Bidirectional resonance DAB converter asymmetric modulation method and device

Abstract

The invention provides an asymmetric modulation method and device for a bidirectional resonant DAB converter, and the method comprises the steps: determining the real-time duty ratio of any switching tube in a primary full bridge through the real-time working parameters of the bidirectional resonant DAB converter, and determining the real-time switching frequencies of a switching tube corresponding to the primary full bridge and a switching tube corresponding to a secondary full bridge, and enabling the real-time duty ratio of other switching tubes located on the same bridge arm with any switching tube to be complementary with the real-time duty ratio of any switching tube, thereby obtaining the real-time duty ratio of any switching tube according to the real-time duty ratio of the switching tube of the primary full bridge, the real-time duty ratio of the switching tube of the secondary full bridge and the real-time switching frequency. And controlling the switching states of a switching tube corresponding to the primary side full bridge and a switching tube corresponding to the secondary side full bridge, and asymmetrically modulating the bidirectional resonant DAB converter, thereby realizing the asymmetrical control of the positive high level duration and the negative high level duration of the midpoint voltage of the bridge arm of the primary side full bridge, and optimizing the reactive power.

Description

Technical Field

[0001] This application relates to the field of bidirectional resonant DAB converter technology, and in particular to an asymmetric modulation method and apparatus for a bidirectional resonant DAB converter. Background Technology

[0002] With the rapid development of new energy vehicles, especially electric vehicles, higher demands are being placed on the performance of their battery charging systems. Electric vehicles typically use high-energy-density battery packs with a wide operating voltage range. Common battery pack voltages range from 200V or even lower to over 800V, depending on the battery type, state of charge (SOC), and vehicle configuration. Therefore, this wide voltage range presents a challenge to the design of DC-DC converters in the charging system. DC-DC converters need to be adaptable to a wide input / output voltage range while maintaining high efficiency across the entire power range.

[0003] Among them, the dual-active-bridge (DAB) DC-DC converter, also known as the bidirectional resonant DAB converter, has advantages such as bidirectional energy flow, simple control, and soft-switching operation. The circuit structure of the bidirectional resonant DAB converter is as follows: Figure 17 As shown, the circuit includes two full-bridge circuits and a resonant cavity. The primary-side full-bridge circuit contains switching transistors S1-S4, and the secondary-side full-bridge circuit contains switching transistors Q1-Q4. The resonant cavity contains a resonant inductor Lr, a resonant capacitor Cr, and a transformer. Because the resonant capacitor is connected in series in the resonant cavity of the bidirectional resonant DAB converter circuit, it can eliminate the DC bias current of the converter. Furthermore, the LC resonant cavity makes the cavity current more sinusoidal, reducing the loss of magnetic components. This provides significant advantages in improving conversion efficiency and achieving high frequency and high power density.

[0004] However, due to the phase difference between the primary and secondary square wave voltages of the transformer in the bidirectional resonant DAB converter, and the presence of the resonant network, the current phase and voltage phase may not be consistent. This causes some energy to be exchanged back and forth between the power supply and the load without being absorbed by the load. As a result, the bidirectional resonant DAB converter inevitably generates backflow power, i.e. reactive power, during operation, leading to a decrease in system efficiency, an increase in current stress, and a deterioration in power quality.

[0005] Among them, existing technologies employ modulation strategies such as single phase shift control (SPS), dual phase shift control (DPS), and even triple phase shift control (TPS) to reduce return current power. However, most of these modulation strategies have complex models and require solving for many parameters, making them difficult to apply to practical engineering or only effective in reducing return current power under certain operating conditions.

[0006] Therefore, how to reduce return power and optimize system operation through modulation strategies has become a hot research topic. Summary of the Invention

[0007] This application provides an asymmetric modulation method and apparatus for a bidirectional resonant DAB converter to solve the technical problems mentioned in the background art.

[0008] In a first aspect, this application provides an asymmetric modulation method for a bidirectional resonant DAB converter, the bidirectional resonant DAB converter comprising: a primary-side full-bridge, a resonant cavity, and a secondary-side full-bridge; the method comprising: Based on the real-time operating parameters of the bidirectional resonant DAB converter, the real-time duty cycle of any switch in the primary-side full bridge is determined, as well as the real-time switching frequency of the corresponding switch in the primary-side full bridge and the corresponding switch in the secondary-side full bridge are determined. The real-time operating parameters include the real-time input voltage, real-time output voltage, and target output voltage of the bidirectional resonant DAB converter. Based on the real-time duty cycle of any given switch, the real-time duty cycles of other switches located on the same bridge arm as the given switch, the real-time duty cycles of other switches located on different bridge arms as the given switch, and the real-time switching frequency, the switching states of the switches corresponding to the primary-side full bridge and the switches corresponding to the secondary-side full bridge are controlled. The real-time duty cycles of other switches located on the same bridge arm as the given switch are complementary to the real-time duty cycle of the given switch, so that the middle voltage of the bridge arm of the primary-side full bridge exhibits unequal durations of positive and negative high levels. Furthermore, the real-time duty cycles of other switches located on different bridge arms as the given switch are preset duty cycles.

[0009] Optionally, determining the real-time duty cycle of any switch in the primary-side full-bridge based on the real-time operating parameters of the bidirectional resonant DAB converter includes: Obtain the operating parameters of the bidirectional resonant DAB converter; The real-time voltage gain is obtained based on the real-time input voltage and the real-time output voltage; Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle of any switch in the primary-side full bridge is determined.

[0010] Optionally, in the Cartesian coordinate system corresponding to the gain-duty cycle angle mapping relationship, there are no discontinuities within the domain of the real-time voltage gain.

[0011] Optionally, determining the real-time duty cycle of any switch in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship includes: Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle angle of any switching transistor is determined. The real-time duty cycle of any switch is determined based on its real-time duty cycle angle.

[0012] Optionally, the gain-duty cycle angle mapping relationship is as follows:

[0013] in, θ 4 represents the real-time duty cycle angle of any of the switching transistors S4; M represents the real-time voltage gain.

