Charging device, control method thereof, and charging power supply

Abstract

The application provides a charging device, a control method thereof and a charging power supply. The charging device comprises: an AC input end; a DC output end; a plurality of flyback conversion modules connected in parallel between the AC input end and the DC output end, used for transmitting power to the DC output end based on the AC input; and a control unit configured to: in a process in which total instantaneous power transmitted by the plurality of flyback conversion modules to the DC output end changes, determine a target number of flyback conversion modules participating in power transmission in the plurality of flyback conversion modules according to a power interval to which the total instantaneous power belongs in a plurality of power intervals; wherein the plurality of power intervals do not overlap with each other, different power intervals correspond to different target numbers, and the target number corresponding to a power interval with a larger upper limit of power is greater than the target number corresponding to a power interval with a smaller upper limit of power. The scheme can reduce the conduction loss and switching loss of the flyback conversion modules in the charging device, and improve the energy conversion efficiency of the charging device.

Description

Technical Field

[0001] This application relates to the field of charging technology, specifically to a charging device and its control method, and a charging power supply. Background Technology

[0002] Charging devices are widely used in electric vehicle charging piles, on-board charging power supplies, and other scenarios. To reduce device costs and increase power density, related technologies can adopt a single-stage AC-DC converter architecture and achieve wide-range voltage conversion through a flyback converter module.

[0003] However, in a single-stage AC-DC converter, the rectified AC input generates a pulsating DC voltage with a frequency twice that of the power frequency, causing the transmitted power to fluctuate periodically with the pulsating DC voltage. During the peak power range, the flyback converter module is susceptible to large instantaneous currents, leading to increased conduction losses. Conversely, during the trough power range, the flyback converter module operates at low power, requiring increased switching frequency to maintain power transmission, resulting in increased switching losses. Summary of the Invention

[0004] This application provides a charging device and its control method, as well as a charging power supply, which can reduce the conduction loss and switching loss of the flyback converter module in the charging device and improve the energy conversion efficiency of the charging device.

[0005] In a first aspect, this application provides a charging device, comprising: an AC input terminal for receiving AC input; a DC output terminal for providing DC output; a plurality of flyback converter modules connected in parallel between the AC input terminal and the DC output terminal for transmitting power to the DC output terminal based on the AC input; and a control unit connected to the plurality of flyback converter modules and configured to: determine a target number of flyback converter modules participating in power transmission based on the power range to which the total instantaneous power is transmitted to the DC output terminal during the process of changes in the total instantaneous power transmitted by the plurality of flyback converter modules; wherein the plurality of power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit; and the target number of flyback converter modules participating in power transmission as operating modules, so that each operating module shares the total instantaneous power.

[0006] Secondly, this application provides a charging power supply, which includes a charging interface and a charging device as described in the first aspect; wherein the charging interface is connected to the DC output terminal of the charging device for transmitting the DC output provided by the DC output terminal to the device to be charged.

[0007] Thirdly, this application provides a control method for a charging device, the charging device including an AC input terminal, a DC output terminal, and multiple flyback converter modules; wherein, the AC input terminal is used to receive AC input, the DC output terminal is used to provide DC output, and the multiple flyback converter modules are connected in parallel between the AC input terminal and the DC output terminal for transmitting power to the DC output terminal based on the AC input; the method includes: during the change of the total instantaneous power transmitted by the multiple flyback converter modules to the DC output terminal, determining a target number of flyback converter modules participating in power transmission according to the power range to which the total instantaneous power belongs in multiple power ranges; wherein, the multiple power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit; and using the target number of flyback converter modules as operating modules to participate in power transmission, so that each operating module shares the total instantaneous power.

[0008] In several embodiments provided in this application, multiple flyback converter modules are connected in parallel between the AC input terminal and the DC output terminal for transmitting power to the DC output terminal based on the AC input. During the change of the total instantaneous power transmitted from the multiple flyback converter modules to the DC output terminal, the control unit determines the target number of flyback converter modules participating in power transmission based on the power range in which the total instantaneous power is located, and uses the target number of flyback converter modules as operating modules to participate in power transmission, allowing each operating module to share the total instantaneous power. Therefore, when the total instantaneous power is high, increasing the number of flyback converter modules participating in power transmission allows more operating modules to share the total instantaneous power, thereby reducing the instantaneous power and instantaneous current borne by a single operating module, which helps reduce the conduction losses of the flyback converter modules in the high-power range. When the total instantaneous power is low, decreasing the number of flyback converter modules participating in power transmission allows fewer operating modules to share the total instantaneous power, preventing too many flyback converter modules from operating in an excessively low-power state, which helps reduce switching losses in the low-power range. In this way, the charging device can dynamically adjust the number of operating modules during the total instantaneous power change, reduce the conduction loss and switching loss of the flyback converter module in the charging device, and improve the energy conversion efficiency of the charging device. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of a charging device provided in one embodiment of this application.

[0011] Figure 2 This is a schematic diagram illustrating the adjustment of the number of operating modules based on changes in total instantaneous power, as provided in one embodiment of this application.

[0012] Figure 3 This is a schematic diagram illustrating the transmission power change during the switching in and switching out process of a flyback converter module, as provided in one embodiment of this application.

[0013] Figure 4 This is a schematic diagram of a charging device provided for another embodiment of this application.

[0014] Figure 5 This is a schematic diagram showing the switching frequency and duty cycle of an operating module as a function of phase angle, provided as an embodiment of this application.

[0015] Figure 6 This is a structural block diagram of a charging power supply provided in one embodiment of this application.

[0016] Figure 7 This is a schematic flowchart of a control method for a charging device provided in one embodiment of this application. Detailed Implementation

[0017] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0018] In the description of the embodiments of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0019] Charging devices are widely used in electric vehicle charging piles, on-board charging power supplies, power adapters, and other scenarios to convert and transmit electrical energy. To reduce device costs and increase power density, a single-stage AC-DC conversion architecture can be adopted. For example, a charging device can use a flyback converter module to convert AC input to DC output to provide charging power to the device being charged. Flyback converter modules feature fewer components, electrical isolation, and a wide voltage conversion range, making them suitable for charging scenarios with high requirements for cost, size, and voltage adaptability.

