BUCK CIRCUIT AND ITS CONTROL METHOD, CONTROLLER, CONTROL DEVICE, AND STORAGE MEDIUM

Abstract

A BUCK circuit, a control method thereof, a controller, a control device, and a storage medium, the control method including a step of identifying load information of the BUCK circuit (S102), a step of determining a control type and a control method of the BUCK circuit based on the load information (S104), and a step of controlling a carrier frequency and a duty ratio of a first switch transistor in the BUCK circuit based on the control type and the control method to change the switching frequency of the BUCK circuit and operate it (S106).

Description

[Technical Field]

[0001] The present disclosure relates to the field of power supply technology, and more particularly to a BUCK circuit and a control method thereof, a controller, a control device, and a storage medium. [Background technology]

[0002] Buck circuits are widely used as step-down circuits in a variety of situations, but currently commonly used buck circuits, as shown in Figure 1, generally perform high-frequency on / off control of the switch transistors Q1 and Q2 during operation using a control method such as that shown in Figure 2. The dotted line frame in Figure 2(b) indicates that both switch transistors Q1 and Q2 are in a high-frequency on / off state throughout the entire step-down operation time, which causes very large switching losses in the circuit and poor circuit efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] The present disclosure aims to solve at least to some extent one of the technical problems in the related art.

[0004] Therefore, a first object of the present disclosure is to provide a control method for a BUCK circuit, which determines the control type and control method of the BUCK circuit based on load information of the BUCK circuit, thereby controlling the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit, causing the BUCK circuit to operate at a different switching frequency, and reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BUCK circuit.

[0005] A second object of the present disclosure is to provide a controller for a BUCK circuit.

[0006] A third object of the present disclosure is to provide a computer-readable storage medium.

[0007] A fourth object of the present disclosure is to provide a control device for a BUCK circuit.

[0008] A fifth object of the present disclosure is to provide a BUCK circuit. [Means for solving the problem]

[0009] In order to achieve the above object, a control method for a buck circuit provided in an embodiment of the first aspect of the present disclosure includes the steps of identifying load information of the buck circuit, determining a control type and a control method for the buck circuit based on the load information, and controlling the carrier frequency and the duty ratio of a first switch transistor in the buck circuit according to the control type and the control method to change the switching frequency of the buck circuit.

[0010] According to the control method for a BUCK circuit according to an embodiment of the present disclosure, the control type and control method for the BUCK circuit are determined based on the load information of the BUCK circuit, and the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit are controlled accordingly, causing the BUCK circuit to operate at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BUCK circuit.

[0011] In order to achieve the above object, a controller for a BUCK circuit provided in an embodiment of the second aspect of the present disclosure includes a memory, a processor, and a control program for the BUCK circuit stored in the memory and running on the processor, and when the processor executes the control program for the BUCK circuit, the above-mentioned control method for the BUCK circuit is realized.

[0012] The BUCK circuit controller according to the embodiment of the present disclosure uses a processor to realize the above-mentioned BUCK circuit control method, and causes the BUCK circuit to operate at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0013] To achieve the above object, a computer-readable storage medium is provided as an embodiment of the third aspect of the present disclosure. A control program for a BUCK circuit is stored on the computer-readable storage medium, and when the control program for the BUCK circuit is executed by a processor, the above-mentioned control method for a BUCK circuit is realized.

[0014] A computer-readable storage medium according to an embodiment of the present disclosure uses the above-mentioned BUCK circuit control method to operate the BUCK circuit at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0015] To achieve the above object, a control device for a buck circuit provided in an embodiment of the fourth aspect of the present disclosure includes: a determination module for identifying load information of the buck circuit and determining a control type and control method of the buck circuit based on the load information; and a control module for controlling the carrier frequency and duty ratio of a first switch transistor in the buck circuit based on the control type and control method, thereby changing the switching frequency of the buck circuit to operate.

[0016] A BUCK circuit control device according to an embodiment of the present disclosure uses a determination module to identify load information of the BUCK circuit, determine a control type and control method for the BUCK circuit based on the load information, and use a control module to control the carrier frequency and duty ratio of the first switch transistor, causing the BUCK circuit to operate at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BUCK circuit.

[0017] In order to achieve the above object, an embodiment of a fifth aspect of the present disclosure provides a BUCK circuit including: an input-side capacitor; a first switch transistor having one end connected to one end of the input-side capacitor; a flyback element having one end connected to the other end of the first switch transistor and the other end connected to the other end of the input-side capacitor; an inductor having one end connected to the other end of the first switch transistor; an output-side capacitor having one end connected to the other end of the inductor and the other end connected to the other end of the flyback element; and a controller used to identify load information of the BUCK circuit, determine a control type and a control method of the BUCK circuit based on the load information, and control a carrier frequency and a duty ratio of the first switch transistor based on the control type and the control method to change the switching frequency of the BUCK circuit and operate it.

[0018] The BUCK circuit according to the embodiment of the present disclosure uses a controller to identify load information of the BUCK circuit, and determines the control type and control method of the BUCK circuit based on the load information, thereby controlling the carrier frequency and duty ratio of the first switch transistor, thereby causing the BUCK circuit to operate at a different switching frequency, and reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BUCK circuit.

[0019] Additional aspects and advantages of the disclosure will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the disclosure. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a circuit diagram of a BUCK circuit in the related art. [Figure 2] FIG. 10 is a diagram showing the relationship between the operation of a switch transistor of a BUCK circuit in the related art and the voltage and current. [Figure 3] FIG. 2 is a circuit diagram of a BUCK circuit according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a circuit diagram of a BUCK circuit according to another embodiment of the present disclosure. [Figure 5] 10 is a flowchart of a method for controlling a BUCK circuit according to an embodiment of the present disclosure. [Figure 6] 10 is a flowchart of a method for controlling a BUCK circuit according to an embodiment of the present disclosure. [Figure 7a] FIG. 10 is a diagram illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present disclosure. [Figure 7b] FIG. 10 is a diagram illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present disclosure. [Figure 7c] FIG. 10 is a diagram illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present disclosure. [Figure 7d] FIG. 10 is a diagram illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present disclosure. [Figure 8] 10 is a flowchart of a control method for a BUCK circuit according to another embodiment of the present disclosure. [Figure 9a] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present disclosure. [Figure 9b] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present disclosure. [Figure 9c] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present disclosure. [Figure 9d] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present disclosure. [Figure 10] 4 is a flowchart of a control method for a BUCK circuit according to an embodiment of the present invention. [Figure 11a] 5A and 5B are diagrams illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present invention. [Figure 11b] 4 is a diagram showing the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present invention. FIG. [Figure 11c] 5A and 5B are diagrams illustrating the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present invention. [Figure 11d] 4 is a diagram showing the relationship between the operation of a switch transistor and voltage and current in a BUCK circuit according to some embodiments of the present invention. FIG. [Figure 12] 4 is a flowchart of a method for controlling a BUCK circuit according to an embodiment of the present invention. [Figure 13] 4 is a flowchart of a method for controlling a BUCK circuit according to an embodiment of the present invention. [Figure 14] 4 is a flowchart of a control method for a BUCK circuit according to an embodiment of the present invention. [Figure 15a] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present invention. [Figure 15b] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage / current in a BUCK circuit according to some other embodiments of the present invention. [Figure 15c] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present invention. [Figure 15d] 10A and 10B are diagrams illustrating the relationship between the operation of a switch transistor and a voltage and current in a BUCK circuit according to some other embodiments of the present invention. [Figure 16] FIG. 2 is a structural schematic diagram of a controller of a BUCK circuit according to an embodiment of the present disclosure. [Figure 17] FIG. 2 is a structural schematic diagram of a control device of a BUCK circuit according to an embodiment of the present disclosure. [Figure 18] FIG. 2 is a circuit diagram of a BUCK circuit according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, the embodiments of the present disclosure shown in the drawings will be described in detail, and in all the drawings, the same or similar reference numerals indicate the same or similar elements or elements having the same or similar functions. The embodiments described through the following reference drawings are illustrative and are intended to explain the present disclosure, and should not be understood as limitations on the present disclosure.

