A control method, device, and electronic equipment for a voltage conversion circuit.

Abstract

This invention provides a control method, apparatus, and electronic device for a voltage conversion circuit. The method includes: acquiring a first voltage and a second voltage, where the first voltage is the voltage between the positive terminal and the neutral point of a DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus; performing a PI calculation based on the error between the first and second voltages to obtain a compensation current or a compensation duty cycle; and obtaining a first duty cycle of the first conversion module and a second duty cycle of the second conversion module after compensation, based on the compensation current or compensation duty cycle, to balance the output power of the first and second conversion modules. This invention can ensure the stability of the DC bus neutral point, balance the power of the first and second conversion modules, and improve the safety and reliability of the voltage conversion circuit.

Description

Technical Field

[0001] This invention relates to the field of new energy charging technology, and in particular to a control method, device and electronic equipment for a voltage conversion circuit. Background Technology

[0002] like Figure 1 The voltage conversion circuit shown includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and its output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive and neutral points of the DC bus, and the input terminal of the second conversion module is connected to the neutral and negative points of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to the load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop, so that the output voltage of the voltage conversion circuit is equal to the target voltage.

[0003] During the control process of the voltage conversion circuit, fluctuations in the mains voltage and dynamic changes in the load cause voltage fluctuations at the neutral point of the PFC module's output, as well as voltage fluctuations in the positive and negative half-arms of the DC bus, resulting in power imbalance on both sides. Severe power imbalance can damage the internal switching transistors of both the first and second conversion modules, leading to low safety and reliability of the voltage conversion circuit. Summary of the Invention

[0004] This invention provides a control method, device, and electronic equipment for a voltage conversion circuit, which can ensure the stability of the DC bus neutral point, balance the power of the first conversion module and the second conversion module, and improve the safety and reliability of the voltage conversion circuit.

[0005] In a first aspect, the present invention provides a control method for a voltage conversion circuit. The voltage conversion circuit includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and its output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive terminal and neutral point of the DC bus, and the input terminal of the second conversion module is connected to the neutral point and negative terminal of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to a load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop to ensure that the output voltage of the voltage conversion circuit equals the target voltage. This control method... This includes: acquiring a first voltage and a second voltage, wherein the first voltage is the voltage between the positive terminal and the neutral point of the DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus; performing PI calculation based on the error between the first voltage and the second voltage to obtain a compensation current or a compensation duty cycle; compensating the output current of the first conversion module and / or the second conversion module in the control loop based on the compensation current, or compensating the duty cycle of the first conversion module and / or the second conversion module in the control loop based on the compensation duty cycle to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation, so as to balance the output power of the first conversion module and the second conversion module.

[0006] This invention provides a control method for a voltage conversion circuit. Based on the error between the first voltage of the positive half-arm of the DC bus and the second voltage of the negative half-arm, a PI calculation is performed to obtain a compensation current or compensation duty cycle. This compensation current or compensation duty cycle is then incorporated into the control loop to compensate for the output current or duty cycle. This incorporates the voltage error between the positive and negative half-arms of the DC bus into the control loop, reducing the voltage error between them, ensuring the stability of the DC bus neutral point, and thus ensuring balanced output power between the first and second conversion modules, improving the safety and reliability of the voltage conversion circuit.

[0007] In one possible implementation, the output current of the first conversion module and the second conversion module in the control loop is compensated based on the compensation current, or the duty cycle of the first conversion module and the second conversion module in the control loop is compensated based on the compensation duty cycle to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation. This includes: obtaining the first duty cycle based on the target duty cycle, the actual duty cycle, and the compensation duty cycle of the first conversion module; and / or obtaining the second duty cycle based on the target duty cycle, the actual duty cycle, and the compensation duty cycle of the second conversion module.

[0008] In one possible implementation, the first duty cycle is obtained based on the target duty cycle, actual duty cycle, and compensated duty cycle of the first transformation module, including: using the target duty cycle of the first transformation module as a given value, using the actual duty cycle of the first transformation module as negative feedback, and using the compensated duty cycle as positive feedback to obtain the first duty cycle; the second duty cycle is obtained based on the target duty cycle, actual duty cycle, and compensated duty cycle of the second transformation module, including: using the target duty cycle of the second transformation module as a given value, using the actual duty cycle of the second transformation module as negative feedback, and using the compensated duty cycle as negative feedback to obtain the second duty cycle.

