A DAB converter and a driving control method thereof

Abstract

This application discloses a DAB converter and its driving control method. The method includes: obtaining the voltage transfer ratio based on the input voltage and output voltage of the DAB converter; obtaining the feedforward power based on the input voltage, voltage transfer ratio, and output current of the DAB converter; obtaining the primary-to-secondary side shift ratio based on the input voltage, output voltage, voltage transfer ratio, input current, and feedforward power of the DAB converter; obtaining the primary-side inward shift ratio and the secondary-side inward shift ratio based on the voltage transfer ratio, feedforward power, and the primary-to-secondary side shift ratio; and driving the DAB converter based on the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-to-secondary side shift ratio. This invention optimizes the values ​​of the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-to-secondary side shift ratio using relevant parameters of the DAB converter to achieve precise driving control of the DAB converter. By adjusting the control parameters of the DAB converter, the soft-switching range can be expanded, current stress reduced, and light-load efficiency improved, while significantly increasing the system's energy conversion rate.

Description

Technical Field

[0001] This invention relates to the field of converter control technology, and in particular to a DAB converter and its drive control method. Background Technology

[0002] With the continuous development of photovoltaic, new energy technologies, and electric vehicle charging technologies, low-loss, high-power-density, and high-reliability DC-DC converters have become a research hotspot. Among the many DC-DC converter topologies, those with easily implemented soft-switching characteristics, relatively simple control methods, and high power density have attracted widespread attention. The DAB (Dual Active Bridge) converter is a representative example. DAB converter circuits have a symmetrical structure and exhibit good operating characteristics in both forward and reverse directions, demonstrating broad prospects and development potential.

[0003] However, the existing three-phase shift control strategy of DAB converters leads to low energy conversion efficiency and instability in practical applications. Therefore, a new method is urgently needed to solve the above problems. Summary of the Invention

[0004] This invention provides a DAB converter and its driving control method, which solves the problem that the three-phase shift control strategy of existing DAB converters leads to low energy conversion efficiency and instability in practical applications.

[0005] To solve the above-mentioned technical problems, the present invention provides a driving control method for a DAB converter, comprising: obtaining a voltage transfer ratio based on the input voltage and output voltage of the DAB converter; obtaining a feedforward power based on the input voltage, voltage transfer ratio, and output current of the DAB converter; obtaining a primary-to-secondary side shift ratio based on the input voltage, output voltage, voltage transfer ratio, input current of the DAB converter, and feedforward power; obtaining a primary-side inward shift ratio and a secondary-side inward shift ratio based on the voltage transfer ratio, feedforward power, and primary-to-secondary side shift ratio; and driving the DAB converter based on the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-to-secondary side shift ratio.

[0006] In some embodiments, obtaining the primary side inward shift ratio and the secondary side inward shift ratio based on the voltage transfer ratio, feedforward power, and primary-secondary side shift ratio includes: calculating the primary side inward shift ratio based on the range of the voltage transfer ratio, the range of the feedforward power, the voltage transfer ratio, and the feedforward power; and calculating the secondary side inward shift ratio based on the voltage transfer ratio, the feedforward power, the primary-secondary side shift ratio, and the primary side inward shift ratio.

[0007] In some embodiments, the voltage transfer ratio satisfies k > 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: Where k is the voltage transfer ratio. D1 is the feedforward power, and D1 is the ratio of the primary side shifted inward.

[0008] In some embodiments, the voltage transfer ratio satisfies k > 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: , The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: , The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: , The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: , in, Compared to the middle shift, D2 is the secondary edge shift inward, and D3 is the original secondary edge shift.

[0009] In some embodiments, the feedforward power is calculated according to the following formula: V_out_ref = V_in * k / n; P for =V_out_ref*I_out; where V_in is the input voltage, k is the voltage transfer ratio, n is the transformer turns ratio of the DAB converter, V_out_ref is the target voltage, I_out is the output current, and P for This is the feedforward power.

