Output voltage ripple control method of dual active bridge and related device

Abstract

The invention provides an output voltage ripple control method of a dual active bridge and a related device, and the method comprises the steps: a controller obtains a plurality of first circuit parameters and an (n-1) th ripple voltage peak-to-peak value under a current working condition, and the plurality of first circuit parameters comprise a plurality of jitter frequency related frequency values and a first phase shift angle; determining a phase shift angle regulation variable based on the (n-1) th ripple voltage peak-to-peak value; determining a second phase shift angle based on the phase shift angle regulation variable, the (n-1) th ripple voltage peak-to-peak value, the nth ripple voltage peak-to-peak value and the first phase shift angle; determining a target phase shift angle based on the second phase shift angle and the plurality of jitter frequency related frequency values; and when the frequency is turned to the (n + 1) th jitter frequency period, performing phase shift angle compensation operation based on the target phase shift angle. Therefore, when phase shift angle reverse compensation operation is carried out based on the ripple voltage peak-to-peak value, power transmission errors caused by frequency deviation are offset, the problem of output power unbalance at the moment of frequency change is relieved to a great extent, and the deterioration degree of output voltage ripples is reduced.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular, to an output voltage ripple control method and related device for a dual active bridge. Background Art

[0002] With the vigorous development of the new energy industry, the dual active bridge (DAB) converter has become an important power electronic device for electric vehicle fast charging and energy storage systems due to its high-efficiency bidirectional energy transfer ability. In the DAB converter, the rapid on / off operation of high-frequency switching devices generates extremely high current change rates and voltage change rates, resulting in voltage spikes and current harmonics at the switching nodes. These interferences propagate outward through conduction and radiation paths, causing electromagnetic interference (EMI). To suppress the electromagnetic interference caused by high-frequency switching, the frequency dithering control technology has become the mainstream EMI solution in the design of switching power supplies by dynamically adjusting the switching frequency to disperse harmonic energy.

[0003] However, the power transfer characteristics of the dual active bridge determine that its maximum output power is highly correlated with the switching frequency, and the actual output power is achieved by adjusting the phase shift angle. After adding the frequency dithering technology, the switching frequency will fluctuate periodically. To maintain the target output power, the phase shift angle must compensate for the frequency change in real time. However, this dynamic adjustment process exposes the problem of increased output voltage ripple in actual operation. The reason is that the sudden change of the switching frequency and the response delay of the phase shift angle control loop lead to power output imbalance, forming low-frequency voltage ripple on the output side. The introduction of the frequency dithering technology in the DAB converter has led to a significant deterioration of the output voltage ripple, and this contradiction limits the application of the DAB converter.

[0004] Currently, the methods of mainly increasing the output filter network or restricting the frequency dithering range are used to suppress the deterioration of the voltage ripple, but it will lead to an increase in the cost and volume of the converter, weaken the EMI improvement effect, and it is difficult to meet the requirements of some standards. Furthermore, the dynamic coupling relationship between the switching frequency and the output power is not decoupled or weakened, and the output power is imbalanced at the moment of frequency change, resulting in the problem that the deterioration of the output voltage ripple has not been optimized from the control level. Summary of the Invention

[0005] The embodiments of the present application provide an output voltage ripple control method and related device for a dual active bridge, which can greatly alleviate the output power imbalance problem at the moment of frequency change and reduce the degree of deterioration of the output voltage ripple.

[0006] In a first aspect, the embodiments of the present application provide an output voltage ripple control method for a dual active bridge, which is applied to a controller of a dual active bridge system and includes: Obtain a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th dither frequency period. The plurality of first circuit parameters include a plurality of dither frequency-related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th dither frequency period, where n is an integer greater than or equal to 2; Determine a phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage; Determine a second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth dither frequency period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth dither frequency period; Determine a target phase shift angle based on the second phase shift angle and the plurality of dither frequency-related frequency values. The target phase shift angle is the phase shift angle used for phase shift angle compensation. And when transitioning to the (n + 1)th dither frequency period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

[0007] In a possible embodiment, the determining the second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle includes: Determine a third phase shift angle based on the first phase shift angle and the phase shift angle regulation variable; Perform a compensation operation based on the third phase shift angle to obtain the peak-to-peak value of the nth ripple voltage generated by the compensation based on the third phase shift angle; Determine a phase shift angle adjustment strategy based on the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage. The phase shift angle adjustment strategy is used to adjust the first phase shift angle based on the phase shift angle regulation variable; Determine the second phase shift angle based on the phase shift angle adjustment strategy and the first phase shift angle.

[0008] In a possible embodiment, the determining the phase shift angle adjustment strategy based on the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage includes: If the peak-to-peak value of the nth ripple voltage is less than the peak-to-peak value of the (n - 1)th ripple voltage, then determine that the phase shift angle adjustment strategy is to perform a summation operation based on the phase shift angle regulation variable and the first phase shift angle; If the peak-to-peak value of the nth ripple voltage is greater than the peak-to-peak value of the (n - 1)th ripple voltage, then determine that the phase shift angle adjustment strategy is to perform a subtraction operation based on the phase shift angle regulation variable and the first phase shift angle.

[0009] In a possible embodiment, determining the phase-shift angle regulation variable based on the peak-to-peak value of the (n-1)th ripple voltage includes: Obtain a plurality of second circuit parameters under the current working condition, where the second circuit parameters include performance parameters of the dual-active-bridge system, and the performance parameters include a response speed parameter and / or a stability parameter; Determine a phase-shift angle regulation parameter based on the second circuit parameters, where the phase-shift angle regulation parameter is associated with the plurality of second circuit parameters of the dual-active-bridge system; Determine the phase-shift angle regulation variable based on the phase-shift angle regulation parameter and the peak-to-peak value of the (n-1)th ripple voltage.

[0010] In a possible embodiment, determining the phase-shift angle regulation parameter based on the second circuit parameters includes: Determine a transfer function based on a preset small-signal model and circuit information parameters, where the transfer function is used to reflect the dynamic influence of the duty-cycle perturbation on the output voltage, and the duty-cycle perturbation is a perturbation generated by regulating the first phase-shift angle based on the phase-shift angle regulation variable; Determine the phase-shift angle regulation parameter based on the transfer function, a regulation parameter regulation calculation model, and the second circuit parameters, where the regulation parameter calculation model is used to constrain the association relationship between the phase-shift angle regulation parameter and the plurality of second circuit parameters and the boundary threshold of the regulation parameter, and the boundary threshold of the regulation parameter is used to constrain the maximum and minimum values of the phase-shift angle regulation parameter.

[0011] In a possible embodiment, determining the phase-shift angle regulation variable based on the peak-to-peak value of the (n-1)th ripple voltage further includes: Determine a first simulation result based on the phase-shift angle regulation parameter and a preset simulation regulation model, where the first simulation result is used to characterize the change trend of the simulated peak-to-peak value of the nth ripple voltage of the dual-active-bridge system if the phase-shift angle regulation parameter is adopted, and the preset simulation regulation model is a model for simulating the dual-active-bridge system; Determine an nth simulation response rate parameter based on the first simulation result, where the nth simulation response rate parameter is used to characterize the response speed of the simulated peak-to-peak value of the nth ripple voltage within a preset time length, and the preset time length is a preset desired response time length; If the nth simulation response rate parameter is not within the preset response rate threshold range, then fine-tune based on the phase-shift angle regulation variable; if the nth simulation response rate parameter is within the preset response rate threshold range, then determine the phase-shift angle regulation variable.

