Isolation level direct current converter transfer function construction method and device, and medium

Abstract

The invention relates to an isolation level direct current converter transfer function construction method and device and a medium, and the method comprises the steps: determining a calculation model of the output power of a direct current converter, and determining a calculation model of an input average current and an output average current based on the calculation model of the output power; establishing an average switch equivalent model of the DC converter, introducing disturbance quantity into the average switch equivalent model, and substituting the disturbance quantity into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model; and converting the average switch equivalent model into a small signal model, and obtaining a voltage transfer function of the DC converter based on the small signal model. According to the invention, the complexity of the model can be reduced, and the behavior of the converter in the whole switching period can be uniformly expressed.

Description

Technical Field

[0001] The present invention relates to the technical field of converters, and in particular to a method, a device and a medium for constructing a transfer function of an isolation-level direct current converter. Background Art

[0002] In the fields of distributed power generation, electric vehicles, UPS (Uninterruptible Power Supply) and SST (Solid State Transformer), switching converters with isolated bidirectional working capabilities have broad prospects. The transmission power level of isolated bidirectional DC / DC converters is proportional to the number of switches. Among them, the DAB (Dual Active Bridge) bidirectional active bridge with eight switches has been widely studied due to its advantages such as structural symmetry, bidirectional energy flow, and easy soft switching. In order to design an effective control strategy, it is necessary to establish a mathematical model of the converter. Through the mathematical model, the dynamic response and stability of the converter can be analyzed, so as to design a controller that can meet specific performance requirements. When the number of switches is large and the switching sequence is complex, it is more complicated to use the converter dynamics equation to establish the mathematical model of the converter, and it cannot uniformly describe the behavior of the converter in the entire switching cycle. Therefore, it is necessary to construct an isolation-level DC / DC converter transfer function model to replace the complex mathematical model. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method, device, equipment and medium for constructing a transfer function of an isolation-level DC converter, which can reduce the complexity of the model and can uniformly describe the behavior of the converter in the entire switching cycle.

[0004] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for constructing a transfer function of an isolation-level DC converter, comprising the following steps:

[0005] Determine a calculation model for the output power of the DC converter, and determine a calculation model for the input average current and the output average current based on the calculation model for the output power;

[0006] Establishing an average switch equivalent model of a DC converter, introducing a disturbance amount into the average switch equivalent model, and bringing the disturbance amount into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model;

[0007] The average switch equivalent model with the introduced disturbance quantity is converted into a small signal model, and the voltage transfer function of the DC converter is obtained based on the small signal model.

[0008] The calculation model of the output power of the DC converter is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

[0009] The calculation model of the input average current is expressed as: Where i1 is the average input current.

[0010] The calculation model of the output average current is expressed as: Among them, i2 is the output average current.

[0011] The disturbance input current model is expressed as: in, is the disturbed input current, n is the turns ratio between the primary and secondary sides of the transformer, V dc2 is the output voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the output voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0012] The disturbance output current model is expressed as: in, is the disturbed output current, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the input voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0013] The voltage transfer function of the DC converter includes a transfer function from input to output and a transfer function from controlling the duty cycle to output voltage.

[0014] The input to output transfer function is expressed as: Among them, G w (s) is the transfer function from input to output, d(s)=0 indicates that the duty cycle function remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0015] The transfer function of the control duty cycle to output voltage is expressed as: Among them, G vd(s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s) = 0 means that the input voltage of the DAB converter remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0016] The technical solution adopted by the present invention to solve the technical problem is: to provide an isolation-level DC converter transfer function construction device, comprising:

[0017] A determination module, used to determine a calculation model of the output power of the DC converter, and determine a calculation model of the input average current and the output average current based on the calculation model of the output power;

[0018] An establishment module is used to establish an average switch equivalent model of a DC converter, introduce a disturbance amount into the average switch equivalent model, and bring the disturbance amount into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model;

[0019] The conversion module is used to convert the average switch equivalent model with the introduced disturbance into a small signal model, and obtain the voltage transfer function of the DC converter based on the small signal model.

[0020] The calculation model of the output power determined by the determination module is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

[0021] The calculation model of the input average current determined by the determination module is expressed as: Where i1 is the average input current.