[0020] However, in a single-stage AC-DC converter, the rectified AC input generates a pulsating DC voltage twice the power frequency, causing the total instantaneous power transmitted from the flyback converter module to the DC output to vary periodically. In the higher power range, the flyback converter module needs to transmit a larger instantaneous power, resulting in a larger instantaneous current flowing through the power devices and windings, which can easily lead to increased conduction losses. In the lower power range, the flyback converter module operates at low power, and to maintain power transmission, the switching frequency usually needs to be increased, increasing the number of switching operations per unit time, which can easily lead to increased switching losses.

[0021] For charging devices containing multiple flyback converter modules, parallel connection of multiple flyback converter modules can meet the demand for higher power transmission. However, if a fixed number of flyback converter modules participate in power transmission during changes in total instantaneous power, it is difficult to simultaneously meet the loss optimization requirements under different power ranges. Specifically, if the number of flyback converter modules participating in power transmission is small, when the total instantaneous power is high, a single flyback converter module needs to bear a large instantaneous power, which can easily lead to an increase in instantaneous current and conduction losses. If the number of flyback converter modules participating in power transmission is large, when the total instantaneous power is low, the total instantaneous power is shared by too many flyback converter modules, and the transmission power of a single flyback converter module is too low. This can easily cause each flyback converter module to operate in a low-power state with a high proportion of switching losses, thereby increasing switching losses due to the increase in switching frequency.

[0022] Therefore, how to balance the loss optimization requirements under different power ranges in order to reduce the conduction and switching losses of the flyback converter module in the charging device has become a technical problem that urgently needs to be solved in this field.

[0023] Please see Figure 1This application provides a charging device 100, which includes an AC input terminal 110, a DC output terminal 120, multiple flyback converter modules 130, and a control unit 140. The AC input terminal 110 receives AC input. The DC output terminal 120 provides DC output. The multiple flyback converter modules 130 are connected in parallel between the AC input terminal 110 and the DC output terminal 120, and are used to transmit power to the DC output terminal 120 based on the AC input. The control unit 140 is connected to multiple flyback converter modules 130 and is configured to: during the process of the total instantaneous power transmission from the multiple flyback converter modules 130 to the DC output terminal 120, determine the target number of flyback converter modules 130 participating in power transmission based on the power range to which the total instantaneous power belongs among multiple power ranges; wherein the multiple power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit; and use the target number of flyback converter modules 130 as operating modules to participate in power transmission, so that each operating module shares the total instantaneous power.

[0024] The charging device 100 is a device for converting electrical energy and outputting charging energy. Specifically, the charging device 100 can convert AC input into DC output to provide charging energy to the device to be charged. Exemplarily, the charging device 100 can be applied to scenarios such as electric vehicle charging piles, power adapters, or energy storage charging devices. The embodiments in this application are not specifically limited herein.

[0025] The AC input terminal 110 is a port for receiving AC power. The AC input terminal 110 can be used to connect to an AC power grid, AC power generation equipment, or other AC power sources capable of providing AC power. The DC output terminal 120 is a port for outputting DC power. The DC output terminal 120 can be used to provide DC output to a device to be charged. The device to be charged may include a battery, an electric vehicle, an energy storage device, or other equipment that needs to receive DC charging power. This application does not specifically limit the embodiments described herein.

[0026] The flyback converter module 130 is a power conversion module used to transfer power from the AC input to the DC output terminal 120. Specifically, the flyback converter module 130 can realize the power transfer between the AC input side and the DC output side through flyback conversion. The flyback converter module 130 has the characteristics of electrical isolation, wide voltage conversion range and fewer components, thus helping to reduce the component cost and size of the charging device 100 while meeting the isolation and wide output range requirements of the charging device 100.

[0027] Multiple flyback converter modules 130 are connected in parallel between the AC input terminal 110 and the DC output terminal 120. This can be understood as the input sides of multiple flyback converter modules 130 being connected to the AC input terminal 110, and the output sides of multiple flyback converter modules 130 being connected to the DC output terminal 120. Therefore, the multiple flyback converter modules 130 can form multiple parallel power transmission branches and jointly transmit power to the DC output terminal 120.

[0028] The control unit 140 is a device for controlling the operating status of multiple flyback converter modules 130. Specifically, the control unit 140 can be connected to multiple flyback converter modules 130 to send drive signals, enable signals, power commands or other control signals to the multiple flyback converter modules 130, thereby controlling whether each flyback converter module 130 participates in power transmission and its operating status when participating in power transmission.

[0029] In some embodiments, the control unit 140 may include at least one hardware structure selected from a processor, a memory, a sampling interface, a driving interface, and a communication interface. The processor may include, but is not limited to, a digital signal processor (DSP), a microcontroller unit (MCU), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), etc.

[0030] The total instantaneous power is used to characterize the total power transmitted by multiple flyback converter modules 130 to the DC output terminal 120 at a certain moment. Specifically, when all flyback converter modules 130 participate in power transmission, the total instantaneous power can be formed by the transmission power of all flyback converter modules 130; when one or some flyback converter modules 130 participate in power transmission, the total instantaneous power can be formed by the transmission power of one or some flyback converter modules 130 participating in power transmission, and the transmission power of flyback converter modules 130 not participating in power transmission can be considered zero. The total instantaneous power can be determined based on the input voltage and input current of the AC input terminal 110, or based on the output voltage and output current of the DC output terminal 120, or based on the power command or power estimation result sent by the control unit 140 to the multiple flyback converter modules 130. This application does not impose specific limitations on the embodiments herein.

[0031] Since power is related to voltage and current, during the operation of the charging device 100, when the AC input is rectified to form a pulsating DC voltage, the trend of the total instantaneous power changing with the AC input can be illustrated by the curve of the equivalent current corresponding to the total instantaneous power changing with the phase angle θ. For example... Figure 2 As shown, in a scenario where the AC input is rectified to form a pulsating DC voltage, the equivalent current can gradually increase from the trough to the peak range with the phase angle θ, and then gradually decrease from the peak range to the trough range. Correspondingly, the total instantaneous power transmitted from the multiple flyback converter modules 130 to the DC output terminal 120 can also exhibit a trend of changing from low to high and then from high to low.