[0009] In one possible implementation, the control method further includes: acquiring the actual output voltage of the voltage conversion circuit; acquiring the actual output current of the first conversion module before compensation; acquiring the actual output current of the second conversion module before compensation; acquiring the actual duty cycle of the first conversion module before compensation; acquiring the actual duty cycle of the second conversion module before compensation; acquiring the target output current of the first conversion module and the target output current of the second conversion module based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit; acquiring the first current error of the first conversion module based on the error between the target output current and the actual output current of the first conversion module; acquiring the target duty cycle of the first conversion module based on the first current error; acquiring the second current error of the second conversion module based on the error between the target output current and the actual output current of the second conversion module; and acquiring the target duty cycle of the second conversion module based on the second current error.

[0010] In one possible implementation, the output currents of the first and second conversion modules in the control loop are compensated based on the compensation current, or the duty cycles of the first and second conversion modules in the control loop are compensated based on the compensation duty cycle, to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation. This includes: obtaining a first current error after compensation based on the target output current, actual output current, and compensation current of the first conversion module; obtaining the target duty cycle of the first conversion module based on the first current error after compensation; and determining the first duty cycle based on the target duty cycle and actual duty cycle of the first conversion module; and / or obtaining a second current error after compensation based on the target output current, actual output current, and compensation current of the second conversion module; obtaining the target duty cycle of the second conversion module based on the second current error after compensation; and determining the second duty cycle based on the target duty cycle and actual duty cycle of the second conversion module.

[0011] In one possible implementation, a first current error after compensation is obtained based on the target output current, actual output current, and compensation current of the first conversion module, including: using the target output current of the first conversion module as a given value, using the actual output current of the first conversion module as negative feedback, and using the compensation current as positive feedback to obtain the first current error after compensation; a second current error after compensation is obtained based on the target output current, actual output current, and compensation current of the second conversion module, including: using the target output current of the second conversion module as a given value, using the actual output current of the second conversion module as negative feedback, and using the compensation current as positive feedback to obtain the second current error after compensation.

[0012] In one possible implementation, the control method further includes: acquiring the actual output voltage of the voltage conversion circuit; and obtaining the target output current of the first conversion module and the target output current of the second conversion module based on the error between the target output voltage of the voltage conversion circuit and the actual output voltage.

[0013] Secondly, embodiments of the present invention provide a control device for a voltage conversion circuit. The voltage conversion circuit includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and its output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive terminal and neutral point of the DC bus, and the input terminal of the second conversion module is connected to the neutral point and negative terminal of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to a load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop to ensure that the output voltage of the voltage conversion circuit equals the target voltage. The control device includes a communication module. The module is used to acquire a first voltage and a second voltage, where the first voltage is the voltage between the positive terminal and the neutral point of the DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus. The processing module is used to perform PI calculation based on the error between the first voltage and the second voltage to obtain a compensation current or a compensation duty cycle. The output current of the first conversion module and / or the second conversion module in the control loop is compensated based on the compensation current, or the duty cycle of the first conversion module and / or the second conversion module in the control loop is compensated based on the compensation duty cycle to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation, so as to balance the output power of the first conversion module and the second conversion module.

[0014] In one possible implementation, the processing module is specifically used to obtain a first duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the first transformation module; and / or, to obtain a second duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the second transformation module.

[0015] In one possible implementation, the processing module is specifically used to obtain a first duty cycle by taking the target duty cycle of the first transformation module as a given value, taking the actual duty cycle of the first transformation module as negative feedback, and taking the compensation duty cycle as positive feedback; and to obtain a second duty cycle by taking the target duty cycle of the second transformation module as a given value, taking the actual duty cycle of the second transformation module as negative feedback, and taking the compensation duty cycle as negative feedback.

