Pulse width modulation method and system of three-level Boost converter

Abstract

The invention belongs to the technical field of electric power engineering. The invention provides a pulse width modulation method and system for a three-level Boost converter, and the method comprises the steps: entering sampling control interruption, carrying out the feedback closed-loop control of an output voltage in combination with an input voltage, and carrying out the calculation to obtain a conduction time width; when the voltage of the first capacitor is greater than the voltage of the second capacitor, assigning the voltage of the first capacitor to vh, calculating an adjustable variable according to the vh, adding the adjustable variable to the conduction time width of the first switch element, executing pulse width modulation, and then exiting sampling control interruption; otherwise, assigning the voltage of the second capacitor to vh, calculating an adjustable variable according to the vh, adding the adjustable variable to the conduction time width of the second switch element, executing pulse width modulation, and then exiting sampling control interruption; the variable-adjustable equation is simple and clear, and the advantages of low ripple and high efficiency of the three-level Boost converter can be brought into full play.

Description

Technical Field

[0001] The present invention relates to the field of electric power engineering technology, and in particular to a pulse width modulation method of a three-level Boost converter, a pulse width modulation system of a three-level Boost converter, a computer device, a computer-readable storage medium and a computer program product. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] Among DC / DC step-up converters, Boost converter is the most commonly used one. However, the conventional Boost converter is a two-level topology with strong electromagnetic radiation, which requires a larger filter element, which increases the volume and weight as well as the operating loss. Compared with the conventional Boost converter, the three-level Boost converter has lower voltage stress, and the electromagnetic radiation and switching loss caused by the switching action are significantly reduced, which greatly reduces the requirements for the filter element. For the three-level Boost converter, the voltage balance of the two capacitors at the output port must be ensured during operation, so a reasonable pulse width modulation method needs to be designed.

[0004] However, most existing pulse width modulation methods require additional voltage and current sensors, which increases hardware costs. The formula for adjusting the time variable is relatively complex and has a large computational overhead, which is not convenient for DSP and FPGA programming and real-time operation, and is not suitable for occasions with high switching frequencies. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present invention provides a pulse width modulation method and system for a three-level Boost converter, which does not require additional voltage and current sensors, does not increase hardware costs, has simple formulas for adjustable variables, and has little computational overhead. It can give full play to the advantages of low ripple and high efficiency of the three-level Boost converter, is easy to implement and run in real time through DSP and FPGA programming, and can be suitable for occasions with higher switching frequencies.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a pulse width modulation method for a three-level Boost converter.

[0008] A pulse width modulation method for a three-level Boost converter, the three-level Boost converter comprising: a first switch element and a second switch element connected in series, a first capacitor and a second capacitor connected in series, wherein a connection portion between the first switch element and the second switch element is connected to a connection portion between the first capacitor and the second capacitor, and the method comprises the following steps:

[0009] Entering a sampling control interrupt to obtain an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0010] The output voltage is feedback closed-loop controlled in combination with the input voltage, and the conduction time width is calculated;

[0011] When the voltage of the first capacitor is greater than the voltage of the second capacitor, the voltage of the first capacitor is assigned to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0012] When the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, the voltage of the second capacitor is assigned to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0013] As a further limitation of the first aspect of the present invention, according to the v h Calculates adjustable variables including:

[0014]

[0015] Among them, v in is the input voltage, T on is the on-time width, v h is the voltage of the first capacitor v C1 and the voltage of the second capacitor v C2 The higher one, t sw is the switching period of the current sampling control point, v o is the output voltage, T on is the on-time width.

[0016] As a further limitation of the first aspect of the present invention, adding the adjustable variable to the on-time width of the first switch element includes:

[0017] The on-time width of the first switching element minus the value of the adjustable variable is used as the final on-time width of the first switching element.

[0018] As a further limitation of the first aspect of the present invention, adding the adjustable variable to the on-time width of the second switch element comprises:

[0019] The on-time width of the second switching element minus the value of the adjustable variable is used as the final on-time width of the second switching element.

[0020] As a further limitation of the first aspect of the present invention, the three-level Boost converter further includes: an inductor, a resistor, a first diode and a second diode, the inductor is respectively connected to the first switching element and the first diode, the second diode is respectively connected to the second capacitor and the second switching element, the resistor is connected in parallel to the first capacitor and the second capacitor connected in series, and the two ends of the input voltage are respectively connected to the inductor and the second switching element.