[0032] A power range is a range used to characterize the total instantaneous power. The control unit 140 can divide the total power range that the multiple flyback converter modules 130 can transmit into multiple power ranges and configure a corresponding target quantity for each power range. The multiple power ranges do not overlap; that is, for any given total instantaneous power, it belongs to at most one power range among the multiple power ranges. The multiple power ranges can be determined based on at least one of the following factors: efficiency characteristics, rated power, switching loss characteristics, and conduction loss characteristics of the flyback converter modules 130. This application does not specifically limit the embodiments described herein.

[0033] Each power range can have a lower power limit and a higher power limit. The upper power limit represents the upper boundary of the power range covered by the power range, and the lower power limit represents the lower boundary. Different power ranges can correspond to different target quantities, with a power range having a larger upper power limit corresponding to a greater number of targets than a power range having a smaller upper power limit. In other words, the control unit 140 can establish a correspondence between total instantaneous power and the number of targets based on multiple non-overlapping power ranges, such that when the total instantaneous power is in a power range with a larger upper power limit, it corresponds to a larger number of targets; and when the total instantaneous power is in a power range with a smaller upper power limit, it corresponds to a smaller number of targets.

[0034] The target number is the number of flyback converter modules 130 participating in power transmission among the multiple flyback converter modules 130. The target number can be an integer greater than or equal to 1 and less than or equal to the total number of flyback converter modules 130. The control unit 140 can determine the target number based on the power range in which the total instantaneous power is located. For example, when the total instantaneous power is in a lower power range, the target number can be 1; when the total instantaneous power is in a middle power range, the target number can be 2; and when the total instantaneous power is in a higher power range, the target number can be 3 or more. The target number corresponding to the higher power range is greater than the target number corresponding to the lower power range. That is, as the power range in which the total instantaneous power is located increases, the target number of flyback converter modules 130 participating in power transmission can increase accordingly. Thus, when the total instantaneous power is high, a larger number of flyback converter modules 130 can jointly undertake power transmission; when the total instantaneous power is low, a smaller number of flyback converter modules 130 can undertake power transmission.

[0035] by Figure 2 For example, as the total instantaneous power changes from low to high, the control unit 140 can initially control one flyback converter module 130 to participate in power transmission. As the total instantaneous power increases to a power range with a larger power upper limit, the control unit 140 can sequentially increase the number of flyback converter modules 130 participating in power transmission, for example, from 1 to 2, from 2 to 3, until N flyback converter modules 130 participate in power transmission, where N is an integer greater than 1 and less than or equal to the total number of flyback converter modules 130. Correspondingly, as the total instantaneous power changes from high to low, the control unit 140 can sequentially decrease the number of flyback converter modules 130 participating in power transmission, for example, from N to 3, from 3 to 2, and from 2 to 1.

[0036] The operating module is the flyback converter module 130 that participates in power transmission among multiple flyback converter modules 130. The control unit 140 can select a target number of flyback converter modules 130 as operating modules from the multiple flyback converter modules 130, and control each operating module to transmit power to the DC output terminal 120 based on the AC input. Flyback converter modules 130 that are not determined as operating modules may not participate in power transmission, or may be in a standby state, a shutdown state, or other states that do not output effective power to the DC output terminal 120.

[0037] In some embodiments, the control unit 140 can select a target number of flyback converter modules 130 as operating modules from a plurality of flyback converter modules 130 in a preset order. In other embodiments, the control unit 140 can also select a target number of flyback converter modules 130 as operating modules based on factors such as temperature, cumulative operating time, or efficiency characteristics of the plurality of flyback converter modules 130. Thus, while meeting the target quantity requirement, the operational balance and reliability among the plurality of flyback converter modules 130 can be further considered.

[0038] The sharing of total instantaneous power by each operating module can be understood as each operating module bearing a portion of the total instantaneous power. Specifically, the operating modules can share the total instantaneous power equally or differently. For example, when multiple operating modules have the same rated power or similar efficiency characteristics, they can share the total instantaneous power approximately equally. As another example, when multiple operating modules have different rated power, temperature, or efficiency characteristics, they can also share the total instantaneous power according to a preset weight. The embodiments in this application are not specifically limited herein.

[0039] During the process of varying total instantaneous power transmitted from multiple flyback converter modules 130 to the DC output terminal 120, the control unit 140 can dynamically adjust the number of operating modules based on the power range to which the total instantaneous power belongs among multiple power ranges. Specifically, when the total instantaneous power is in a power range with a larger upper limit, the control unit 140 can determine a larger target number and use a larger number of flyback converter modules 130 as operating modules to participate in power transmission. This reduces the instantaneous power borne by a single operating module, thereby reducing the instantaneous current flowing through the power devices and windings in a single operating module, which helps to reduce the conduction losses of the flyback converter module 130 in the high-power range.

[0040] When the total instantaneous power is within a power range with a relatively small upper limit, the control unit 140 can determine a smaller target quantity and use a smaller number of flyback converter modules 130 as operating modules to participate in power transmission, so that the total instantaneous power is shared by fewer operating modules. This reduces or avoids the situation where too many flyback converter modules 130 share the total instantaneous power, resulting in excessively low transmission power for a single operating module. It also helps to prevent the flyback converter modules 130 from operating in a low-power state with a high proportion of switching losses for extended periods, thereby reducing switching losses in the low-power range.

[0041] In summary, the charging device 100 of this embodiment can dynamically determine the target number of flyback converter modules 130 participating in power transmission based on the power range in which the total instantaneous power falls during the process of total instantaneous power change, and control the target number of flyback converter modules 130 to participate in power transmission as operating modules, so that each operating module shares the total instantaneous power. Therefore, the optimization requirements of conduction loss and switching loss can be considered in different power ranges, allowing the flyback converter modules 130 to maintain a relatively efficient operating condition during the process of total instantaneous power change, thereby reducing the conduction loss and switching loss of the flyback converter modules 130 in the charging device 100 and improving the energy conversion efficiency of the charging device 100.

[0042] In some embodiments, the control unit 140 may be configured to: determine the target transmission power of each operating module based on the total instantaneous power and the target number; and adjust the transmission power of each operating module based on the target transmission power.

[0043] In this embodiment, the target transmission power is a target power value used to characterize the power that the operating module needs to transmit. After the control unit 140 determines the target quantity based on the power range in which the total instantaneous power is located, the control unit 140 can further allocate the total instantaneous power according to the total instantaneous power and the target quantity to obtain the target transmission power corresponding to each operating module.