[0022] The control method of the present disclosure can be applied to the buck circuit shown in Fig. 3 or 4. As shown in Figs. 3 and 4, the buck circuit includes an input-side capacitor C1, a first switch transistor Q1, a flyback element, an inductor L1, and an output-side capacitor C2, and the flyback element can be the diode D shown in Fig. 3 or the second switch transistor Q2 shown in Fig. 4. One end of the first switch transistor Q1 is connected to one end of the input-side capacitor C1, one end of the flyback element is connected to the other end of the first switch transistor Q1, the other end of the flyback element is connected to the other end of the input-side capacitor C1, one end of the inductor L1 is connected to the other end of the first switch transistor Q1, one end of the output-side capacitor C2 is connected to the other end of the inductor L1, and the other end of the output-side capacitor C2 is connected to the other end of the flyback element. As shown in Figure 4, by controlling the on / off of the first switch transistor Q1 and the second switch transistor Q2, the step-down function of the BUCK circuit can be realized, and the input voltage (i.e., the voltage across the input-side capacitor C1) is stepped down to obtain the output voltage (i.e., the voltage across the output-side capacitor C2), and the input voltage is larger than the output voltage. As shown in Figure 3, by controlling the on / off of the first switch transistor Q1, the step-down function of the BUCK circuit can be realized.

[0023] 5 is a flowchart of a control method for a buck circuit according to an embodiment of the present disclosure. For simplicity of explanation, the following description will be mainly based on an example in which the control method is used for the buck circuit shown in FIG.

[0024] As shown in FIG. 5, the control method for the BUCK circuit may include the following steps.

[0025] S102: Identify the load information of the BUCK circuit.

[0026] The load information of the buck circuit may include the load type and the load size. The load type may be divided into a current-sensitive type and a voltage-sensitive type. The current-sensitive type means that current fluctuations in the buck circuit have a significant effect on the load and may cause load failure. The voltage-sensitive type means that voltage fluctuations in the buck circuit have a significant effect on the load and may cause load failure.

[0027] S104: Determine the control type and control method of the buck circuit based on the load information.

[0028] The control types of the buck circuit can include a current control type and a voltage control type. The current control type controls the buck circuit based on a current parameter so that the current parameter meets a preset requirement, and the voltage control type controls the buck circuit based on a voltage parameter so that the voltage parameter meets a preset requirement. Both types are applicable to different loads. For example, if the load is sensitive to a current parameter, the buck circuit can be controlled using the current control type, and if the load is sensitive to a voltage parameter, the buck circuit can be controlled using the voltage control type. The control method of the buck circuit refers to a method of controlling the carrier frequency and duty cycle of the first switch transistor in the buck circuit based on the corresponding voltage parameter or current parameter.

[0029] In some embodiments, determining a control type and a control method of the BUCK circuit based on the load information includes determining the control type according to the load type and determining the control method according to the magnitude of the load, and the control type includes a current control type and a voltage control type.

[0030] Specifically, different load types correspond to different control types. For example, if the load type is current-sensitive, the buck circuit is controlled using a current control type to limit the inductor current within an appropriate range. If the load type is voltage-sensitive, the buck circuit is controlled using a voltage control type to limit the output capacitor voltage within an appropriate range. After identifying the load type, the load size (i.e., the load power) can be determined using multiple methods, and the buck circuit control method can be determined based on the load size. For example, a current detection module can be installed on the input side of the converter shown in Figure 3, and the current detected by the current detection module can be used as the input current. The input voltage is a fixed value, and for example, the input voltage can be a standard 220V commercial voltage. Therefore, the load size can be determined based on the input current, and the buck circuit control method can be determined based on the load size.

[0031] Note that the method of determining the load size according to the input current is merely an illustrative example and does not limit the present disclosure. The load size may also be determined directly by detecting the output voltage and output current at the load end and calculating the load power based on the product of the two.

[0032] Furthermore, the step of determining the control method according to the magnitude of the load includes determining the control method to be a control method with a low carrier frequency and a high duty ratio when the load of the BUCK circuit is equal to or greater than a preset value, and determining the control method to be a control method with a high carrier frequency and a high duty ratio when the load of the BUCK circuit is smaller than the preset value.

[0033] In other words, different load sizes correspond to different control methods; for example, when the load is large, a control method with a low carrier frequency and a high duty ratio is adopted, and when the load is small, a control method with a high carrier frequency and a high duty ratio is adopted.

[0034] For example, when the input current of the buck circuit is greater than or equal to a predetermined current threshold, it indicates that the load is greater than or equal to a predetermined value. In this case, the control mode is set to a low carrier frequency and a high duty ratio to increase the inductor current and the output capacitor voltage, and the low carrier frequency control mode reduces the switching loss of the first switch transistor. When the input current is less than the predetermined current threshold, it indicates that the load is less than the predetermined value. In this case, the control mode is set to a high carrier frequency and a high duty ratio to increase the inductor current and the output capacitor voltage. In addition, the high carrier frequency control mode reduces the ripple current and ripple voltage of the first switch transistor, preventing excessive ripple current from affecting the load operation.

[0035] S106: Control the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit according to the control type and control method, and make the BUCK circuit operate by changing the switching frequency.

[0036] The carrier frequency affects the switching loss of the first switch transistor; that is, the higher the carrier frequency, the higher the switching loss of the first switch transistor, and the lower the carrier frequency, the lower the switching loss of the first switch transistor. The duty ratio affects the tendency of change in the inductor current and the output capacitor voltage of the BUCK circuit; that is, when the duty is large, the inductor current and the output capacitor voltage increase, and when the duty is small, the inductor current and the output capacitor voltage decrease.

[0037] When the control type and control method of the buck circuit are determined by the above steps, the carrier frequency and duty ratio of the first switch transistor are controlled based on the control type and control method, causing the buck circuit to operate at a different switching frequency, which not only satisfies the load demand but also lowers the switching frequency of the switch transistor by changing the switching frequency of the buck circuit and controlling the first switch transistor at a low frequency during certain timings, thereby reducing the switching loss of the switch transistor and improving the efficiency of the buck circuit.

[0038] In one implementation, when the BUCK circuit is controlled using a current control type, the step of controlling the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit includes a step of acquiring a current of an inductor of the BUCK circuit when the first switch transistor is controlled by a control method of a low carrier frequency and a high duty ratio, and when the inductor current reaches a first predetermined current, controlling the first switch transistor by a control method of a high carrier frequency and a low duty ratio to reduce the inductor current to a second predetermined current, or a step of acquiring a current of an inductor of the BUCK circuit when the first switch transistor is controlled by a control method of a high carrier frequency and a high duty ratio, and when the inductor current reaches the first predetermined current, controlling the first switch transistor by a control method of a low carrier frequency and a low duty ratio to reduce the inductor current to a second predetermined current.

[0039] Specifically, as shown in FIGS. 3 and 6, if the load type is current-sensitive and the corresponding control type is current-controlled, when the BUCK circuit operates, the load size can be determined by acquiring the input current of the BUCK circuit (although other methods for determining the load size are also possible and are not limited here). If the load of the BUCK circuit is determined to be greater than a predetermined value based on the input current, the first switch transistor Q1 is first controlled using a low carrier frequency and high duty ratio control method. At this time, the relationship between the operation of the switch transistor and the voltage and current is as shown in FIG. 7a or 7b. The duty ratio is relatively high, the inductor current increases, and the switching frequency is low, thereby reducing the switching loss of the first switch transistor Q1. When the inductor current increases to a first predetermined current, the control method for the first switch transistor Q1 is adjusted, i.e., the first switch transistor Q1 continues to be controlled using a high carrier frequency and low duty ratio control method. The duty ratio decreases, the inductor current decreases, and the switching frequency is high, thereby reducing the ripple current in the BUCK circuit and preventing excessive ripple current from affecting the operation of the load. Once the inductor current has decreased to a second predetermined current, the input current is again sensed to determine the load size.