[0016] In one possible implementation, the communication module is further configured to acquire the actual output voltage of the voltage conversion circuit, the actual output current of the first conversion module before compensation, the actual output current of the second conversion module before compensation, the actual duty cycle of the first conversion module before compensation, and the actual duty cycle of the second conversion module before compensation; the processing module is further configured to, based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit, obtain the target output current of the first conversion module and the target output current of the second conversion module; based on the error between the target output current and the actual output current of the first conversion module, obtain the first current error of the first conversion module; based on the first current error, obtain the target duty cycle of the first conversion module; based on the error between the target output current and the actual output current of the second conversion module, obtain the second current error of the second conversion module; and based on the second current error, obtain the target duty cycle of the second conversion module.

[0017] In one possible implementation, the processing module is specifically configured to: obtain a compensated first current error based on the target output current, actual output current, and compensation current of the first conversion module; obtain a target duty cycle of the first conversion module based on the compensated first current error; and determine a first duty cycle based on the target duty cycle and actual duty cycle of the first conversion module; and / or obtain a compensated second current error based on the target output current, actual output current, and compensation current of the second conversion module; obtain a target duty cycle of the second conversion module based on the compensated second current error; and determine a second duty cycle based on the target duty cycle and actual duty cycle of the second conversion module.

[0018] In one possible implementation, the processing module is specifically used to obtain a compensated first current error by taking the target output current of the first conversion module as a given value, the actual output current of the first conversion module as negative feedback, and the compensation current as positive feedback; and to obtain a compensated second current error by taking the target output current of the second conversion module as a given value, the actual output current of the second conversion module as negative feedback, and the compensation current as positive feedback.

[0019] In one possible implementation, the communication module is further configured to acquire the actual output voltage of the voltage conversion circuit; the processing module is further configured to obtain the target output current of the first conversion module and the target output current of the second conversion module based on the error between the target output voltage of the voltage conversion circuit and the actual output voltage.

[0020] Thirdly, embodiments of the present invention provide an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the processor being configured to call and run the computer program stored in the memory to perform the steps of the method as described in the first aspect and any possible implementation thereof.

[0021] Fourthly, embodiments of the present invention provide a voltage conversion circuit, including a PFC module, a first conversion module, a second conversion module, and a control device as described in the second aspect and any possible implementation thereof; wherein, the input terminal of the PFC module is connected to an AC power supply, and the output terminal is connected to a DC bus; the input terminal of the first conversion module is connected to the positive terminal and the neutral point of the DC bus, the input terminal of the second conversion module is connected to the neutral point and the negative terminal of the DC bus, and the output terminals of the first conversion module and the second conversion module are connected in parallel to a load; the control device is used to control the duty cycle of the switching transistors in the first conversion module and the second conversion module through a control loop, so that the output voltage of the voltage conversion circuit is equal to the target voltage.

[0022] Fifthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, characterized in that, when executed by a processor, the computer program implements the steps of the method as described in the first aspect and any possible implementation thereof.

[0023] The technical effects of any of the implementation methods in the second to fifth aspects mentioned above can be found in the technical effects of the corresponding implementation method in the first aspect, and will not be repeated here. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a voltage conversion circuit provided in an embodiment of the present invention;

[0026] Figure 2This is a control flowchart of a voltage conversion circuit provided in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of another voltage conversion circuit provided in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of another voltage conversion circuit provided in an embodiment of the present invention;

[0029] Figure 5 This is a schematic diagram of another voltage conversion circuit provided in an embodiment of the present invention;

[0030] Figure 6 This is a schematic flowchart of a control method for a voltage conversion circuit provided in an embodiment of the present invention;

[0031] Figure 7 This is a control flowchart of another voltage conversion circuit provided in an embodiment of the present invention;

[0032] Figure 8 This is a control flowchart of another voltage conversion circuit provided in an embodiment of the present invention;

[0033] Figure 9 This is a schematic flowchart of another control method for a voltage conversion circuit provided in an embodiment of the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of a control device for a voltage conversion circuit provided in an embodiment of the present invention;

[0035] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0036] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0037] In the description of this invention, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" and "more than one" refer to two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0038] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0039] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not limited to the steps or modules listed, but may optionally include other steps or modules not listed, or may optionally include other steps or modules inherent to such process, method, product, or device.