[0044] In some embodiments, each operating module can share the total instantaneous power equally. For example, when the target number is N and the total instantaneous power is P, the control unit 140 can determine the target transmission power of each operating module as P / N. Here, N is an integer greater than or equal to 1 and less than or equal to the total number of flyback converter modules 130. This allows each operating module to share the total instantaneous power approximately equally, reducing the risk of a single operating module experiencing excessive instantaneous power in the high-power range.

[0045] In other embodiments, each operating module may also share the total instantaneous power according to different power levels. Specifically, the control unit 140 can determine the power allocation weight corresponding to each operating module based on factors such as the rated power, efficiency characteristics, temperature, cumulative operating time, or health status of each operating module, and determine the target transmission power of each operating module based on the total instantaneous power and the power allocation weight. Thus, while achieving total instantaneous power sharing, the thermal balance or efficiency optimization requirements among the operating modules can also be taken into account.

[0046] The control unit 140 adjusts the transmission power of each operating module according to the target transmission power. This can be understood as the control unit 140 using the target transmission power corresponding to each operating module as a control target or reference, adjusting the operating parameters of each operating module to ensure that the actual transmission power of each operating module reaches the corresponding target transmission power. Specifically, the control unit 140 can send power commands, current commands, drive signals, or other control signals to each operating module to adjust its transmission power.

[0047] In some embodiments, the control unit 140 can generate corresponding switching control parameters based on the target transmission power of each operating module, and control the operation of the switching devices in each operating module through the switching control parameters. The switching control parameters may include at least one of duty cycle, switching frequency, peak current reference value, on-time, or off-time. Thus, the operating module can perform flyback switching according to the corresponding switching control parameters, so that its transmission power approaches or reaches the target transmission power.

[0048] This embodiment determines the target transmission power of each operating module based on the total instantaneous power and the target number, and adjusts the transmission power of each operating module according to the target transmission power. This allows the total instantaneous power to be distributed among the target number of operating modules in the expected manner. Therefore, it reduces problems such as localized overcurrent, localized overheating, or efficiency degradation caused by uneven power distribution among operating modules, improves the accuracy of power distribution during dynamic adjustment of the number of operating modules, and further enhances the operational reliability of the charging device 100 during changes in total instantaneous power.

[0049] In some embodiments, the control unit 140 may be configured to: enter a transition period in response to a target quantity switching from a first quantity to a second quantity; wherein, the target transmission power of each operating module under the first quantity is the first target transmission power, and the target transmission power of each operating module under the second quantity is the second target transmission power; when the first quantity is less than the second quantity, during the transition period, control the transmission power of each operating module that has been switched in to change from the first target transmission power to the second target transmission power, and control the transmission power of the flyback converter module 130 to be switched in to increase from zero to the second target transmission power; or, when the first quantity is greater than the second quantity, during the transition period, control the transmission power of each flyback converter module 130 that remains an operating module after the switch to change from the first target transmission power to the second target transmission power, and control the transmission power of the flyback converter module 130 to be switched out to decrease from the first target transmission power to zero.

[0050] In this embodiment, the first quantity is the number of flyback converter modules 130 participating in power transmission before the target quantity switch, and the second quantity is the number of flyback converter modules 130 participating in power transmission after the target quantity switch. The first target transmission power is the target transmission power corresponding to each operating module under the first quantity, and the second target transmission power is the target transmission power corresponding to each operating module under the second quantity. Each operating module that has been switched in can be a flyback converter module 130 that has already participated in power transmission as an operating module before the target quantity switch.

[0051] For example, when each operating module shares the total instantaneous power equally, if the total instantaneous power is P0, the first quantity is N1, and the second quantity is N2, then the first target transmission power can be P0 / N1, and the second target transmission power can be P0 / N2. Here, N1 and N2 are both integers greater than or equal to 1 and less than or equal to the total number of flyback converter modules 130. It is understood that when the total instantaneous power changes over time, the first target transmission power and the second target transmission power can also be determined based on the total instantaneous power at the corresponding control moment.

[0052] The transition period is a time interval set during the process of switching the target quantity from a first quantity to a second quantity. Specifically, the transition period can begin when the control unit 140 determines that the target quantity needs to be switched, and end when the transmission power of each flyback converter module 130 participating in the switch reaches the corresponding target transmission power. The duration of the transition period can be a preset fixed duration, or it can be determined based on factors such as the rate of change of the total instantaneous power, the response speed of the flyback converter module 130, or the allowable rate of change of current. This embodiment of the application does not impose specific limitations here.

[0053] Please combine Figure 2 During the process of the total instantaneous power changing from low to high, the target quantity can switch from a first quantity to a second quantity greater than the first quantity. In this case, at least one flyback converter module 130 that was not originally involved in power transmission needs to be switched into the power transmission process. The flyback converter module 130 to be switched in is the flyback converter module 130 that was not involved in power transmission before the target quantity switch, but needs to participate in power transmission as an operating module after the target quantity switch.

[0054] When the first quantity is less than the second quantity, the control unit 140 can control the transmission power of each already switched-in operating module to change from the first target transmission power to the second target transmission power during the transition period, and control the transmission power of the flyback converter module 130 to be switched in to increase from zero to the second target transmission power. Thus, the flyback converter module 130 to be switched in can gradually take on a portion of the total instantaneous power, while each already switched-in operating module can gradually adjust its own transmission power until the switched-in operating modules participate in power transmission according to the second target transmission power.

[0055] Please see Figure 3 In this embodiment, the total instantaneous power can vary with the phase angle θ. For example, the total instantaneous power can be expressed as 2P·sin²θ, where P can represent the transmission power of the charging device 100. During the increase of the total instantaneous power, under light load, only the flyback converter module 1 can act as the operating module to carry out power transmission, and the transmission power of the flyback converter modules 2 and 3 can be zero. At this time, the transmission power of the flyback converter module 1 can correspond to 2P·sin²θ.