[0040] When the input current determines that the load of the BCUK circuit is less than a predetermined value, the first switch transistor Q1 is first controlled using a high carrier frequency and high duty ratio control scheme. At this time, the relationship between the switch transistor operation and the voltage and current is as shown in Figures 7c and 7d. The duty ratio is relatively high, causing the inductor current to rise. The high switching frequency reduces the ripple current, preventing excessive ripple current from affecting the load operation. When the inductor current rises to a first predetermined current, the control scheme for the first switch transistor Q1 is adjusted, i.e., the first switch transistor Q1 continues to be controlled using a low carrier frequency and low duty ratio control scheme. The duty ratio decreases, the inductor current decreases, and the switching frequency is low, reducing the switching loss of the first switch transistor Q1. When the inductor current drops to a second predetermined current, the input current is redetected to determine the load size.

[0041] The above process is repeated until the BUCK circuit stops the step-down operation.

[0042] To ensure that each component is not damaged by excessive current (e.g., to ensure that the first switch transistor does not break down and the inductor does not saturate), the first predetermined current must be equal to or less than the maximum current required by the load and equal to or less than the maximum allowable current of each component in the BUCK circuit (e.g., equal to or less than the smaller of the withstand current of the first switch transistor and the saturation current of the inductor). The second predetermined current must be greater than or equal to zero and less than the first predetermined current. As shown in Figures 7a and 7c, the second predetermined current is zero, and as shown in Figures 7b and 7d, the second predetermined current is greater than zero and less than the first predetermined current. The current difference between the first predetermined current and the second predetermined current is the current ripple, which must meet the operating requirements of the load. The average current of the inductor must be equal to the operating current required by the load, ensuring normal operation of the load.

[0043] In the above embodiment, different control methods for the first switch transistor are selected according to the magnitude of the load. In the different control methods, high and low frequencies are alternately used to control the first switch transistor, and the current of the inductor of the buck circuit is controlled within a target range, thereby ensuring that the load can operate normally and reducing the average switching frequency of the first switch transistor without affecting the operating state of the load, thereby reducing the switching loss of the switch transistor and improving the efficiency of the buck circuit.

[0044] In another embodiment, when the BUCK circuit is controlled using the voltage control type, controlling the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit includes, when the first switch transistor is controlled by a control method of a low carrier frequency and a high duty ratio, acquiring the voltage of an output-side capacitor of the BUCK circuit, and when the voltage of the output-side capacitor reaches a first predetermined voltage, controlling the first switch transistor by a control method of a high carrier frequency and a low duty ratio to reduce the voltage of the output-side capacitor to a second predetermined voltage; or, when the first switch transistor is controlled by a control method of a high carrier frequency and a high duty ratio, acquiring the voltage of the output-side capacitor of the BUCK circuit, and when the voltage of the output-side capacitor reaches the first predetermined voltage, controlling the first switch transistor by a control method of a low carrier frequency and a low duty ratio to reduce the voltage of the output-side capacitor to the second predetermined voltage.

[0045] Specifically, as shown in FIGS. 3 and 8, if the load type is voltage-sensitive and the corresponding control type is voltage-controlled, the load magnitude can be determined by obtaining the input current of the BUCK circuit when the BUCK circuit is activated (although other methods for determining the load magnitude are also possible and are not limited herein). If the load of the BUCK circuit is determined to be greater than a predetermined value based on the input current, the first switch transistor Q1 is first controlled using a low carrier frequency, high duty ratio control method. At this time, the relationship between the operation of the switch transistor and the voltage and current is as shown in FIG. 7a or 7b. The duty ratio is relatively high, the voltage across the output capacitor increases, and the switching frequency is relatively low, resulting in low switching loss in the first switch transistor Q1. When the voltage across the output capacitor reaches a first predetermined voltage, the control method for the first switch transistor Q1 is adjusted, i.e., the first switch transistor Q1 continues to be controlled using a high carrier frequency, low duty ratio control method. The duty cycle decreases, the voltage of the output capacitor decreases, and the switching frequency is relatively high, so the ripple voltage of the buck circuit is small, preventing the ripple voltage from being excessively large and affecting load operation.When the voltage of the output capacitor decreases to a second predetermined voltage, the input current is detected again to identify the magnitude of the load.

[0046] When the load of the BCUK circuit is determined to be less than a predetermined value based on the input current, the first switch transistor Q1 is first controlled using a high carrier frequency and high duty ratio control scheme. At this time, the relationship between the switch transistor operation and the voltage and current is shown in Figures 7c and 7d. The relatively high duty ratio increases the output capacitor voltage, while the relatively high switching frequency reduces the ripple voltage, preventing excessive ripple voltage from affecting load operation. When the output capacitor voltage increases to a first predetermined voltage, the control scheme for the first switch transistor Q1 is adjusted, i.e., the first switch transistor Q1 continues to be controlled using a low carrier frequency and low duty ratio control scheme. The duty ratio decreases, the output capacitor voltage decreases, and the relatively low switching frequency reduces the switching loss of the first switch transistor Q1. When the output capacitor voltage decreases to a second predetermined voltage, the input current is redetected to determine the load size.

[0047] The above process is repeated until the BUCK circuit stops the step-down operation.

[0048] To prevent the output capacitor from being destroyed by overvoltage, the first predetermined voltage must be equal to or less than the maximum voltage required by the load and equal to or less than the withstand voltage of each element in the buck circuit, such as the withstand voltage of the output capacitor. The second predetermined voltage must be greater than zero and less than the first predetermined voltage. As shown in Figures 7a-7d, the second predetermined voltages are all greater than zero and less than the first predetermined voltage. The voltage difference between the first and second predetermined voltages is the voltage ripple, and this voltage ripple must meet the load operating requirements.

[0049] In the above embodiment, different control methods for the first switch transistor are selected depending on the magnitude of the load. In the different control methods, high and low frequencies are alternately used to control the first switch transistor, and the voltage of the output capacitor of the buck circuit is controlled within a target range, thereby ensuring normal operation of the load and reducing the average switching frequency of the first switch transistor without affecting the operating state of the load. This reduces the switching loss of the switch transistor and improves the efficiency of the buck circuit.

[0050] In some embodiments, when the flyback element in the BUCK circuit is a second switch transistor, the method further includes the steps of: controlling the second switch transistor to be off when controlling the first switch transistor to be on; and controlling the second switch transistor to be on when controlling the first switch transistor to be off.

[0051] Specifically, as shown in Figure 4, a second switch transistor Q2 can be used instead of diode D. In this case, the relationship between the operation of the switch transistor and the voltage and current is as shown in Figures 9a-9d. When the first switch transistor Q1 is turned off, the second switch transistor Q2 is turned on, providing a flyback circuit for inductor L1. When the first switch transistor Q1 is turned on, the second switch transistor Q2 is turned off, disconnecting the circuit and not affecting the buck circuit's ability to supply power to the load. This allows the second switch transistor Q2 to perform all the functions of diode D.

[0052] In the case of a BUCK circuit in which the flyback element is the second switch transistor, the only difference from when the flyback element is a diode is the control of the second switch transistor, but the control of the first switch transistor is the same, so it has the same effect as when the flyback element is a diode. For details, please refer to the above explanation, and the explanation will not be repeated here.

[0053] 10 is a flowchart of a control method for a buck circuit according to an embodiment of the present invention. For simplicity of explanation, the following description will be mainly based on an example in which the control method is applied to the buck circuit shown in FIG.

[0054] As shown in FIG. 10, the control method for the BUCK circuit can include the following steps:

[0055] S202, identify the load type of the BUCK circuit.

[0056] The load types of buck circuits can be divided into current-sensitive and voltage-sensitive types. The current-sensitive type means that current fluctuations in the buck circuit have a significant effect on the load and may cause load failure. The voltage-sensitive type means that voltage fluctuations in the buck circuit have a significant effect on the load and may cause load failure.

[0057] In step S204, when the buck circuit is controlled using a current control type according to the load type, the magnitude of the load of the buck circuit is acquired.