[0040] To make the objectives, technical solutions, and advantages of the present invention clearer, the following description will be provided in conjunction with the accompanying drawings and specific embodiments.

[0041] like Figure 1 The voltage conversion circuit shown includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and the output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive terminal and the neutral point of the DC bus, and the input terminal of the second conversion module is connected to the neutral point and the negative terminal of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to the load. The control device is used to control the duty cycle of the switching transistors in the first and second conversion modules through a control loop so that the output voltage of the voltage conversion circuit is equal to the target voltage.

[0042] Figure 2 for Figure 1The diagram shows the control flowchart of the voltage conversion circuit. This process controls the duty cycle of the first and second conversion modules based on the output voltage and output current. During the control process of the voltage conversion circuit, fluctuations in the mains voltage and dynamic changes in the load cause fluctuations in the neutral point voltage at the output of the PFC module, as well as voltage fluctuations in the positive and negative half-arms of the DC bus, resulting in power imbalance on both sides. Severe power imbalance may damage the internal switching transistors of the first and second conversion modules. Therefore, the voltage conversion circuit has relatively low safety and reliability.

[0043] To address the aforementioned technical problems, embodiments of the present invention provide a control method for a voltage conversion circuit, applicable to... Figure 1 The voltage conversion circuit shown.

[0044] As one possible implementation, such as Figure 3 As shown, the first conversion module in the voltage conversion circuit may include a first LLC circuit and a first Buck circuit. The second conversion module may include a second LLC circuit and a second Buck circuit.

[0045] For example, the control device can control the duty cycle of the switching transistor in the Buck circuit by acquiring the output current of the Buck circuit.

[0046] Another example is that the control device can control the duty cycle of the switching transistor in the Buck circuit by acquiring the input current of the Buck circuit (not shown in the figure).

[0047] As another possible implementation, such as Figure 4 As shown, the first conversion module in the voltage conversion circuit may include a first LLC circuit and a first Boost circuit. The second conversion module may include a second LLC circuit and a second Boost circuit.

[0048] For example, the control device can control the duty cycle of the switching transistor in the Boost circuit by acquiring the output current of the Boost circuit (not shown in the figure).

[0049] Another example is that the control device can control the duty cycle of the switching transistor in the Boost circuit by acquiring the input current of the Boost circuit.

[0050] As another possible implementation, such as Figure 5 As shown, the first conversion module in the voltage conversion circuit may include a first buck-boost circuit and a first LLC circuit. The second conversion module may include a second buck-boost circuit and a second LLC circuit.

[0051] For example, the control device can control the duty cycle of the switching transistors in the first buck-boost circuit and the second buck-boost circuit by collecting the output current of the first buck-boost circuit and the second buck-boost circuit.

[0052] As another example, the control device can control the duty cycle of the switching transistors in the first buck-boost circuit and the second buck-boost circuit by collecting the input current (not shown in the figure) of the first buck-boost circuit and the second buck-boost circuit.

[0053] Figure 6 This is a flowchart illustrating a control method for a voltage conversion circuit according to an embodiment of the present invention. The control method includes steps S101-S103.

[0054] S101, Obtain the first voltage and the second voltage.

[0055] In this embodiment, the first voltage is the voltage between the positive terminal and the neutral point of the DC bus.

[0056] For example, the control device can detect Figure 3 The voltage between the positive terminal and the neutral point of the PFC module output determines the first voltage. For example, the voltage of Bus-p.

[0057] In this embodiment, the second voltage is the voltage between the neutral point and the negative terminal of the DC bus.

[0058] For example, the control device can detect Figure 3 The voltage between the neutral point and the negative terminal of the PFC module output determines the first voltage. For example, the voltage of Bus-n.

[0059] S102. Based on the error between the first voltage and the second voltage, perform PI calculation to obtain the compensation current or compensation duty cycle.

[0060] As one possible implementation, such as Figure 7 As shown, the control device can perform PI calculation on the error between the first voltage and the second voltage to obtain the compensation duty cycle.

[0061] As another possible implementation, such as Figure 8 As shown, the control device can perform PI calculation on the error between the first voltage and the second voltage to obtain the compensation current.