[0010] In some embodiments, the primary-secondary side shift ratio is calculated according to the following formulas: e_v = V_out_ref - V_out; I_ref = Kp_v * e_v + Ki_v * ∫ e_v dt; e_i = I_ref - I_in; PI out =Kp_i*e_i+Ki_i*∫ e_i dt; D3= P for +PI outWhere V_out is the output voltage, e_v is the voltage error, Kp_v is the preset voltage loop proportional parameter, Ki_v is the preset voltage loop integral parameter, ∫ e_v dt is the integral of the voltage error e_v with respect to time t, I_ref is the reference current, I_in is the input current, e_i is the current error, Kp_i is the preset current loop proportional parameter, Ki_i is the preset current loop integral parameter, ∫ e_i dt is the integral of the current error e_i with respect to time t, PI out D3 represents the first power, and D3 represents the ratio of primary to secondary side shift.

[0011] In some embodiments, the voltage transfer ratio is calculated according to the following formula: k = n * V_out / V_in; where V_in is the input voltage and V_out is the output voltage.

[0012] The present invention also provides a DAB converter, including a controller, the controller being used to execute any of the above-described drive control methods.

[0013] In some embodiments, the system further includes an inverter circuit, a transformer, and a rectifier circuit connected in sequence. The inverter circuit is used to connect to a solar panel, and the rectifier circuit is used to connect to an energy storage battery. A controller is connected to the inverter circuit and the rectifier circuit and is used to drive the inverter circuit and the rectifier circuit according to the drive control method described above.

[0014] In some embodiments, the rectifier circuit has multiple output ports, each of which is used to connect to an energy storage battery, enabling the DAB converter to charge multiple energy storage batteries simultaneously.

[0015] The beneficial effects of this invention are: This invention is based on a three-phase shift control strategy. By optimizing the values ​​of the primary-side inward shift ratio, secondary-side inward shift ratio, and primary-secondary-side shift ratio using relevant parameters of the DAB converter (input voltage, output voltage, output current, input current, etc.), precise drive control of the DAB converter can be achieved. By adjusting the control parameters of the DAB converter (primary-side inward shift ratio, secondary-side inward shift ratio, and primary-secondary-side shift ratio), circulating current losses under light loads can be effectively reduced; zero-voltage switching can be achieved over a wider load range, significantly reducing switching losses; the effective value of the inductor current can be reduced, decreasing conduction losses; and the inductor current can be stabilized, reducing heat loss caused by current instability. The coordinated control of the three control parameters makes the system respond more quickly to changes in load and input voltage, greatly improving the system's energy conversion efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating an embodiment of a drive control method for a DAB converter according to the present invention. Figure 2 This is a circuit diagram of a DAB converter according to the present invention; Figure 3 This is a schematic diagram of the composition of a DAB converter according to the present invention; Figure 4 This is a schematic diagram illustrating an application scenario of a DAB converter according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “including,” when used in this specification, identify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0020] It should be noted that in the embodiments of this application, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0021] Please see Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of a drive control method for a DAB converter provided in this application. The method includes: S1: The voltage transfer ratio is obtained based on the input and output voltages of the DAB converter.

[0022] S2: The feedforward power is obtained based on the input voltage, voltage transfer ratio, and output current of the DAB converter.

[0023] S3: The primary and secondary side shift ratio is obtained based on the input voltage, output voltage, voltage transfer ratio, input current of the DAB converter, and feedforward power.

[0024] S4: Based on the voltage transfer ratio, feedforward power, and primary-secondary side shift ratio, the primary-side inward shift ratio and the secondary-side inward shift ratio are obtained.

[0025] S5: Drives the DAB converter based on the ratio of primary side inward shift, the ratio of secondary side inward shift, and the ratio of primary to secondary side shift.

[0026] This invention is based on a Triple Phase-Shift (TPS) control strategy. By optimizing the values ​​of the primary-side inward shift ratio, secondary-side inward shift ratio, and primary-secondary side shift ratio using relevant parameters of the DAB converter (input voltage, output voltage, output current, input current, etc.), precise drive control of the DAB converter can be achieved. By adjusting the control parameters of the DAB converter (primary-side inward shift ratio, secondary-side inward shift ratio, and primary-secondary side shift ratio), circulating current losses under light loads can be effectively reduced; zero-voltage switching (ZVS) can be achieved over a wider load range, significantly reducing switching losses; the effective value of the inductor current can be reduced, decreasing conduction losses and enabling stable inductor current operation, thus reducing heat loss caused by current instability. The coordinated control of the three parameters makes the system respond more rapidly to changes in load and input voltage, greatly improving the system's energy conversion efficiency.