[0058] Specifically, different load types correspond to different control types. For example, if the load type is current-sensitive, the control type is current-controlled; if the load type is voltage-sensitive, the control type is voltage-controlled. If the currently identified load type is current-sensitive, the buck circuit can be controlled using the current-controlled control type. In this case, the load size of the buck circuit (i.e., the load power) can be obtained in various ways. For example, a current detection module can be installed on the input side of the converter shown in Figure 3, and the current detected by the current detection module can be used as the input current of the buck circuit. Because the input voltage of the converter is a fixed value, the input power is proportional to the input current. Furthermore, because the conversion efficiency of the converter and the buck circuit is constant, the load power is proportional to the input power. Therefore, the load size can be determined based on the input current.

[0059] Note that the method of determining the load size according to the input current is merely an illustrative example and does not limit the present application. The load size may also be directly determined by detecting the output voltage and output current and calculating the load power based on the product of the two.

[0060] S206: When the load of the BUCK circuit is equal to or greater than a preset value, the first switch transistor in the BUCK circuit is controlled to be turned on to increase the current of the inductor of the BUCK circuit, and when the current of the inductor has increased to a first predetermined current, the first switch transistor is subjected to high-frequency switching control to decrease the current of the inductor to a second predetermined current.

[0061] Specifically, to determine whether the load is greater than a predetermined value, a corresponding threshold value can be set for the physical quantity detected to identify the load. For example, when a method for identifying the load based on the input current is adopted, if the input current of the buck circuit is equal to or greater than a predetermined current threshold, the load of the buck circuit can be identified as being greater than or equal to the predetermined value. In this case, the first switch transistor in the buck circuit can be controlled to remain on so that the current in the inductor of the buck circuit continues to rise. When the inductor current rises to a first predetermined current, high-frequency switching control is performed on the first switch transistor. By rationally setting the duty ratio of the first switch transistor, the inductor current continues to decrease from the first predetermined current until it decreases to a second predetermined current. The load of the buck circuit is then re-identified, and when the load is equal to or greater than the predetermined value, the first switch transistor is again controlled to remain on, and this process is repeated.

[0062] Furthermore, as shown in Figures 3 and 11a-11b, if the load type is a current-sensitive type and the corresponding control type is a current-controlled type, the load size can be determined by acquiring the input current of the BUCK circuit when the BUCK circuit operates (other methods may be used to determine the load size, but this is not a limitation). If the load of the BUCK circuit is determined to be greater than a predetermined value based on the input current, the first switch transistor Q1 is first controlled to remain on. At this time, the input voltage charges inductor L1 and output capacitor C2 through the first switch transistor Q1, causing the inductor current to continue to rise. When the inductor current rises to a first predetermined current, the control method for the first switch transistor Q1 is changed, i.e., the first switch transistor Q1 is controlled to be turned on and off using a high-frequency switching control method. During this period, as shown in the dotted-line frame in Figures 11a-11b, when the first switch transistor Q1 is turned off, inductor L1 is flybacked by diode D, and the inductor current decreases. When the first switch transistor Q1 is turned on, the input voltage charges the inductor L1 and the output capacitor C2 through the first switch transistor Q1, causing the inductor current to rise. By setting an appropriate duty ratio, the inductor current can be made to exhibit a general decreasing trend, gradually decreasing from a first predetermined current to a second predetermined current. Then, the input current of the BUCK circuit is acquired again. If the load of the BCUK circuit is determined to be equal to or greater than a predetermined value based on the input current, the first switch transistor Q1 is again controlled to remain on, and this process is repeated.

[0063] Furthermore, when the load is greater than a predetermined value, the duty cycle is not increased too much during high-frequency operation of the first switch transistor to ensure that the inductor current remains low. To ensure that excessive current does not damage each component (e.g., the first switch transistor does not break down and the inductor does not saturate), the first predetermined current must be less than the maximum current required by the load and less than the maximum allowable current of each component in the buck circuit (e.g., less than the smaller of the withstand current of the first switch transistor and the saturation current of the inductor). The second predetermined current must be greater than zero but less than the first predetermined current. As shown in Figure 11a, the second predetermined current is zero, and as shown in Figure 11b, the second predetermined current is greater than zero but less than the first predetermined current. The current difference between the first predetermined current and the second predetermined current is the current ripple, which must meet the operating requirements of the load. The average current of the inductor must be equal to the operating current required by the load, ensuring normal operation of the load.

[0064] In some embodiments, when the load of the BUCK circuit is smaller than a preset value, high-frequency switching control is performed on the first switch transistor to increase the current of the inductor of the BUCK circuit, and when the current of the inductor increases to a first predetermined current, the first switch transistor is controlled to be turned off to decrease the current of the inductor to a second predetermined current.

[0065] Specifically, when the input current of the buck circuit is less than a predetermined current threshold, the load of the buck circuit is determined to be less than a predetermined value. In this case, the first switch transistor in the buck circuit is first subjected to high-frequency switching control. By rationally setting the duty ratio of the first switch transistor, the current in the buck circuit's inductor continues to rise. When the inductor current reaches a first predetermined current, the first switch transistor is controlled to remain off, and the inductor current continues to decrease until it decreases to a second predetermined current. The load of the buck circuit is then determined again. When the load is less than the predetermined value, the first switch transistor is again subjected to high-frequency switching control, and this process is repeated.

[0066] Furthermore, as shown in Figures 3 and 11c-11d, if the load type is a current-sensitive type and the corresponding control type is a current-controlled type, the load size can be determined by acquiring the input current of the BUCK circuit when the BUCK circuit is activated (other methods may be used to determine the load size, but this is not a limitation). If the load of the BUCK circuit is determined to be smaller than a preset value based on the input current, the first switch transistor Q1 is controlled to be turned on and off using a high-frequency switching control method. As shown in the dotted-line frame in Figures 11c-11d, during this period, when the first switch transistor Q1 is turned on, the input voltage charges inductor L1 and output capacitor C2 through the first switch transistor Q1, causing the inductor current to rise. When the first switch transistor Q1 is turned off, inductor L1 is flybacked by diode D, causing the inductor current to fall. By setting an appropriate duty cycle, the inductor current generally shows an upward trend until it rises to a first predetermined current, and then the control method of the first switch transistor Q1 is changed, i.e., the first switch transistor Q1 is controlled to remain off, at which point the inductor current continues to decrease until it drops to a second predetermined current. After that, the input current of the BUCK circuit is obtained again, and if it is determined based on the input current that the load of the BCUK circuit is smaller than the preset value, the first switch transistor Q1 is again controlled to be turned on and off using the high-frequency switching control method, and so on.

[0067] When the load is less than a predetermined value, the duty cycle is not made too small during high-frequency operation of the first switch transistor to ensure that the inductor current is rising. Figures 11a and 11b show the relationship between the operation of the switch transistor and voltage / current when all loads are equal to or greater than a predetermined value, while Figures 11c and 11d show the relationship between the operation of the switch transistor and voltage / current when all loads are less than the predetermined value. In actual use, the load and input current may change, so the load may be greater than, less than, or equal to the predetermined value during operation of the buck circuit. For details, please refer to the above description and Figure 12, and a detailed description will not be repeated here.

[0068] In the above embodiment, when the control type is determined to be the current control type according to the load type, intermittent high-frequency switching control is performed on the first switch transistor according to the magnitude of the load when the BUCK circuit operates. This not only ensures that the BUCK circuit meets the needs of the load, but also reduces the switching loss of the switch transistor in the BUCK circuit and improves the operating efficiency of the BCUK circuit. At the same time, by rationally setting the first predetermined current, it is possible to prevent each element in the BUCK circuit from being damaged by excessive current.

[0069] In some embodiments, as shown in FIG. 13, after determining the load type of the BUCK circuit, the method further includes the following steps:

[0070] In step S210, when the buck circuit is controlled using a voltage control type according to the load type, the magnitude of the load of the buck circuit is acquired.