[0022] The calculation model of the output average current determined by the determination module is expressed as: Among them, i2 is the output average current.

[0023] The disturbance input current model established by the establishment module is expressed as: in, is the disturbed input current, n is the turns ratio between the primary and secondary sides of the transformer, V dc2 is the output voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the output voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0024] The disturbance output current model established by the establishment module is expressed as: in, is the disturbed output current, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the input voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0025] The voltage transfer function of the DC converter obtained by the conversion module includes a transfer function from input to output and a transfer function from controlling the duty cycle to the output voltage.

[0026] The input to output transfer function is expressed as: Among them, G w (s) is the transfer function from input to output, d(s)=0 indicates that the duty cycle function remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0027] The transfer function of the control duty cycle to output voltage is expressed as: Among them, G vd (s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s) = 0 means that the input voltage of the DAB converter remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0028] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned isolation-level DC converter transfer function construction method when executing the computer program.

[0029] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned isolation-level DC converter transfer function construction method are implemented.

[0030] Beneficial Effects

[0031] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: the present invention adds disturbance to the DAB signal model for analysis, and obtains the transfer function of a single DAB output current and output voltage. Compared with the existing mathematical model of the converter established by using the converter dynamics equation, the transfer function model constructed by the present invention has lower complexity and can uniformly describe the behavior of the converter in the entire switching cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart showing the steps of a method for constructing a transfer function of an isolation-level DC converter according to a first embodiment of the present invention.

[0033] Figure 2 A schematic diagram showing the topology of the DAB main circuit in the first embodiment of the present invention is shown.

[0034] Figure 3 A schematic diagram showing an average switch equivalent model of DAB in the first embodiment of the present invention is shown.

[0035] Figure 4 A schematic diagram of a DAB small signal model in the first embodiment of the present invention is shown. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0037] The first embodiment of the present invention relates to a method for constructing a transfer function of an isolation-level DC converter, such as Figure 1 As shown, this embodiment is described by taking a DAB converter as an example, wherein the DAB converter transfer function includes a current part and a voltage part, and specifically includes the following steps:

[0038] Step 101: determine a calculation model for the output power of a DAB converter, and determine calculation models for an input average current and an output average current based on the calculation model for the output power.

[0039] like Figure 2As shown in the figure, in order to study the influence of the parameters such as capacitor and inductor in the DAB converter and the controller parameters on the DAB output characteristics, it is necessary to first model and analyze the DAB to provide a theoretical basis for the subsequent controller design. The modeling of the DAB converter can be done by using the small signal analysis method, adding disturbances to the DAB small signal model for analysis.

[0040] The calculation model of the output power of the DAB converter is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

[0041] Based on the output power of the DAB converter, the calculation model of the input average current and the calculation model of the output average current can be obtained. Among them, the calculation model of the input average current can be expressed as: Among them, i1 is the input average current; the calculation model of the output average current can be expressed as: Among them, i2 is the output average current.

[0042] Step 102, establishing an average switch equivalent model of the DAB converter, introducing a disturbance into the average switch equivalent model, and bringing the disturbance into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model.

[0043] Figure 3 The schematic diagram of the average switch equivalent model of DAB is shown, C1 and C2 are the input side capacitor and output side capacitor of the DAB converter respectively, and R0 is the load connected to the output side. In the switch equivalent model, the full bridge circuit is equivalent to two current sources i1 and i2, so there is no need to consider the specific working conditions inside the converter of each switch state, which can simplify the DAB analysis.

[0044] This step uses the perturbation method to solve the average switch equivalent model, that is, the input current state variable I1, the output current state variable I2, the input voltage state variable V dc1 , output variable state variable V dc2 , the phase-shift duty cycle state variable D introduces small disturbances It is expressed as:

[0045]

[0046] Substituting the disturbance into the calculation model of the input average current, we can get:

[0047]

[0048] Ignoring the steady-state parameters and second-order and higher AC terms in the formula, we can obtain:

[0049]

[0050] Similarly, we can get:

[0051] The obtained disturbance input current model and disturbance output current model are the current part of the DAB converter transfer function.