[0012] In a possible embodiment, the multiple frequency hopping related frequency values include at least one of a switching frequency, a frequency hopping frequency, a frequency hopping frequency upper limit, and a frequency hopping frequency lower limit. The switching frequency is a dynamically variable quantity, and the frequency hopping frequency, the frequency hopping frequency upper limit, and the frequency hopping frequency lower limit are static quantities. Determining the target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values includes: Determine a proportionality coefficient based on the second phase shift angle, the frequency hopping frequency upper limit, the frequency hopping frequency lower limit, and a proportionality coefficient formula, where the proportionality coefficient formula includes: , where is the proportionality coefficient, is the second phase shift angle, is the frequency hopping frequency upper limit, is the frequency hopping frequency lower limit; Determine the target phase shift angle based on the proportionality coefficient, the switching frequency, the frequency hopping frequency, and a target phase shift angle formula, where the target phase shift angle formula includes: , where f is the switching frequency, is the frequency hopping frequency.

[0013] In a second aspect, an output voltage ripple control device for a dual active bridge provided by an embodiment of the present application is applied to a controller of a dual active bridge system. The device includes: An acquisition module, configured to acquire a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th frequency hopping period. The plurality of first circuit parameters include a plurality of frequency hopping related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th frequency hopping period, where n is an integer greater than or equal to 2; A first determination module, configured to determine a phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage; A second determination module, configured to determine a second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth frequency hopping period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth frequency hopping period; A third determination module, configured to determine a target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values. The target phase shift angle is the phase shift angle used for phase shift angle compensation; and when transitioning to the (n + 1)th frequency hopping period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

[0014] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, on which a program for controlling the output voltage ripple of a dual active bridge is stored. The program for controlling the output voltage ripple of the dual active bridge includes execution instructions, and when the execution instructions are executed by a processor, the processor executes some or all of the steps described in the first aspect.

[0015] In a fourth aspect, an embodiment of the present application provides an electronic device, including a processor, a memory, a communication interface, and one or more programs. Among them, the above one or more programs are stored in the above memory and are configured to be executed by the above processor. When the one or more programs are executed by the processor, the processor executes some or all of the steps described in the first aspect.

[0016] In a fifth aspect, an embodiment of the present application provides a computer program product. Among them, the computer program product includes a non-transitory computer-readable storage medium storing a computer program, and the computer program is operable to cause a computer to execute some or all of the steps described in the first aspect of the embodiments of the present application. The computer program product can be a software installation package.

[0017] By implementing the embodiments of the present application, the controller obtains a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th frequency hopping period. The plurality of first circuit parameters include a plurality of frequency values related to frequency hopping and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th frequency hopping period, where n is an integer greater than or equal to 2; determining a phase shift angle adjustment variable based on the peak-to-peak value of the (n - 1)th ripple voltage; determining a second phase shift angle based on the phase shift angle adjustment variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth frequency hopping period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth frequency hopping period; determining a target phase shift angle based on the second phase shift angle and the plurality of frequency values related to frequency hopping. The target phase shift angle is the phase shift angle used for phase shift angle compensation; and when transitioning to the (n + 1)th frequency hopping period, performing a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple. In this way, when performing a reverse phase shift angle compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the output power imbalance problem during the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the following will describe the drawings required for use in the embodiments of the present invention or the background art.

[0019] Figure 1a is a schematic structural diagram of a dual-active-bridge system provided by an embodiment of the present application; Figure 1b is a schematic structural diagram of a main circuit module of a dual-active bridge provided by an embodiment of the present application; Figure 2 is a schematic flowchart of a method for controlling the output voltage ripple of a dual-active bridge provided by an embodiment of the present application; Figure 3 is a schematic flowchart of a method for determining a phase-shift angle regulation variable provided by an embodiment of the present application; Figure 4 is a schematic flowchart of another method for controlling the output voltage ripple of a dual-active bridge provided by an embodiment of the present application; Figure 5 is a schematic structural diagram of a device for controlling the output voltage ripple of a dual-active bridge proposed by an embodiment of the present application; Figure 6 is a schematic structural diagram of another device for controlling the output voltage ripple of a dual-active bridge provided by an embodiment of the present application; Figure 7 is a schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0020] In order to enable those skilled in the art of the present technology to better understand the solution of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0021] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or electronic device that includes a series of steps or units is not limited to the listed steps or units, but in an alternative example, it further includes steps or units not listed, or in an alternative example, it further includes other steps or units inherent to these processes, methods, products, or electronic devices.

[0022] References to "embodiments" in this specification mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] The power transmission characteristics of the dual-active bridge determine that its maximum output power is highly correlated with the switching frequency, and the actual output power is achieved by adjusting the phase-shift angle. After adding the frequency dithering technique, the switching frequency will exhibit periodic fluctuations. To maintain the target output power, the phase-shift angle must compensate for the frequency change in real time. However, this dynamic adjustment process exposes the problem of increased output voltage ripple during actual operation. The reason is that there are sudden changes in the switching frequency and a delay in the response of the phase-shift angle control loop, resulting in power output imbalance and forming low-frequency voltage ripple on the output side. The introduction of the frequency dithering technique in the dual-active bridge converter has led to a significant deterioration of the output voltage ripple, and this contradiction limits the application of the dual-active bridge converter.

[0024] Currently, the methods mainly used to suppress the deterioration of voltage ripple are to increase the output filter network or limit the frequency dithering range, but this will lead to an increase in the cost and volume of the converter, weaken the EMI improvement effect, and it is difficult to meet the requirements of some standards. Furthermore, the dynamic coupling relationship between the switching frequency and the output power is not decoupled or weakened, and the output power is imbalanced at the moment of frequency change, resulting in the problem that the deterioration of the output voltage ripple cannot be optimized from the control level.

[0025] In view of the above problems, the embodiments of the present application provide a method and related device for controlling the output voltage ripple of a dual-active bridge. When performing a reverse compensation operation on the phase-shift angle based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the degree of deterioration of the output voltage ripple is reduced.

[0026] The method for controlling the output voltage ripple of the dual-active bridge provided by the embodiments of the present application can be applied to a dual-active bridge system as Figure 1a shown. Please refer to Figure 1a , Figure 1a which is a schematic diagram of the architecture of a dual-active bridge system provided by the embodiments of the present application. The dual-active bridge system 100 includes a dual-active bridge main circuit module 110 and a controller 120. The dual-active bridge main circuit module 110 can communicate with the controller 120 through a network and accept the control of the controller 120.

[0027] In this solution, the controller 120 refers to a computer used to handle a large number of computing tasks, store data, and perform control operations. In this solution, multiple models are deployed on the controller 120, and the controller 120 can also be used to collect data during the use of the models for controlling the output voltage ripple of the dual-active bridge. The controller 120 can send control information to the dual-active bridge main circuit module 110 so that the corresponding components in the dual-active bridge main circuit module 110 operate according to the value obtained after phase-shift angle compensation.

[0028] Please refer to Figure 1b , Figure 1b which is a schematic diagram of the architecture of a dual-active bridge main circuit module provided by an embodiment of the present application. As Figure 1b shown, the forward transmission direction is defined as to . The dual-active bridge main circuit module 110 includes an input DC source voltage , an output voltage , an input bus filter capacitor , an output bus filter capacitor , multiple switching tubes, a energy storage inductor , a DC-blocking capacitor and , a main transformer ; among them, the multiple switching tubes include , is a primary-side energy transfer switching tube, is a secondary-side energy transfer switching tube, and the turns ratio of the main transformer is n:1; among them, the transmission power of the dual-active bridge is , where is the switching frequency, D is the phase-shift angle of the primary and secondary square-wave voltages, and its output power is related to the input voltage, output voltage, and frequency. After adding frequency dithering control, the switching frequency changes periodically with time. As a result, when the input voltage, output voltage, etc. remain unchanged, due to the delay in the phase-shift angle control loop, the output power and the switching frequency will show the same periodic change. As the frequency increases, the transmission power decreases and the output voltage decreases; as the frequency decreases, the transmission power increases and the output voltage increases. Based on the above architecture, this solution proposes a control strategy for the dual-active bridge under frequency dithering control to adjust and compensate the above phase-shift angle.