[0056] When the total instantaneous power exceeds the first cut-in point, the control unit 140 can switch the target quantity from 1 to 2 and control the flyback converter module 2 to participate in power transmission as the flyback converter module 130 to be cut in. During the transition period corresponding to the first cut-in, the control unit 140 can control the transmission power of the already cut-in flyback converter module 1 to smoothly change from the first target transmission power to the second target transmission power, and control the transmission power of the flyback converter module 2 to smoothly increase from zero to the second target transmission power. For example, when each operating module equally shares the total instantaneous power, the transmission power of the flyback converter module 1 can smoothly change from 2P·sin²θ to P·sin²θ, and the transmission power of the flyback converter module 2 can smoothly increase from zero to P·sin²θ. After the transition period ends, both the flyback converter module 1 and the flyback converter module 2 participate in power transmission as operating modules, and can share the total instantaneous power according to P·sin²θ respectively.

[0057] When the total instantaneous power continues to rise and exceeds the second cut-in point, the control unit 140 can switch the target number from 2 to 3 and control the flyback converter module 3 to participate in the power transmission process as the flyback converter module 130 to be cut in. During the transition period corresponding to the second cut-in, the control unit 140 can control the transmission power of the already cut-in flyback converter modules 1 and 2 to smoothly change from the first target transmission power to the second target transmission power, and control the transmission power of flyback converter module 3 to smoothly increase from zero to the second target transmission power. For example, when each operating module equally shares the total instantaneous power, the transmission power of flyback converter module 1 and flyback converter module 2 can smoothly change from P·sin²θ to 2P·sin²θ / 3, respectively, and the transmission power of flyback converter module 3 can smoothly increase from zero to 2P·sin²θ / 3. After the transition period ends, flyback converter modules 1, 2, and 3 all participate in power transmission as operating modules and can share the total instantaneous power according to 2P·sin²θ / 3.

[0058] Similarly, as the total instantaneous power changes from high to low, the target quantity can switch from a first quantity to a second quantity that is less than the first quantity. In this case, at least one flyback converter module 130 that was originally involved in power transmission needs to be switched out of the power transmission process. The flyback converter module 130 to be switched out is the flyback converter module 130 that participated in power transmission as an operating module before the target quantity switch and no longer participates in power transmission as an operating module after the target quantity switch.

[0059] When the first number is greater than the second number, the control unit 140 can, during the transition period, control the transmission power of each flyback converter module 130 that remains an operating module after the switchover from the first target transmission power to the second target transmission power, and control the transmission power of the flyback converter module 130 to be switched out to decrease from the first target transmission power to zero. Thus, the flyback converter module 130 to be switched out can gradually withdraw from the power transmission process, while the flyback converter modules 130 that remain operating modules after the switchover can gradually adjust their own transmission power until each operating module participates in power transmission according to the second target transmission power.

[0060] For example, such as Figure 3 As shown, when the target number is switched from 3 to 2, the control unit 140 can control the transmission power of the flyback converter module 130 to be switched out to smoothly decrease from the first target transmission power 2P·sin²θ / 3 to zero, and control the transmission power of the two flyback converter modules 130 that remain as operating modules after the switch to smoothly change from the first target transmission power 2P·sin²θ / 3 to the second target transmission power P·sin²θ. As another example, when the target number is switched from 2 to 1, the control unit 140 can control the transmission power of the flyback converter module 130 to be switched out to smoothly decrease from the first target transmission power P·sin²θ to zero, and control the transmission power of the flyback converter module 130 that remains as operating modules after the switch to smoothly change from the first target transmission power P·sin²θ to the second target transmission power 2P·sin²θ.

[0061] In some embodiments, the control unit 140 may control the transmission power of the flyback converter module 130 whose transmission power needs to be adjusted to change according to a preset rule during the transition period; wherein, the flyback converter module whose transmission power needs to be adjusted includes: the flyback converter module 130 to be switched in, the flyback converter module 130 to be switched out, and the flyback converter module 130 that is a running module before and after the switch; the preset rule includes a ramp change rule or a nonlinear continuous change rule.

[0062] In this embodiment, the flyback converter module 130 whose transmission power needs adjustment is the flyback converter module 130 whose transmission power needs to change during the process of switching the target number from a first number to a second number. Specifically, when the first number is less than the second number, the flyback converter module 130 whose transmission power needs adjustment may include the flyback converter module 130 to be switched in, and the flyback converter module 130 that operates before and after the switch. When the first number is greater than the second number, the flyback converter module 130 whose transmission power needs adjustment may include the flyback converter module 130 to be switched out, and the flyback converter module 130 that operates before and after the switch.

[0063] The preset rule is used to define the pattern of how the transmission power of each flyback converter module 130 changes over time during the transition period, which requires adjustment of transmission power. Specifically, the preset rule can be used to constrain the change path of transmission power from the initial power value to the final power value, so as to reduce sudden changes in transmission power.

[0064] In some embodiments, the preset law may include a slope variation law. The slope variation law can represent that the transmitted power changes linearly during the transition period. Therefore, the transmitted power can change at a stable slope during the transition period, making control implementation relatively simple.

[0065] In other embodiments, the preset law may include a nonlinear continuous variation law. A nonlinear continuous variation law can represent the transmission power changing according to a continuous nonlinear curve during the transition period. For example, the nonlinear continuous variation law may include one of a sine variation law, a cosine variation law, an exponential variation law, or a polynomial variation law. Therefore, the variation curve of the transmission power can be flexibly set according to the dynamic response capability of the flyback converter module 130 and the current quality requirements of the charging device 100.

[0066] The control unit 140 can adjust at least one of the power command, current command, or switching control parameters of the flyback converter modules 130 whose transmission power needs adjustment, so that the transmission power of each flyback converter module 130 whose transmission power needs adjustment changes according to a preset rule. The switching control parameters may include at least one of the following: duty cycle, switching frequency, peak current reference value, on-time, or off-time. This application embodiment does not impose specific limitations here.

[0067] This embodiment sets a transition period when the target number switches from a first number to a second number, and during the transition period, controls the transmission power of each flyback converter module 130 whose transmission power needs to be adjusted to change according to a preset law. This can reduce or avoid sudden changes in the transmission power of the flyback converter module 130 during the switching-in or switching-out process. As a result, the impact of the switching process of the number of operating modules on the total instantaneous power, input current, and DC output can be reduced, which helps to improve the stability of the power transmission process and improve the operational reliability of the charging device 100 during the dynamic adjustment of the number of operating modules.