[0021] In a second aspect, the present invention provides a pulse width modulation system of a three-level Boost converter.

[0022] A pulse width modulation system of a three-level Boost converter, the three-level Boost converter comprising: a first switch element and a second switch element connected in series, a first capacitor and a second capacitor connected in series, wherein a connection portion of the first switch element and the second switch element is connected to a connection portion of the first capacitor and the second capacitor, comprising:

[0023] The data acquisition unit is configured to: enter a sampling control interrupt to acquire an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0024] The feedback closed-loop control unit is configured to: perform feedback closed-loop control of the output voltage in combination with the input voltage, and calculate the conduction time width;

[0025] The first modulation unit is configured to: when the voltage of the first capacitor is greater than the voltage of the second capacitor, assign the voltage of the first capacitor to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0026] The second modulation unit is configured to: when the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, assign the voltage of the second capacitor to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0027] As a further limitation of the second aspect of the present invention, according to the v h Calculates adjustable variables including:

[0028]

[0029] Among them, v in is the input voltage, T on is the on-time width, v h is the voltage of the first capacitor vC1 and the voltage of the second capacitor v C2 The higher one, t sw is the switching period of the current sampling control point, v o is the output voltage.

[0030] In a third aspect, the present invention provides a computer device, comprising: a processor and a computer-readable storage medium;

[0031] a processor adapted to execute a computer program;

[0032] A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by the processor, the pulse width modulation method of the three-level Boost converter as described in the first aspect of the present invention is implemented.

[0033] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program is suitable for being loaded by a processor and executing the pulse width modulation method of the three-level Boost converter as described in the first aspect of the present invention.

[0034] In a fifth aspect, the present invention provides a computer program product, which includes a computer program. When the computer program is executed by a processor, it implements the pulse width modulation method of the three-level Boost converter as described in the first aspect of the present invention.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention innovatively proposes a pulse width modulation strategy for a three-level Boost converter. C1 and v C2 The higher one of them, the conduction time of the corresponding switch element will be reduced by t α , thereby reducing the maintenance time of its charging state and causing the voltage to drop. No additional voltage and current sensors are required, and the hardware cost is not increased. The formula for the adjustable variables is concise and the calculation overhead is very small. The advantages of low ripple and high efficiency of the three-level Boost converter can be fully utilized, which is convenient for DSP and FPGA programming and real-time operation, and can be suitable for occasions with higher switching frequencies.

[0037] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0039] Figure 1 A schematic diagram of the circuit topology of a three-level Boost converter provided in Embodiment 1 of the present invention;

[0040] Figure 2 A schematic diagram of a pulse width modulation method for a three-level Boost converter provided in Embodiment 1 of the present invention;

[0041] Figure 3 A schematic diagram of the pulse width modulation method provided in Example 1 of the present invention;

[0042] Figure 4 Provide T for Example 1 of the present invention on Schematic diagram of the calculation method;

[0043] Figure 5 The voltage and current waveforms of the three-level Boost converter provided in Example 1 of the present invention during operation;

[0044] Figure 6 A schematic diagram of a pulse width modulation system of a three-level Boost converter provided in Embodiment 2 of the present invention;

[0045] Figure 7 A schematic diagram of a computer device provided in Example 3 of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0047] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0048] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0049] Embodiment 1:

[0050] This implementation proposes a pulse width modulation method for a three-level Boost converter. Figure 1 As shown, the three-level Boost converter includes: a first switch element T1 and a second switch element T2 connected in series, a first capacitor C1 and a second capacitor C2 connected in series, an inductor L, a resistor R L, a first diode D1 and a second diode D2, an inductor L is connected to the first switch element T1 and the first diode D1 respectively, a second diode D2 is connected to the second capacitor C2 and the second switch element T2 respectively, a resistor R L The first capacitor C1 and the second capacitor C2 are connected in parallel with each other, and the input voltage v in The two ends are connected to the inductor L and the second switch element T2 respectively, and the connection part of the first switch element T1 and the second switch element T2 is connected to the connection part of the first capacitor C1 and the second capacitor C2.