[0014] Optionally, before determining the real-time duty cycle of any switch in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the method further includes: Based on Fourier transform, the intermediate voltage of the bridge arm of the primary side full bridge and the intermediate voltage of the bridge arm of the secondary side full bridge are determined. The equivalent circuit of the resonant cavity is determined. Based on the equivalent circuit of the resonant cavity, the intermediate voltage of the bridge arm of the primary full bridge and the intermediate voltage of the bridge arm of the secondary full bridge, the phasor of the equivalent bridge arm of the primary full bridge, the phasor of the equivalent bridge arm of the secondary full bridge and the impedance of the equivalent circuit are determined. Based on the equivalent bridge arm intermediate voltage phasor of the primary-side full bridge, the equivalent bridge arm intermediate voltage phasor of the secondary-side full bridge, the impedance of the equivalent circuit, and Kirchhoff's voltage law, determine the fundamental phasor of the primary-side resonant inductor on one side of the primary-side full bridge and the fundamental phasor of the secondary-side resonant inductor on one side of the secondary-side full bridge. The expression for the reactive power of the bidirectional resonant DAB converter is determined based on the fundamental phasor of the primary resonant inductor on one side of the primary full-bridge and the fundamental phasor of the secondary resonant inductor on one side of the secondary full-bridge. Based on the expression for the reactive power of the bidirectional resonant DAB converter and the reactive power optimization objective, the gain-duty cycle angle mapping relationship is determined.

[0015] Optionally, based on the real-time operating parameters of the bidirectional resonant DAB converter, the real-time switching frequencies of the switching transistors corresponding to the primary-side full-bridge and the secondary-side full-bridge are determined, including: Based on the real-time output voltage and the target output voltage, determine the real-time switching frequencies of the switching transistors corresponding to the primary-side full bridge and the secondary-side full bridge.

[0016] Secondly, this application provides an asymmetric modulation device for a bidirectional resonant DAB converter, wherein the bidirectional resonant DAB converter includes: a primary-side full-bridge, a resonant cavity, and a secondary-side full-bridge; the device includes: The determination module is used to determine the real-time duty cycle of any switch in the primary-side full bridge and the real-time switching frequency of the corresponding switch in the primary-side full bridge and the corresponding switch in the secondary-side full bridge, based on the real-time operating parameters of the bidirectional resonant DAB converter. The real-time operating parameters include the real-time input voltage, real-time output voltage and target output voltage of the bidirectional resonant DAB converter. The modulation module is used to control the switching states of the switching transistors corresponding to the primary-side full bridge and the secondary-side full bridge based on the real-time duty cycle of any switching transistor, the real-time duty cycle of other switching transistors located on the same bridge arm as the any switching transistor, the real-time duty cycle of other switching transistors located on different bridge arms as the any switching transistor, and the real-time switching frequency. The real-time duty cycles of other switching transistors located on the same bridge arm as the any switching transistor are complementary to the real-time duty cycle of the any switching transistor, so that the duration of the positive high level and the duration of the negative high level in the middle of the bridge arm of the primary-side full bridge are not equal. The real-time duty cycles of other switching transistors located on different bridge arms as the any switching transistor are preset duty cycles.

[0017] Optionally, the determining module determines the real-time duty cycle of any switch in the primary-side full-bridge based on the real-time operating parameters of the bidirectional resonant DAB converter, specifically for: Obtain the operating parameters of the bidirectional resonant DAB converter; The real-time voltage gain is obtained based on the real-time input voltage and the real-time output voltage; Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle of any switch in the primary-side full bridge is determined.

[0018] Optionally, in the Cartesian coordinate system corresponding to the gain-duty cycle angle mapping relationship, there are no discontinuities within the domain of the real-time voltage gain.

[0019] Optionally, the determining module determines the real-time duty cycle of any switch in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship, specifically for: Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle angle of any switching transistor is determined. The real-time duty cycle of any switch is determined based on its real-time duty cycle angle.

[0020] Optionally, the gain-duty cycle angle mapping relationship is as follows:

[0021] in, θ 4 is the switching transistor S 4 real-time duty cycle angle; M represents the real-time voltage gain.

[0022] Optionally, before determining the real-time duty cycle of any switch in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the determining module is further configured to: Based on Fourier transform, the intermediate voltage of the bridge arm of the primary side full bridge and the intermediate voltage of the bridge arm of the secondary side full bridge are determined. The equivalent circuit of the resonant cavity is determined. Based on the equivalent circuit of the resonant cavity, the intermediate voltage of the bridge arm of the primary full bridge and the intermediate voltage of the bridge arm of the secondary full bridge, the phasor of the equivalent bridge arm of the primary full bridge, the phasor of the equivalent bridge arm of the secondary full bridge and the impedance of the equivalent circuit are determined. Based on the equivalent bridge arm intermediate voltage phasor of the primary-side full bridge, the equivalent bridge arm intermediate voltage phasor of the secondary-side full bridge, the impedance of the equivalent circuit, and Kirchhoff's voltage law, determine the fundamental phasor of the primary-side resonant inductor on one side of the primary-side full bridge and the fundamental phasor of the secondary-side resonant inductor on one side of the secondary-side full bridge. The expression for the reactive power of the bidirectional resonant DAB converter is determined based on the fundamental phasor of the primary resonant inductor on one side of the primary full-bridge and the fundamental phasor of the secondary resonant inductor on one side of the secondary full-bridge. Based on the expression for the reactive power of the bidirectional resonant DAB converter and the reactive power optimization objective, the gain-duty cycle angle mapping relationship is determined.

[0023] Optionally, the determining module determines the real-time switching frequencies of the switching transistors corresponding to the primary-side full-bridge and the secondary-side full-bridge based on the real-time operating parameters of the bidirectional resonant DAB converter, specifically for: Based on the real-time output voltage and the target output voltage, determine the real-time switching frequencies of the switching transistors corresponding to the primary-side full bridge and the secondary-side full bridge.

[0024] Thirdly, this application provides an electronic device, including: a processor and a memory; The memory stores the instructions that the computer executes; The processor executes computer execution instructions stored in memory, causing the processor to perform the method as described in any of the first aspects.