[0068] In some embodiments, the flyback converter module 130 may include: a rectifier circuit, the input terminal of which is connected to the AC input terminal, for rectifying the AC input to output a pulsating DC voltage; and a flyback converter circuit, the input terminal of which is connected to the output terminal of the rectifier circuit, and the output terminal of which is connected to the DC output terminal, for performing flyback conversion based on the pulsating DC voltage and transmitting power to the DC output terminal.

[0069] Please see Figure 4 In this embodiment, the flyback converter module 130 includes a rectifier circuit 131 and a flyback converter circuit 132. The rectifier circuit 131 is used to convert AC input into a pulsating DC voltage. Specifically, the input terminal of the rectifier circuit 131 is connected to the AC input terminal 110. The AC input terminal 110 can be connected to the AC power grid, and a first electromagnetic compatibility circuit (EMC1) and an input filter circuit can be provided between the AC power grid and the AC input terminal 110. The first EMC1 can be used to suppress electromagnetic interference on the AC input side. The input filter circuit can include an inductor L1 and a capacitor C1 to filter out high-frequency ripple of the AC input, thereby improving the power quality of the AC input terminal 110.

[0070] In this embodiment, the rectifier circuit 131 may include an uncontrolled rectifier bridge, which may include a bridge rectifier circuit composed of multiple diodes. In other embodiments, the rectifier circuit 131 may include a controlled rectifier bridge. For example, the controlled rectifier bridge may include a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT). Thus, the specific operating mode of the rectifier circuit 131 can be configured according to the requirements of the charging device 100, such as cost, efficiency, or voltage level.

[0071] The flyback converter circuit 132 is a circuit used for flyback conversion based on pulsating DC voltage. Specifically, the input terminal of the flyback converter circuit 132 is connected to the output terminal of the rectifier circuit 131 to receive the pulsating DC voltage output by the rectifier circuit 131; the output terminal of the flyback converter circuit 132 is connected to the DC output terminal 120 to transfer power to the DC output terminal 120. In some embodiments, such as Figure 4 As shown, the flyback converter circuit 132 may include a flyback transformer T1, a switching device Q1, and an output rectifier D1. The flyback transformer T1 may include a primary winding and a secondary winding. The switching device Q1 may be connected in the power circuit containing the primary winding. The output rectifier D1 may be connected between the secondary winding and the DC output terminal 120.

[0072] During the operation of the flyback converter circuit 132, the control unit 140 can control the switching device Q1 to turn on, so that the pulsating DC voltage output by the rectifier circuit 131 acts on the primary winding of the flyback transformer T1, thereby allowing the flyback transformer T1 to store energy. When the control unit 140 controls the switching device Q1 to turn off, the energy stored in the flyback transformer T1 can be transferred to the DC output terminal 120 via the secondary winding and the output rectifier device D1. Thus, the flyback converter circuit 132 can transfer power to the DC output terminal 120 based on the pulsating DC voltage.

[0073] Multiple flyback converter modules 130 can be connected in parallel between the AC input terminal 110 and the DC output terminal 120. Each flyback converter module 130 may include a corresponding rectifier circuit 131 and a flyback converter circuit 132, so that each flyback converter module 130 can generate a corresponding pulsating DC voltage based on the AC input and transmit power to the DC output terminal 120 based on the pulsating DC voltage.

[0074] In some embodiments, the DC output terminal 120 can be connected to the second electromagnetic compatibility circuit EMC2, which can be used to suppress electromagnetic interference of the DC output and reduce the impact of the switching process of the flyback converter circuit 132 on the charging device or external circuit.

[0075] In this embodiment, the rectifier circuit 131 and the flyback converter circuit 132 work together to form a single-stage AC-DC conversion path. While realizing the conversion from AC input to DC output, it reduces the dependence on additional DC conversion stages, which helps to reduce the number of devices and circuit complexity of the charging device 100 and improve the power density of the charging device 100.

[0076] In some embodiments, the control unit 140 may be configured to control each operating module to operate at the same switching frequency; wherein the switching frequency is determined based on the AC input voltage of the AC input terminal 110, the DC output voltage of the DC output terminal 120, the magnetizing inductance of the flyback converter circuit, and the transmission power of the operating module.

[0077] In this embodiment, the switching frequency is the frequency at which the switching device Q1 in the flyback converter circuit 132 of the operating module periodically turns on and off. The control unit 140 controls each operating module to operate at the same switching frequency, which can be understood as the control unit 140 providing the same switching frequency command to each operating module at the same control moment or within the same control cycle, so that the switching device Q1 in each operating module operates at the same switching frequency.

[0078] The AC input voltage can be the input voltage received at AC input terminal 110. The DC output voltage can be the output voltage provided at DC output terminal 120. The magnetizing inductance is the inductance parameter used to store magnetic energy in the flyback converter circuit 132. For example, in... Figure 4 When the flyback converter circuit 132 shown includes a flyback transformer T1, the magnetizing inductor can be the magnetizing inductor of the flyback transformer T1. During operation, the flyback converter circuit 132 can store energy through the magnetizing inductor when the switching device Q1 is turned on, and release energy to the DC output terminal 120 when the switching device Q1 is turned off.

[0079] In some embodiments, the control unit 140 can determine the switching frequency that enables the operating module to operate in a target operating state based on the AC input voltage, DC output voltage, the magnetizing inductance of the flyback converter circuit 132, and the transmission power of the operating module. The target operating state may include a critical discontinuous state. A critical discontinuous state can be understood as a state in which, within one switching cycle, the magnetizing current of the flyback converter circuit 132 rises from a low current value during the on-state of the switching device Q1, and then drops to zero or near zero during the off-state of the switching device Q1 before entering the next switching cycle. This reduces the discontinuity time of the flyback converter circuit 132 within one switching cycle, helping to reduce unnecessary switching losses and improve current quality.

[0080] In some embodiments, the switching frequency can be determined by the following formula: .

[0081] in, Indicates the switching frequency. Indicates AC input voltage, Indicates DC output voltage, This represents the magnetizing inductance of the flyback converter circuit. This indicates the transmission power of the running module.

[0082] In some embodiments, the control unit 140 may be configured to adjust the transmission power of each operating module according to the duty cycle; wherein the duty cycle is determined based on the AC input voltage, switching frequency, excitation inductance of the flyback converter circuit, and transmission power of the operating module.

