Soft start method and device for bidirectional DC / DC converter and computer equipment

Abstract

The invention is suitable for the technical field of power electronic control, and provides a soft start method and device for a bidirectional DC / DC converter and computer equipment. The method comprises the following steps of: keeping the starting frequency # imgabs0 #, and increasing the duty ratio of the bidirectional DC / DC converter from 0 to the duty ratio # imgabs1 # of a first switching point; predicting the working frequency and the primary and secondary side duty ratios of the bidirectional DC / DC converter by using a pre-trained neural network model, and adjusting the primary and secondary side duty ratios according to a predicted value until the duty ratio # imgabs2 is increased to the maximum value of the duty ratio from the first switching point duty ratio # imgabs2 #; and under the condition that the duty ratios of the primary side and the secondary side are kept at the maximum value, the working frequency is adjusted according to the load condition of the bidirectional DC / DC converter, and the bidirectional DC / DC converter completes soft start and enters a steady-state working stage. According to the method, the working frequency and the duty ratios of the primary side and the secondary side of the bidirectional DC / DC converter are predicted and adjusted, so that the duty ratios of the primary side and the secondary side are smoothly transited to be increased to the maximum value of the duty ratios, and the overall state transition in the soft start process is smooth without large impact current.

Description

Technical Field

[0001] The present application belongs to the field of power electronic control technology, and in particular to a bidirectional DC / DC converter soft start method, device and computer equipment. Background Art

[0002] Existing bidirectional DC / DC converters not only have good soft switching and high power density characteristics, but also can work at a higher voltage level, which has attracted widespread attention in the industry. However, when the bidirectional DC / DC converter is started, due to factors such as the large charging current of the filter capacitor and the small input impedance, the resonant cavity will generate a large current, which places high current stress requirements on the components in the circuit, and may cause damage to the converter or trigger overcurrent protection. Therefore, bidirectional DC / DC converters generally use two modulation methods, symmetrical pulse width modulation and high-frequency startup, to reduce the startup current.

[0003] The existing technology usually adopts a pulse width and frequency reduction hybrid modulation method, combining the advantages of the above two modulation methods. Specifically, symmetrical pulse width modulation is used in the early stage of soft start, maintaining a fixed frequency state (generally lower than the resonant frequency), and the duty cycle of the primary and secondary switch tubes of the transformer is slowly increased to the maximum value according to the preset curve, and then enters the frequency adjustment stage, and the output voltage is stabilized at the target value through frequency adjustment. This method can avoid excessive gain when the frequency reduction start-up frequency drops to the resonant frequency, and the serious circulating current problem caused by the parallel start of multiple converters. At the same time, by slowly increasing the duty cycle, the problem of voltage overshoot caused by the large gain caused by the low frequency and large duty cycle in the early stage of startup and the large impact current generated at the moment of startup can be solved.

[0004] However, the soft start method of the prior art only considers the forward gain of the soft start process of the bidirectional converter, and seeks a pulse width frequency reduction mixed modulation curve with monotonic and continuous forward gain. However, the overall gain of the converter is determined by the forward gain and the reverse gain. If only the forward gain is monotonic and continuous, the overall gain will be non-monotonic due to the non-monotonic reverse gain in certain duty cycle intervals at certain frequencies. When the duty cycle increases and passes through the endpoint of this non-monotonic interval, the state of the converter changes, and an inrush current is generated. Summary of the invention

[0005] The embodiments of the present application provide a bidirectional DC / DC converter soft-start method, apparatus and computer equipment, which can solve the problem of overall gain non-monotonicity caused by reverse gain non-monotonicity during duty cycle increase.