[0025] Fourthly, this application provides a computer-readable storage medium including a program or instructions that, when run on a computer, execute the method described in any of the first aspects above.

[0026] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the method as described in any of the first aspects.

[0027] The asymmetric modulation method and apparatus for a bidirectional resonant DAB converter provided in this application determine the real-time duty cycle of any switch in the primary-side full-bridge and the real-time switching frequency of the corresponding switches in the primary and secondary full-bridges by using the real-time operating parameters of the bidirectional resonant DAB converter. It also complements the real-time duty cycles of other switches located on the same bridge arm as any given switch with the real-time duty cycle of that switch. Based on the real-time duty cycles of the primary and secondary full-bridge switches and their real-time switching frequencies, the switching states of the corresponding switches in the primary and secondary full-bridges are controlled. This asymmetric modulation of the bidirectional resonant DAB converter achieves asymmetric control of the duration of the positive high level and the duration of the negative high level at the midpoint of the primary-side full-bridge arm voltage, thereby optimizing reactive power. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A flowchart of an asymmetric modulation method for a bidirectional resonant DAB converter provided in an embodiment of this application; Figure 2 A flowchart of an asymmetric modulation method for a bidirectional resonant DAB converter provided in another embodiment of this application; Figure 3 This is a closed-loop control block diagram of an asymmetric modulation method for a bidirectional resonant DAB converter provided in an embodiment of this application; Figure 4 A diagram illustrating the derivation process of the gain-duty cycle angle mapping relationship provided in an embodiment of this application; Figure 5 A waveform diagram corresponding to a full-bridge topology provided in an embodiment of this application; Figure 6 This is a waveform diagram corresponding to a half-bridge topology provided in an embodiment of this application; Figure 7Equivalent circuit of a resonant cavity provided in one embodiment of this application; Figure 8 A coordinate graph of real-time duty cycle angle versus real-time voltage gain provided in an embodiment of this application; Figure 9 A coordinate graph of real-time duty cycle versus real-time voltage gain provided in an embodiment of this application; Figure 10 This is a circuit diagram of a bidirectional resonant DAB converter corresponding to a half-bridge topology provided in an embodiment of this application; Figure 11 A circuit diagram of a bidirectional resonant DAB converter corresponding to the real-time duty cycle change of the switch S4 provided in an embodiment of this application; Figure 12 A simulation diagram provided for one embodiment of this application; Figure 13 A simulation diagram provided for another embodiment of this application; Figure 14 A simulation diagram provided for yet another embodiment of this application; Figure 15 A schematic diagram of the structure of an asymmetric modulation device for a bidirectional resonant DAB converter provided in an embodiment of this application; Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application; Figure 17 A schematic diagram of the circuit structure of a bidirectional resonant DAB converter provided by the prior art. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0031] To address the issue of significant reactive power generation during the operation of bidirectional resonant DAB converters, existing technologies have proposed various methods, including single-phase control (SPS), dual-phase control (DPS), and even triple-phase control (TPS). For example, quantitative analysis of the return power characteristics under dual-phase control (DPS) has led to the proposal of an optimal modulation ratio to achieve minimum return power operation. However, this method still generates substantial reactive power when the voltage gain is mismatched. Another approach, based on DPS, involves establishing an equivalent reactive power model for bidirectional resonant DAB converters under EPS modulation and deriving the optimal phase shift angle through mathematical analysis to reduce current stress and reactive power. However, this method suffers from complex models and limited optimization accuracy. Yet another approach aims to achieve the minimum effective inductor current value by simultaneously adjusting the duty cycle of the switching transistors and three phase shift angles, further improving efficiency. However, this method introduces too many degrees of freedom, still relies on intelligent algorithm lookup tables, and the expression for the optimal effective inductor current value is overly complex, making it difficult to apply in practical engineering.

[0032] However, despite the achievements of various control strategies in reactive power optimization and current stress control, existing methods generally suffer from the following shortcomings: 1. Existing multi-phase-shift control and PWM modulation strategies are difficult to be compatible with both full-bridge and half-bridge topologies, thus limiting their application scope; 2. Existing asymmetric variable duty cycle modulation strategies can only achieve inconsistent zero-level durations on both sides of the high level, and cannot generate bridge arm midpoint voltages with asymmetrical positive and negative high-level durations, thus limiting further optimization of reactive power. 3. Current phase-shifting and duty cycle control methods generally suffer from problems such as a large number of control variables, complex modeling and analysis, lack of clear analytical relationship between modulation parameters and converter gain, difficulty in achieving online calculation and rapid adjustment, and insufficient engineering practicality.

[0033] Therefore, to solve at least one technical problem in the prior art, this application proposes an asymmetric modulation method and apparatus for a bidirectional resonant DAB converter. This method adjusts the real-time duty cycle of one of the switches in the primary-side full-bridge, as well as the switching frequencies of the switches in the primary and secondary-side full-bridge, to achieve a bridge arm midpoint voltage with inconsistent positive and negative high-level durations. This increases control freedom, allowing the harmonic content of the output voltage waveform to be changed by adjusting the duty cycle, thereby affecting the current waveform in the resonant network and optimizing reactive power. Furthermore, in this application, the real-time duty cycle of one of the switches in the primary-side full-bridge changes continuously with the voltage gain. As the voltage gain M of the bidirectional resonant DAB converter changes from 1 to 0.5, the real-time duty cycle of the switch gradually increases, and when M=0.5, the real-time duty cycle continuously changes to 1, achieving a smooth switch from a full-bridge topology to a half-bridge topology. Furthermore, this application establishes a Fourier series equivalent model of the bidirectional resonant DAB converter, which eliminates the need for complex operating mode judgments and allows for the unified derivation of mathematical expressions under this modulation method. This leads to the construction of a simplified analysis model, effectively reducing the complexity of control modeling and calculation. Subsequently, based on the goal of minimizing reactive power, the control parameters are solved in real time by calculating the optimal duty cycle corresponding to each voltage gain point, providing theoretical support for the online application of the control chip.