[0083] In this embodiment, the control unit 140 can adjust the transmission power of each operating module according to the duty cycle. The duty cycle is the proportion of the time that the switching device Q1 in the operating module is in the conducting state within a switching cycle. With a fixed switching frequency, the control unit 140 can adjust the duty cycle of the switching device Q1 to change the energy stored and released by the flyback converter circuit 132 in a single switching cycle, thereby adjusting the power transmitted by the operating module to the DC output terminal 120.

[0084] In some embodiments, the duty cycle can be determined based on the AC input voltage, switching frequency, magnetizing inductance of flyback converter 132, and transmission power of the operating module. For example, after the switching frequency is determined, if the transmission power of the operating module increases, the control unit 140 can correspondingly increase the duty cycle to increase the energy transmitted by the operating module in a single switching cycle; if the transmission power of the operating module decreases, the control unit 140 can correspondingly decrease the duty cycle to reduce the energy transmitted by the operating module in a single switching cycle.

[0085] In some embodiments, the duty cycle D can be determined by the following formula: .

[0086] In some embodiments, during the transition period when the target quantity is switched from the first quantity to the second quantity, the control unit 140 can keep each operating module running at the same switching frequency, and adjust the duty cycle of each flyback converter module 130 participating in the switching so that the transmission power of each flyback converter module 130 changes according to a preset rule.

[0087] Please see Figure 5In this embodiment, during the transition period when the target quantity changes from a first quantity to a second quantity, and the first quantity is less than the second quantity, the duty cycle of the flyback converter module 130 to be switched in can be gradually increased from zero until the transmission power of the flyback converter module 130 to be switched in reaches the second target transmission power. Simultaneously, the duty cycle of the flyback converter module 130 that was already operating before the switch can be adjusted accordingly based on its transmission power, so that its transmission power changes from the first target transmission power to the second target transmission power. During the transition period when the first quantity is greater than the second quantity, the duty cycle of the flyback converter module 130 to be switched out can be gradually decreased to zero, so that the transmission power of the flyback converter module 130 to be switched out decreases from the first target transmission power to zero. Therefore, during the switching in or out process of the flyback converter module 130, a smooth change in transmission power can be achieved through continuous adjustment of the duty cycle.

[0088] Meanwhile, during the dynamic adjustment of the number of operating modules, the switching frequency of each operating module can remain the same, and this switching frequency can vary with the phase angle θ. However, no difference in switching frequency occurs between different operating modules within the same control moment or the same control cycle. Furthermore, the duty cycle of each operating module can be adjusted according to the transmission power. Therefore, the flyback converter module 130 can operate in a higher efficiency power range as much as possible within the pulsation cycle, thereby further reducing the conduction and switching losses of the flyback converter module 130.

[0089] Please see Figure 6 This application also provides a charging power supply 200, which includes a charging interface 210 and a charging device 100 as described in the foregoing embodiments. The charging interface 210 is connected to the DC output terminal of the charging device 100 and is used to transmit the DC output provided by the DC output terminal to the device to be charged.

[0090] Please see Figure 7 This application also provides a control method for a charging device. The charging device includes an AC input terminal, a DC output terminal, and multiple flyback converter modules. The AC input terminal receives AC input, the DC output terminal provides DC output, and the multiple flyback converter modules are connected in parallel between the AC input terminal and the DC output terminal to transmit power to the DC output terminal based on the AC input. This control method can be applied to a control device for the charging device. The control device can be an electronic device with certain computing capabilities. Alternatively, the control device can refer to a software program running on an electronic device. In one specific embodiment, the control device can be a controller for the charging device.

[0091] The control method for the charging device may include the following steps.

[0092] S110, during the process of the change in the total instantaneous power transmitted from multiple flyback converter modules to the DC output terminal, the target number of flyback converter modules participating in power transmission is determined according to the power range to which the total instantaneous power belongs in multiple power ranges; wherein, the multiple power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit.

[0093] S120 uses the target number of flyback converter modules as operating modules to participate in power transmission, so that each operating module shares the total instantaneous power.

[0094] This embodiment can dynamically adjust the number of operating modules during the total instantaneous power change, reduce the conduction loss and switching loss of the flyback converter module in the charging device, and improve the energy conversion efficiency of the charging device.

[0095] In some embodiments, the control device may determine the target transmission power of each operating module based on the total instantaneous power and the target quantity; and adjust the transmission power of each operating module according to the target transmission power.

[0096] In some embodiments, the control device may enter a transition period in response to a target quantity switching from a first quantity to a second quantity; wherein, the target transmission power of each operating module under the first quantity is the first target transmission power, and the target transmission power of each operating module under the second quantity is the second target transmission power; when the first quantity is less than the second quantity, during the transition period, the transmission power of each operating module that has been switched in is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched in is controlled to increase from zero to the second target transmission power; or, when the first quantity is greater than the second quantity, during the transition period, the transmission power of each flyback converter module that remains an operating module after the switch is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched out is controlled to decrease from the first target transmission power to zero.

[0097] In some embodiments, the control device can control each operating module to operate at the same switching frequency; wherein the switching frequency is determined based on the AC input voltage at the AC input terminal, the DC output voltage at the DC output terminal, the excitation inductance of the flyback converter module, and the transmission power of the operating module.

[0098] In some embodiments, the control device can adjust the transmission power of each operating module according to the duty cycle; wherein the duty cycle is determined based on the AC input voltage, switching frequency, excitation inductance of the flyback converter module, and transmission power of the operating module.

[0099] Other specific functions and effects of each step in the control method of the charging device can be explained by referring to the foregoing embodiments, and will not be repeated here.

[0100] This application also provides a controller, which includes a memory and a processor; wherein the memory stores at least one computer program, and the at least one computer program is loaded and executed by the processor to implement the control method of the charging device as described in the foregoing embodiments.

[0101] In this embodiment, it can be implemented entirely or partially by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape) or a semiconductor medium (e.g., solid-state disk (SSD)).

[0102] It is understood that the term "connection" in the embodiments of this application can be interpreted as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc. can transmit electrical signals or data to each other.

[0103] It is understood that the specific examples in this document are only intended to help those skilled in the art better understand the embodiments of this application, and are not intended to limit the scope of the invention.