[0051] Specifically, Figure 2 As shown, the pulse width modulation method of the three-level Boost converter described in this implementation includes the following process:

[0052] S1: Enter the sampling control interrupt to obtain the input voltage v in , the voltage of the first capacitor v C1 and the voltage of the second capacitor v C2 ;

[0053] S2: Combined input voltage v in The output voltage v o The feedback closed-loop control is used to calculate the conduction time width T on ;

[0054] S3: When the voltage v of the first capacitor C1 Greater than the voltage v of the second capacitor C2 When the voltage of the first capacitor v C1 Assign to v h , according to the v h Calculate the adjustable variable and convert the adjustable variable v C1 Added to the on-time width of the first switch element T1, the sampling control interrupt is exited after pulse width modulation is performed;

[0055] S4: When the voltage v of the first capacitor C1 Less than or equal to the second capacitance v C2 When the voltage of the second capacitor v C2 The voltage is assigned to v h , according to the v h Calculate the adjustable variable and convert the adjustable variable t α The time is added to the on-time width of the second switch element T2, and the sampling control interruption is exited after the pulse width modulation is performed.

[0056] like Figure 3 As shown, v C1 and v C2 is the voltage of the output capacitor, i L is the inductor current, v ois the output voltage, S1 and S2 are the conduction time widths of the switch elements T1 and T2 respectively, t sw,1 ,t sw,2 ,t sw,3 and t sw,4 is the switching period of the current sampling control point. These physical quantities can be obtained through AD sampling and feedback control strategy.

[0057] An adjustable variable is added to the pulse width of the two switching elements, denoted as t α ,like Figure 3 As shown in the last line, t α The value of changes with the degree of output voltage imbalance. The specific calculation method is shown in the following formula.

[0058]

[0059] In the formula, v in is the input voltage, T on is the conduction time width, v h v C1 and v C2 The higher one, t sw is the switching period of the current sampling control point, such as Figure 3 t in sw,1 ,t sw,2 ,t sw,3 and t sw,4 For v C1 and v C2 The higher one of them, the conduction time of the corresponding switch element will be reduced by t α , thereby reducing the time its charging state is maintained and causing the voltage to drop.

[0060] T on Through feedback control, such as Figure 4 As shown, the output voltage command value V o * With the output voltage V o After the difference is made, it is input into PI regulator 1. The output after limiting link 1 is equal to the inductor current i L (i L The difference is made with the flow to the output side as the positive direction, and the difference result is input to the limit link 2. The result of the limit link 2 is equal to the input voltage V in Execute the division operation, and the result of the division operation is obtained after the limit link 3 to obtain T on .

[0061] With the help of the method of the present invention, the advantages of low ripple and high efficiency of the three-level Boost converter can be fully utilized and used in occasions such as DC microgrids; no additional voltage and current sensors are required, and the hardware cost is not increased; the formula for adjusting the time variable (that is, the adjustable variable) is concise and the calculation overhead is small, which is convenient for DSP and FPGA programming and real-time operation, and can be suitable for occasions with higher switching frequencies.

[0062] Taking an actual three-level Boost converter as an example, the switching element adopts 1.2kV / 45A IGBT, the input side inductance is 6mH, and the output side capacitance is 1mF; the controller adopts DSP and 12-bit precision ADC chip, and the sampling control frequency and the switching frequency are both 10kHz, which is used to implement the pulse width modulation algorithm of the present invention.

[0063] The voltage and current curves of the three-level Boost converter during operation are shown in Figure 2. Figure 5 As shown in the figure, i L Inductor current, v C1 and v C2 is the output capacitor voltage, v unb is the difference between the two capacitor voltages, i o2 -i o1 is the difference between the two capacitor currents. It can be seen that the input side inductor current i L When the load is balanced, the output voltage v C1 and v C2 are all around 180V; when the load has a step change and there is a 1.2A imbalance, v C1 and v C2 are all around 170V. During the entire operation, v C1 and v C2 The difference is maintained at about 4V, which is relatively balanced and meets the requirements of practical applications.

[0064] Embodiment 2:

[0065] like Figure 6 As shown, the present implementation provides a pulse width modulation system of a three-level Boost converter, the three-level Boost converter comprising: a first switch element and a second switch element connected in series, a first capacitor and a second capacitor connected in series, the connection part of the first switch element and the second switch element is connected to the connection part of the first capacitor and the second capacitor, comprising:

[0066] The data acquisition unit is configured to: enter a sampling control interrupt to acquire an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0067] The feedback closed-loop control unit is configured to: perform feedback closed-loop control of the output voltage in combination with the input voltage, and calculate the conduction time width;

[0068] The first modulation unit is configured to: when the voltage of the first capacitor is greater than the voltage of the second capacitor, assign the voltage of the first capacitor to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0069] The second modulation unit is configured to: when the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, assign the voltage of the second capacitor to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0070] The specific working method is described in Example 1 and will not be repeated here.