[0034] Figure 1 This is a flowchart illustrating an embodiment of an asymmetric modulation method for a bidirectional resonant DAB converter. The execution entity of the method shown in this embodiment is, for example, a device equipped with the aforementioned control chip, such as a controller corresponding to the DAB converter. This controller can be deployed on an electric vehicle or a charging device. The method shown in this embodiment is applied to, for example... Figure 17 The bidirectional resonant DAB converter shown is an example. Figure 1 As shown, the method in this embodiment includes: S101. Based on the real-time operating parameters of the bidirectional resonant DAB converter, determine the real-time duty cycle of any switch in the primary-side full bridge, and determine the real-time switching frequency of the corresponding switch in the primary-side full bridge and the corresponding switch in the secondary-side full bridge.

[0035] The real-time operating parameters include: the real-time input voltage, real-time output voltage, and target output voltage of the bidirectional resonant DAB converter.

[0036] In this step, the modulation method of the bidirectional resonant DAB converter is explained using an electric vehicle charging scenario as an example: During electric vehicle charging, fluctuations in grid voltage and the gradual increase in battery voltage as charging continues cause dynamic fluctuations in the input and output voltages of the bidirectional resonant DAB converter. Therefore, it is necessary to monitor the real-time input voltage, real-time output voltage, and target output voltage of the bidirectional resonant DAB converter in real time. The real-time input voltage of the bidirectional resonant DAB converter is denoted as V1, the real-time output voltage as V2, and the target output voltage, for example, can be the voltage of the electric vehicle's battery when fully charged, denoted as V0. 2ref .

[0037] For bidirectional resonant DAB converters, the reactive power (or return power) is mainly due to the phase difference between the square wave voltages on the primary and secondary sides of the transformer. Furthermore, due to the presence of the resonant network, the current phase may not be in sync with the voltage phase, causing some energy to be exchanged between the source and the load without being absorbed by the load. This increases the current stress and conduction losses of the switching devices, reducing efficiency. Therefore, the phase difference between the primary and secondary square wave voltages can be adjusted by regulating the duration of the positive and negative high-level signals in the intermediate voltage of the corresponding bridge arm of the primary full-bridge converter, thus optimizing reactive power.

[0038] During the charging process, fluctuations in grid voltage and the gradual increase in battery voltage as charging continues can cause changes in the operating parameters of the bidirectional resonant DAB converter. Therefore, in order to further optimize reactive power, in this embodiment, the real-time duty cycle of any switch in the primary-side full bridge is adjusted according to the real-time operating parameters of the bidirectional resonant DAB converter, so that the real-time duty cycle of any switch is adapted to the real-time operating parameters of the bidirectional resonant DAB converter, thereby improving the effect of reactive power optimization.

[0039] Furthermore, in order to accelerate the optimization of reactive power efficiency and enable the real-time output voltage to reach the target output voltage as soon as possible, this embodiment also determines the real-time switching frequency of the primary-side full-bridge corresponding switches S1-S4 and the secondary-side full-bridge corresponding switches Q1-Q4 based on the real-time operating parameters of the bidirectional resonant DAB converter.

[0040] S102. Based on the real-time duty cycle of any switch, the real-time duty cycle of other switches located on the same bridge arm as any switch, the real-time duty cycle of other switches located on different bridge arms as any switch, and the real-time switching frequency, control the switching state of the corresponding switches in the primary-side full bridge and the corresponding switches in the secondary-side full bridge.

[0041] Among them, the real-time duty cycle of other switches located on the same bridge arm as any switch is complementary to the real-time duty cycle of any switch, so that the middle voltage of the bridge arm of the primary side full bridge has unequal positive high level duration and negative high level duration, and the real-time duty cycle of other switches located on different bridge arms as any switch is a preset duty cycle.

[0042] In this step, any switch in the primary-side full bridge is used... Figure 1 Taking the switching transistor S4 as an example, since the real-time duty cycle D4 of the switching transistor S3 is set to be complementary to the real-time duty cycle D3 of the switching transistor S4, the real-time duty cycle D3 of the switching transistor S3 can be obtained after determining the real-time duty cycle D4 of the switching transistor S4.

[0043] Among them, such as Figure 5 As shown, by setting the real-time duty cycles of the switches located on the same bridge arm to be complementary, it is possible to achieve the phenomenon that the duration of the positive high level and the duration of the negative high level in the middle voltage of the primary side full bridge arm are not equal. For example, Figure 5 In the process, the real-time duty cycle of switch S4 is greater than that of switch S3, and the duration of the positive high level of the bridge arm midpoint voltage Uab of the primary-side full bridge is greater than the duration of the negative high level. When the real-time duty cycle of switch S4 is less than that of switch S3, the duration of the positive high level of the bridge arm midpoint voltage Uab is less than the duration of the negative high level. Thus, by adjusting the real-time duty cycle of switch S4, an asymmetrical bridge arm midpoint voltage Uab with unequal durations of positive and negative high levels can be achieved.

[0044] For the switching rings on other arms of the original full bridge, namely switching transistors S1 and S2, the corresponding duty cycle is the preset duty cycle, which is generally 0.5.

[0045] The determination of the real-time duty cycle of the switching transistors Q1-Q4 of the secondary full-bridge can be referred to existing technologies, and will not be elaborated here.

[0046] After determining the real-time duty cycle and switching frequency of the switches S1-S4 on the primary side of the full bridge and the switches Q1-Q4 on the secondary side of the full bridge, the corresponding complementary drive signals can be generated by the PWM generator to control all switches S1~S4 and Q1~Q4 of the full bridge topology, thereby optimizing reactive power.

[0047] In this embodiment, the real-time duty cycle of any switch in the primary-side full-bridge is determined by the real-time operating parameters of the bidirectional resonant DAB converter. The real-time switching frequencies of the corresponding switches in the primary and secondary full-bridges are also determined. Furthermore, the real-time duty cycles of other switches located on the same bridge arm as any given switch are complementary to the real-time duty cycle of that switch. Based on the real-time duty cycles of the primary and secondary full-bridge switches and their real-time switching frequencies, the switching states of the corresponding switches in the primary and secondary full-bridges are controlled. This asymmetric modulation of the bidirectional resonant DAB converter achieves asymmetric control of the duration of the positive and negative high-level voltages at the midpoint of the primary-side full-bridge arms, optimizing reactive power.