[0104] It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0105] It is understood that the various embodiments described in this application can be implemented individually or in combination, and the embodiments of this application are not limited in this respect.

[0106] Unless otherwise stated, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The term "and / or" as used in this application includes any and all combinations of one or more of the associated listed items. The singular forms "a," "the," and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0107] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0108] The above description is merely a specific embodiment of this application, but the scope of protection of this invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this invention should be determined by the scope of the claims.

Claims

1. A charging device, characterized in that, include: AC input terminal, used to receive AC input; DC output terminal, used to provide DC output; Multiple flyback converter modules are connected in parallel between the AC input terminal and the DC output terminal for transmitting power to the DC output terminal based on the AC input. The control unit, connected to the plurality of flyback converter modules, is configured as follows: During the process of the total instantaneous power transmission from the multiple flyback converter modules to the DC output terminal, the target number of flyback converter modules participating in power transmission is determined according to the power range to which the total instantaneous power belongs in the multiple power ranges; wherein, the multiple power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit. The target number of flyback converter modules are used as operating modules to participate in power transmission, so that each operating module shares the total instantaneous power.

2. The charging device according to claim 1, characterized in that, The control unit is configured to: The target transmission power of each of the operating modules is determined based on the total instantaneous power and the target quantity; Adjust the transmission power of each of the operating modules according to the target transmission power.

3. The charging device according to claim 2, characterized in that, The control unit is configured to: In response to the target quantity switching from a first quantity to a second quantity, a transition period is entered; wherein, the target transmission power of each operating module under the first quantity is the first target transmission power, and the target transmission power of each operating module under the second quantity is the second target transmission power; When the first quantity is less than the second quantity, during the transition period, the transmission power of each of the already switched-in operating modules is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched in is controlled to increase from zero to the second target transmission power; or, When the first quantity is greater than the second quantity, during the transition period, the transmission power of each flyback converter module that remains as the operating module after the switch is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched out is controlled to decrease from the first target transmission power to zero.

4. The charging device according to claim 3, characterized in that, The control unit is configured to: During the transition period, the transmission power of the flyback converter module whose transmission power needs to be adjusted changes according to a preset rule; wherein, the flyback converter module whose transmission power needs to be adjusted includes: the flyback converter module to be switched in, the flyback converter module to be switched out, and the flyback converter module that serves as the operating module before and after the switch; the preset rule includes a ramp change rule or a nonlinear continuous change rule.

5. The charging device according to any one of claims 1 to 4, characterized in that, The flyback converter module includes: A rectifier circuit, wherein the input terminal of the rectifier circuit is connected to the AC input terminal, and is used to rectify the AC input to output a pulsating DC voltage; A flyback converter circuit, wherein the input terminal of the flyback converter circuit is connected to the output terminal of the rectifier circuit, and the output terminal of the flyback converter circuit is connected to the DC output terminal, for performing flyback conversion based on the pulsating DC voltage and transmitting power to the DC output terminal.

6. The charging device according to claim 5, characterized in that, The control unit is configured to: Each of the aforementioned operating modules is controlled to operate at the same switching frequency; wherein the switching frequency is determined based on the AC input voltage of the AC input terminal, the DC output voltage of the DC output terminal, the magnetizing inductance of the flyback converter circuit, and the transmission power of the operating module.

7. The charging device according to claim 6, characterized in that, The control unit is configured to: The transmission power of each operating module is adjusted according to the duty cycle; wherein the duty cycle is determined based on the AC input voltage, the switching frequency, the magnetizing inductance of the flyback converter circuit, and the transmission power of the operating module.

8. A charging power supply, characterized in that, It includes a charging interface and a charging device as described in any one of claims 1 to 7; wherein the charging interface is connected to the DC output terminal of the charging device and is used to transmit the DC output provided by the DC output terminal to the device to be charged.

9. A control method for a charging device, characterized in that, The charging device includes an AC input terminal, a DC output terminal, and multiple flyback converter modules; wherein, the AC input terminal is used to receive AC input, the DC output terminal is used to provide DC output, and the multiple flyback converter modules are connected in parallel between the AC input terminal and the DC output terminal to transmit power to the DC output terminal based on the AC input; The method includes: During the process of the total instantaneous power transmission from the multiple flyback converter modules to the DC output terminal, the target number of flyback converter modules participating in power transmission is determined according to the power range to which the total instantaneous power belongs in the multiple power ranges; wherein, the multiple power ranges do not overlap, different power ranges correspond to different target numbers, and the target number corresponding to the power range with a larger power upper limit is greater than the target number corresponding to the power range with a smaller power upper limit. The target number of flyback converter modules are used as operating modules to participate in power transmission, so that each operating module shares the total instantaneous power.

10. The method according to claim 9, characterized in that, The method includes: The target transmission power of each of the operating modules is determined based on the total instantaneous power and the target quantity; Adjust the transmission power of each of the operating modules according to the target transmission power.

11. The method according to claim 10, characterized in that, The method includes: In response to the target quantity switching from a first quantity to a second quantity, a transition period is entered; wherein, the target transmission power of each operating module under the first quantity is the first target transmission power, and the target transmission power of each operating module under the second quantity is the second target transmission power; When the first quantity is less than the second quantity, during the transition period, the transmission power of each of the already switched-in operating modules is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched in is controlled to increase from zero to the second target transmission power; or, When the first quantity is greater than the second quantity, during the transition period, the transmission power of each flyback converter module that remains as the operating module after the switch is controlled to change from the first target transmission power to the second target transmission power, and the transmission power of the flyback converter module to be switched out is controlled to decrease from the first target transmission power to zero.

12. The method according to any one of claims 9 to 11, characterized in that, The method includes: Each of the aforementioned operating modules is controlled to operate at the same switching frequency; wherein the switching frequency is determined based on the AC input voltage of the AC input terminal, the DC output voltage of the DC output terminal, the magnetizing inductance of the flyback converter module, and the transmission power of the operating module.

13. The method according to claim 12, characterized in that, The method includes: The transmission power of each operating module is adjusted according to the duty cycle; wherein the duty cycle is determined based on the AC input voltage, the switching frequency, the excitation inductance of the flyback converter module, and the transmission power of the operating module.

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