, the ratio of the duration of the resonant half-cycle to the duration of the voltage regulation half-cycle is adjusted. Specifically, the fixed duration of the working cycle t of the DC-DC converter 100 can also be understood as the fixed operating frequency of the DC-DC converter 100. In this case, the control module 40 can adjust the duration of the DC-DC converter 100 operating in the resonant half-cycle t2 and the duration of the DC-DC converter 100 operating in the voltage regulation half-cycle t1 to achieve a proportional change between the duration of the voltage regulation half-cycle t1 and the duration of the resonant half-cycle t2, thereby realizing closed-loop voltage regulation of the output voltage Vout.

[0132] Understandably, by adjusting the duration of the resonant half-cycle and the voltage regulation half-cycle separately, the ratio between their durations can be adjusted, thereby enabling closed-loop regulation of the DC-DC converter 100's output voltage Vout. In other words, in this embodiment, a control method that uses a fixed duty cycle and simultaneously adjusts the durations of the resonant half-cycle and the voltage regulation half-cycle can be employed to achieve closed-loop voltage regulation and stable output of the DC-DC converter 100, further improving its conversion efficiency.

[0133] For example, the duration of the resonant half-cycle is fixed, and the closed-loop voltage regulation of the DC converter 100 is achieved by adjusting the duration of one working cycle t and the duration of the voltage regulation half-cycle respectively.

[0134] Specifically, the control module 40 can control the DC converter 100 to operate at a fixed duration of the resonant half-cycle t2, and can adjust the duration of the DC converter 100 to operate at the voltage regulation half-cycle t1 to achieve the ratio of the duration of the voltage regulation half-cycle t1 to the duration of the resonant half-cycle t2, thereby controlling the stability of the output voltage Vout.

[0135] Understandably, when the duration of the resonant half-cycle of the DC-DC converter 100 is fixed, the closed-loop voltage regulation effect of the DC-DC converter 100 can be achieved by adjusting the duration of the operating period t and the duration of the voltage regulation half-cycle, thereby improving the stability of the output voltage Vout provided by the DC-DC converter 100 to the load. In other words, in this embodiment, a control method that keeps the resonant half-cycle duration constant while simultaneously adjusting the duration of the operating period t and the duration of the voltage regulation half-cycle can be used to achieve closed-loop voltage regulation and stable output of the DC-DC converter 100, further improving the conversion efficiency of the DC-DC converter 100.

[0136] For example, the duration of the resonant half-cycle is equal to half the duration of the resonant period of the transformer module. The duration of the resonant period of the transformer module 20 is: 2π√LrCr. Where Lr is the inductance of the resonant inductor in the transformer module 20, and Cr is the capacitance of the resonant capacitor in the transformer module 20. Specifically, the control module 40 controls the DC-DC converter 100 to operate at a fixed duration of the resonant half-cycle t2, which is equal to or approximately equal to half the resonant period of the transformer. At this time, the control module 40 can adjust the duration of the DC-DC converter 100 operating at the voltage regulation half-cycle t1 to achieve closed-loop voltage regulation of the output voltage Vout.

[0137] By setting the duration of the resonant half-cycle to be determined by the duration of the resonant period of the transformer module 20, the duration of the DC converter 100 operating in the resonant half-cycle can be fixed. Furthermore, by adjusting the duration of the operating period t and the duration of the voltage regulation half-cycle, the DC converter 100 can achieve closed-loop voltage regulation and stable output, thereby further improving the conversion efficiency of the DC converter 100.

[0138] It should be noted that the embodiments provided in this application specification are only exemplified by the control module 40 using a fixed-period or variable-period control method to achieve closed-loop voltage regulation of the output voltage Vout of the DC-DC converter 100. However, this does not limit the control module 40 of the DC-DC converter 100 provided in this application embodiment to only using a fixed-period or variable-period control method to regulate the output voltage Vout provided by the DC-DC converter 100 to the load 1001. In other embodiments of this application, the control module 40 can also use a hybrid control method of fixed-period and variable-period to achieve stable regulation and output of the output voltage Vout of the DC-DC converter 100. This application embodiment does not specifically limit this approach.