[0062] S103. Compensate the output current of the first conversion module and / or the second conversion module in the control loop based on the compensation current, or compensate the duty cycle of the first conversion module and / or the second conversion module in the control loop based on the compensation duty cycle, to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation, so as to balance the output power of the first conversion module and the second conversion module.

[0063] It should be noted that the control device can compensate for the duty cycle of the first conversion module in the control loop based on the compensation duty cycle, that is, compensate for the positive half-arm of the PFC module output, to achieve power balance between the positive and negative half-arms. Alternatively, the control device can also compensate for the duty cycle of the second conversion module in the control loop, that is, compensate for the negative half-arm of the PFC module output, to achieve power balance between the positive and negative half-arms. Or, the control device can simultaneously compensate for the duty cycles of the first and second conversion modules in the control loop based on the compensation duty cycle, that is, simultaneously compensate for the positive and negative half-arms of the PFC module output, to achieve power balance between the positive and negative half-arms.

[0064] As one possible implementation, the control device can obtain the first duty cycle based on the target duty cycle, the actual duty cycle, and the compensated duty cycle of the first conversion module;

[0065] For example, the control device can use the target duty cycle of the first conversion module as a given value, the actual duty cycle of the first conversion module as negative feedback, and the compensation duty cycle as positive feedback to obtain the first duty cycle.

[0066] As another possible implementation, the control device can obtain the second duty cycle based on the target duty cycle, the actual duty cycle, and the compensated duty cycle of the second conversion module.

[0067] For example, the control device can use the target duty cycle of the second conversion module as a given value, the actual duty cycle of the second conversion module as negative feedback, and the compensation duty cycle as negative feedback to obtain the second duty cycle.

[0068] It should be noted that the control device can compensate the output current of the first conversion module in the control loop based on the compensation current, that is, compensate the positive half-arm of the PFC module output, to achieve power balance between the positive and negative half-arms. Alternatively, the control device can also compensate the output current of the second conversion module in the control loop, that is, compensate the negative half-arm of the PFC module output, to achieve power balance between the positive and negative half-arms. Or, the control device can simultaneously compensate the output current of the first and second conversion modules in the control loop based on the compensation current, that is, simultaneously compensate the positive and negative half-arms of the PFC module output, to achieve power balance between the positive and negative half-arms.

[0069] As one possible implementation, the control device can obtain the compensated first current error based on the target output current, actual output current, and compensated current of the first conversion module; obtain the target duty cycle of the first conversion module based on the compensated first current error; and determine the first duty cycle based on the target duty cycle and actual duty cycle of the first conversion module.

[0070] For example, the control device can use the target output current of the first conversion module as a given value, the actual output current of the first conversion module as negative feedback, and the compensation current as positive feedback to obtain the compensated first current error.

[0071] As another possible implementation, the control device can obtain the compensated second current error based on the target output current, actual output current and compensation current of the second conversion module; obtain the target duty cycle of the second conversion module based on the compensated second current error; and determine the second duty cycle based on the target duty cycle and actual duty cycle of the second conversion module.

[0072] For example, the control device can use the target output current of the second conversion module as a given value, the actual output current of the second conversion module as negative feedback, and the compensation current as positive feedback to obtain the compensated second current error.

[0073] For example, the control device can obtain the actual output voltage of the voltage conversion circuit; based on the error between the target output voltage of the voltage conversion circuit and the actual output voltage, it can obtain the target output current of the first conversion module and the target output current of the second conversion module.

[0074] This invention provides a control method for a voltage conversion circuit. Based on the error between the first voltage of the positive half-arm of the DC bus and the second voltage of the negative half-arm, a PI calculation is performed to obtain a compensation current or compensation duty cycle. This compensation current or compensation duty cycle is then incorporated into the control loop to compensate for the output current or duty cycle. This incorporates the voltage error between the positive and negative half-arms of the DC bus into the control loop, reducing the voltage error between them, ensuring the stability of the DC bus neutral point, and thus ensuring balanced output power between the first and second conversion modules, improving the safety and reliability of the voltage conversion circuit.

[0075] Optional, such as Figure 9 As shown, the control method for the voltage conversion circuit provided in this embodiment of the invention further includes steps S201-S206.