[0052] Step 103: convert the average switch equivalent model with the introduced disturbance into a small signal model, and then determine the voltage transfer function (ie, the voltage part of the DAB converter transfer function).

[0053] In order to further transform the model, the following substitutions can be made: The small signal model after substitution is as follows Figure 4 The small signal model can be used to obtain the transfer function from input to output and the transfer function from control duty cycle to output voltage.

[0054] The transfer function from input to output is expressed as:

[0055]

[0056] Among them, G w (s) is the transfer function from input to output, d is the phase shift duty cycle, d(s) is the function of the duty cycle, d(s)=0 means that the duty cycle function remains unchanged, and s represents the Laplace operator.

[0057] The transfer function from control duty cycle to output voltage is expressed as:

[0058]

[0059] Among them, G vd (s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s)=0 means that the input voltage of the DAB converter remains unchanged.

[0060] It can be seen that the present invention adopts the small signal analysis method to obtain the transfer functions of the output current and output voltage of a single DAB, and then according to the above transfer functions, the design analysis of the current and voltage controller of the DAB can also be carried out.

[0061] A second embodiment of the present invention relates to a device for constructing a transfer function of an isolation-level DC converter, comprising:

[0062] A determination module, used to determine a calculation model of the output power of the DC converter, and determine a calculation model of the input average current and the output average current based on the calculation model of the output power;

[0063] An establishment module is used to establish an average switch equivalent model of a DC converter, introduce a disturbance amount into the average switch equivalent model, and bring the disturbance amount into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model;

[0064] The conversion module is used to convert the average switch equivalent model with the introduced disturbance into a small signal model, and obtain the voltage transfer function of the DC converter based on the small signal model.

[0065] The calculation model of the output power determined by the determination module is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

[0066] The calculation model of the input average current determined by the determination module is expressed as: Where i1 is the average input current.

[0067] The calculation model of the output average current determined by the determination module is expressed as: Among them, i2 is the output average current.

[0068] The disturbance input current model established by the establishment module is expressed as: in, is the disturbed input current, n is the turns ratio between the primary and secondary sides of the transformer, V dc2 is the output voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the output voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0069] The disturbance output current model established by the establishment module is expressed as: in, is the disturbed output current, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the input voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

[0070] The voltage transfer function of the DC converter obtained by the conversion module includes a transfer function from input to output and a transfer function from controlling the duty cycle to the output voltage.

[0071] The input to output transfer function is expressed as: Among them, G w (s) is the transfer function from input to output, d(s)=0 indicates that the duty cycle function remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0072] The transfer function of the control duty cycle to output voltage is expressed as: Among them, G vd (s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s) = 0 means that the input voltage of the DAB converter remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

[0073] The third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the isolation-level DC converter transfer function construction method of the first embodiment when executing the computer program.

[0074] The fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method for constructing a transfer function of an isolation-level DC converter of the first embodiment are implemented.

[0075] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0076] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0079] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for constructing a transfer function of an isolation-level DC converter, characterized in that: The following steps are involved: Determine a calculation model for the output power of the DC converter, and determine a calculation model for the input average current and the output average current based on the calculation model for the output power; Establishing an average switch equivalent model of a DC converter, introducing a disturbance amount into the average switch equivalent model, and bringing the disturbance amount into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model; The average switch equivalent model with the introduced disturbance quantity is converted into a small signal model, and the voltage transfer function of the DC converter is obtained based on the small signal model.

2. The isolation-level DC converter transfer function construction method according to claim 1, characterized in that: The calculation model of the output power of the DC converter is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

3. The isolation-level DC converter transfer function construction method according to claim 2, characterized in that: The calculation model of the input average current is expressed as: Where i1 is the average input current.

4. The isolation-level DC converter transfer function construction method according to claim 2, characterized in that: The calculation model of the output average current is expressed as: Among them, i2 is the output average current.