[0006] In a first aspect, an embodiment of the present application provides a bidirectional DC / DC converter soft start method, comprising: Maintain startup frequency , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle ; According to the voltage sampling value collected in real time And current sampling value , predict and adjust the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle; When the duty ratio of the primary and secondary sides is maintained at the maximum value, the operating frequency is adjusted according to the load condition of the bidirectional DC / DC converter, and the bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

[0007] In a possible implementation of the first aspect, predicting the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter includes: By setting different operating frequencies and primary and secondary duty ratios of the bidirectional DC / DC converter, a series of voltage sampling values ​​are obtained through experiments. And current sampling value ; The series of voltage sampling values And current sampling value As input values ​​of the neural network model, the operating frequency of the bidirectional DC / DC converter and the primary and secondary duty ratios are used as expected output values ​​of the neural network model to train the neural network model; The current preset value and the voltage preset value are input into the trained neural network model to obtain the output predicted values ​​of the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter.

[0008] Exemplarily, the neural network model obtains the predicted values ​​of the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter according to a preset output voltage curve, while ensuring that the current is less than the current threshold, so that the output voltage of the bidirectional DC / DC converter using the predicted value conforms to the preset output voltage curve.

[0009] Exemplarily, the neural network model is a BP neural network model, which includes an input layer, a hidden layer and an output layer.

[0010] Exemplarily, the duty cycle of the bidirectional DC / DC converter is increased from 0 to a first switching point duty cycle In the process, the output voltage and duty cycle are positively correlated.

[0011] In a second aspect, an embodiment of the present application provides a bidirectional DC / DC converter soft start device, comprising: Symmetrical pulse width modulation module to maintain the starting frequency , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle ; Pulse width frequency hybrid modulation module is used to collect voltage sampling values ​​in real time And current sampling value , predict and adjust the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle; The variable frequency modulation module is used to adjust the operating frequency according to the load condition of the above-mentioned bidirectional DC / DC converter while maintaining the duty ratio of the primary and secondary sides at the maximum duty ratio, so that the above-mentioned bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

[0012] In a third aspect, an embodiment of the present application provides a computer device, including: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method described in any one of the first aspects is implemented.

[0013] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method as described in any one of the first aspects is implemented.

[0014] In a fifth aspect, an embodiment of the present application provides a computer program product, which, when executed on a computer device, enables the computer device to execute any of the methods described in the first aspect above.

[0015] It can be understood that the beneficial effects of the second to fifth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0016] Compared with the prior art, the embodiments of the present application have the following beneficial effects: a frequency modulation and duty cycle adjustment process is inserted between the fixed frequency and frequency modulation stages of the converter soft start process, and the process combines the voltage sampling value and the current sampling value to predict and adjust the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter, so that the problem of overall gain non-monotonicity caused by non-monotonicity of reverse gain in certain duty cycle intervals at certain frequencies will not occur because only the forward gain of the bidirectional converter soft start process is considered and a pulse width frequency reduction hybrid modulation curve with monotonic and continuous forward gain is sought. The present application can make the overall gain of the bidirectional DC / DC converter soft start process monotonic, the state transition smooth, and without large impact current, and is generally applicable to soft start under various working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 This is a schematic diagram of a typical half-bridge LLC circuit provided by an embodiment of the present application; Figure 2 This is a schematic diagram of a soft-start process of a bidirectional DC / DC converter provided in an embodiment of the present application; Figure 3 This is a schematic diagram of the relationship between duty cycle and output voltage in the symmetrical pulse width modulation stage provided by an embodiment of the present application; Figure 4 It is a schematic diagram of the relationship between duty cycle-output voltage and duty cycle-frequency in the pulse width frequency hybrid modulation stage provided by an embodiment of the present application; Figure 5 This is a schematic diagram of the relationship between voltage, frequency, and duty cycle during the variable frequency modulation stage provided by an embodiment of the present application; Figure 6 It is a structural schematic diagram of a bidirectional DC / DC converter soft start device provided in one embodiment of the present application; Figure 7 It is a structural diagram of a computer device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0019] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0020] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, integers, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0021] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0022] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0023] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0024] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0025] The technical solutions in the embodiments of the present application are described in detail below.