[0029] Based on this, the present application provides a method and related device for controlling the output voltage ripple of a dual-active bridge. The present application will be described in detail below with reference to the accompanying drawings.

[0030] Please refer to Figure 2 , Figure 2It is a schematic flowchart of a method for controlling the output voltage ripple of a dual active bridge provided by an embodiment of the present application, which is applied to a controller of a dual active bridge system, such as Figure 2 As shown, the method includes the following steps: S210, obtaining a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition, where the peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th switching frequency modulation period. The plurality of first circuit parameters include a plurality of switching frequency modulation related frequency values and a first phase shift angle, and the first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th switching frequency modulation period, where n is an integer greater than or equal to 2.

[0031] Among them, the current working condition refers to the actual operating state of a power electronic device (such as a DC-DC converter, an inverter, etc.) at a certain moment, including parameters such as input voltage, load, and switching frequency. The peak-to-peak value of the ripple voltage refers to the difference between the peak value and the valley value of the ripple component in the output voltage, reflecting the amplitude of voltage fluctuation. The switching frequency modulation period refers to the period of dynamic adjustment of the switching frequency, which is usually used for soft switching optimization or efficiency regulation. The first circuit parameters are circuit parameters related to switching frequency modulation control, including switching frequency modulation related frequency values and a first phase shift angle. Numbered in order with the switching frequency modulation period as the unit (n = 2, 3,...), the (n - 1)th switching frequency modulation period is a certain period of the entire period changing with time. When it is currently within the nth switching frequency modulation period, the specific value of the phase shift angle that needs to be compensated is calculated through the maximum phase shift angle, that is, the first phase shift angle, obtained within the (n - 1)th switching frequency modulation period by the control strategy or closed-loop feedback within the (n - 1)th switching frequency modulation period.

[0032] S220, determining a phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage.

[0033] Among them, the phase shift angle regulation variable is associated with the current working condition and the actual situation of the dual active bridge system; the phase shift angle regulation variable is used to determine a second phase shift angle, the phase shift angle regulation variable can be dynamically determined, and the phase shift angle regulation variable is a variable constant value.

[0034] In a possible embodiment, determining the phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage includes: obtaining a plurality of second circuit parameters under the current working condition, where the second circuit parameters include performance parameters of the dual active bridge system, and the performance parameters include a response speed parameter and / or a stability parameter; determining a phase shift angle regulation parameter based on the second circuit parameters, where the phase shift angle regulation parameter is associated with the plurality of second circuit parameters of the dual active bridge system; and determining the phase shift angle regulation variable based on the phase shift angle regulation parameter and the peak-to-peak value of the (n - 1)th ripple voltage.

[0035] Among them, the second circuit parameter can be determined based on a small-signal model or directly obtained preset. The above small-signal model can be a pre-trained model obtained by training based on circuit topology and relevant circuit information. The second circuit parameter can be a performance parameter of the dual-active-bridge system. The performance parameter can be used to characterize the performance of the dual-active-bridge system, such as transmission speed and stability. The performance parameter can be at least one of a response speed parameter and a stability parameter. Among them, the response speed parameter can be the bandwidth , and the phase-shift angle regulation variable can be the phase margin , among which, the bandwidth is higher, the stronger the system's ability to track fast inputs. The phase margin is higher, the stronger the system's ability to resist interference and model uncertainty. However, too high a bandwidth may amplify noise and may cause overshoot or oscillation, and too large a phase margin may sacrifice the response speed (such as reducing the bandwidth). The above second circuit parameter is dynamically variable. When the circuit is regulated based on some parameters, such as the target phase-shift angle required by this solution, the actual second circuit parameter in the circuit may also change. The changed second circuit parameter can be determined based on the current actual situation within each dither frequency period.

[0036] Among them, the phase-shift angle regulation parameter is associated with the second circuit parameter. Specifically, the phase-shift angle regulation parameter has a proportional relationship with multiple second circuit parameters. Based on this relationship, the value of the phase-shift angle regulation parameter is determined. Then, based on the phase-shift angle regulation parameter and the peak-to-peak value of the (n - 1)th ripple voltage, the phase-shift angle regulation variable is regulated.

[0037] Among them, the phase-shift angle regulation variable can be determined based on the following formula, the phase-shift angle regulation parameter, and the peak-to-peak value of the (n - 1)th ripple voltage: D cycle =k×V pp (n - 1), where D cycle is the phase-shift angle regulation variable, k is the phase-shift angle regulation parameter, and V pp (n - 1) is the peak-to-peak value of the (n - 1)th ripple voltage. By the dynamically adjustable phase-shift angle regulation parameter k and D cycle dynamically determined based on k, the compensation of the phase-shift angle can be made more accurate.

[0038] Among them, if a small-signal model is used to determine multiple second circuit parameters, first, the small-signal model is determined. The small-signal model is based on an equivalent circuit constructed from the circuit of the actual dual-active-bridge system. The equivalent circuit includes multiple key working variables. The multiple key working variables include the duty cycle D, the input voltage V g , and the load current I o . In the model, small-signal perturbations are applied to the above multiple key working variables: , , , where, , , is the small-signal perturbation quantity, , , are the key operating variables under steady state; perform Taylor expansion on the above and retain the first-order small-signal terms, ignoring the higher-order terms, to obtain multiple linearized equations. Then, based on the above linearized equations, convert them into an equivalent circuit model. Apply circuit analysis methods (such as Kirchhoff's laws, Laplace transform) to the small-signal equivalent circuit to find the output variables and output variables. Determine the transfer function based on the output variables and input variables, and the transfer function is , where, is the output variable, is the input variable. The transfer function describes the dynamic influence of the duty cycle perturbation on the output voltage perturbation , such that the determination of the k value meets the requirement of not having an adverse effect on the output voltage.

[0039] Among them, if proportional control is adopted, the second circuit parameter includes the bandwidth , based on the bandwidth substitute it into the transfer function, then the determination method of the k value can be the following formula: . First, obtain a preset k value, or the k determined in the (n - 1)th dithering period, and then based on this (such as ), gradually increase it and observe the system response. When the load suddenly changes, the output voltage recovery time is short and there is no oscillation; at steady state, the ripple V pp meets the requirements.

[0040] It can be seen that in this embodiment, by the phase-shift angle regulation parameter k that can be dynamically regulated and the D dynamically determined based on the dynamically regulated k cycle the compensation of the phase-shift angle can be made more accurate. Furthermore, when performing phase-shift angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0041] In a possible embodiment, the determining the phase-shift angle regulation parameter based on the second circuit parameter includes: determining a transfer function based on a preset small-signal model and circuit information parameters, where the transfer function is used to reflect the dynamic influence of the duty-cycle perturbation on the output voltage, and the duty-cycle perturbation is the perturbation generated by regulating the first phase-shift angle based on the phase-shift angle regulation variable; determining the phase-shift angle regulation parameter based on the transfer function, the regulation parameter regulation calculation model, and the second circuit parameter, where the regulation parameter calculation model is used to constrain the association relationship between the phase-shift angle regulation parameter, the multiple second circuit parameters, and the regulation parameter boundary threshold, and the regulation parameter boundary threshold is used to constrain the maximum and minimum values of the phase-shift angle regulation parameter.