[0076] S201. Obtain the actual output voltage of the voltage conversion circuit, the actual output current of the first conversion module before compensation, the actual output current of the second conversion module before compensation, the actual duty cycle of the first conversion module before compensation, and the actual duty cycle of the second conversion module before compensation.

[0077] S202. Based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit, the target output current of the first conversion module and the target output current of the second conversion module are obtained.

[0078] S203. Based on the error between the target output current and the actual output current of the first conversion module, the first current error of the first conversion module is obtained.

[0079] S204. Based on the first current error, the target duty cycle of the first conversion module is obtained.

[0080] S205. Based on the error between the target output current and the actual output current of the second conversion module, the second current error of the second conversion module is obtained.

[0081] S206. Based on the second current error, the target duty cycle of the second conversion module is obtained.

[0082] In this way, the control device can compensate for the duty cycle of the first conversion module and the second conversion module, ensuring that the output power of the first conversion module and the second conversion module is balanced, and improving the safety and reliability of the voltage conversion circuit.

[0083] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0084] The following are device embodiments of the present invention. For details not described in detail, please refer to the corresponding method embodiments described above.

[0085] Figure 10 A schematic diagram of a control device for a voltage conversion circuit according to an embodiment of the present invention is shown. The control device 300 includes a communication module 301 and a processing module 302.

[0086] The communication module 301 is used to acquire a first voltage and a second voltage. The first voltage is the voltage between the positive terminal and the neutral point of the DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus.

[0087] The processing module 302 is used to perform PI calculation based on the error between the first voltage and the second voltage to obtain the compensation current or the compensation duty cycle; to compensate the output current of the first conversion module and / or the second conversion module in the control loop based on the compensation current, or to compensate the duty cycle of the first conversion module and / or the second conversion module in the control loop based on the compensation duty cycle, so as to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation, so as to balance the output power of the first conversion module and the second conversion module.

[0088] In one possible implementation, the processing module 302 is specifically used to obtain a first duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the first transformation module; and / or, to obtain a second duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the second transformation module.

[0089] In one possible implementation, the processing module 302 is specifically used to obtain a first duty cycle by taking the target duty cycle of the first transformation module as a given value, taking the actual duty cycle of the first transformation module as negative feedback, and taking the compensation duty cycle as positive feedback; and to obtain a second duty cycle by taking the target duty cycle of the second transformation module as a given value, taking the actual duty cycle of the second transformation module as negative feedback, and taking the compensation duty cycle as negative feedback.

[0090] In one possible implementation, the communication module 301 is further configured to acquire the actual output voltage of the voltage conversion circuit, the actual output current of the first conversion module before compensation, the actual output current of the second conversion module before compensation, the actual duty cycle of the first conversion module before compensation, and the actual duty cycle of the second conversion module before compensation; the processing module 302 is further configured to, based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit, obtain the target output current of the first conversion module and the target output current of the second conversion module; based on the error between the target output current and the actual output current of the first conversion module, obtain the first current error of the first conversion module; based on the first current error, obtain the target duty cycle of the first conversion module; based on the error between the target output current and the actual output current of the second conversion module, obtain the second current error of the second conversion module; and based on the second current error, obtain the target duty cycle of the second conversion module.

[0091] In one possible implementation, the processing module 302 is specifically configured to: obtain a compensated first current error based on the target output current, actual output current, and compensation current of the first conversion module; obtain a target duty cycle of the first conversion module based on the compensated first current error; and determine a first duty cycle based on the target duty cycle and actual duty cycle of the first conversion module; and / or obtain a compensated second current error based on the target output current, actual output current, and compensation current of the second conversion module; obtain a target duty cycle of the second conversion module based on the compensated second current error; and determine a second duty cycle based on the target duty cycle and actual duty cycle of the second conversion module.

[0092] In one possible implementation, the processing module 302 is specifically used to obtain a compensated first current error by taking the target output current of the first conversion module as a given value, the actual output current of the first conversion module as negative feedback, and the compensation current as positive feedback; and to obtain a compensated second current error by taking the target output current of the second conversion module as a given value, the actual output current of the second conversion module as negative feedback, and the compensation current as positive feedback.