[0071] If the currently determined load type is a voltage sensitive type, the buck circuit can be controlled using a voltage control type. In this case, the load size of the buck circuit (i.e., the load power size) can be obtained in various ways. For example, a current detection module can be installed on the input side of the converter shown in FIG. 3, and the current detected by the current detection module can be used as the input current of the buck circuit.

[0072] S212, the magnitude of the load of the BUCK circuit is determined based on the input voltage.

[0073] S214: When the load of the BUCK circuit is equal to or greater than a preset value, the first switch transistor in the BUCK circuit is controlled to be turned on to increase the voltage of the output capacitor of the BUCK circuit, and when the voltage of the output capacitor has increased to a first predetermined voltage, high-frequency switching control is performed on the first switch transistor to decrease the voltage of the output capacitor to a second predetermined voltage.

[0074] Specifically, when the input current of the buck circuit is equal to or greater than a predetermined current threshold, the load of the buck circuit is determined to be equal to or greater than a predetermined value. At this time, the first switch transistor in the buck circuit is first controlled to remain on so that the output voltage of the buck circuit (i.e., the voltage across the output capacitor C2) continues to rise. When the output voltage rises to a first predetermined voltage, high-frequency switching control is performed on the first switch transistor. By rationally setting the duty ratio of the first switch transistor, the output voltage continues to decrease from the first predetermined voltage until it drops to a second predetermined voltage. The magnitude of the load of the buck circuit is then re-determined, and when the load is equal to or greater than the predetermined value, the first switch transistor is again controlled to be on, and this process is repeated.

[0075] Furthermore, as shown in Figures 3, 11a, and 11b, if the load type is voltage-sensitive and the corresponding control type is voltage-controlled, the load size can be determined by acquiring the input current of the BUCK circuit during operation (although other methods may be used to determine the load size, and this is not a limitation). If the load of the BUCK circuit is determined to be greater than or equal to a predetermined value based on the input current, the first switch transistor Q1 is first controlled to remain on. At this time, the input voltage is charged by the first switch transistor Q1 to the inductor L1 and the output capacitor C2, and the output voltage continues to rise. When the output voltage rises to a first predetermined voltage, the control method for the first switch transistor Q1 is changed, i.e., the first switch transistor Q1 is controlled to be turned on and off using a high-frequency switching control method. As shown in the dotted-line frame in Figures 11a and 11b, during this period, when the first switch transistor Q1 is turned off, the output capacitor C2 supplies power to the load, causing the output voltage to drop. When the first switch transistor Q1 is turned on, the input voltage charges the inductor L1 and the output capacitor C2 through the first switch transistor Q1, causing the output voltage to rise. By setting an appropriate duty ratio, the output voltage tends to decrease overall, and the output voltage can be gradually reduced from the first predetermined voltage to the second predetermined voltage. After that, the input current of the BUCK circuit is obtained again. If the load of the BCUK circuit is determined to be equal to or greater than the preset value based on the input current, the first switch transistor Q1 is again controlled to remain on, and this process is repeated.

[0076] Furthermore, when the load is greater than a predetermined value, the duty cycle is not increased too much during high-frequency operation of the first switch transistor to ensure that the output voltage remains low. To ensure that the output capacitor is not destroyed by overvoltage, the first predetermined voltage must be less than the maximum voltage required by the load and less than the withstand voltage of each element in the buck circuit, such as the withstand voltage of the output capacitor. The second predetermined voltage must be greater than zero but less than the first predetermined voltage. As shown in Figures 11a and 11b, both the second predetermined voltages are greater than zero but less than the first predetermined voltage. The voltage difference between the first and second predetermined voltages is the voltage ripple, which must meet the load operating requirements.

[0077] In some embodiments, when the load of the BUCK circuit is smaller than a preset value, high-frequency switching control is performed on the first switch transistor to increase the voltage of the output-side capacitor of the BUCK circuit, and when the voltage of the output-side capacitor has increased to a first predetermined voltage, the first switch transistor is controlled to be turned off to decrease the voltage of the output-side capacitor to a second predetermined voltage.

[0078] Specifically, when the input current of the buck circuit is less than a predetermined current threshold, the load of the buck circuit can be determined to be less than a predetermined value. In this case, high-frequency switching control is first performed on the first switch transistor in the buck circuit. By rationally setting the duty ratio of the first switch transistor, the output voltage of the buck circuit continues to rise. When the output voltage rises to a first predetermined voltage, the first switch transistor is controlled to remain off, and the output voltage continues to decrease until it drops to a second predetermined voltage. The load of the buck circuit is then determined again. When the load is less than the predetermined value, high-frequency switching control is again performed on the first switch transistor, and this process is repeated.

[0079] Furthermore, as shown in Figures 3 and 11c-11d, if the load type is voltage-sensitive and the corresponding control type is voltage-controlled, the load size can be determined by acquiring the input current of the BUCK circuit during operation (although other methods may be used to determine the load size, and this is not a limitation). If the load of the BUCK circuit is determined to be smaller than a preset value based on the input current, the first switch transistor Q1 is first controlled to be turned on and off using a high-frequency switching control method. As shown in the dotted-line frame in Figures 11c-11d, during this period, when the first switch transistor Q1 is turned on, the input voltage charges inductor L1 and output capacitor C2 through the first switch transistor Q1, causing the output voltage to rise. When the first switch transistor Q1 is turned off, the output capacitor C2 supplies power to the load, causing the output voltage to drop. By setting an appropriate duty ratio, the output voltage will generally show an upward trend until it rises to a first predetermined voltage, and then by changing the control method of the first switch transistor Q1, i.e., controlling the first switch transistor Q1 to remain off, the output voltage will continue to decrease until it drops to a second predetermined voltage. After that, the input current of the BUCK circuit is acquired again, and when it is determined that the load of the BCUK circuit is smaller than the preset value according to the input current, the first switch transistor Q1 is again controlled to be turned on and off using the high-frequency switching control method, and this process is repeated.

[0080] In addition, when the load is smaller than a predetermined value, the duty cycle is not made too small during high-frequency operation of the first switch transistor to ensure that the output voltage is in a rising state. Figures 11a and 11b show the relationship between the operation of the switch transistor and voltage / current when all loads are equal to or greater than a predetermined value, while Figures 11c and 11d show the relationship between the operation of the switch transistor and voltage / current when all loads are smaller than a predetermined value. In actual use, the load and input current change, so that the load may be greater than, less than, or equal to the predetermined value during operation of the buck circuit. For details, please refer to the above description and Figure 14, and a detailed description will not be repeated here.

[0081] In the above embodiment, when the control type is determined to be the voltage control type according to the load type, intermittent high-frequency switching control is performed on the first switch transistor according to the magnitude of the load when the BUCK circuit operates. This not only ensures that the BUCK circuit meets the needs of the load, but also reduces the switching loss of the switch transistor in the BUCK circuit and improves the operating efficiency of the BCUK circuit. At the same time, by rationally setting the first predetermined voltage, it is possible to prevent each element in the BUCK circuit from being damaged by excessive voltage.

[0082] In some embodiments, when the flyback element in the BUCK circuit is a second switch transistor, the method further includes the steps of: controlling the second switch transistor to be off when controlling the first switch transistor to be on; and controlling the second switch transistor to be on when controlling the first switch transistor to be off.

[0083] Specifically, as shown in Figure 4, a second switch transistor Q2 can be used instead of diode D. In this case, the relationship between the operation of the switch transistor and the voltage and current is as shown in Figures 15a-15d. When the first switch transistor Q1 is turned off, the second switch transistor Q2 is turned on, providing a flyback circuit to inductor L1. When the first switch transistor Q1 is turned on, the second switch transistor Q2 is turned off, disconnecting the circuit and not affecting the buck circuit's ability to supply power to the load. This allows the second switch transistor Q2 to perform all the functions of diode D.

[0084] In the case of a BUCK circuit in which the flyback element is the second switch transistor, the only difference from when the flyback element is a diode is the control of the second switch transistor, but the control of the first switch transistor is the same, so it has the same effect as when the flyback element is a diode. For details, please refer to the above explanation, and the explanation will not be repeated here.