[0042] Among them, the specific description of the small-signal model can refer to the specific explanation in the above embodiment and will not be elaborated here. The regulation parameter calculation model is used to constrain the association relationship between the phase-shift angle regulation parameter, the multiple second circuit parameters, and the regulation parameter boundary threshold. Ensure that the phase-shift angle regulation parameter k does not exceed the maximum and minimum values of the preset phase-shift angle regulation parameter k to avoid system out-of-control. The boundary threshold is used to limit the value range of the phase-shift angle regulation parameter k. For example: the maximum value k max : Prevent the phase-shift angle from being too large, which may deteriorate the soft-switching condition or increase the switching loss; the minimum value k min : Prevent the phase-shift angle from being too small, which may increase the ripple voltage or decrease the efficiency. If it is detected that the k value is greater than the maximum value k max , then the output k = the maximum value k max ; if it is detected that the k value is less than the minimum value k min , then the output k = the minimum value k min .

[0043] It can be seen that in this embodiment, by analyzing the influence of the duty-cycle perturbation on the output voltage through the small-signal model and the transfer function, combining the real-time circuit parameters and the regulation model to dynamically adjust the phase-shift angle regulation parameter k, and ensuring the stable operation of the system through the constraint of the boundary threshold. Furthermore, when performing the phase-shift angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by the frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0044] In a possible embodiment, please refer to Figure 3 , Figure 3 which is a schematic flow diagram of determining the phase-shift angle regulation variable provided by an embodiment of the present application. As Figure 3 shown, the determining the phase-shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage further includes: S221. Determine a first simulation result based on the phase-shift angle regulation parameter and a pre-set simulation regulation model. The first simulation result is used to characterize the change trend of the peak-to-peak value of the n-th ripple voltage of the dual-active-bridge system if the phase-shift angle regulation parameter is adopted. The pre-set simulation regulation model is a model that simulates the dual-active-bridge system. Determine an n-th simulation response rate parameter based on the first simulation result. The n-th simulation response rate parameter is used to characterize the response speed of the peak-to-peak value of the n-th ripple voltage within a pre-set time length, and the pre-set time length is a pre-set desired response time length.

[0045] S222. If the n-th simulation response rate parameter is not within the pre-set response rate threshold range, then fine-tune based on the phase-shift angle regulation variable.

[0046] S223. If the n-th simulation response rate parameter is within the pre-set response rate threshold range, then determine the phase-shift angle regulation variable.

[0047] Among them, a pre-established dynamic model of the dual-active-bridge system is used to simulate the influence of the phase-shift angle Dn on the ripple voltage. The pre-established dynamic model of the dual-active-bridge system is associated with the above-mentioned small-signal model. Input the determined phase-shift angle regulation variable into the dynamic model of the dual-active-bridge system. By inputting the k value, predict the simulated value of the n-th ripple and analyze its change trend (such as the rising / falling rate), that is, the n-th simulation response rate parameter. The n-th simulation response rate parameter can be determined through data analysis or through linear fitting, which is not limited herein. The specific determination method can be through the following formula: ; Among them, is the n-th simulation response rate parameter, is the first simulation result, and T PP is the pre-set time length. R n The larger it is, the faster the ripple changes within T PP (it may overshoot or oscillate); the smaller R n is, the slower the ripple changes (response lags). T PP Usually matches the control period or the system dynamic characteristics, that is, it can correspond to the dither frequency period. If R n responds too slowly, that is, , increase k to accelerate the response; if responds too fast, that is, , decrease k to slow down the change. Re-simulate after fine-tuning until R n enters the pre-set response rate threshold range . If , confirm that the current k is an effective regulation variable and apply it to the actual system.

[0048] It can be seen that in this embodiment, by simulating and regulating the influence of the d value determined by the model on the phase-shifting angle and the ripple voltage, and combining the response rate parameter to evaluate the regulation effect, the optimal k value can be quickly determined and output, avoiding overshoot or oscillation caused by blind adjustment in the actual system. Moreover, by combining the feedforward parameter and various constraint conditions, the determination of the k value can be made more stable and reliable. Furthermore, when performing the phase-shifting angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency deviation, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0049] S230. Determine a second phase-shifting angle based on the phase-shifting angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase-shifting angle. The second phase-shifting angle is the optimal compensation phase-shifting angle within the nth dithering frequency period under the current working condition, and the peak-to-peak value of the nth ripple voltage is the difference between the peak and valley values of the ripple voltage within the nth dithering frequency period.

[0050] Among them, a phase-shifting angle for the current nth dithering frequency period is determined based on the above-mentioned determined phase-shifting angle regulation variable and the first phase-shifting angle. Specifically, it can be to increase or decrease this phase-shifting angle regulation variable on the basis of the first phase-shifting angle. Then, based on this, the current nth dithering frequency period is carried out to obtain the peak-to-peak value of the nth ripple voltage under the current nth dithering frequency period.

[0051] Among them, based on the relationship between the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage, a phase-shifting angle adjustment strategy is determined. Specifically, the relationship between the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage can be: the peak-to-peak value of the nth ripple voltage is greater than the peak-to-peak value of the (n - 1)th ripple voltage, or the peak-to-peak value of the nth ripple voltage is less than the peak-to-peak value of the (n - 1)th ripple voltage. The phase-shifting angle adjustment strategy can be to increase or subtract the phase-shifting angle regulation variable. Based on this, the second phase-shifting angle is determined. The second phase-shifting angle is the optimal compensation phase-shifting angle for the (n + 1)th dithering frequency period. It should be noted that within the (n + 1)th dithering frequency period, all the above steps are carried out based on the second phase-shifting angle. That is, this scheme is a repetitive cycle process, and the above operations are carried out in each cycle, making the phase-shifting angle more and more accurate, and minimizing the offset degree of the output voltage ripple to the greatest extent.

[0052] In a possible embodiment, determining the second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)-th ripple voltage, the peak-to-peak value of the n-th ripple voltage, and the first phase shift angle includes: determining a third phase shift angle based on the first phase shift angle and the phase shift angle regulation variable; performing a compensation operation based on the third phase shift angle to obtain the peak-to-peak value of the n-th ripple voltage generated by compensating based on the third phase shift angle; determining a phase shift angle adjustment strategy based on the peak-to-peak value of the n-th ripple voltage and the peak-to-peak value of the (n - 1)-th ripple voltage, where the phase shift angle adjustment strategy is used to adjust the first phase shift angle based on the phase shift angle regulation variable; and determining the second phase shift angle based on the phase shift angle adjustment strategy and the first phase shift angle.

[0053] Among them, the third phase shift angle is determined by adding or subtracting the phase shift angle regulation variable to / from the first phase shift angle: D max(n) =D max(n-1) +D cycle（n-1） , where D cycle（n-1） is the phase shift angle regulation variable, D max(n-1) is the first phase shift angle, and D max(n) is the third phase shift angle. Control works based on this third phase shift angle, and then the peak-to-peak value of the n-th ripple voltage is obtained; it is judged whether the peak-to-peak value of the n-th ripple voltage is greater than the peak-to-peak value of the (n - 1)-th ripple voltage, or the peak-to-peak value of the n-th ripple voltage is less than the peak-to-peak value of the (n - 1)-th ripple voltage. If the peak-to-peak value of the n-th ripple voltage is greater than the peak-to-peak value of the (n - 1)-th ripple voltage, the phase shift angle adjustment strategy is to subtract the phase shift angle regulation variable; if the peak-to-peak value of the n-th ripple voltage is less than the peak-to-peak value of the (n - 1)-th ripple voltage, the phase shift angle adjustment strategy is to add the phase shift angle regulation variable.