[0071] It is understandable that the above-mentioned modules can be separately or completely combined into one or several other units to constitute, or one (some) of the units can be further divided into multiple smaller units in function to constitute, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present application. The above-mentioned units are divided based on logical functions. In practical applications, the function of one unit can also be realized by multiple units, or the functions of multiple units can be realized by one unit. In other embodiments of the present application, the pulse width modulation system of the three-level Boost converter can also include other units. In practical applications, these functions can also be implemented with the assistance of other units, and can be implemented by the collaboration of multiple units.

[0072] According to another embodiment of the present application, the system described in this embodiment can be constructed, and the pulse width modulation method of the three-level Boost converter of the embodiment of the present application can be implemented by running a computer program (including program code) capable of executing the steps involved in the corresponding method described in Example 1 on a general computing device such as a computer including processing elements and storage elements such as a central processing unit (CPU), random access memory (RAM), and read-only memory (ROM). The computer program can be recorded on, for example, a computer-readable recording medium, and loaded into the above-mentioned computing device through the computer-readable recording medium and run therein.

[0073] Embodiment 3:

[0074] like Figure 7As shown, this implementation provides an electronic device, which includes a processor 1001, a communication interface 1002, and a computer-readable storage medium 1003. The processor 1001, the communication interface 1002, and the computer-readable storage medium 1003 may be connected via a bus or other means.

[0075] Among them, the communication interface 1002 is used to receive and send data, the computer-readable storage medium 1003 can be stored in the memory of the electronic device, the computer-readable storage medium 1003 is used to store a computer program, the computer program includes program instructions, and the processor 1001 is used to execute the program instructions stored in the computer-readable storage medium 1003.

[0076] Processor 1001 (or CPU (Central Processing Unit)) is the computing core and control core of the electronic device, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to implement corresponding method processes or corresponding functions.

[0077] The processor 1001 is configured to execute the following process:

[0078] Entering a sampling control interrupt to obtain an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0079] The output voltage is feedback closed-loop controlled in combination with the input voltage, and the conduction time width is calculated;

[0080] When the voltage of the first capacitor is greater than the voltage of the second capacitor, the voltage of the first capacitor is assigned to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0081] When the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, the voltage of the second capacitor is assigned to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0082] The specific working method is described in Example 1 and will not be repeated here.

[0083] Embodiment 4:

[0084] This implementation provides a computer-readable storage medium (Memory), which is a memory device in an electronic device for storing programs and data. It is understandable that the computer-readable storage medium here can include both built-in storage media in the electronic device and, of course, extended storage media supported by the electronic device. The computer-readable storage medium provides a storage space that stores the processing system of the electronic device.

[0085] In addition, the storage space also stores one or more instructions suitable for being loaded and executed by the processor, and these instructions may be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk storage; optionally, it may also be at least one computer-readable storage medium located away from the aforementioned processor.

[0086] In one embodiment, the computer-readable storage medium stores one or more instructions; the processor loads and executes the one or more instructions stored in the computer-readable storage medium to implement the following process:

[0087] Entering a sampling control interrupt to obtain an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0088] The output voltage is feedback closed-loop controlled in combination with the input voltage, and the conduction time width is calculated;

[0089] When the voltage of the first capacitor is greater than the voltage of the second capacitor, the voltage of the first capacitor is assigned to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0090] When the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, the voltage of the second capacitor is assigned to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0091] The specific working method is described in Example 1 and will not be repeated here.

[0092] Embodiment 5:

[0093] The present implementation provides a computer program product or a computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device performs the following process:

[0094] Entering a sampling control interrupt to obtain an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor;

[0095] The output voltage is feedback closed-loop controlled in combination with the input voltage, and the conduction time width is calculated;

[0096] When the voltage of the first capacitor is greater than the voltage of the second capacitor, the voltage of the first capacitor is assigned to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation;

[0097] When the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, the voltage of the second capacitor is assigned to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

[0098] The specific working method is described in Example 1 and will not be repeated here.

[0099] A person skilled in the art can appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed in this application can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0100] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loading and executing computer program instructions on a computer, the process or function according to the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instruction can be stored in a computer-readable storage medium or transmitted by a computer-readable storage medium. The computer instruction can be transmitted from a website site, a computer, a server or a data center to another website site, a computer, a server or a data center by wired (for example, coaxial cable, optical fiber, digital line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) mode. The computer-readable storage medium can be any available medium that a computer can access or a data processing device such as a server, a data center, etc. that contains one or more available media integration. Available media can be magnetic media (for example, floppy disk, hard disk, tape), optical media (for example, DVD), or semiconductor media (for example, solid-state drive (Solid State Disk, SSD)) and the like.