[0085] As described above, according to the BUCK circuit control method of the embodiment of the present disclosure, the control type and control method of the BUCK circuit are determined based on the load information of the BUCK circuit, and the carrier frequency and duty ratio of the first switch transistor in the BUCK circuit are controlled accordingly, causing the BUCK circuit to operate at a different switching frequency, thereby lowering the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0086] Corresponding to the above embodiment, the embodiment of the present disclosure further provides a controller for the BUCK circuit.

[0087] FIG. 16 is a structural schematic diagram of a controller of a buck circuit according to one embodiment of the present disclosure. As shown in FIG. 10, the controller 110 includes a memory 111, a processor 112, and a control program for the buck circuit that is stored in the memory 111 and can run on the processor 112. When the processor 112 executes the control program for the buck circuit, it realizes the above-mentioned control method for the buck circuit.

[0088] The BUCK circuit controller according to the embodiment of the present disclosure uses a processor to realize the above-mentioned BUCK circuit control method, and causes the BUCK circuit to operate at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0089] Corresponding to the above embodiment, an embodiment of the present disclosure further provides a computer-readable storage medium, in which a control program for a BUCK circuit is stored, and when the control program for the BUCK circuit is executed by a processor, the above-mentioned control method for a BUCK circuit is realized.

[0090] A computer-readable storage medium according to an embodiment of the present disclosure uses the above-mentioned BUCK circuit control method to operate the BUCK circuit at a different switching frequency, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the switching loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0091] Corresponding to the above embodiment, the embodiment of the present disclosure further provides a control device for the BUCK circuit.

[0092] FIG. 17 is a structural schematic diagram of a control device of a BUCK circuit according to an embodiment of the present disclosure. As shown in FIG. 11, the control device 200 includes a determination module 210 and a control module 220.

[0093] The determination module 210 is used to identify load information of the BUCK circuit and determine a control type and a control method of the BUCK circuit based on the load information, and the control module 220 is used to control the carrier frequency and the duty ratio of the first switch transistor Q1 in the BUCK circuit according to the control type and the control method, so as to change the switching frequency of the BUCK circuit.

[0094] According to an embodiment of the present disclosure, the load information includes a load type and a load size, and the determination module 210 is further used to determine a control type according to the load type and determine a control method according to the load size, where the control type includes a current control type and a voltage control type.

[0095] According to an embodiment of the present disclosure, the determination module 210 is further used to determine the control method as a low carrier frequency, high duty cycle control method when the load of the buck circuit is equal to or greater than a preset value, and to determine the control method as a high carrier frequency, high duty cycle control method when the load of the buck circuit is less than the preset value.

[0096] According to an embodiment of the present disclosure, when the buck circuit is controlled using the current control type, the control module 220 is further used to obtain a current through an inductor of the buck circuit when controlling the first switch transistor with a low carrier frequency and a high duty ratio control scheme, and when the inductor current reaches a first predetermined current, control the first switch transistor with a high carrier frequency and a low duty ratio control scheme to reduce the inductor current to a second predetermined current; or when the first switch transistor is controlled with a high carrier frequency and a high duty ratio control scheme, obtain a current through an inductor of the buck circuit when the inductor current reaches the first predetermined current, control the first switch transistor with a low carrier frequency and a low duty ratio control scheme to reduce the inductor current to a second predetermined current.

[0097] According to an embodiment of the present disclosure, when the buck circuit is controlled using the voltage control type, the control module 220 is further configured to: obtain a voltage across an output capacitor of the buck circuit when controlling the first switch transistor with a low carrier frequency and a high duty ratio; and, when the voltage across the output capacitor reaches a first predetermined voltage, control the first switch transistor with a high carrier frequency and a low duty ratio to reduce the voltage across the output capacitor to a second predetermined voltage; or, when controlling the first switch transistor with a high carrier frequency and a high duty ratio, obtain a voltage across the output capacitor of the buck circuit; and, when the voltage across the output capacitor reaches the first predetermined voltage, control the first switch transistor with a low carrier frequency and a low duty ratio to reduce the voltage across the output capacitor to the second predetermined voltage.

[0098] According to one embodiment of the present invention, the determination module 210 is used to identify the load type of the BUCK circuit, and the control module 220 is used to obtain the magnitude of the load of the BUCK circuit when controlling the BUCK circuit using a current control type according to the load type. The control module 220 is further used to control a first switch transistor in the BUCK circuit to turn on when the load of the BUCK circuit is equal to or greater than a preset value, to increase the current of an inductor of the BUCK circuit, and when the current of the inductor increases to a first predetermined current, to perform high-frequency switching control on the first switch transistor to decrease the current of the inductor to a second predetermined current.

[0099] According to an embodiment of the present invention, the control module 220 is further used to perform high-frequency switching control on the first switch transistor to increase the current of the inductor of the BUCK circuit when the load of the BUCK circuit is smaller than a preset value, and to control the turning off of the first switch transistor to decrease the current of the inductor to a second predetermined current when the current of the inductor increases to a first predetermined current.

[0100] According to one embodiment of the present invention, the first predetermined current is equal to or less than the maximum current required by the load and equal to or less than the smaller of the withstand current of the first switch transistor and the saturation current of the inductor, and the second predetermined current is equal to or greater than zero and less than the first predetermined current.

[0101] According to an embodiment of the present invention, after identifying the load type of the BUCK circuit, the control module 220 further obtains the magnitude of the load of the BUCK circuit when controlling the BUCK circuit using a voltage control type according to the load type. When the load of the BUCK circuit is equal to or greater than a predetermined value, the control module 220 controls a first switch transistor in the BUCK circuit to be on to increase the voltage of the output capacitor of the BUCK circuit. When the voltage of the output capacitor increases to a first predetermined voltage, the control module 220 performs high-frequency switching control on the first switch transistor to decrease the voltage of the output capacitor to a second predetermined voltage.

[0102] According to an embodiment of the present invention, the control module 220 is further used to perform high-frequency switching control on the first switch transistor to increase the voltage of the output capacitor of the BUCK circuit when the load of the BUCK circuit is smaller than a preset value, and to control the first switch transistor to turn off when the voltage of the output capacitor increases to a first predetermined voltage, so as to decrease the voltage of the output capacitor to a second predetermined voltage.

[0103] According to one embodiment of the present disclosure, the first predetermined voltage is equal to or less than the maximum voltage required for the load and equal to or less than the withstand voltage value of the output capacitor, and the second predetermined voltage is greater than zero and less than the first predetermined voltage.

[0104] According to an embodiment of the present disclosure, when the flyback element in the BUCK circuit is a second switch transistor, the control module 220 is further used to control the second switch transistor to be off when controlling the first switch transistor to be on, and to control the second switch transistor to be on when controlling the first switch transistor to be off.

[0105] For an explanation of the control device for the buck circuit in the present disclosure, please refer to the relevant explanation of the control method for the buck circuit in the present disclosure, and the details will not be repeated here.

[0106] A BUCK circuit control device according to an embodiment of the present disclosure uses a determination module to identify load information of the BUCK circuit, determine a control type and control method for the BUCK circuit based on the load information, and use a control module to control the carrier frequency and duty ratio of the first switch transistor, thereby causing the BUCK circuit to operate at a different switching frequency and reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing losses in the switch transistor and improving the operating efficiency of the BUCK circuit.

[0107] Corresponding to the above embodiment, the embodiment of the present disclosure further provides a BUCK circuit.

[0108] FIG. 18 is a circuit diagram of a buck circuit according to an embodiment of the present disclosure. As shown in FIG. 18, the buck circuit 100 includes an input-side capacitor C1, a first switch transistor Q1, a flyback element XL, an inductor L1, an output-side capacitor C2, and a controller 110.