[0054] Specifically, determining the phase shift angle adjustment strategy based on the peak-to-peak value of the n-th ripple voltage and the peak-to-peak value of the (n - 1)-th ripple voltage includes: if the peak-to-peak value of the n-th ripple voltage is less than the peak-to-peak value of the (n - 1)-th ripple voltage, determining the phase shift angle adjustment strategy as performing a summation operation based on the phase shift angle regulation variable and the first phase shift angle; if the peak-to-peak value of the n-th ripple voltage is greater than the peak-to-peak value of the (n - 1)-th ripple voltage, determining the phase shift angle adjustment strategy as performing a subtraction operation based on the phase shift angle regulation variable and the first phase shift angle.

[0055] It can be seen that in this embodiment, through the closed-loop logic of "preliminary adjustment → real-time compensation → strategy adjustment → final determination", combined with the feedback of the peak-to-peak values of the (n - 1)-th and n-th ripple voltages, the optimal phase shift angle within each period is dynamically determined, ensuring that the peak-to-peak value of the ripple voltage is minimized and stable under the current working conditions, while improving the dynamic response speed and robustness of the system.

[0056] S240. Determine a target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values, where the target phase shift angle is the phase shift angle used for phase shift angle compensation; and when transitioning to the (n + 1)-th frequency hopping period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

[0057] Among them, the multiple frequency hopping related frequency values may include the upper limit of the frequency hopping frequency, the lower limit of the frequency hopping frequency. When transmitting power in the forward direction, the transmission power of the dual-active-bridge system increases with the increase of the phase shift angle of the primary and secondary square-wave voltages. Therefore, at the frequency hopping frequency , the compensation value is negative; at the frequency hopping frequency , the compensation value is positive. The upper limit of the frequency hopping frequency is , the lower limit of the frequency hopping frequency is , the maximum compensation value of the phase shift angle is , and in the n-th frequency hopping period, it is . During the process where the switching frequency changes from to , the phase shift angle compensation value , that is, the target phase shift angle linearly changes from the second phase shift angle to the negative second phase shift angle .

[0058] Among them, if the multiple frequency hopping related frequency values are known parameters, then determining the second phase shift angle can determine the target phase shift angle. Determine the corresponding second phase shift angle and the target phase shift angle in each hopping period, thereby reducing the offset degree of the output voltage ripple during operation.

[0059] In a possible embodiment, the multiple frequency hopping related frequency values include at least one of the switching frequency, the frequency hopping frequency, the upper limit of the frequency hopping frequency, and the lower limit of the frequency hopping frequency. The switching frequency is a dynamic variable, and the frequency hopping frequency, the upper limit of the frequency hopping frequency, and the lower limit of the frequency hopping frequency are static variables. The determining the target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values includes: determining a proportionality coefficient based on the second phase shift angle, the upper limit of the frequency hopping frequency, the lower limit of the frequency hopping frequency, and a proportionality coefficient formula, where the proportionality coefficient formula includes: , where is the proportionality coefficient, is the second phase shift angle, is the upper limit of the frequency hopping frequency, is the lower limit of the frequency hopping frequency; determining the target phase shift angle based on the proportionality coefficient, the switching frequency, the frequency hopping frequency, and a target phase shift angle formula, where the target phase shift angle formula includes: , where f is the switching frequency, is the frequency hopping frequency.

[0060] Among them, the switching frequency is a predictable quantity, and the second phase-shifting angle is the quantity calculated in the above embodiments. Based on this, the value of the target phase-shifting angle can be determined. .

[0061] Among them, the switching frequency f is the switching frequency of the power switching tubes in the dual active bridge (DAB), which is a dynamically varying quantity (varying with the working conditions or control requirements). The frequency jitter The frequency used to modulate the jitter of the switching frequency is a static quantity (a fixed value), and the upper limit of the frequency jitter is the maximum value allowed for the frequency jitter, which is a static quantity. The lower limit of the frequency jitter is the minimum value allowed for the frequency jitter, which is a static quantity. The proportionality coefficient F correlates the phase-shifting angle change with the frequency jitter range and is used for the subsequent linear mapping of the switching frequency. According to the deviation between the current switching frequency f and the frequency jitter , it is linearly mapped to the target phase-shifting angle through the proportionality coefficient F .

[0062] Specifically, this formula can also be written as: ; For example, please refer to Figure 4 , Figure 4 which is a schematic flowchart of another output voltage ripple control method for the dual active bridge provided by the embodiments of this application. Please refer to Figure 4 , the specific implementation manner of the control method of the present invention is based on the digital control chip of the dual active bridge power module and is realized through the following detailed control process: S401, the dual active bridge topology power supply starts up, and the control process begins.

[0063] S402, initialize relevant control variables, sample the output voltage in real time, and calculate the peak-to-peak value of the ripple voltage within each frequency jitter period.

[0064] S403, calculate the phase-shifting angle regulation variable in real time according to the output voltage ripple.

[0065] Among them, the phase-shifting angle regulation variable D cycle = k × V pp ; where is a constant with a dimension of . It is necessary to select an appropriate k value in combination with the actual model and limit D cycle to ensure that the dynamic response speed and the steady-state ripple meet the design requirements. Calculate according to , and perform compensation on the loop output result in real time to obtain the phase-shifting angle .

[0066] S404. Increase the phase-shift angle regulation variable.

[0067] Among them, the increased phase-shift angle is increased based on the currently existing phase-shift angle. That is, if the current is , then on the basis of , increase the phase-shift angle regulation variable to obtain .

[0068] S405. Compare the peak-to-peak voltage ripple within one dither frequency period before and after increasing the phase-shift angle regulation variable.

[0069] Among them, it is to compare the peak-to-peak voltage ripple within the nth dither frequency period and the (n - 1)th dither frequency period.

[0070] Among them, if the peak-to-peak voltage ripple of the nth dither frequency period is less than that of the (n - 1)th dither frequency period, that is, V pp(n) < V pp(n-1) , then repeat item S404. If the peak-to-peak voltage ripple of the nth dither frequency period is greater than that of the (n - 1)th dither frequency period, that is, V pp(n) > V pp(n-1) , then execute item S406.

[0071] S406. Decrease the phase-shift angle regulation variable.

[0072] S407. Compare the peak-to-peak voltage ripple within one dither frequency period before and after decreasing the phase-shift angle regulation variable.

[0073] Among them, if the peak-to-peak voltage ripple of the nth dither frequency period is less than that of the (n - 1)th dither frequency period, that is, V pp(n) < V pp(n-1) , then repeat item S406. If the peak-to-peak voltage ripple of the nth dither frequency period is greater than that of the (n - 1)th dither frequency period, that is, V pp(n) > V pp(n-1) , then execute item S408.

[0074] S408. Increase the phase-shift angle regulation variable.

[0075] S409. Obtain the optimal third phase-shift angle under the current working condition, so that the peak-to-peak output ripple gradually approaches the minimum.

[0076] S410. Detect whether the working condition has changed.

[0077] Among them, if it is detected that the working condition has changed, then execute item S404. If it is not detected that the working condition has changed, then execute item S411.

[0078] S411. The process ends.