[0026] The bidirectional DC / DC converter used in the embodiment of the present application can be any type of bidirectional DC / DC converter such as a bidirectional DC / DC resonant converter. In addition, according to different topological structures, the current sampling value can be a resonant tank current sampling, a primary current sampling, etc. The application scenario of the present application is illustrated below.

[0027] Figure 1 : is a schematic diagram of a typical half-bridge LLC circuit provided by an embodiment of the present application. Figure 1 As shown, a typical half-bridge LLC circuit includes: input DC power supply , chopper switch and , resonant inductor , resonant capacitor ,transformer , full-bridge synchronous rectification switch - , output filter capacitor and output load The bidirectional DC / DC converter soft start method provided in this application is applicable to Figure 1and any Figure 1 Topology of bidirectional DC / DC converter based on the same principle.

[0028] The following is an explanation of the bidirectional DC / DC converter soft start method provided in the present application.

[0029] Figure 2 1 is a schematic diagram of a soft start process of a bidirectional DC / DC converter provided in an embodiment of the present application. In some embodiments, the process can be applied to a soft start control device, such as a microcontroller. Figure 2 As shown, the process includes: S201, keep the startup frequency at , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle .

[0030] S201 corresponds to the first stage of the soft start process provided in this application, and the first stage is recorded as the symmetrical pulse width modulation stage. The closed-loop control in this stage only controls the duty cycle, and slowly increases the duty cycle from 0 to the preset duty cycle corresponding to the first switching point. (i.e. the duty cycle of the first switching point ). In the early stage of small duty cycle, the gain increases monotonically, and the output voltage can be slowly established. At the same time, because the early duty cycle is small, the power supply has less time to charge the resonant cavity in each cycle, the current rises less time each time, and the current peak is also small, which can effectively reduce the startup impact current. In this stage, the startup frequency is constant. The negative feedback loop of the output voltage will output the required duty cycle. As the output voltage set value increases, the duty cycle will gradually increase, so the output voltage increases with the set value, that is, the output voltage and duty cycle are positively correlated. Figure 3 is a schematic diagram of the relationship between duty cycle and output voltage in the symmetrical pulse width modulation stage provided by an embodiment of the present application, such as Figure 3 As shown, the frequency at point A in the figure is the starting frequency , the specific duty cycle and output voltage selection can be determined according to the actual debugging results.

[0031] S202, predicting and adjusting the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter according to the voltage sampling value and the current sampling value collected in real time, until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle.

[0032] S202 corresponds to the second stage in the soft start process provided by the present application, and the second stage is recorded as the pulse width frequency mixed modulation stage. The operating frequency and duty cycle of this stage can be changed. In one embodiment, the pre-trained neural network model can be used to predict the frequency and the duty cycle of the primary and secondary sides. Specifically, the voltage sampling value and the current sampling value collected in real time can be used as the input data of the neural network model to train the neural network model, and then the current preset value and the voltage preset value are input into the trained neural network model to obtain the output of the bidirectional DC / DC converter The predicted value of the operating frequency and the primary and secondary side duty cycle. Among them, the current preset value and the voltage preset value can be set according to the circuit structure and actual needs. In an example, the neural network model predicts the operating frequency and the primary and secondary side duty cycle according to the preset output voltage curve under the premise of ensuring that the current is small, so that the bidirectional DC / DC converter using the predicted value output by the neural network has an output voltage that meets the preset output voltage curve. Exemplarily, the "low current" and "meeting the preset output voltage curve" in this embodiment can be judged by setting numerical indicators. Taking a bidirectional DC / DC resonant converter as an example, when the resonant tank current is less than the current threshold, it is judged that the resonant tank current is small; for another example, when the difference between the actual output voltage and the preset output voltage curve is within a preset range, it is judged that it conforms to the preset output voltage curve.