[0109] One end of the first switch transistor Q1 is connected to one end of the input capacitor, one end of the flyback element XL is connected to the other end of the first switch transistor Q1, the other end of the flyback element XL is connected to the other end of the input capacitor C1, one end of the inductor L1 is connected to the other end of the first switch transistor Q1, one end of the output capacitor C2 is connected to the other end of the inductor L1, and the other end of the output capacitor C2 is connected to the other end of the flyback element. The controller 110 is used to identify load information of the buck circuit, determine a control type and a control method for the buck circuit 100 based on the load information, and control the carrier frequency and duty ratio of the first switch transistor Q1 according to the control type and control method to cause the buck circuit 100 to operate at a different switching frequency.

[0110] According to one embodiment of the present disclosure, the load information includes a load type and a load size, and the controller 110 is further used to determine a control type according to the load type and determine a control method according to the load size, where the control type includes a current control type and a voltage control type.

[0111] According to an embodiment of the present disclosure, the controller 110 is further used to determine the control method as a low carrier frequency, high duty cycle control method when the load of the buck circuit is equal to or greater than a preset value, and to determine the control method as a high carrier frequency, high duty cycle control method when the load of the buck circuit is less than the preset value.

[0112] According to an embodiment of the present disclosure, when the buck circuit is controlled using the current control type, the controller 110 is further configured to: obtain a current through an inductor of the buck circuit when controlling the first switch transistor Q1 using a control scheme with a low carrier frequency and a high duty ratio; and, when the inductor current reaches a first predetermined current, control the first switch transistor Q1 using a control scheme with a high carrier frequency and a low duty ratio to reduce the inductor current to a second predetermined current; or, when controlling the first switch transistor Q1 using the control scheme with a high carrier frequency and a high duty ratio, obtain a current through an inductor of the buck circuit; and, when the inductor current reaches the first predetermined current, control the first switch transistor Q1 using a control scheme with a low carrier frequency and a low duty ratio to reduce the inductor current to a second predetermined current.

[0113] According to an embodiment of the present disclosure, when the buck circuit is controlled using the voltage control type, the controller 110 is further configured to: obtain a voltage across an output capacitor of the buck circuit when controlling the first switch transistor Q1 using a control scheme with a low carrier frequency and a high duty ratio; and, when the voltage across the output capacitor reaches a first predetermined voltage, control the first switch transistor Q1 using a control scheme with a high carrier frequency and a low duty ratio to reduce the voltage across the output capacitor to a second predetermined voltage; or, when controlling the first switch transistor Q1 using the control scheme with a high carrier frequency and a high duty ratio, obtain a voltage across the output capacitor of the buck circuit; and, when the voltage across the output capacitor reaches the first predetermined voltage, control the first switch transistor Q1 using a control scheme with a low carrier frequency and a low duty ratio to reduce the voltage across the output capacitor to the second predetermined voltage.

[0114] According to one embodiment of the present invention, when the controller 110 identifies the load type of the buck circuit and controls the buck circuit using a current control type according to the load type, it obtains the magnitude of the load of the buck circuit, and when the load of the buck circuit is equal to or greater than a preset value, it controls a first switch transistor in the buck circuit to turn on to increase the current of an inductor of the buck circuit, and when the current of the inductor has increased to a first predetermined current, it performs high-frequency switching control on the first switch transistor to decrease the current of the inductor to a second predetermined current.

[0115] According to one embodiment of the present invention, the controller 110 is further used to perform high-frequency switching control on the first switch transistor to increase the current of the inductor of the BUCK circuit when the load of the BUCK circuit is smaller than a preset value, and to control the turning off of the first switch transistor to decrease the current of the inductor to a second predetermined current when the current of the inductor increases to a first predetermined current.

[0116] According to one embodiment of the present invention, the first predetermined current is equal to or less than the maximum current required by the load and equal to or less than the smaller of the withstand current of the first switch transistor and the saturation current of the inductor, and the second predetermined current is equal to or greater than zero and less than the first predetermined current.

[0117] According to one embodiment of the present invention, after identifying the load type of the buck circuit, the controller 110 further, when controlling the buck circuit using a voltage control type according to the load type, obtains the magnitude of the load of the buck circuit, and when the load of the buck circuit is equal to or greater than a preset value, controls the on-state of a first switch transistor in the buck circuit to increase the voltage of an output-side capacitor of the buck circuit, and when the voltage of the output-side capacitor has increased to a first predetermined voltage, performs high-frequency switching control on the first switch transistor to decrease the voltage of the output-side capacitor to a second predetermined voltage.

[0118] According to an embodiment of the present invention, the controller 110 is further used to perform high-frequency switching control on the first switch transistor to increase the voltage of the output capacitor of the BUCK circuit when the load of the BUCK circuit is smaller than a preset value, and to control the first switch transistor to turn off when the voltage of the output capacitor increases to a first predetermined voltage, thereby decreasing the voltage of the output capacitor to a second predetermined voltage.

[0119] According to one embodiment of the present disclosure, the first predetermined voltage is equal to or less than the maximum voltage required for the load and equal to or less than the withstand voltage value of the output capacitor, and the second predetermined voltage is greater than zero and less than the first predetermined voltage.

[0120] According to an embodiment of the present disclosure, when the flyback element in the BUCK circuit is a second switch transistor, the controller 110 is further used to control the second switch transistor to be off when controlling the first switch transistor Q1 to be on, and to control the second switch transistor to be on when controlling the first switch transistor Q1 to be off.

[0121] For the explanation of the BUCK circuit in this disclosure, please refer to the relevant explanation of the control method of the BUCK circuit in this disclosure, and the specific details will not be repeated here.

[0122] The BUCK circuit according to the embodiment of the present disclosure uses a controller to identify load information of the BUCK circuit, determines the control type and control method of the BUCK circuit based on the load information, and controls the carrier frequency and duty ratio of the first switch transistor accordingly to change the switching frequency to operate the BCUK circuit, thereby reducing the average switching frequency of the switch transistor without affecting the normal operation of the load, thereby effectively reducing the loss of the switch transistor and improving the operating efficiency of the BCUK circuit.

[0123] It should be noted that the logic and / or steps depicted in flowcharts or otherwise described herein can be considered, for example, as an ordered listing of executable instructions for implementing logical functions, and can be tangibly embodied in any computer-readable medium for use in or in conjunction with an instruction execution system, apparatus, or device (e.g., a computer-based system, such as a system including a processor or a system that reads instructions from an instruction execution system, device, or device and executes the instructions). For purposes of this specification, a "computer-readable medium" may be any device that contains, stores, communicates, propagates, or transmits a program, and can be used in or in conjunction with an instruction execution system, device, or device. More specific examples (non-exhaustive list) of computer-readable media include an electrical connection having one or more wires (electronic devices), a portable computer disk cartridge (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable editable read-only memory (EPROM or flash memory), fiber optic devices, and portable disk read-only memory (CD-ROM). The computer readable medium may also be paper or other suitable medium on which the program is printed, for example by optically scanning the paper or other suitable medium and then editing, interpreting or processing in any other suitable manner as required to obtain the program in electronic form, which is then stored in computer memory.

[0124] It should be understood that each part of the present disclosure can be realized by hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be realized by software or firmware stored in a memory and executed by an appropriate instruction execution system. When realized by hardware, as in other embodiments, the hardware can be realized by any one or a combination of technologies known in the art, such as a discrete logic circuit having logic gate circuits for implementing logic functions on data signals, a dedicated integrated circuit having appropriate combinational logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0125] In the description herein, references such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" mean that the specific features, structures, materials, or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the description herein, exemplary references to the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0126] Additionally, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as expressing or implying relative importance or the number of technical features being presented. Thus, a feature qualified by "first" or "second" can explicitly or implicitly include at least one of that feature. In the description of this disclosure, "plurality" means at least two, e.g., two, three, etc., unless otherwise limited.

[0127] In the present disclosure, unless otherwise specified or limited, terms such as "attached," "coupled," "connected," and "fixed" should be understood in a broad sense, and may mean, for example, fixedly connected, detachably connected, or integrated, mechanically connected, electrically connected, directly connected, indirectly connected via an intermediate medium, internal communication between two elements, or an interactive relationship between two elements. Unless otherwise clearly limited, a person skilled in the art can understand the specific meaning of the above terms in the present disclosure depending on the situation.