[0027] The following is combined with Figures 1 to 4 The present application will be further described in detail with reference to specific embodiments.

[0028] The drive control method of this application is used to control, for example, Figure 2 The DAB converter shown includes an inverter circuit (Q1, Q2, Q3, Q4), a transformer T1, and a rectifier circuit (S11, S12, S13, S14, S21, S22, S23, S24).

[0029] Combination Figure 1 As shown in the embodiments of this application, the driving control method of the DAB converter is described in detail below: S1: The voltage transfer ratio is obtained based on the input and output voltages of the DAB converter.

[0030] First, system initialization and soft start are performed. The controller collects the input voltage, output voltage, input current, and output current of the DAB converter in real time; and simultaneously obtains the turns ratio of transformer T1 in the DAB converter to provide data support for subsequent calculations.

[0031] Furthermore, based on the input and output voltages of the DAB converter, the voltage transfer ratio of the DAB converter is calculated. The calculation formula is as follows: k = n * V_out / V_in Where V_in is the input voltage, V_out is the output voltage, k is the voltage transfer ratio, and n is the turns ratio of transformer T1.

[0032] S2: The feedforward power is obtained based on the input voltage, voltage transfer ratio, and output current of the DAB converter.

[0033] First, the target voltage of the DAB converter is calculated based on the input voltage, voltage transfer ratio, and turns ratio of transformer T1. The calculation formula is as follows: V_out_ref=V_in*k / n Where V_in is the input voltage, V_out_ref is the target voltage, k is the voltage transfer ratio, and n is the turns ratio of transformer T1 in the DAB converter.

[0034] Furthermore, the feedforward power is calculated based on the target voltage and the output current of the DAB converter. The calculation formula is as follows: P for =V_out_ref * I_out Where V_out_ref is the target voltage, I_out is the output current, and P for This is the feedforward power.

[0035] By using feedforward power to provide a feedforward basis for subsequent power references, the actual power can respond more quickly.

[0036] S3: The primary and secondary side shift ratio is obtained based on the input voltage, output voltage, voltage transfer ratio, input current of the DAB converter, and feedforward power.

[0037] First, when the DAB converter has one output port, the voltage error can be calculated from the target voltage and the output voltage, using the following formula: e_v=V_out_ref-V_out Where V_out is the output voltage, e_v is the voltage error, and V_out_ref is the target voltage.

[0038] In some other embodiments, when the DAB converter has multiple output ports (e.g., three), the voltage error can be calculated using the target voltage and the three output voltages, as shown in the following formula: e_v = V_out_ref - V_out_avg; V_out_avg=(V_out1+V_out2+V_out3) / 3 Where e_v is the voltage error, V_out_ref is the target voltage, V_out_avg is the average output voltage, V_out1 is the first port output voltage, V_out2 is the second port output voltage, and V_out3 is the third port output voltage.

[0039] Secondly, the voltage error is input into the controller to calculate the reference current. The calculation formula is as follows: I_ref=Kp_v*e_v+Ki_v*∫ e_v dt Where e_v is the voltage error, Kp_v is the preset voltage loop proportional parameter, Ki_v is the preset voltage loop integral parameter, ∫ e_v dt is the integral of the voltage error e_v with respect to time t, and I_ref is the reference current.

[0040] In this embodiment, the reference current is the inductor current reference command reflecting the total power demand of the system. An upper limit is set for ∫e_v dt to prevent saturation limiting. When the calculated ∫e_v dt is greater than the set upper limit, the final value of ∫e_v dt is equal to the upper limit; when the calculated ∫e_v dt is less than the set upper limit, the calculated value is used to prevent integral saturation.

[0041] Furthermore, the current error is calculated using the reference current and the input current, as shown in the following formula: e_i=I_ref-I_in Where I_ref is the reference current, I_in is the input current, and e_i is the current error.

[0042] Furthermore, the current error is input into the controller to calculate the first power, using the following formula: PI out =Kp_i*e_i+Ki_i*∫ e_i dt Where e_i is the current error, Kp_i is the preset current loop proportional parameter, Ki_i is the preset current loop integral parameter, ∫ e_i dt is the integral of the current error e_i with respect to time t, and PI out This is the highest power output.