[0139] Please see Figure 10 , Figure 10 This is a schematic planar structure diagram of the DC-DC converter 100 provided in an embodiment of this application. Figure 10 In the illustrated embodiment, the second terminal T2 of the second sub-switch Q2 and the second terminal T2 of the fourth sub-switch Q4 are simultaneously coupled to at least one of the cathode of the first diode D1 and one end L1 of an inductor L. Specifically, the inverter module 10, transformer module 20, and rectifier module 30 of the DC-DC converter 100 can also adopt a non-isolated closed-loop connection method. For example... Figure 10 As shown, the second terminal T2 of the second sub-switch Q2 is coupled to the second terminal T2 of the fourth sub-switch Q4, and the second terminal T2 of the second sub-switch Q2 and the second terminal T2 of the fourth sub-switch Q4 are also coupled to the negative terminal of the first diode D and one end L1 of the inductor L.

[0140] Understandable, Figure 10In the illustrated embodiment, by setting the internal topology of the DC-DC converter 100 to a non-isolated closed-loop connection mode, and by replacing one of the switching transistors in the full-bridge rectifier module 30 with an inductor L, the impedance in the DC-DC converter 100 can be reduced, thereby improving the conversion efficiency and power density of the DC-DC converter 100, and further realizing the miniaturization design of the DC-DC converter 100.

[0141] Please see Figure 11 , Figure 11 This is a schematic diagram illustrating the workflow of the DC-DC conversion method provided in this application embodiment. This application embodiment provides a DC-DC conversion method that can be applied to, or implemented using, the DC-DC converter 100 provided in any of the above embodiments. Figure 11 The DC-DC conversion method provided in the embodiments shown in this application includes the following steps:

[0142] S100, the inverter module 10 receives the input first DC power and inverts the first DC power into first AC power. The inverter module 10 is a full-bridge structure and includes multiple first switching devices.

[0143] S200 and transformer module 20 convert the first AC power into the second AC power;

[0144] S300, the rectifier module 30 rectifies the second AC power into a second DC power, and the second DC power is supplied to the load. The rectifier module 30 includes an inductor L and a plurality of second switching devices. The inductor and a second switching device correspond to two first switching devices in one of the bridge arms of the inverter module 10, respectively.

[0145] S400: Control the second switching device, which has a corresponding relationship, to be turned on synchronously with the first switching device and the turn-on time is the same.

[0146] Specifically, in Figure 11 Steps S100-S400 provided in the illustrated embodiment can be achieved through... Figures 5-10 The DC-DC converter 100 in any of the embodiments shown is implemented. It can be understood that the DC-DC conversion method provided in this application, in the process of rectifying the second AC power into the second DC power through the rectifier module 30, controls the second switching device and its corresponding first switching device to conduct synchronously for the same duration. That is, one or the other two first switching devices in the rectifier module 30 are synchronously turned on with the corresponding two first switching devices in the inverter module 10 for the same duration, enabling the rectifier module 30 to unidirectionally and synchronously rectify the second AC power into the second DC power.

[0147] Meanwhile, since the inductor and a second switching device in the rectifier module 30 correspond to the two first switching devices in one of the bridge arms of the inverter module 10, the current transmission path in the rectifier module 30 can be shortened. Therefore, the current transmission efficiency within the rectifier module 30 can be improved, and the current loss during transmission can be reduced. The DC-DC conversion method provided in this application improves the current transmission efficiency by reducing the current transmission path, reducing the average effective value of the current, and reducing the loss value, thereby improving the conversion efficiency of the DC-DC converter 100 and achieving a miniaturized design of the DC-DC converter 100. Furthermore, when the conversion efficiency of the DC-DC converter 100 is improved, the heat generation of the DC-DC converter 100 can be reduced, thus reducing the heat dissipation requirements while achieving a miniaturized design of the DC-DC converter 100.

[0148] In one embodiment, step S100, "the inverter module 10 receives the input first DC power and inverts the first DC power into the first AC power," further includes:

[0149] The two first switching devices located diagonally opposite each other are controlled to conduct synchronously for the same duration.

[0150] Understandably, in this embodiment, by controlling the two first switching devices in the inverter module 10 to be synchronously turned on in a diagonally opposite direction and for the same duration, the inverter module 10 converts the first DC power supplied by the external power source into the first AC power and provides it to the transformer module 20. This achieves the inversion effect of the inverter module 10.