[0079] It can be seen that, in this embodiment, this step associates the second phase shift angle with the dither frequency range through a proportionality coefficient, and then linearly maps to obtain the target phase shift angle according to the deviation between the current switching frequency and the dither frequency. This design realizes the dynamic adjustment of the phase shift angle, ensures that the ripple voltage remains stable when the switching frequency changes, and at the same time improves the robustness and response speed of the system. Furthermore, when performing a phase shift angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, it greatly alleviates the output power imbalance problem at the moment of frequency change and reduces the deterioration degree of the output voltage ripple.

[0080] In a possible embodiment, when transitioning to the (n + 1)-th dither cycle, the output voltage ripple control method of the dual-active bridge includes: obtaining a plurality of first circuit parameters and the n-th ripple voltage peak-to-peak value under the current working condition, where the n-th ripple voltage peak-to-peak value is the difference between the peak value and the valley value of the ripple voltage within the n-th dither cycle, and the plurality of first circuit parameters include a plurality of dither-related frequency values and a fourth phase shift angle, that is, the above-mentioned target phase shift angle, which is described as the first target phase shift angle at this time; determining a phase shift angle regulation variable based on the n-th ripple voltage peak-to-peak value; determining a fifth phase shift angle based on the phase shift angle regulation variable, the n-th ripple voltage peak-to-peak value, the (n + 1)-th ripple voltage peak-to-peak value, and the fourth phase shift angle, where the fifth phase shift angle is the optimal compensation phase shift angle within the (n + 2)-th dither cycle under the current working condition, and the (n + 1)-th ripple voltage peak-to-peak value is the difference between the peak value and the valley value of the ripple voltage within the (n + 1)-th dither cycle; determining a second target phase shift angle based on the fifth phase shift angle and the plurality of dither-related frequency values, where the second target phase shift angle is the phase shift angle used for phase shift angle compensation; and, when transitioning to the (n + 2)-th dither cycle, performing a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

[0081] It can be seen that in this embodiment, the controller obtains a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th dither frequency period. The plurality of first circuit parameters include a plurality of dither frequency-related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th dither frequency period, where n is an integer greater than or equal to 2. Determine a phase shift angle adjustment variable based on the peak-to-peak value of the (n - 1)th ripple voltage. Determine a second phase shift angle based on the phase shift angle adjustment variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth dither frequency period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth dither frequency period. Determine a target phase shift angle based on the second phase shift angle and the plurality of dither frequency-related frequency values. The target phase shift angle is the phase shift angle used for phase shift angle compensation. And when transitioning to the (n + 1)th dither frequency period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple. In this way, when performing a phase shift angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0082] Please refer to Figure 5 , Figure 5 FIG. is a schematic structural diagram of an output voltage ripple control device for a dual active bridge proposed in an embodiment of the present application. This device is applied to the controller of a dual active bridge system. The output voltage ripple control device 500 of the dual active bridge includes: an acquisition module 510, a first determination module 520, a second determination module 530, and a third determination module 540, where: The acquisition module 510 is configured to acquire a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th dither frequency period. The plurality of first circuit parameters include a plurality of dither frequency-related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th dither frequency period, where n is an integer greater than or equal to 2. The first determination module 520 is configured to determine a phase shift angle adjustment variable based on the peak-to-peak value of the (n - 1)th ripple voltage. The second determination module 530 is configured to determine a second phase shift angle based on the phase shift angle adjustment variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth dither frequency period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth dither frequency period. A third determination module 540, configured to determine a target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values, where the target phase shift angle is a phase shift angle for performing phase shift angle compensation; and when transitioning to the (n + 1)-th frequency hopping period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

[0083] In a possible embodiment, the second determination module 530, when determining the second phase shift angle based on the phase shift angle regulation variable, the (n - 1)-th ripple voltage peak-to-peak value, the n-th ripple voltage peak-to-peak value, and the first phase shift angle, is specifically configured to: Determine a third phase shift angle based on the first phase shift angle and the phase shift angle regulation variable; Perform a compensation operation based on the third phase shift angle, and obtain the n-th ripple voltage peak-to-peak value generated by compensation based on the third phase shift angle; Determine a phase shift angle adjustment strategy based on the n-th ripple voltage peak-to-peak value and the (n - 1)-th ripple voltage peak-to-peak value, where the phase shift angle adjustment strategy is used to adjust the first phase shift angle based on the phase shift angle regulation variable; Determine the second phase shift angle based on the phase shift angle adjustment strategy and the first phase shift angle.

[0084] In a possible embodiment, the second determination module 530, when determining the phase shift angle adjustment strategy based on the n-th ripple voltage peak-to-peak value and the (n - 1)-th ripple voltage peak-to-peak value, is specifically configured to: If the n-th ripple voltage peak-to-peak value is less than the (n - 1)-th ripple voltage peak-to-peak value, determine that the phase shift angle adjustment strategy is to perform a summation operation based on the phase shift angle regulation variable and the first phase shift angle; If the n-th ripple voltage peak-to-peak value is greater than the (n - 1)-th ripple voltage peak-to-peak value, determine that the phase shift angle adjustment strategy is to perform a subtraction operation based on the phase shift angle regulation variable and the first phase shift angle.

[0085] In a possible embodiment, the first determination module 520, when determining the phase shift angle regulation variable based on the (n - 1)-th ripple voltage peak-to-peak value, is specifically further configured to: Obtain multiple second circuit parameters under the current working condition, where the second circuit parameters include performance parameters of the dual active bridge system, and the performance parameters include a response speed parameter and / or a stability parameter; Determine a phase shift angle regulation parameter based on the second circuit parameters, where the phase shift angle regulation parameter is associated with the multiple second circuit parameters of the dual active bridge system; Determine the phase shift angle regulation variable based on the phase shift angle regulation parameter and the (n - 1)-th ripple voltage peak-to-peak value.

[0086] In a possible embodiment, the first determination module 520 is specifically configured to determine the phase shift angle regulation parameter based on the second circuit parameter as follows: Determine a transfer function based on a preset small-signal model and circuit information parameters, where the transfer function is used to reflect the dynamic influence of the duty cycle perturbation on the output voltage, and the duty cycle perturbation is a perturbation generated by regulating the first phase shift angle based on the phase shift angle regulation variable; Determine the phase shift angle regulation parameter based on the transfer function, the regulation parameter regulation calculation model, and the second circuit parameter, where the regulation parameter calculation model is used to constrain the association relationship between the phase shift angle regulation parameter and the multiple second circuit parameters and the regulation parameter boundary threshold, and the regulation parameter boundary threshold is used to constrain the maximum and minimum values of the phase shift angle regulation parameter.

[0087] In a possible embodiment, the first determination module 520 is further specifically configured to determine the phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage as follows: Determine a first simulation result based on the phase shift angle regulation parameter and a preset simulation regulation model, where the first simulation result is used to characterize the change trend of the simulated peak-to-peak value of the nth ripple voltage of the dual-active-bridge system if the phase shift angle regulation parameter is adopted, and the preset simulation regulation model is a model for simulating the dual-active-bridge system; Determine the nth simulation response rate parameter based on the first simulation result, where the nth simulation response rate parameter is used to characterize the response speed of the simulated peak-to-peak value of the nth ripple voltage within a preset time length, and the preset time length is a preset desired response time length; If the nth simulation response rate parameter is not within the preset response rate threshold range, then fine-tune based on the phase shift angle regulation variable; if the nth simulation response rate parameter is within the preset response rate threshold range, then determine the phase shift angle regulation variable.