[0033] The duty cycle of both the primary and secondary sides reaches the maximum value, marking the end of this stage. The frequency at this time is recorded as the second switching point frequency When the duty cycle is greater than the first switching point duty cycle When the bidirectional DC / DC converter is in parallel operation, the forward gain brought by pulse width modulation increases very slowly or even decreases, but the reverse gain increases rapidly, so the overall external gain is not monotonic. If this process is not improved, when the bidirectional DC / DC converter enters the frequency modulation stage, a large impact current will be generated due to the drastic jump in gain. Moreover, if the bidirectional DC / DC converter is in parallel operation, the newly added converter may not be able to participate in the parallel current sharing normally because it does not need to maintain the port voltage and may work in a high-frequency, small-duty-cycle fixed-frequency current-limiting state.

[0034] In one embodiment, a BP (Back Propagation) neural network is used to predict the frequency and duty cycle. Exemplarily, the BP neural network is specifically a three-layer BP neural network, including an input layer, a hidden layer, and an output layer. When training the BP neural network, the bidirectional DC / DC converter can be tested in an open-loop start-up according to a series of frequencies and a series of duty cycles, and a sample space S is formed according to the final test results. The output voltage sampling value and current sampling value of each sample point in the sample space S are taken as input values, and the frequency and the primary and secondary duty cycles are used as the expected output values ​​to train the neural network. The BP neural network is a multi-layer feedforward neural network. It can learn the input-output mapping relationship through back propagation algorithm training and is widely used in tasks such as classification and regression. Its implementation details and training methods have relatively mature existing technologies, which will not be repeated here. More specifically, when training the BP neural network, after a series of open-loop experiments, by setting different operating frequencies and primary and secondary duty ratios, a series of output voltages and resonant tank currents are obtained, and then the series of output voltages and resonant tank currents are used as input quantities of the BP neural network, and the operating frequency and the primary and secondary duty ratios are used as the desired output quantities to train the BP neural network. In actual use, the output voltage sampling value of the current bidirectional DC / DC converter is used as the starting value, the preset curve is used as the first input quantity, and a smaller resonant tank current is used as the second input quantity, which are input into the trained BP neural network to obtain the operating frequency, the predicted value of the primary and secondary duty ratios, and at the same time, a certain limit should be made to the output quantity of the BP neural network.

[0035] According to the technical solution provided in the present application, the overall gain is kept monotonic in the later stage of the duty cycle increase, the state switching gain is smooth, and no large impact current is generated. At the same time, the influence of the reverse gain is also taken into account and a variable frequency modulation method is adopted and added at the same time, so that the overall gain continues to increase. When the duty cycle reaches the maximum, this stage can be ended to ensure that the gain in this stage is still increasing, and the output voltage can still continue to increase without overshoot. Figure 4 FIG. 1 is a schematic diagram of the relationship between duty cycle and output voltage and duty cycle and frequency in the pulse width frequency hybrid modulation stage provided by an embodiment of the present application. Figure 4 As shown in the figure, the duty cycle at point B reaches the maximum, and the frequency when the duty cycle reaches the maximum value is recorded as the second switching point frequency The selection of operating frequency and output voltage can be determined according to the actual debugging results.

[0036] S203, when the duty ratios of the primary and secondary sides are kept at the maximum value, the operating frequency is adjusted according to the load condition of the bidirectional DC / DC converter, and the bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

[0037] S203 corresponds to the third stage in the soft start process provided by this application. The third stage is recorded as the variable frequency modulation stage. In this stage, the closed loop output is only related to the frequency, and the frequency changes with the load, and then enters the steady-state working stage. The duty cycle has reached the maximum in this stage, and the required working frequency can be determined directly according to the working state (i.e., load state) at this moment. At this point, the soft start process of the entire converter is over. The whole process switches smoothly, the gain is monotonic, no large impact is generated, and no large circulating current will be generated. Figure 5 It is a schematic diagram of the changing relationship between voltage, frequency, and duty cycle in the variable frequency modulation stage provided by an embodiment of the present application.