[0101] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pulse width modulation method for a three-level Boost converter, the three-level Boost converter comprising: A first switch element and a second switch element are connected in series, a first capacitor and a second capacitor are connected in series, and a connection part of the first switch element and the second switch element is connected to a connection part of the first capacitor and the second capacitor, characterized in that the process includes the following steps: Entering a sampling control interrupt to obtain an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor; The output voltage is feedback closed-loop controlled in combination with the input voltage, and the conduction time width is calculated; When the voltage of the first capacitor is greater than the voltage of the second capacitor, the voltage of the first capacitor is assigned to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation; When the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, the voltage of the second capacitor is assigned to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

2. The pulse width modulation method of the three-level Boost converter according to claim 1, characterized in that: According to the v h Calculates adjustable variables including: Among them, v in is the input voltage, T on is the conduction time width, v h is the voltage of the first capacitor v C1 and the voltage of the second capacitor v C2 The higher one, t sw is the switching period of the current sampling control point, v o is the output voltage, T on is the on-time width.

3. The pulse width modulation method of the three-level Boost converter according to claim 1 or 2, characterized in that: Adding the adjustable variable to the on-time width of the first switching element comprises: The on-time width of the first switching element minus the value of the adjustable variable is used as the final on-time width of the first switching element.

4. The pulse width modulation method of the three-level Boost converter according to claim 1 or 2, characterized in that: Adding the adjustable variable to the on-time width of the second switch element comprises: The on-time width of the second switching element minus the value of the adjustable variable is used as the final on-time width of the second switching element.

5. The pulse width modulation method of the three-level Boost converter according to claim 1 or 2, characterized in that: The three-level Boost converter also includes: an inductor, a resistor, a first diode and a second diode, the inductor is connected to the first switch element and the first diode respectively, the second diode is connected to the second capacitor and the second switch element respectively, the resistor is connected in parallel to the first capacitor and the second capacitor connected in series, and the two ends of the input voltage are connected to the inductor and the second switch element respectively.

6. A pulse width modulation system of a three-level Boost converter, the three-level Boost converter comprising: A first switch element and a second switch element connected in series, a first capacitor and a second capacitor connected in series, a connection point between the first switch element and the second switch element and a connection point between the first capacitor and the second capacitor connected, characterized in that it includes: The data acquisition unit is configured to: enter a sampling control interrupt to acquire an input voltage, a voltage of the first capacitor, and a voltage of the second capacitor; The feedback closed-loop control unit is configured to: perform feedback closed-loop control of the output voltage in combination with the input voltage, and calculate the conduction time width; The first modulation unit is configured to: when the voltage of the first capacitor is greater than the voltage of the second capacitor, assign the voltage of the first capacitor to v h , according to the v h Calculating an adjustable variable, adding the adjustable variable to the on-time width of the first switch element, and exiting the sampling control interrupt after executing pulse width modulation; The second modulation unit is configured to: when the voltage of the first capacitor is less than or equal to the voltage of the second capacitor, assign the voltage of the second capacitor to v h , according to the v h An adjustable variable is calculated, the adjustable variable is added to the on-time width of the second switch element, and the sampling control interrupt is exited after pulse width modulation is performed.

7. The pulse width modulation system of the three-level Boost converter according to claim 6, characterized in that: According to the v h Calculates adjustable variables including: Among them, v in is the input voltage, T on is the conduction time width, v h is the voltage of the first capacitor v C1 and the voltage of the second capacitor v C2 The higher one, t sw is the switching period of the current sampling control point, v o is the output voltage.

8. A computer device, characterized in that: include: A processor and a computer readable storage medium; a processor adapted to execute a computer program; A computer-readable storage medium, wherein a computer program is stored in the computer-readable storage medium, and when the computer program is executed by the processor, the pulse width modulation method of the three-level Boost converter according to any one of claims 1 to 5 is implemented.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is suitable for being loaded by a processor and executing the pulse width modulation method of the three-level Boost converter according to any one of claims 1 to 5.

10. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the pulse width modulation method of the three-level Boost converter according to any one of claims 1 to 5 is implemented.

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