[0088] In a possible embodiment, the multiple frequency hopping related frequency values include at least one of a switching frequency, a frequency hopping frequency, a frequency hopping frequency upper limit, and a frequency hopping frequency lower limit, the switching frequency is a dynamic variable, and the frequency hopping frequency, the frequency hopping frequency upper limit, and the frequency hopping frequency lower limit are static variables. The third determination module 540 is specifically configured to determine the target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values as follows: Determine a proportionality coefficient based on the second phase shift angle, the frequency hopping frequency upper limit, the frequency hopping frequency lower limit, and a proportionality coefficient formula, where the proportionality coefficient formula includes: , where is the proportionality coefficient, is the second phase shift angle, is the frequency hopping frequency upper limit, is the lower limit of the dither frequency; Determine the target phase shift angle based on the proportionality coefficient, the switching frequency, the dither frequency, and the target phase shift angle formula, where the target phase shift angle formula includes: , where f is the switching frequency, is the dither frequency.

[0089] It can be seen that in this embodiment, the device obtains multiple first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition through the controller. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th dither period. The multiple first circuit parameters include multiple dither-related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th dither period, where n is an integer greater than or equal to 2; determine the phase shift angle adjustment variable based on the peak-to-peak value of the (n - 1)th ripple voltage; determine the second phase shift angle based on the phase shift angle adjustment variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth dither period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth dither period; determine the target phase shift angle based on the second phase shift angle and the multiple dither-related frequency values. The target phase shift angle is the phase shift angle used for phase shift compensation; and when transitioning to the (n + 1)th dither period, perform a phase shift compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple. In this way, when performing a phase shift reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the problem of output power imbalance at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0090] It should be noted that for the specific functional implementation manner of the output voltage ripple control device 500 of the dual-active bridge, refer to the above Figure 2Description of the output voltage ripple control method of the dual active bridge shown, for example, the acquisition module 510 is used to implement the relevant content of executing S210, the first determination module 520 is used to implement the relevant content of executing S220, the second determination module 530 is used to implement the relevant content of executing S230, and the third determination module 540 is used to implement the relevant content of executing S240. Each unit or module in the output voltage ripple control device 500 of the dual active bridge can be respectively or all combined into one or several other units or modules to form, or some of the units or modules can be further split into multiple smaller units or modules in terms of function to form, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present invention. The above units or modules are divided based on logical functions. In practical applications, the functions of one unit (or module) are implemented by multiple units (or modules), or the functions of multiple units (or modules) are implemented by one unit (or module).

[0091] In the case of adopting integrated units, please refer to Figure 6 , Figure 6 is a schematic structural diagram of another output voltage ripple control device of the dual active bridge provided by the embodiments of the present application. As Figure 6 shown, the output voltage ripple control device 500 of the dual active bridge includes: a processing module 502 and a communication module 501. The processing module 502 is used to control and manage the actions of the output voltage ripple control device 500 of the dual active bridge. For example, it executes the steps of the acquisition module 510, the first determination module 520, the second determination module 530, and the third determination module 540, and / or is used to execute other processes of the technology described herein. The communication module 501 is used for the interaction between the output voltage ripple control device 500 of the dual active bridge and other devices. As Figure 6 shown, the output voltage ripple control device 500 of the dual active bridge may further include a storage module 503, and the storage module 503 is used to store the program code and data of the output voltage ripple control device 500 of the dual active bridge.

[0092] Among them, the processing module 502 can be a processor or a controller. For example, it can be a Central Processing Unit (CPU), a general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute various exemplary logic blocks, modules, and circuits described in connection with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and so on. The communication module 501 can be a transceiver, an RF circuit, or a communication interface, etc. The storage module 503 can be a memory.

[0093] Among them, all relevant contents of each scenario involved in the above method embodiment can be cited in the function description of the corresponding functional module, and will not be elaborated here. The above output voltage ripple control device 500 of the dual active bridge can execute the above Figure 2 shown output voltage ripple control method of the dual active bridge.

[0094] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of an electronic device proposed in an embodiment of this application. As Figure 7 shown, the electronic device 700 includes a processor 710, a memory 720, a communication interface 730, and one or more programs 721. The above one or more programs 721 are stored in the above memory 720 and are configured to be executed by the above processor 710.

[0095] The processor 710, the memory 720, and the communication interface 730 are interconnected and complete communication with each other; Among them, the memory 720 can be a volatile memory such as a Dynamic Random Access Memory (DRAM), or a non-volatile memory such as a mechanical hard disk. The above memory 720 is used to store a set of executable program codes. The above processor 710 is used to call one or more programs 721 stored in the memory 720 and can execute some or all of the steps of any output voltage ripple control method of the dual active bridge described in the above Figures 2 - 4 embodiment.

[0096] Among them, the electronic device 700 may include a smart phone (such as an Android phone, an iOS phone, a Windows Phone, etc.), a tablet computer, a handheld computer, a driving recorder, an in-vehicle electronic device, a server, a laptop computer, a mobile Internet electronic device (MID, Mobile Internet Devices), or a wearable electronic device (such as a smart watch, a Bluetooth headset), etc. The above are only examples, not an exhaustive list, including but not limited to the above electronic devices.

[0097] It can be seen that the electronic device 700 obtains a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th dither frequency period. The plurality of first circuit parameters include a plurality of dither frequency-related frequency values and a first phase shift angle. The first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th dither frequency period, where n is an integer greater than or equal to 2; determines a phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage; determines a second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle. The second phase shift angle is the optimal compensation phase shift angle within the nth dither frequency period under the current working condition. The peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth dither frequency period; determines a target phase shift angle based on the second phase shift angle and the plurality of dither frequency-related frequency values. The target phase shift angle is the phase shift angle used for phase shift angle compensation; and, when transitioning to the (n + 1)th dither frequency period, performs a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple. In this way, when performing a phase shift angle reverse compensation operation based on the peak-to-peak value of the ripple voltage to offset the power transmission error caused by frequency offset, the output power imbalance problem at the moment of frequency change is greatly alleviated, and the deterioration degree of the output voltage ripple is reduced.

[0098] The embodiment of the present application also provides a computer storage medium. Among them, this computer storage medium stores a computer program for electronic data exchange, and this computer program enables a computer to execute part or all of the steps of any method recorded in the above method embodiments. The above computer includes an electronic device.

[0099] The embodiment of the present application also provides a computer program product. The above computer program product includes a non-transitory computer-readable storage medium storing a computer program. The above computer program is operable to enable a computer to execute part or all of the steps of any method recorded in the above method embodiments. This computer program product can be a software installation package. The above computer includes an electronic device.

[0100] It should be noted that, for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that this application is not limited by the described action sequence, because according to this application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0101] In the above embodiments, the descriptions of the respective embodiments have their own focuses. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] In several embodiments provided by this application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the above division of units is only a logical function division. In actual implementation, there can be other division methods. For example, 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 displayed or discussed coupling or direct coupling or communication connection to each other can be through some interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0103] The units described as separate components above may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0104] In addition, in each embodiment of this application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0105] If the above 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 memory. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions to enable a computer electronic device (which can be a personal computer, an electronic device, or a network electronic device, etc.) to execute all or part of the steps of the above methods in various embodiments of this application. And the aforementioned memory includes: USB flash drives, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), mobile hard disks, magnetic disks, or optical discs and other various media that can store program codes.

[0106] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program. This program can be stored in a computer-readable memory, and the memory can include: flash drives, read-only memories (English: Read-Only Memory, abbreviated: ROM), random access memories (English: Random Access Memory, abbreviated: RAM), magnetic disks, or optical discs, etc.