[0048] Optionally, based on the above embodiments, such as Figure 2 and Figure 3 As shown, the method provided in this embodiment includes: S201. Obtain the real-time input voltage, real-time output voltage, and target output voltage of the bidirectional resonant DAB converter.

[0049] In this step, the real-time input voltage V1 and real-time output voltage V2 are collected in real time using a voltage detection device. The target output voltage is the voltage set at the factory when the battery leaves the factory.

[0050] S202. Obtain the real-time voltage gain based on the real-time input voltage and the real-time output voltage.

[0051] In this step, the real-time voltage gain M is obtained according to Formula 1: Formula 1 Where N is the number of turns of the primary winding of the transformer in the bidirectional resonant DAB converter.

[0052] S203. Determine the real-time duty cycle of any switch in the primary-side full bridge based on the real-time voltage gain and the gain-duty cycle angle mapping relationship.

[0053] In this step, the gain-duty cycle angle mapping relationship is a predetermined mapping relationship between real-time voltage gain and duty cycle angle. Based on the real-time voltage gain, the real-time duty cycle of any switch in the primary-side full bridge can be obtained, that is, the real-time duty cycle of switch S4 can be obtained.

[0054] Optionally, in the Cartesian coordinate system corresponding to the gain-duty cycle angle mapping relationship, there are no discontinuities within the domain of the real-time voltage gain, where the domain of the real-time voltage gain is [0, 1].

[0055] Optionally, one specific implementation of S203 is as follows: S2031. Determine the real-time duty cycle angle of any switching transistor based on the real-time voltage gain and the gain-duty cycle angle mapping relationship.

[0056] Specifically, the gain-duty cycle angle mapping relationship is shown in Formula 2: Formula 2 in, θ 4 represents the real-time duty cycle angle of the switching transistor S4.

[0057] The derivation of Formula 2 is described below and will not be repeated here.

[0058] S2032. Determine the real-time duty cycle of any switching transistor based on its real-time duty cycle angle.

[0059] Specifically, according to θ 4 = 2π D 4. Obtain the real-time duty cycle D4 of the switching transistor S4.

[0060] S204. Based on the real-time output voltage and the target output voltage, determine the real-time switching frequency of the switching transistors corresponding to the primary-side full-bridge and the secondary-side full-bridge.

[0061] In this step, during the charging process, at the beginning of charging, the actual voltage of the battery is relatively small, that is, the real-time output voltage is relatively small, resulting in a large difference between the real-time output voltage and the target output voltage. As the battery charges, the real-time output voltage gradually increases, which gradually reduces the difference between the real-time output voltage and the target output voltage until the real-time output voltage reaches the target output voltage.

[0062] Therefore, during the charging process, the switching frequency is dynamically adjusted by the PI controller based on the difference between the real-time output voltage and the target output voltage to compensate for the voltage gain, so that the real-time output voltage can reach the target output voltage.

[0063] S205. Based on the real-time duty cycle of any switch, the real-time duty cycle of other switches located on the same bridge arm as any switch, the real-time duty cycle of other switches located on different bridge arms as any switch, and the real-time switching frequency, control the switching state of the corresponding switches in the primary-side full bridge and the corresponding switches in the secondary-side full bridge.

[0064] Among them, the real-time duty cycle of other switches located on the same bridge arm as any switch is complementary to the real-time duty cycle of any switch, so that the middle voltage of the bridge arm of the primary side full bridge has unequal positive high level duration and negative high level duration, and the real-time duty cycle of other switches located on different bridge arms as any switch is a preset duty cycle.

[0065] The specific implementation of S205 in this step can be found in S102, and will not be repeated here.

[0066] In this embodiment, the real-time duty cycle of the switching transistor S4 is continuously changed with the change of real-time voltage gain through the gain-duty cycle angle mapping relationship, so as to achieve smooth switching between full bridge and half bridge.

[0067] Figure 4 This diagram illustrates the derivation process of the gain-duty cycle angle mapping relationship provided in one embodiment of this application. Figure 4 As shown, the method includes: S401. Based on Fourier transform, determine the intermediate voltage of the bridge arm of the primary side full bridge and the intermediate voltage of the bridge arm of the secondary side full bridge. S402. Determine the equivalent circuit of the resonant cavity. Based on the equivalent circuit of the resonant cavity, as well as the intermediate voltage of the bridge arm of the primary full-bridge and the intermediate voltage of the bridge arm of the secondary full-bridge, determine the phasor of the intermediate voltage of the equivalent bridge arm of the primary full-bridge, the phasor of the intermediate voltage of the equivalent bridge arm of the secondary full-bridge, and the impedance of the equivalent circuit. S403. Based on the equivalent bridge arm intermediate voltage phasor of the primary side full bridge, the equivalent bridge arm intermediate voltage phasor of the secondary side full bridge, the impedance of the equivalent circuit, and Kirchhoff's voltage law, determine the fundamental phasor of the primary resonant inductor on one side of the primary side full bridge and the fundamental phasor of the secondary resonant inductor on one side of the secondary side full bridge corresponding to the equivalent circuit of the resonant cavity. S404. Based on the fundamental phasor of the primary resonant inductor on one side of the primary full-bridge and the fundamental phasor of the secondary resonant inductor on one side of the secondary full-bridge, determine the expression for the reactive power of the bidirectional resonant DAB converter. S405. Based on the expression for the reactive power of the bidirectional resonant DAB converter and the reactive power optimization objective, determine the gain-duty cycle angle mapping relationship.

[0068] right Figure 4 The detailed explanation of the derivation process is as follows: use Figure 2 The method shown involves setting the real-time duty cycles of switching transistors S1 and S2 to a fixed 0.5, and controlling the real-time duty cycle D4 of switching transistor S4 via... Figure 2 The method shown allows for adjustment where the real-time duty cycle of switch S3 is complementary to that of switch S4, thereby achieving the desired effect. Figure 5 The diagram shows the bridge arm mid-voltage Uab of an asymmetrical primary-side full bridge where the durations of the positive and negative high-level signals are unequal. According to... Figure 6 It can be seen that when the real-time duty cycle of the switching transistor S4 is 1, the bidirectional resonant DAB converter switches from full-bridge mode to half-bridge mode. At the same time, the voltage gain M is compensated in real time by dynamically adjusting the switching period Ts, i.e. the switching frequency fs.