[0093] In one possible implementation, the communication module 301 is further configured to acquire the actual output voltage of the voltage conversion circuit; the processing module 302 is further configured to obtain the target output current of the first conversion module and the target output current of the second conversion module based on the error between the target output voltage of the voltage conversion circuit and the actual output voltage.

[0094] Figure 11 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. For example... Figure 11 As shown, the electronic device 400 of this embodiment includes: a processor 401, a memory 402, and a computer program 403 stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program 403, it implements the steps in the above-described method embodiments, for example... Figure 6 Steps 101 to 103 are shown. Alternatively, when the processor 401 executes the computer program 403, it implements the functions of each module / unit in the above-described device embodiments, for example... Figure 10 The functions of the communication module 301 and the processing module 302 shown are illustrated.

[0095] For example, the computer program 403 can be divided into one or more modules / units, which are stored in the memory 402 and executed by the processor 401 to complete the present invention. The one or more modules / units can be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 403 in the electronic device 400. For example, the computer program 403 can be divided into... Figure 10 The communication module 301 and the processing module 302 are shown.

[0096] The processor 401 may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0097] The memory 402 can be an internal storage unit of the electronic device 400, such as a hard disk or memory of the electronic device 400. The memory 402 can also be an external storage device of the electronic device 400, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 400. Furthermore, the memory 402 can include both internal and external storage units of the electronic device 400. The memory 402 is used to store the computer program and other programs and data required by the terminal. The memory 402 can also be used to temporarily store data that has been output or will be output.

[0098] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0099] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0100] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0101] In the embodiments provided by this invention, it should be understood that the disclosed devices / terminals and methods can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0102] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0103] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0104] If the integrated module / unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the methods of the above embodiments can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0105] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A control method for a voltage conversion circuit, characterized in that, The voltage conversion circuit includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and its output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive and neutral points of the DC bus, and the input terminal of the second conversion module is connected to the neutral and negative points of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to the load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop to ensure that the output voltage of the voltage conversion circuit equals the target voltage. The control method includes: Obtain a first voltage and a second voltage, wherein the first voltage is the voltage between the positive terminal and the neutral point of the DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus; Based on the error between the first voltage and the second voltage, a PI calculation is performed to obtain the compensation current or compensation duty cycle. The output currents of the first and second conversion modules in the control loop are compensated based on the compensation current, or the duty cycles of the first and second conversion modules in the control loop are compensated based on the compensation duty cycle to obtain a first duty cycle of the first conversion module and a second duty cycle of the second conversion module after compensation, so as to balance the output power of the first and second conversion modules; including: obtaining the first duty cycle based on the target duty cycle, actual duty cycle, and compensation duty cycle of the first conversion module; obtaining the second duty cycle based on the target duty cycle, actual duty cycle, and compensation duty cycle of the second conversion module; or... Based on the target output current, actual output current, and compensation current of the first conversion module, the compensated first current error is obtained; based on the compensated first current error, the target duty cycle of the first conversion module is obtained, and the first duty cycle is determined based on the target duty cycle and actual duty cycle of the first conversion module; based on the target output current, actual output current, and compensation current of the second conversion module, the compensated second current error is obtained; based on the compensated second current error, the target duty cycle of the second conversion module is obtained, and the second duty cycle is determined based on the target duty cycle and actual duty cycle of the second conversion module.

2. The control method for the voltage conversion circuit according to claim 1, characterized in that, The step of obtaining the first duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the first transformation module includes: taking the target duty cycle of the first transformation module as a given value, taking the actual duty cycle of the first transformation module as negative feedback, and taking the compensated duty cycle as positive feedback to obtain the first duty cycle; The process of obtaining the second duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the second transformation module includes: using the target duty cycle of the second transformation module as a given value, the actual duty cycle of the second transformation module as negative feedback, and the compensated duty cycle as negative feedback to obtain the second duty cycle.