[0043] In this embodiment, an upper limit is set for ∫ e_i dt to prevent saturation limiting. When the calculated ∫ e_i dt is greater than the set upper limit, the final value of ∫ e_i dt is equal to the upper limit; when the calculated ∫ e_i dt is less than the set upper limit, the calculated value is used, which can prevent integral saturation.

[0044] Finally, the primary and secondary side shifts are calculated based on the first power and the feedforward power, using the following formula: D3=P for +PI out Among them, P for For feedforward power, PI out D3 represents the first power, and D3 represents the ratio of primary to secondary side shift.

[0045] It should be noted that in the three-phase shift control strategy, D3 is used to control the phase difference between the primary and secondary sides, which determines the direction and magnitude of power transmission.

[0046] S4: Based on the voltage transfer ratio, feedforward power, and primary-secondary side shift ratio, the primary-side inward shift ratio and the secondary-side inward shift ratio are obtained.

[0047] First, the primary side shift ratio is calculated based on the range of voltage transfer ratio, the range of feedforward power, voltage transfer ratio, and feedforward power.

[0048] Specifically, when the voltage transfer ratio satisfies k>1 and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula:

[0049] Where k is the voltage transfer ratio. D1 is the feedforward power, and D1 is the ratio of the primary side shifted inward.

[0050] When the voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula:

[0051] Where k is the voltage transfer ratio. D1 is the feedforward power, and D1 is the ratio of the primary side shifted inward.

[0052] When the voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula:

[0053] Where k is the voltage transfer ratio. D1 is the feedforward power, and D1 is the ratio of the primary side shifted inward.

[0054] When the voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula:

[0055] Where k is the voltage transfer ratio. D1 is the feedforward power, and D1 is the ratio of the primary side shifted inward.

[0056] Secondly, the ratio of the secondary side to the inner shift is calculated based on the voltage transfer ratio, feedforward power, ratio of primary to secondary side shift, and ratio of primary side to inner shift.

[0057] Specifically, when the voltage transfer ratio satisfies k>1 and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: ,

[0058] in, D1 is the ratio of the shift in the middle, D2 is the ratio of the shift in the secondary side, D3 is the ratio of the shift in the primary and secondary sides, k is the voltage transfer ratio, and D1 is the ratio of the shift in the primary side.

[0059] When the voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: ,

[0060] in, D1 is the ratio of the shift in the middle, D2 is the ratio of the shift in the secondary side, D3 is the ratio of the shift in the primary and secondary sides, k is the voltage transfer ratio, and D1 is the ratio of the shift in the primary side.

[0061] When the voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: ,

[0062] in, D1 is the ratio of the shift in the middle, D2 is the ratio of the shift in the secondary side, D3 is the ratio of the shift in the primary and secondary sides, k is the voltage transfer ratio, and D1 is the ratio of the shift in the primary side.

[0063] When the voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: ,

[0064] in, D1 is the ratio of the shift in the middle, D2 is the ratio of the shift in the secondary side, D3 is the ratio of the shift in the primary and secondary sides, k is the voltage transfer ratio, and D1 is the ratio of the shift in the primary side.

[0065] It should be noted that in the three-phase-shift control strategy, D1 is used to control the conduction phase difference between the left and right arms of the primary side, thus determining the duty cycle of the primary side voltage. D2 is used to control the conduction phase difference between the left and right arms of the secondary side, thus determining the duty cycle of the secondary side voltage.

[0066] In summary, the calculation formulas for the ratio of the original side to the secondary side inward shift are shown in Table 1 below: Table 1

[0067] S5: Drives the DAB converter based on the ratio of primary side inward shift, the ratio of secondary side inward shift, and the ratio of primary to secondary side shift.

[0068] Finally, based on the calculated ratios of primary side inward shift, secondary side inward shift, and primary / secondary side shift, the controller controls the operating state of the DAB converter in real time.