5. The isolation-level DC converter transfer function construction method according to claim 1, characterized in that: The disturbance input current model is expressed as: in, is the disturbed input current, n is the turns ratio between the primary and secondary sides of the transformer, V dc2 is the output voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the output voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

6. The method for constructing the transfer function of the isolation-level DC converter according to claim 1, characterized in that: The disturbance output current model is expressed as: in, is the disturbed output current, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the input voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

7. The isolation-level DC converter transfer function construction method according to claim 1, characterized in that: The voltage transfer function of the DC converter includes a transfer function from input to output and a transfer function from controlling the duty cycle to output voltage.

8. The method for constructing the transfer function of the isolation-level DC converter according to claim 7, characterized in that: The input to output transfer function is expressed as: Among them, G w (s) is the transfer function from input to output, d(s)=0 indicates that the duty cycle function remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

9. The method for constructing the transfer function of the isolation-level DC converter according to claim 7, characterized in that: The transfer function of the control duty cycle to output voltage is expressed as: Among them, G vd (s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s) = 0 means that the input voltage of the DAB converter remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

10. A device for constructing a transfer function of an isolation-level DC converter, characterized in that: include: A determination module, used to determine a calculation model of the output power of the DC converter, and determine a calculation model of the input average current and the output average current based on the calculation model of the output power; An establishment module is used to establish an average switch equivalent model of a DC converter, introduce a disturbance amount into the average switch equivalent model, and bring the disturbance amount into the calculation model of the input average current and the output average current to obtain a disturbance input current model and a disturbance output current model; The conversion module is used to convert the average switch equivalent model with the introduced disturbance into a small signal model, and obtain the voltage transfer function of the DC converter based on the small signal model.

11. The isolation-level DC converter transfer function construction device according to claim 10, characterized in that: The calculation model of the output power determined by the determination module is: Where P0 is the output power, n is the turns ratio of the primary and secondary sides of the transformer; d is the phase shift duty cycle; v dc1 and v dc2 are the input voltage and output voltage of the DC converter respectively; f is the frequency of the control signal, and L is the equivalent inductance value of the DC converter.

12. The isolation-level DC converter transfer function construction device according to claim 11, characterized in that: The calculation model of the input average current determined by the determination module is expressed as: Where i1 is the average input current.

13. The isolation-level DC converter transfer function construction device according to claim 11, characterized in that: The calculation model of the output average current determined by the determination module is expressed as: Among them, i2 is the output average current.

14. The isolation-level DC converter transfer function construction device according to claim 10, characterized in that: The disturbance input current model established by the establishment module is expressed as: in, is the disturbed input current, n is the turns ratio between the primary and secondary sides of the transformer, V dc2 is the output voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the output voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

15. The isolation-level DC converter transfer function construction device according to claim 10, characterized in that: The disturbance output current model established by the establishment module is expressed as: in, is the disturbed output current, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, is the phase shift duty cycle disturbance, is the input voltage disturbance, f is the frequency of the control signal, and L is the equivalent inductance of the DC converter.

16. The isolation-level DC converter transfer function construction device according to claim 10, characterized in that: The voltage transfer function of the DC converter obtained by the conversion module includes a transfer function from input to output and a transfer function from controlling the duty cycle to the output voltage.

17. The isolation-level DC converter transfer function construction device according to claim 16, characterized in that: The input to output transfer function is expressed as: Among them, G w (s) is the transfer function from input to output, d(s)=0 indicates that the duty cycle function remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

18. The isolation-level DC converter transfer function construction device according to claim 16, characterized in that: The transfer function of the control duty cycle to output voltage is expressed as: Among them, G vd (s) is the transfer function from the control duty cycle to the output voltage, v dc1 (s) = 0 means that the input voltage of the DAB converter remains unchanged, n is the turns ratio between the primary and secondary sides of the transformer, V dc1 is the input voltage state variable, D is the phase shift duty cycle state variable, f is the frequency of the control signal, L is the equivalent inductance of the DC converter, R0 is the load on the output side of the DC converter, C2 is the output side capacitance of the DC converter, and s represents the Laplace operator.

19. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for constructing the transfer function of the isolation-level DC converter as claimed in any one of claims 1 to 9 are implemented.

20. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for constructing a transfer function of an isolation-level DC converter as claimed in any one of claims 1 to 9 are implemented.

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