[0038] It should be noted that Figure 3-Figure 5 The curve in the figure is a schematic curve. The actual curve equation is obtained by debugging and fitting in actual applications, and it only needs to meet the monotonicity.

[0039] So far, the Figure 2 Description of the process shown.

[0040] based on Figure 2 The process shown in the figure inserts a frequency modulation and duty cycle adjustment process (i.e. the pulse width frequency mixed modulation stage mentioned above) between the fixed frequency and frequency modulation stages of the converter soft start process, in order to solve the problem that the overall gain is not monotonic due to the non-monotonic reverse gain during the duty cycle increase process. In the pulse width frequency mixed modulation stage, the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter are predicted through the BP neural network according to the real-time voltage sampling value and current sampling value, so as to adjust the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter. This method makes the overall gain of the entire bidirectional DC / DC converter soft start process monotonic, the state transition is smooth, and there is no large impact current. It is a soft start method that can adapt to various working conditions.

[0041] Corresponding to the bidirectional DC / DC converter soft start method described in the above embodiment, Figure 6 A structural block diagram of a bidirectional DC / DC converter soft start device provided in an embodiment of the present application is shown. For ease of explanation, only the parts related to the embodiment of the present application are shown.

[0042] Reference Figure 6 , the device comprises: Symmetrical pulse width modulation module 601, used to maintain the startup frequency , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle ; The pulse width frequency hybrid modulation module 602 is used to obtain the voltage sampling value in real time. And current sampling value , predict and adjust the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle ; The frequency conversion modulation module 603 is used to maintain the maximum duty ratio of the primary and secondary sides. In this case, the operating frequency is adjusted according to the load condition of the bidirectional DC / DC converter, and the bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

[0043] In one embodiment, the pulse width frequency hybrid modulation module 602 is specifically used for: By setting different operating frequencies and primary and secondary duty ratios of the bidirectional DC / DC converter, a series of voltage sampling values ​​are obtained through experiments. And current sampling value ; A series of voltage sampling values And current sampling value As input values ​​of the neural network model, the operating frequency of the bidirectional DC / DC converter and the primary and secondary duty ratios are used as expected output values ​​of the neural network model to train the neural network model; The current preset value and the voltage preset value are input into the trained neural network model to obtain the output predicted values ​​of the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter.

[0044] In one embodiment, the neural network model obtains the predicted values ​​of the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter according to a preset output voltage curve, while ensuring that the current is less than the current threshold, so that the output voltage of the bidirectional DC / DC converter using the predicted value conforms to the preset output voltage curve.

[0045] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units / modules are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0046] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0047] An embodiment of the present application also provides a computer device, which includes: at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor, wherein the processor implements the steps of any of the above-mentioned method embodiments when executing the computer program.

[0048] An embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0049] An embodiment of the present application provides a computer program product. When the computer program product runs on a mobile terminal, the mobile terminal can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0050] Figure 7 This is a schematic diagram of the structure of a computer device provided in one embodiment of the present application. Figure 7 As shown, the computer device of this embodiment includes: at least one processor 70 ( Figure 7 Only one is shown in the figure), a memory 71, and a computer program 72 stored in the memory 71 and executable on the at least one processor 70, wherein the processor 70 implements the steps of any of the above-mentioned visual programming method embodiments when executing the computer program 72.

[0051] The computer device may include, but is not limited to, a processor 70 and a memory 71. Those skilled in the art will appreciate that Figure 7It is only an example of a computer device and does not constitute a limitation of the computer device. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0052] The processor 70 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0053] In some embodiments, the memory 71 may be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. In other embodiments, the memory 71 may also be an external storage device of the computer device, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device. Further, the memory 71 may also include both an internal storage unit of the computer device and an external storage device. The memory 71 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory 71 may also be used to temporarily store data that has been output or is to be output.