[0069] Specifically, based on the calculated primary-side shift ratio D1, secondary-side shift ratio D2, and primary-secondary-side shift ratio D3, drive signals for all power switches are generated in real time. Q1 activation time: ton_Q1=0; Q2 activation time: ton_Q2=D1×Ts; Q3 activation time: ton_Q3 = 0.5 × Ts; Q4 activation time: ton_Q4=(0.5+D1)×Ts; S11 activation time: ton_S11=D3×Ts; S12 activation time: ton_S12=(D3+D2)×Ts; S13 activation time: ton_S13=(0.5+D3)×Ts; S14 activation time: ton_S14=(0.5+D3+D2)×Ts; S21 activation time: ton_S21=D3×Ts; S22 activation time: ton_S22=(D3+D2)×Ts; S23 activation time: ton_S23=(0.5+D3)×Ts; S24 activation time: ton_S24=(0.5+D3+D2)×Ts; Where Ts = 1 / fs is the switching period, and fs is the switching frequency. This drive timing ensures that the DAB converter operates at its optimal operating point, while maximizing efficiency and reliability.

[0070] In other embodiments, under light load conditions, the values ​​of the primary-side shift ratio D1 and the secondary-side shift ratio D2 are appropriately increased to increase the amplitude of the inductor current at the switching moment. Under heavy load conditions, the values ​​of the primary-side shift ratio D1 and the secondary-side shift ratio D2 are decreased to reduce current stress. The shift ratios are dynamically adjusted by real-time monitoring of the inductor current direction and the switching transistor voltage to ensure zero-voltage switching performance (ZVS).

[0071] This application optimizes the values ​​of the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-secondary-side shift ratio based on a three-phase shift control strategy to achieve precise drive control of the DAB converter. By adjusting the control parameters of the DAB converter, circulating current losses under light loads can be effectively reduced; the effective value of the inductor current is minimized, reducing conduction losses and enabling stable inductor current operation, thus reducing heat loss caused by current instability. The coordinated control of the three parameters makes the system respond more quickly to changes in load and input voltage, significantly improving the system's energy conversion efficiency.

[0072] Corresponding to the drive control method of the DAB converter in the above embodiment, Figure 3 A schematic diagram of the composition of the DAB converter provided in the embodiments of this application is shown. For ease of explanation, only the parts related to the embodiments of this application are shown.

[0073] refer to Figure 3 The DAB converter 1 includes a controller 14, which is used to execute the drive control method described above.

[0074] Furthermore, the DAB converter 1 of this application also includes an inverter circuit 11, a transformer 12 and a rectifier circuit 13 connected in sequence. The inverter circuit 11 is used to connect the solar panel 2 and the rectifier circuit 13 is used to connect the energy storage battery 3.

[0075] The controller 14 is connected to the inverter circuit 11 and the rectifier circuit 13, and the controller 14 is used to drive the inverter circuit 11 and the rectifier circuit 13 according to the above-described drive control method.

[0076] In some other embodiments, such as Figure 4 As shown, the rectifier circuit 13 of the DAB converter 1 has multiple output ports, each of which is used to connect to an energy storage battery 3, enabling the DAB converter 1 to charge multiple energy storage batteries 3 simultaneously. Preferably, the rectifier circuit 13 of the DAB converter 1 has three output ports for simultaneously charging three energy storage batteries 3.

[0077] It should be noted that since the above-mentioned DAB converter 1 is based on the same concept as the method embodiment of this application, its specific functions, the process by which each module implements its respective functions, and the resulting technical effects can be specifically referred to the description of the aforementioned drive control method embodiment, and will not be repeated here.

[0078] Therefore, this invention discloses a DAB converter and its driving control method. The method includes: obtaining the voltage transfer ratio based on the input voltage and output voltage of the DAB converter; obtaining the feedforward power based on the input voltage, voltage transfer ratio, and output current of the DAB converter; obtaining the primary-to-secondary side shift ratio based on the input voltage, output voltage, voltage transfer ratio, input current, and feedforward power; obtaining the primary-side inward shift ratio and the secondary-side inward shift ratio based on the voltage transfer ratio, feedforward power, and the primary-to-secondary side shift ratio; and driving the DAB converter based on the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-to-secondary side shift ratio. This invention is based on a three-phase shift control strategy, optimizing the values ​​of the primary-side inward shift ratio, the secondary-side inward shift ratio, and the primary-to-secondary side shift ratio using relevant parameters of the DAB converter (input voltage, output voltage, output current, input current, etc.) to achieve precise driving control of the DAB converter. By adjusting the control parameters of the DAB converter (comparison of primary-side inward shift, secondary-side inward shift, and primary-secondary-side shift), circulating current losses under light loads can be effectively reduced; zero-voltage switching can be achieved over a wider load range, significantly reducing switching losses; the effective value of the inductor current can be reduced, decreasing conduction losses and enabling stable inductor current operation, thus reducing heat loss caused by current instability. The coordinated control of these three parameters makes the system respond more rapidly to changes in load and input voltage, greatly improving the system's energy conversion efficiency.