[0107] The above has introduced the embodiments of this application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A method for controlling the output voltage ripple of a dual active bridge, characterized in that, A controller applied to a dual-active bridge system, comprising: Obtaining a plurality of first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition, where the peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the (n - 1)th frequency hopping period, the plurality of first circuit parameters include a plurality of frequency hopping related frequency values and a first phase shift angle, and the first phase shift angle is the maximum compensation phase shift angle within the (n - 1)th frequency hopping period, where n is an integer greater than or equal to 2; Determining a phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage; Determining a second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle, where the second phase shift angle is the optimal compensation phase shift angle within the nth frequency hopping period under the current working condition, and the peak-to-peak value of the nth ripple voltage is the difference between the peak value and the valley value of the ripple voltage within the nth frequency hopping period; Determining a target phase shift angle based on the second phase shift angle and the plurality of frequency hopping related frequency values, where the target phase shift angle is the phase shift angle for performing phase shift angle compensation; and when transitioning to the (n + 1)th frequency hopping period, performing a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

2. The method according to claim 1, wherein The determining the second phase shift angle based on the phase shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase shift angle includes: Determining a third phase shift angle based on the first phase shift angle and the phase shift angle regulation variable; Performing a compensation operation based on the third phase shift angle to obtain the peak-to-peak value of the nth ripple voltage generated by the compensation based on the third phase shift angle; Determining a phase shift angle adjustment strategy based on the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage, where the phase shift angle adjustment strategy is used to adjust the first phase shift angle based on the phase shift angle regulation variable; Determining the second phase shift angle based on the phase shift angle adjustment strategy and the first phase shift angle.

3. The method according to claim 2, characterized in that, The determining the phase shift angle adjustment strategy based on the peak-to-peak value of the nth ripple voltage and the peak-to-peak value of the (n - 1)th ripple voltage includes: If the peak-to-peak value of the nth ripple voltage is less than the peak-to-peak value of the (n - 1)th ripple voltage, determining the phase shift angle adjustment strategy as performing a summation operation based on the phase shift angle regulation variable and the first phase shift angle; If the peak-to-peak value of the nth ripple voltage is greater than the peak-to-peak value of the (n - 1)th ripple voltage, determining the phase shift angle adjustment strategy as performing a subtraction operation based on the phase shift angle regulation variable and the first phase shift angle.

4. The method according to claim 1, wherein The determining the phase shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage includes: Obtaining a plurality of second circuit parameters under the current working condition, where the second circuit parameters include performance parameters of the dual-active bridge system, and the performance parameters include a response speed parameter and / or a stability parameter; Determining a phase shift angle regulation parameter based on the second circuit parameters, where the phase shift angle regulation parameter is associated with the plurality of second circuit parameters of the dual-active bridge system; Determining the phase shift angle regulation variable based on the phase shift angle regulation parameter and the peak-to-peak value of the (n - 1)th ripple voltage.

5. The method according to claim 4, wherein The determination of the phase-shift angle regulation parameter based on the second circuit parameter includes: Determining a transfer function based on a preset small-signal model and circuit information parameters, where the transfer function is used to reflect the dynamic influence of the duty-cycle perturbation on the output voltage, and the duty-cycle perturbation is a perturbation generated by regulating the first phase-shift angle based on the phase-shift angle regulation variable; Determining the phase-shift angle regulation parameter based on the transfer function, a regulation parameter regulation calculation model, and the second circuit parameter, where the regulation parameter calculation model is used to constrain the correlation between the phase-shift angle regulation parameter and the multiple second circuit parameters and the regulation parameter boundary threshold, and the regulation parameter boundary threshold is used to constrain the maximum and minimum values of the phase-shift angle regulation parameter.

6. The method according to claim 4 or 5, characterized in that The determination of the phase-shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage further includes: Determining a first simulation result based on the phase-shift angle regulation parameter and a preset simulation regulation model, where the first simulation result is used to characterize the change trend of the simulated peak-to-peak value of the nth ripple voltage of the dual-active-bridge system if the phase-shift angle regulation parameter is adopted, and the preset simulation regulation model is a model for simulating the dual-active-bridge system; Determining the nth simulation response rate parameter based on the first simulation result, where the nth simulation response rate parameter is used to characterize the response speed of the simulated peak-to-peak value of the nth ripple voltage within a preset time length, and the preset time length is a preset desired response time length; If the nth simulation response rate parameter is not within the preset response rate threshold range, then fine-tuning based on the phase-shift angle regulation variable; if the nth simulation response rate parameter is within the preset response rate threshold range, then determining the phase-shift angle regulation variable.

7. The method according to claim 1, characterized in that, The multiple frequency-hopping related frequency values include at least one of a switching frequency, a frequency-hopping frequency, a frequency-hopping frequency upper limit, and a frequency-hopping frequency lower limit. The switching frequency is a dynamically variable quantity, and the frequency-hopping frequency, the frequency-hopping frequency upper limit, and the frequency-hopping frequency lower limit are static quantities. The determination of the target phase-shift angle based on the second phase-shift angle and the multiple frequency-hopping related frequency values includes: Determine the proportionality coefficient based on the second phase shift angle, the upper limit of the frequency hopping frequency, the lower limit of the frequency hopping frequency, and the proportionality coefficient formula, where the proportionality coefficient formula includes: , where is the proportionality coefficient, is the second phase shift angle, is the upper limit of the frequency hopping frequency, is the lower limit of the frequency hopping frequency; Determine the target phase shift angle based on the proportionality coefficient, the switching frequency, the frequency jittering frequency, and the target phase shift angle formula, where the target phase shift angle formula includes: , where f is the switching frequency, is the frequency jittering frequency.

8. An output voltage ripple control device for a dual active bridge, characterized in that A controller applied to a dual-active-bridge system, the device includes: An acquisition module, configured to acquire multiple first circuit parameters and the peak-to-peak value of the (n - 1)th ripple voltage under the current working condition. The peak-to-peak value of the (n - 1)th ripple voltage is the difference between the peak and valley values of the ripple voltage within the (n - 1)th frequency-hopping period. The multiple first circuit parameters include multiple frequency-hopping related frequency values and a first phase-shift angle, and the first phase-shift angle is the maximum compensation phase-shift angle within the (n - 1)th frequency-hopping period, where n is an integer greater than or equal to 2; A first determination module, configured to determine a phase-shift angle regulation variable based on the peak-to-peak value of the (n - 1)th ripple voltage; A second determination module, configured to determine a second phase-shift angle based on the phase-shift angle regulation variable, the peak-to-peak value of the (n - 1)th ripple voltage, the peak-to-peak value of the nth ripple voltage, and the first phase-shift angle. The second phase-shift angle is the optimal compensation phase-shift angle within the nth frequency-hopping period under the current working condition, and the peak-to-peak value of the nth ripple voltage is the difference between the peak and valley values of the ripple voltage within the nth frequency-hopping period; A third determination module, configured to determine a target phase shift angle based on the second phase shift angle and the multiple frequency hopping related frequency values, where the target phase shift angle is a phase shift angle for performing phase shift angle compensation; and when transitioning to the (n + 1)-th frequency hopping period, perform a phase shift angle compensation operation based on the target phase shift angle to reduce the offset degree of the output voltage ripple.

9. A computer-readable storage medium, characterized in that, It stores an output voltage ripple control program for a dual active bridge, and the output voltage ripple control program for the dual active bridge includes execution instructions, and when the execution instructions are executed by a processor, the processor executes the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that, It includes a processor, a memory, a communication interface, and one or more programs, where the one or more programs are stored in the memory and are configured to be executed by the processor; When the processor executes the one or more programs, the processor executes the method according to any one of claims 1 to 7.

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