[0069] The waveforms of the intermediate voltage Uab of the primary-side full-bridge arm and the intermediate voltage Ucd of the secondary-side full-bridge arm are shown in the figure. Figure 5 and Figure 6 As shown, since both the intermediate voltage Uab of the primary-side full-bridge arm and the intermediate voltage Ucd of the secondary-side full-bridge arm are square waves, with Uab being an asymmetrical square wave and Ucd a symmetrical square wave, the intermediate voltage Uab of the primary-side full-bridge arm acquires even-order square waves and odd-order harmonics, while the intermediate voltage Ucd of the secondary-side full-bridge arm acquires odd-order harmonics. Through Fourier transform, the expressions for the intermediate voltages Uab of the primary-side full-bridge arm and Ucd of the secondary-side full-bridge arm are shown in Equation 3: Formula 3 in, ω =2π f s The switching angular frequency, fs Let k be the switching frequency, k be the harmonic order, and the coefficients A0, Ak, Bk, Ck, and Dk satisfy the following: Formula 4 Figure 7 Let Z be the equivalent circuit of the resonant cavity, where Z is the equivalent impedance. U̇ab is the equivalent bridge arm mid-voltage phasor of the primary-side full bridge, and NU̇cd is the voltage phasor of the secondary side referred to the primary side, i.e., the equivalent bridge arm mid-voltage phasor of the secondary-side full bridge. Since the bidirectional resonant DAB converter contains a resonant capacitor Cr, the DC component of the bridge arm mid-point voltage can be filtered out. The k-th harmonic voltage phasor entering the resonant cavity is derived from formulas 3 and 4 as follows: Formula 5 according to Figure 7 The expression for the equivalent impedance Z is: Formula 6 Since the fundamental component accounts for a large proportion of the output of a bidirectional resonant DAB converter, analyzing only the fundamental component is sufficient to accurately characterize the voltage and current characteristics. Figure 7 Based on Kirchhoff's voltage law, the fundamental phasor İ of the primary-side resonant inductor on one side of the primary-side full-bridge can be obtained. Lr1 The secondary resonant inductor phasor on one side of the secondary full-bridge is referred to the fundamental phasor on the primary side. Lr2 for: Formula 7 According to formulas 5-7, we can obtain: Formula 8 Therefore, the expression for the reactive power P of the bidirectional resonant DAB converter is determined according to Formula 8; Formula 9 The objective of this application, namely the reactive power optimization objective, is to minimize reactive power. Therefore, according to Formula 9, The closer the value is to 0, the smaller the reactive power. Therefore, the expression for the gain-duty cycle angle mapping relationship between the real-time duty cycle angle of switch S4 and the real-time voltage gain M is:

[0070] like Figure 8 and Figure 9 As shown, based on the expression for the gain-duty cycle angle mapping relationship, the coordinate diagrams of the real-time duty cycle angle of switch S4 and the real-time duty cycle of switch S4 relative to the real-time voltage gain M can be obtained. Figure 8 and Figure 9 It can be seen that, to achieve the minimum reactive power, when 0.5 < M ≤ 1, the real-time duty cycle of switch S4 will continuously change with M. When the real-time voltage gain is 0.5, it switches from a full-bridge structure to a half-bridge structure with a duty cycle of 1 for switch S4. When the real-time voltage gain M ≤ 0.5, the real-time duty cycle of switch S4 is 1, which is optimal for both half-bridge configurations. The circuit structures for real-time voltage gain M ≤ 0.5 and 0.5 < M ≤ 1 are as follows: Figure 10 and Figure 11 As shown.

[0071] It should be noted that in existing technologies, a DC bias voltage exists across the resonant capacitor Cr. Since the capacitor voltage cannot change abruptly, if the modulation mode suddenly switches, for example, from a full-bridge to a half-bridge, the resonant capacitor Cr will be unable to instantly establish the DC bias voltage required for the new modulation mode. This leads to a significant resonant current inrush on the primary and secondary sides, severely affecting the converter's operational stability and reliability. Furthermore, abrupt changes in the modulation mode may also cause output voltage drops or spikes during the switching transient, posing a potential hazard to the load equipment.

[0072] However, in this application, the voltage at the midpoint of the bridge arm has waveforms with unequal durations of positive and negative high levels, resulting in a DC bias A0 with a value of (D4-0.5)V1. When converted to a half-bridge, D4=1, and the DC bias is 0.5V1. This is based on the expression for the gain-duty cycle angle mapping relationship and... Figure 8 and Figure 9 It can be seen that the adoption Figure 2The modulation method shown enables the real-time duty cycle of switch S4 to change continuously and monotonically with the real-time voltage gain M. Therefore, the voltage change across the resonant capacitor Cr transitions smoothly, avoiding large DC bias voltage jumps. This effectively prevents drastic fluctuations in the resonant current and ensures smooth switching of the bidirectional resonant DAB converter under different gain conditions. Specifically, when the real-time voltage gain M approaches 0.5, the DC bias across the resonant capacitor Cr corresponding to this modulation method also exhibits a natural transition state, solving the problem of the DC bias jumping instantaneously from 0 to 0.5Vin during traditional full-bridge and half-bridge switching. Therefore, this modulation method also possesses the ability to achieve smooth switching between full-bridge and half-bridge modes.

[0073] The following simulation verification is performed to validate the asymmetric modulation method of the bidirectional resonant DAB converter proposed in this application. Figure 12 The simulation diagram corresponds to M=0.4 and D4=0.5. Figure 13 The simulation diagram corresponds to M=0.5 and D4=0.5. Figure 14 The simulation diagram is for M=0.6 and D4=0.875.

[0074] from Figures 12-14 It can be seen that the optimal reactive power is achieved under half-bridge conditions when M=0.4 and M=0.5. When M=0.6, the duty cycle is 0.875, the inductor current is positive when the voltage at the midpoint of the bridge arm is high, and the inductor current is basically negative when the voltage at the midpoint of the bridge arm is low, thus achieving the optimal reactive power.