[0128] Although the embodiments of the present disclosure have been shown and described, the above embodiments are merely illustrative and should not be construed as limiting the present disclosure, and it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to the above embodiments within the scope of the present disclosure.

[0129] This disclosure claims priority to a Chinese patent application filed on July 22, 2022, bearing application number 202210869341.7, entitled "BUCK CIRCUIT AND ITS CONTROL METHOD, CONTROLLER, CONTROL DEVICE, AND STORAGE MEDIUM," and a Chinese patent application filed on July 22, 2022, bearing application number 202210872129.6, entitled "BUCK CIRCUIT AND ITS CONTROL METHOD, CONTROLLER, CONTROL DEVICE, AND STORAGE MEDIUM," the entire contents of which are incorporated herein by reference.

Claims

1. A method for controlling a BUCK circuit, comprising: Identifying load information of the BUCK circuit; determining a control type and a control method of the BUCK circuit based on the load information; and controlling a carrier frequency and a duty ratio of a first switch transistor in the BUCK circuit according to the control type and control method, thereby causing the BUCK circuit to operate at a different switching frequency.

2. The load information includes a load type and a load size, and the step of determining a control type and a control method of the BUCK circuit based on the load information includes:

2. The control method for a BUCK circuit according to claim 1, further comprising the steps of: determining the control type according to the load type; and determining the control method according to the magnitude of the load; wherein the control type includes a current control type and a voltage control type.

3. The step of determining the control method according to the magnitude of the load includes: determining the control method to be a low carrier frequency, high duty ratio control method when the load of the BUCK circuit is equal to or greater than a preset value; 3. The method for controlling a BUCK circuit according to claim 2, further comprising the step of: determining, when a load of the BUCK circuit is smaller than a preset value, that the control method is a high carrier frequency, high duty ratio control method.

4. When the BUCK circuit is controlled using the current control type, the step of controlling the carrier frequency and the duty ratio of the first switch transistor in the BUCK circuit includes: When the first switch transistor is controlled by a control method with a low carrier frequency and a high duty ratio, a current of an inductor of the BUCK circuit is acquired, and when the current of the inductor reaches a first predetermined current, the first switch transistor is controlled by a control method with a high carrier frequency and a low duty ratio to reduce the current of the inductor to a second predetermined current; or 4. The control method for a BUCK circuit according to claim 3, further comprising the steps of: acquiring a current of an inductor of the BUCK circuit when the first switch transistor is controlled by a control method with a high carrier frequency and a high duty ratio; and, when the current of the inductor reaches a first predetermined current, controlling the first switch transistor by a control method with a low carrier frequency and a low duty ratio to reduce the current of the inductor to a second predetermined current.

5. When the BUCK circuit is controlled using the voltage control type, the step of controlling the carrier frequency and the duty ratio of the first switch transistor in the BUCK circuit includes: a step of acquiring a voltage of an output-side capacitor of the BUCK circuit when the first switch transistor is controlled by a control method with a low carrier frequency and a high duty ratio, and controlling the first switch transistor by a control method with a high carrier frequency and a low duty ratio when the voltage of the output-side capacitor reaches a first predetermined voltage, thereby reducing the voltage of the output-side capacitor to a second predetermined voltage; or 4. The control method for a BUCK circuit according to claim 3, further comprising the steps of: acquiring a voltage of an output-side capacitor of the BUCK circuit when the first switch transistor is controlled by a control method with a high carrier frequency and a high duty ratio; and, when the voltage of the output-side capacitor reaches a first predetermined voltage, controlling the first switch transistor by a control method with a low carrier frequency and a low duty ratio to reduce the voltage of the output-side capacitor to a second predetermined voltage.

6. identifying a load type of the BUCK circuit; When the BUCK circuit is controlled using a current control type according to the load type, a step of acquiring the magnitude of the load of the BUCK circuit; 2. The control method for a BUCK circuit according to claim 1, further comprising the steps of: when a load of the BUCK circuit is equal to or greater than a preset value, controlling a first switch transistor in the BUCK circuit to be on to increase a current in an inductor of the BUCK circuit; and when the current in the inductor has increased to a first predetermined current, performing high-frequency switching control on the first switch transistor to decrease the current in the inductor to a second predetermined current.

7. When the load of the BUCK circuit is smaller than a preset value, the control method of the BUCK circuit includes:

7. The control method for a BUCK circuit according to claim 6, further comprising the step of: performing high-frequency switching control on the first switch transistor to increase a current in an inductor of the BUCK circuit; and, when the current in the inductor has increased to a first predetermined current, controlling the first switch transistor to be turned off to decrease the current in the inductor to a second predetermined current.

8. 7. The control method for a BUCK circuit according to claim 4, wherein the first predetermined current is equal to or less than a maximum current required for a load and equal to or less than the smaller of a withstand current of the first switch transistor and an inductor saturation current, and the second predetermined current is equal to or greater than zero and smaller than the first predetermined current.

9. After the step of identifying the load type of the BUCK circuit, the control method for the BUCK circuit includes: When the BUCK circuit is controlled using a voltage control type according to the load type, a step of acquiring a magnitude of the load of the BUCK circuit; 7. The control method for a BUCK circuit according to claim 6, further comprising the steps of: when a load of the BUCK circuit is equal to or greater than a preset value, controlling a first switch transistor in the BUCK circuit to be on to increase the voltage of an output-side capacitor of the BUCK circuit; and when the voltage of the output-side capacitor has increased to a first predetermined voltage, performing high-frequency switching control on the first switch transistor to decrease the voltage of the output-side capacitor to a second predetermined voltage.

10. When the load of the BUCK circuit is smaller than a preset value, the control method of the BUCK circuit includes:

10. The control method for a BUCK circuit according to claim 9, further comprising the step of: performing high-frequency switching control on the first switch transistor to increase the voltage of an output-side capacitor of the BUCK circuit; and, when the voltage of the output-side capacitor has increased to a first predetermined voltage, controlling the first switch transistor to be turned off to decrease the voltage of the output-side capacitor to a second predetermined voltage.

11. 9. The control method for a BUCK circuit according to claim 5, wherein the first predetermined voltage is equal to or less than a maximum voltage required for a load and equal to or less than a breakdown voltage of an output capacitor, and the second predetermined voltage is greater than zero and less than the first predetermined voltage.

12. When the flyback element in the BUCK circuit is a second switch transistor, the control method of the BUCK circuit includes: controlling the second switch transistor to be off when controlling the first switch transistor to be on; 12. The control method for a BUCK circuit according to claim 1, further comprising the step of: controlling the second switch transistor to be on when controlling the first switch transistor to be off.

13. A controller for a BUCK circuit, comprising a memory, a processor, and a control program for a BUCK circuit that is stored in the memory and can run on the processor, wherein when the processor executes the control program for the BUCK circuit, the control method for the BUCK circuit according to any one of claims 1 to 12 is realized.

14. A computer-readable storage medium storing a control program for a BUCK circuit, the control method for a BUCK circuit according to any one of claims 1 to 12 being realized when the control program for the BUCK circuit is executed by a processor.

15. A control device for a BUCK circuit, a determination module for identifying load information of the BUCK circuit and determining a control type and a control method of the BUCK circuit based on the load information; a control module that controls a carrier frequency and a duty ratio of a first switch transistor in the BUCK circuit according to the control type and control method, and causes the BUCK circuit to operate at a different switching frequency.

16. A BUCK circuit, An input capacitor, a first switch transistor having one end connected to one end of the input-side capacitor; a flyback element having one end connected to the other end of the first switch transistor and the other end connected to the other end of the input-side capacitor; an inductor having one end connected to the other end of the first switch transistor; an output-side capacitor having one end connected to the other end of the inductor and the other end connected to the other end of the flyback element; a controller that is used to identify load information of the BUCK circuit, determine a control type and a control method of the BUCK circuit based on the load information, and control a carrier frequency and a duty ratio of the first switch transistor in accordance with the control type and the control method to change a switching frequency of the BUCK circuit and operate it.

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