[0151] In one embodiment, step S300, "rectifier module 30 rectifies the second AC power into a second DC power," includes:

[0152] During the period when the second alternating current flows through the inductor L and a second switching device, the two first switching devices corresponding to the inductor L and the second switching device are turned on.

[0153] In one embodiment, step S300, "rectifier module 30 rectifies the second AC power into a second DC power," includes:

[0154] The second alternating current passes through two other second switching devices of the plurality of second switching devices, controlling the two first switching devices corresponding to the other two second switching devices to conduct.

[0155] Understandably, in the above embodiment of step S300, during the second AC current flowing through inductor L and a second switching device, the DC converter 100 can operate in the resonant half-cycle by controlling the conduction of two first switching devices corresponding to inductor L and a second switching device. When the second AC current flows through the remaining two second switching devices of the plurality of second switching devices, the DC converter 100 can operate in the voltage regulation half-cycle by controlling the conduction of two first switching devices corresponding to the remaining two second switching devices. At this time, the DC conversion method provided in this application embodiment can further adjust at least one of the duration of the DC converter 100 operating in the voltage regulation half-cycle or the duration of the resonant half-cycle to achieve a stable output voltage Vout of the second DC current, thereby improving the accuracy and stability of the output voltage Vout provided to the load by the DC conversion method.

[0156] Of course, the above-described embodiments can be applied individually or in combination. The above description is the preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. A DC-DC converter, characterized in that, The DC-DC converter includes: An inverter module is used to invert a first direct current into a first alternating current. The inverter module has a full-bridge structure and includes multiple first switching devices. A transformer module is used to convert the first AC power into a second AC power. A rectifier module is used to rectify the second AC power into a second DC power, the voltage of which is different from the voltage of the first DC power. The rectifier module includes an inductor and a plurality of second switching devices. The inductor and one second switching device correspond to two first switching devices in one arm of the inverter module, and the other two second switching devices correspond to two first switching devices in another arm of the inverter module, wherein: The drives of the two first switching devices located in the same bridge arm in the inverter module are complementary; The second switching device and its corresponding first switching device are synchronously turned on and have the same on-time.

2. The DC-DC converter according to claim 1, characterized in that, During one operating cycle of the DC-DC converter, when the second AC current flows through the inductor and one of the second switching devices, the DC-DC converter operates in the resonant half-cycle; when the second AC current flows through the other two second switching devices, the DC-DC converter operates in the voltage regulation half-cycle, wherein: The sum of the duration of the resonant half-cycle and the duration of the voltage regulation half-cycle is equal to the duration of one working cycle.

3. The DC-DC converter according to claim 2, characterized in that, The duration of one working cycle is fixed. The ratio of the duration of the resonant half-cycle to the duration of the voltage regulation half-cycle is adjusted by respectively adjusting the duration of the resonant half-cycle and the duration of the voltage regulation half-cycle.

4. The DC-DC converter according to claim 2, characterized in that, The duration of the resonant half-cycle is fixed. By adjusting the duration of one working cycle and the duration of the voltage regulation half-cycle respectively, the closed-loop voltage regulation of the DC converter can be achieved.

5. The DC-DC converter according to claim 4, characterized in that, The duration of the resonant half-cycle is equal to half the duration of the resonant period of the transformer module. The duration of the resonant period of the transformer module is: 2π√LrCr, where Lr is the inductance of the resonant inductor in the transformer module and Cr is the capacitance of the resonant capacitor in the transformer module.

6. The DC-DC converter according to any one of claims 1-5, characterized in that, The transformer module includes a primary winding and a secondary winding. The primary winding is coupled to the inverter module, and the secondary winding is coupled to the rectifier module. The plurality of second switching devices include a first diode, a second diode, and a third diode, wherein: The cathode of the first diode is coupled to one end of the inductor, the anode of the first diode is coupled to the cathode of the second diode, the anode of the second diode is coupled to the anode of the third diode, and the cathode of the third diode is coupled to the other end of the inductor. One end of the secondary coil of the transformer module is coupled between the inductor and the third diode, and the other end of the secondary coil of the transformer module is coupled between the first diode and the second diode.