[0075] Figure 15 This is a schematic diagram of the structure of an asymmetric modulation device for a bidirectional resonant DAB converter provided in an embodiment of this application. Figure 15 The apparatus shown includes a determining module 1401 and a modulation module 1402.

[0076] The determination module 1401 is used to determine the real-time duty cycle of any switch in the primary-side full bridge and the real-time switching frequency of the corresponding switch in the primary-side full bridge and the corresponding switch in the secondary-side full bridge based on the real-time operating parameters of the bidirectional resonant DAB converter. The real-time operating parameters include the real-time input voltage, real-time output voltage and target output voltage of the bidirectional resonant DAB converter. The modulation module 1402 is used to control the switching states of the switching transistors corresponding to the primary-side full bridge and the secondary-side full bridge based on the real-time duty cycle of any switching transistor, the real-time duty cycle of other switching transistors located on the same bridge arm as the any switching transistor, the real-time duty cycle of other switching transistors located on different bridge arms as the any switching transistor, and the real-time switching frequency. The real-time duty cycle of other switching transistors located on the same bridge arm as the any switching transistor is complementary to the real-time duty cycle of the any switching transistor, so that the middle voltage of the bridge arm of the primary-side full bridge exhibits unequal durations of positive and negative high levels. Furthermore, the real-time duty cycle of other switching transistors located on different bridge arms as the any switching transistor is a preset duty cycle.

[0077] Optionally, the determining module 1401 determines the real-time duty cycle of any switch in the primary-side full bridge based on the real-time operating parameters of the bidirectional resonant DAB converter, specifically for: Obtain the operating parameters of the bidirectional resonant DAB converter; The real-time voltage gain is obtained based on the real-time input voltage and the real-time output voltage; Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle of any switch in the primary-side full bridge is determined.

[0078] Optionally, in the Cartesian coordinate system corresponding to the gain-duty cycle angle mapping relationship, there are no discontinuities within the domain of the real-time voltage gain.

[0079] Optionally, the determining module 1401 determines the real-time duty cycle of any switching transistor in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship, specifically for: Based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the real-time duty cycle angle of any switching transistor is determined. The real-time duty cycle of any switch is determined based on its real-time duty cycle angle.

[0080] Optionally, the gain-duty cycle angle mapping relationship is as follows:

[0081] in, θ 4 is the switching transistor S 4 real-time duty cycle angle; M represents the real-time voltage gain.

[0082] Optionally, before determining the real-time duty cycle of any switch in the primary-side full-bridge of the bidirectional resonant DAB converter based on the real-time voltage gain and gain-duty cycle angle mapping relationship, the determining module 1401 is further configured to: Based on Fourier transform, the intermediate voltage of the bridge arm of the primary side full bridge and the intermediate voltage of the bridge arm of the secondary side full bridge are determined. The equivalent circuit of the resonant cavity is determined. Based on the equivalent circuit of the resonant cavity, the intermediate voltage of the bridge arm of the primary full bridge and the intermediate voltage of the bridge arm of the secondary full bridge, the phasor of the equivalent bridge arm of the primary full bridge, the phasor of the equivalent bridge arm of the secondary full bridge and the impedance of the equivalent circuit are determined. Based on the equivalent bridge arm intermediate voltage phasor of the primary-side full bridge, the equivalent bridge arm intermediate voltage phasor of the secondary-side full bridge, the impedance of the equivalent circuit, and Kirchhoff's voltage law, determine the fundamental phasor of the primary-side resonant inductor on one side of the primary-side full bridge and the fundamental phasor of the secondary-side resonant inductor on one side of the secondary-side full bridge. The expression for the reactive power of the bidirectional resonant DAB converter is determined based on the fundamental phasor of the primary resonant inductor on one side of the primary full-bridge and the fundamental phasor of the secondary resonant inductor on one side of the secondary full-bridge. Based on the expression for the reactive power of the bidirectional resonant DAB converter and the reactive power optimization objective, the gain-duty cycle angle mapping relationship is determined.

[0083] Optionally, the determining module 1401 determines the real-time switching frequencies of the switching transistors corresponding to the primary-side full-bridge and the secondary-side full-bridge based on the real-time operating parameters of the bidirectional resonant DAB converter, specifically for: Based on the real-time output voltage and the target output voltage, determine the real-time switching frequencies of the switching transistors corresponding to the primary-side full bridge and the secondary-side full bridge.

[0084] The dust accumulation detection device on the surface of the photovoltaic panel provided in this application embodiment can be referred to the above method embodiment for its specific implementation process. The implementation principle and technical effect are similar, and will not be repeated here.

[0085] Figure 16 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may be an electronic device equipped with the aforementioned control chip, such as a charging station or a charging gun. Figure 16 As shown, the electronic device includes a processor 1501 and a memory 1502.

[0086] The memory 1502 stores computer-executed instructions.

[0087] The processor 1501 executes the computer execution instructions stored in the memory 1502, causing the processor 1501 to perform the method described in any of the above embodiments.

[0088] The electronic device provided in this application embodiment can be referred to the above method embodiment for its specific implementation process. The implementation principle and technical effect are similar, and will not be repeated here.

[0089] In the above Figure 16 In the illustrated embodiments, it should be understood that the processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), etc. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the method disclosed in this invention can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor.

[0090] The memory may include high-speed RAM, and may also include non-volatile storage (NVM), such as at least one disk storage.

[0091] The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, the buses shown in the accompanying drawings are not limited to a single bus or a single type of bus.

[0092] This application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the method shown in the above-described method embodiments.

[0093] The aforementioned computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, magnetic disk, or optical disk. The readable storage medium can be any available medium accessible to a general-purpose or special-purpose computer.

[0094] An exemplary readable storage medium is coupled to a processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can reside in an application-specific integrated circuit (ASIC). Alternatively, the processor and the readable storage medium can exist as discrete components in the device.