[0054] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned various method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device that can carry the computer program code to the device / computer device, recording medium, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0055] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0056] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example 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 performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0057] In the embodiments provided in the present application, it should be understood that the disclosed apparatus / computer equipment and methods can be implemented in other ways. For example, the apparatus / computer equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of the apparatus or unit, which can be electrical, mechanical or other forms.

[0058] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0059] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A bidirectional DC / DC converter soft start method, characterized in that: include: Maintain startup frequency , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle ; According to the voltage sampling value collected in real time And current sampling value , predicting and adjusting the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle; When the duty ratios of the primary and secondary sides are kept at the maximum duty ratios, the operating frequency is adjusted according to the load condition of the bidirectional DC / DC converter, and the bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

2. The method according to claim 1, characterized in that Predicting the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter includes: By setting different operating frequencies and primary and secondary duty cycles of the bidirectional DC / DC converter, a series of voltage sampling values ​​are obtained through experiments. And current sampling value ; The series of voltage sampling values And current sampling value As input values ​​of the neural network model, the operating frequency of the bidirectional DC / DC converter and the primary and secondary duty ratios are used as expected output values ​​of the neural network model to train the neural network model; The current preset value and the voltage preset value are input into the trained neural network model to obtain the output predicted values ​​of the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter.

3. The method according to claim 2, characterized in that Under the premise of ensuring that the current is less than the current threshold, the neural network model obtains the predicted values ​​of the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter according to the preset output voltage curve, so that the output voltage of the bidirectional DC / DC converter using the predicted value conforms to the preset output voltage curve.

4. The method according to any one of claims 2 to 3, characterized in that: The neural network model is a BP neural network model, and the BP neural network model comprises an input layer, a hidden layer and an output layer.

5. The method according to any one of claims 1 to 3, characterized in that: The duty cycle of the bidirectional DC / DC converter is increased from 0 to the first switching point duty cycle In the process, the output voltage and duty cycle are positively correlated.

6. A bidirectional DC / DC converter soft start device, characterized in that: include: Symmetrical pulse width modulation module to maintain the starting frequency , increasing the duty cycle of the bidirectional DC / DC converter from 0 to the first switching point duty cycle ; Pulse width frequency hybrid modulation module is used to collect voltage sampling values ​​in real time And current sampling value , predicting and adjusting the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter until the primary and secondary duty ratios change from the first switching point duty ratio to the secondary duty ratio. Increase to the maximum duty cycle; The variable frequency modulation module is used to adjust the operating frequency according to the load condition of the bidirectional DC / DC converter while the primary and secondary duty cycles maintain the maximum duty cycles, so that the bidirectional DC / DC converter completes the soft start and enters the steady-state working stage.

7. The device according to claim 6, characterized in that The pulse width frequency hybrid modulation module is specifically used for: By setting different operating frequencies and primary and secondary duty cycles of the bidirectional DC / DC converter, a series of voltage sampling values ​​are obtained through experiments. And current sampling value ; The series of voltage sampling values And current sampling value As input values ​​of the neural network model, the operating frequency of the bidirectional DC / DC converter and the primary and secondary duty ratios are used as expected output values ​​of the neural network model to train the neural network model; The current preset value and the voltage preset value are input into the trained neural network model to obtain the output predicted values ​​of the operating frequency and the primary and secondary duty ratios of the bidirectional DC / DC converter.

8. The device according to claim 7, characterized in that Under the premise of ensuring that the current is less than the current threshold, the neural network model obtains the predicted values ​​of the operating frequency and the primary and secondary duty cycles of the bidirectional DC / DC converter according to the preset output voltage curve, so that the output voltage of the bidirectional DC / DC converter using the predicted value conforms to the preset output voltage curve.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 5 is implemented.

10. A computer program product, characterized in that When the computer program product is executed on a computer device, the computer device is caused to execute the method according to any one of claims 1 to 5.

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