[0079] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A drive control method for a DAB converter, characterized in that, include: The voltage transfer ratio is obtained based on the input and output voltages of the DAB converter. The feedforward power is obtained based on the input voltage, the voltage transfer ratio, and the output current of the DAB converter. The primary and secondary side shifts are obtained based on the input voltage, the output voltage, the voltage transfer ratio, the input current of the DAB converter, and the feedforward power; The primary-side inward shift ratio and the secondary-side inward shift ratio are obtained based on the voltage transmission ratio, the feedforward power, and the primary-secondary-side shift ratio, including: The secondary side inward shift ratio is calculated based on the voltage transmission ratio, the feedforward power, the primary-to-secondary side shift ratio, and the primary side inward shift ratio. The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the secondary side is shifted inward, the following formula is used to calculate the ratio: Where k is the voltage transmission ratio. Where D1 is the feedforward power, and D1 is the ratio of the original side to the inner shift. Compared to the intermediate shift, D2 is the comparison of the inner shift of the secondary edge, and D3 is the comparison of the original secondary edge shift; The DAB converter is driven based on the primary side inward shift ratio, the secondary side inward shift ratio, and the primary and secondary side shift ratio.

2. The drive control method according to claim 1, characterized in that, The method of obtaining the primary side inward shift ratio and the secondary side inward shift ratio based on the voltage transmission ratio, the feedforward power, and the primary-secondary side shift ratio further includes: The original side inward shift ratio is calculated based on the range of the voltage transfer ratio, the range of the feedforward power, the voltage transfer ratio, and the feedforward power.

3. The drive control method according to claim 2, characterized in that: The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k>1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: The voltage transfer ratio satisfies k < 1, and the feedforward power satisfies When the original side is shifted inward, the ratio is calculated according to the following formula: Where k is the voltage transmission ratio. D1 is the feedforward power, and D1 is the ratio of the original side to the inner shift.

4. The drive control method according to claim 1, characterized in that, The feedforward power is calculated using the following formula: V_out_ref=V_in*k / n P for =V_out_ref*I_out V_in * k * n = V_out_ref * I_out + P_feedforward for V_in * k * n = V_out_ref * I_out + P_feedforward 5. The drive control method according to claim 4, characterized in that, The primary and secondary side shifts are calculated using the following formula: e_v=V_out_ref-V_out I_ref=Kp_v*e_v+Ki_v*∫ e_v dt e_i=I_ref-I_in PI out = Kp_i * e_i + Ki_i * ∫ e_i dt D3= P for + PI out Wherein, V_out is the output voltage, e_v is a voltage error, Kp_v is a preset voltage loop proportional parameter, Ki_v is a preset voltage loop integral parameter, ∫ e_v dt is an integral of the voltage error e_v with respect to time t, I_ref is a reference current, I_in is the input current, e_i is a current error, Kp_i is a preset current loop proportional parameter, Ki_i is a preset current loop integral parameter, ∫ e_i dt is an integral of the current error e_i with respect to time t, PI out is a first power, and D3 is the primary-secondary phase-shift ratio.

6. The drive control method according to claim 1, characterized in that, The voltage transfer ratio is calculated using the following formula: k = n * V_out / V_in Wherein, V_in is the input voltage and V_out is the output voltage.

7. A DAB converter, characterized in that, Includes a controller for performing the drive control method according to any one of claims 1 to 6.

8. The DAB converter according to claim 7, characterized in that, It also includes an inverter circuit, a transformer and a rectifier circuit connected in sequence, wherein the inverter circuit is used to connect to the solar panel and the rectifier circuit is used to connect to the energy storage battery; The controller is connected to the inverter circuit and the rectifier circuit, and the controller is used to drive the inverter circuit and the rectifier circuit according to any one of claims 1 to 6.

9. The DAB converter according to claim 8, characterized in that, The rectifier circuit has multiple output ports, each of which is used to connect to an energy storage battery, enabling the DAB converter to charge multiple energy storage batteries simultaneously.

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