3. The control method for the voltage conversion circuit according to claim 1, characterized in that, The control method further includes: Obtain the actual output voltage of the voltage conversion circuit, the actual output current of the first conversion module before compensation, the actual output current of the second conversion module before compensation, the actual duty cycle of the first conversion module before compensation, and the actual duty cycle of the second conversion module before compensation. Based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit, the target output current of the first conversion module and the target output current of the second conversion module are obtained. Based on the error between the target output current and the actual output current of the first conversion module, the first current error of the first conversion module is obtained. Based on the first current error, the target duty cycle of the first conversion module is obtained; Based on the error between the target output current and the actual output current of the second conversion module, the second current error of the second conversion module is obtained. Based on the second current error, the target duty cycle of the second conversion module is obtained.

4. The control method for the voltage conversion circuit according to claim 1, characterized in that, The method of obtaining the compensated first current error based on the target output current, actual output current and compensation current of the first conversion module includes: taking the target output current of the first conversion module as a given value, taking the actual output current of the first conversion module as negative feedback and taking the compensation current as positive feedback to obtain the compensated first current error. The method of obtaining the compensated second current error based on the target output current, actual output current, and compensation current of the second conversion module includes: using the target output current of the second conversion module as a given value, using the actual output current of the second conversion module as negative feedback, and using the compensation current as positive feedback to obtain the compensated second current error.

5. The control method for the voltage conversion circuit according to claim 1, characterized in that, The control method further includes: Obtain the actual output voltage of the voltage conversion circuit; Based on the error between the target output voltage and the actual output voltage of the voltage conversion circuit, the target output current of the first conversion module and the target output current of the second conversion module are obtained.

6. A control device for a voltage conversion circuit, characterized in that, The voltage conversion circuit includes a PFC module, a first conversion module, a second conversion module, and a control device. The input terminal of the PFC module is connected to an AC power supply, and its output terminal is connected to a DC bus. The input terminal of the first conversion module is connected to the positive and neutral points of the DC bus, and the input terminal of the second conversion module is connected to the neutral and negative points of the DC bus. The output terminals of the first and second conversion modules are connected in parallel to the load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop to ensure that the output voltage of the voltage conversion circuit equals the target voltage. The control device includes: The communication module is used to acquire a first voltage and a second voltage, wherein the first voltage is the voltage between the positive terminal and the neutral point of the DC bus, and the second voltage is the voltage between the neutral point and the negative terminal of the DC bus; The processing module is used to perform PI calculation based on the error between the first voltage and the second voltage to obtain a compensation current or a compensation duty cycle; to compensate the output current of the first conversion module and the second conversion module in the control loop based on the compensation current, or to compensate the duty cycle of the first conversion module and the second conversion module in the control loop based on the compensation duty cycle, so as to obtain the first duty cycle of the first conversion module and the second duty cycle of the second conversion module after compensation, so as to balance the output power of the first conversion module and the second conversion module. The processing module is specifically used to obtain the first duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the first transformation module; and to obtain the second duty cycle based on the target duty cycle, actual duty cycle, and compensated duty cycle of the second transformation module; or, Based on the target output current, actual output current, and compensation current of the first conversion module, the compensated first current error is obtained; based on the compensated first current error, the target duty cycle of the first conversion module is obtained, and the first duty cycle is determined based on the target duty cycle and actual duty cycle of the first conversion module; based on the target output current, actual output current, and compensation current of the second conversion module, the compensated second current error is obtained; based on the compensated second current error, the target duty cycle of the second conversion module is obtained, and the second duty cycle is determined based on the target duty cycle and actual duty cycle of the second conversion module.

7. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program, and the processor is used to call and run the computer program stored in the memory to perform the control method of the voltage conversion circuit as described in any one of claims 1 to 5.

8. A voltage conversion circuit, characterized in that, It includes a PFC module, a first conversion module, a second conversion module, and a control device for the voltage conversion circuit as described in claim 6; The PFC module has its input connected to an AC power source and its output connected to a DC bus. The first conversion module has its input connected to the positive and neutral points of the DC bus, and the second conversion module has its input connected to the neutral and negative points of the DC bus. The outputs of the first and second conversion modules are connected in parallel to the load. The control device controls the duty cycle of the switching transistors in the first and second conversion modules through a control loop to make the output voltage of the voltage conversion circuit equal to the target voltage.

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