7. The DC-DC converter according to claim 6, characterized in that, The plurality of first switching devices include a plurality of sub-switches, each sub-switch including a first electrode, a second electrode, and a control electrode, wherein the control electrode is used to control the conduction duration between the first electrode and the second electrode, and the plurality of sub-switches include a first sub-switch, a second sub-switch, a third sub-switch, and a fourth sub-switch, wherein: The first terminal of the first sub-switch transistor is coupled to the first terminal of the third sub-switch transistor, the second terminal of the first sub-switch transistor is coupled to the first terminal of the second sub-switch transistor, the second terminal of the second sub-switch transistor is coupled to the second terminal of the fourth sub-switch transistor, and the first terminal of the fourth sub-switch transistor is coupled to the second terminal of the third sub-switch transistor. One end of the primary coil is coupled between the third sub-switch and the fourth sub-switch, and the other end of the primary coil is coupled between the first sub-switch and the second sub-switch.

8. The DC-DC converter according to claim 7, characterized in that, The second terminal of the second sub-switch and the second terminal of the fourth sub-switch are simultaneously coupled to at least one of the cathode of the first diode and one end of the inductor.

9. The DC-DC converter according to claim 7, characterized in that, The DC-DC converter further includes a control module, which is coupled to the control electrode of each sub-switch and is used to adjust the on-time of each sub-switch.

10. The DC-DC converter according to any one of claims 6-9, characterized in that, The DC-DC converter includes two capacitors, one of which is connected in series with the primary winding and the other of which is connected in series with the secondary winding.

11. The DC-DC converter according to any one of claims 1-10, characterized in that, The plurality of first switching devices include at least one of a relay, a wide bandgap device, a metal-oxide-semiconductor field-effect transistor, a bipolar junction transistor, an insulated-gate bipolar transistor, a gallium nitride switching device, and a silicon carbide switching device.

12. A DC-DC conversion method applied to a DC-DC converter, the DC-DC converter comprising: An inverter module, a transformer module, and a rectifier module; characterized in that the method includes: The inverter module receives the input first DC power and inverts the first DC power into first AC power. The inverter module is a full-bridge structure and includes multiple first switching devices. The transformer module converts the first AC power into a second AC power. The rectifier module rectifies the second AC power into a second DC power, which is then supplied to the load. The rectifier module includes an inductor and a plurality of second switching devices, and the inductor and one second switching device correspond to two first switching devices in one of the bridge arms of the inverter module, respectively. The second switching device, which has a corresponding relationship with the first switching device, is turned on synchronously and for the same duration.

13. The DC-DC conversion method according to claim 12, characterized in that, The inverter module receives the input first direct current and inverts the first direct current into a first alternating current, including: The two first switching devices located diagonally opposite each other are controlled to conduct synchronously for the same duration.

14. The DC-DC conversion method according to claim 12 or 13, characterized in that, The rectifier module rectifies the second AC power into a second DC power, including: During the period when the second alternating current flows through the inductor and a second switching device, the two first switching devices corresponding to the inductor and the second switching device are controlled to be turned on. Alternatively, during the period when the second alternating current passes through two other second switching devices among the plurality of second switching devices, the two first switching devices corresponding to the other two second switching devices are controlled to turn on.

15. An electrical appliance, characterized in that, The electrical equipment includes a load and a DC-DC converter as described in any one of claims 1-11, wherein the DC-DC converter is used to convert a first DC power supplied by an external power source into a second DC power and supply it to the load; Alternatively, the electrical equipment may also employ the DC conversion method according to any one of claims 12-14.

16. A photovoltaic system, characterized in that, The photovoltaic system includes a photovoltaic device, an energy storage device, and a DC-DC converter as described in any one of claims 1-11. The DC-DC converter is coupled between the photovoltaic device and the energy storage device. The photovoltaic device is used to provide a first DC power to the DC-DC converter. The DC-DC converter is used to convert the first DC power into a second DC power and provide it to the energy storage device. The energy storage device is used to store electrical energy. Alternatively, the electrical equipment may also employ the DC conversion method according to any one of claims 12-14.

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