[0095] Those skilled in the art will understand that all or part of the steps of the above-described method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments; and the aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method of asymmetric modulation of a bidirectional resonant DAB converter, characterized in that, The bidirectional resonant DAB converter comprises a primary full-bridge, a resonant cavity and a secondary full-bridge; and the method comprises: According to real-time working parameters of the bidirectional resonant DAB converter, determining a real-time duty cycle of any switching tube in the primary full-bridge, and determining real-time switching frequencies of corresponding switching tubes of the primary full-bridge and the secondary full-bridge, wherein the real-time working parameters comprise real-time input voltage, real-time output voltage and target output voltage of the bidirectional resonant DAB converter; According to the real-time duty cycle of the any switching tube, real-time duty cycles of other switching tubes located in the same bridge arm as the any switching tube, real-time duty cycles of other switching tubes located in different bridge arms from the any switching tube and the real-time switching frequencies, controlling switching states of the corresponding switching tubes of the primary full-bridge and the secondary full-bridge, wherein the real-time duty cycles of the other switching tubes located in the same bridge arm as the any switching tube are complementary to the real-time duty cycle of the any switching tube, so that there is a phenomenon that a positive high level duration and a negative high level duration of a bridge arm intermediate voltage of the primary full-bridge are not equal, and the real-time duty cycles of the other switching tubes located in different bridge arms from the any switching tube are preset duty cycles.

2. The method of claim 1, wherein, The method comprises: According to real-time working parameters of the bidirectional resonant DAB converter, determining a real-time duty cycle of any switching tube in the primary full-bridge, and determining real-time switching frequencies of corresponding switching tubes of the primary full-bridge and the secondary full-bridge, wherein the real-time working parameters comprise real-time input voltage, real-time output voltage and target output voltage of the bidirectional resonant DAB converter; According to the real-time input voltage and the real-time output voltage, obtaining a real-time voltage gain; According to the real-time voltage gain and a gain-duty cycle angle mapping relationship, determining the real-time duty cycle of the any switching tube in the primary full-bridge.

3. The method of claim 2, wherein, The gain-duty cycle angle mapping relationship corresponds to a plane rectangular coordinate system without an interval point in a definition domain of the real-time voltage gain.

4. The method according to claim 2 or 3, characterized in that, The method comprises: According to the real-time voltage gain and the gain-duty cycle angle mapping relationship, determining a real-time duty cycle angle of the any switching tube; According to the real-time duty cycle angle of the any switching tube, determining the real-time duty cycle of the any switching tube.

5. The method of claim 4, wherein, The gain-duty cycle angle mapping relationship is: ； wherein, θ 4 is the real-time duty angle of the any switch tube S 4. M is the real-time voltage gain.

6. The method of claim 1, wherein, Before the determining, the method further comprises: Based on Fourier transform, determining a bridge arm intermediate voltage of the primary full-bridge and a bridge arm intermediate voltage of the secondary full-bridge; Determining an equivalent circuit of the resonant cavity, and according to the equivalent circuit of the resonant cavity, the bridge arm intermediate voltage of the primary full-bridge and the bridge arm intermediate voltage of the secondary full-bridge, determining an equivalent bridge arm intermediate voltage phasor of the primary full-bridge, an equivalent bridge arm intermediate voltage phasor of the secondary full-bridge and an impedance of the equivalent circuit; determine, according to the equivalent bridge arm intermediate voltage phasor of the primary side full bridge, the equivalent bridge arm intermediate voltage phasor of the secondary side full bridge, and the impedance of the equivalent circuit, and Kirchhoff's voltage law, a fundamental wave phasor of a primary side resonant inductance of one side of the primary side full bridge corresponding to the equivalent circuit of the resonant cavity, and a fundamental wave phasor of a secondary side resonant inductance phasor of one side of the secondary side full bridge; determine, according to the fundamental wave phasor of the primary side resonant inductance of one side of the primary side full bridge and the fundamental wave phasor of the secondary side resonant inductance phasor of one side of the secondary side full bridge, an expression of the reactive power of the bidirectional resonant DAB converter; determine, according to the expression of the reactive power of the bidirectional resonant DAB converter and a reactive power optimization target, the gain-duty angle mapping relationship.

7. The method of claim 2, wherein, determine, according to real-time working parameters of the bidirectional resonant DAB converter, real-time switching frequencies of the switching tubes corresponding to the primary side full bridge and the switching tubes corresponding to the secondary side full bridge, including: determine, according to the real-time output voltage and the target output voltage, the real-time switching frequencies of the switching tubes corresponding to the primary side full bridge and the switching tubes corresponding to the secondary side full bridge.

8. A bidirectional resonant DAB converter asymmetric modulation apparatus, characterized in that, The bidirectional resonant DAB converter includes a primary side full bridge, a resonant cavity, and a secondary side full bridge; and the device includes: a determination module configured to determine, according to real-time working parameters of the bidirectional resonant DAB converter, a real-time duty cycle of any switching tube of the primary side full bridge, and real-time switching frequencies of the switching tubes corresponding to the primary side full bridge and the switching tubes corresponding to the secondary side full bridge, wherein the real-time working parameters include a real-time input voltage, a real-time output voltage, and a target output voltage of the bidirectional resonant DAB converter; a modulation module configured to control switching states of the switching tubes corresponding to the primary side full bridge and the switching tubes corresponding to the secondary side full bridge according to the real-time duty cycle of the any switching tube, real-time duty cycles of other switching tubes located in the same bridge arm as the any switching tube, real-time duty cycles of other switching tubes located in different bridge arms from the any switching tube, and the real-time switching frequencies, wherein the real-time duty cycles of the other switching tubes located in the same bridge arm as the any switching tube are complementary to the real-time duty cycle of the any switching tube, so that a phenomenon that a positive high level duration and a negative high level duration of a bridge arm intermediate voltage of the primary side full bridge are not equal exists, and the real-time duty cycles of the other switching tubes located in different bridge arms from the any switching tube are preset duty cycles.

9. An electronic device, comprising: including: a processor and a memory; the memory stores computer execution instructions; the processor executes the computer execution instructions stored in the memory, so that the processor executes the method of any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer execution instructions, and when the processor executes the computer execution instructions, the method of any one of claims 1-7 is implemented.

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