Multi-path parallel BUCK circuit and control method

Abstract

The embodiment of the invention provides a multi-path parallel BUCK circuit and a control method, and belongs to the technical field of current conversion. The control method comprises the following steps: acquiring the output current of each branch circuit connected in parallel; determining the average current of each branch according to the current; judging whether current sharing control is needed at present; calculating an adjustment error according to the current error of the current branch under the condition of judging that the current sharing control is needed; calculating an increment value according to a formula (1); and adjusting the current branch according to the increment value. According to the circuit, the capacitors of the multiple BUCK units are shared, parallel connection of the multiple BUCK units is achieved, and the design size of equipment is reduced. According to the control method, the current output by each path is sampled and calculated, comprehensive monitoring of the circuit is achieved, finally, feedback control of the circuit is achieved in combination with calculation of the current, and therefore the control efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of current conversion, and in particular to a multi-channel parallel BUCK circuit and a control method. Background Art

[0002] BUCK circuits (step-down circuits) are widely used in power management, battery charging and other fields due to their efficient energy conversion characteristics. When multiple BUCK circuits work in parallel, in order to ensure the stability and reliability of the system, it is necessary to achieve balanced distribution of current in each circuit, that is, current sharing. Traditional current sharing methods have problems such as complex control and slow response speed, which are difficult to meet the needs of high-performance applications. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a multi-parallel BUCK circuit and a control method, wherein the circuit and the control method thereof can achieve the control efficiency of the multi-buck circuit.

[0004] In order to achieve the above object, an embodiment of the present invention provides a multi-channel parallel BUCK circuit, including: Obtain the output current of each branch connected in parallel; Determine the average current of each branch based on the current; Determine whether current sharing control is currently required; When it is determined that current sharing control is required, the regulation error is calculated based on the current error of the current branch; Calculate the increment value according to formula (1) : , (1) in, To adjust the error, is the adjustment error of the previous stage, is the proportionality coefficient, is the integration coefficient, is the differential coefficient; According to the increment value Adjust the current branch.

[0005] Optionally, determining whether current sharing control is currently required includes: Calculate the current error between each current and the average current respectively; Determining whether the absolute value of the current error is greater than or equal to a preset threshold; When it is determined that the absolute value is greater than or equal to the threshold, it is determined that the current branch requires current sharing control.

[0006] Optionally, calculating the regulation error according to the current error of the current branch includes: Calculate the current error between each current and the average current respectively; The branch with the largest absolute value of the current error is selected as the current branch.

[0007] Optionally, calculating the regulation error according to the current error of the current branch includes: Calculate the deviation value of each current and the average current respectively; The maximum positive value and the maximum negative value of the deviation value are selected as the current branch.

[0008] Optionally, calculating the regulation error according to the current error of the current branch includes: The adjustment error is calculated according to formula (2): , (2) in, To adjust the error, is the current error, To adjust the intensity.

[0009] Optionally, it also includes: After the current sharing control is completed, it is determined whether the current sharing control is still needed within a predetermined time length; When it is determined that current sharing control is not required, it is determined that current sharing control is completed, and the duty cycle of the current current sharing control is used as a control parameter for the next stage.

[0010] Optionally, it also includes: Determine whether the absolute value of the current error of any branch is greater than or equal to a preset maximum difference; When it is determined that the absolute value is greater than or equal to the maximum difference, the PWM controller is controlled to stop working.

[0011] On the other hand, the present invention also provides a multi-channel parallel BUCK circuit, comprising: A plurality of branches, each branch comprising a first controllable switch, a second controllable switch and an inductor, wherein one end of the first controllable switch is used to be connected to a power source, one end of the second controllable switch is connected to the other end of the first controllable switch, and one end of the inductor is connected to the other end of the first controllable switch; A capacitor, one end of which is connected to the other end of each inductor; A current acquisition module is connected to the other end of each inductor; A dynamic election module is connected to the current acquisition module; The control module is connected to the current acquisition module, the dynamic election module, the first controllable switch and the second controllable switch, and is used to execute any of the control methods described above.

[0012] Optionally, the control module includes: A main controller connected to the current acquisition module; A current sharing controller connected to a dynamic election module; The PWM controller is connected to the main controller and the current sharing controller.

[0013] On the other hand, the present invention also provides a power supply, which includes the multi-channel parallel BUCK circuit and the DC source component as described above, wherein the DC source component is used to output source current, and the circuit is used to process the source current to further obtain output current.

[0014] Through the above technical solution, the embodiment of the present invention provides a multi-channel parallel BUCK circuit and a control method, which realizes the parallel connection of multiple BUCK units by sharing the capacitance of multiple BUCK units, thereby reducing the design volume of the device. The control method realizes comprehensive monitoring of the circuit by sampling and calculating the current of each output, and finally, realizes feedback control of the circuit in combination with the calculation of the current, thereby improving the control efficiency.

[0015] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings: Figure 1 is a flow chart of a control method of a multi-channel parallel BUCK circuit according to an embodiment of the present invention; Figure 2 is a circuit diagram of a multi-channel parallel BUCK circuit according to an embodiment of the present invention; Figure 3 is a circuit diagram of a multi-channel parallel BUCK circuit according to an embodiment of the present invention; Figure 4 4 is a circuit diagram of a multi-channel parallel BUCK circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0017] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0018] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of laws and regulations. In the embodiments of this application, some existing solutions in the industry such as certain software, components, and models may be mentioned, which should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of this application, but it does not mean that the applicant has or will necessarily use the solution.

[0019] like Figure 1 FIG. 1 is a flow chart of a control method for a multi-channel parallel BUCK circuit according to an embodiment of the present invention. Figure 1 In the control method, the control method may include the following steps: In step S10, the output current of each branch connected in parallel is obtained; In step S11, the average current of each branch is determined according to the current; In step S12, it is determined whether current sharing control is currently required; In step S13, when it is determined that current sharing control is required, the adjustment error is calculated according to the current error of the current branch; In step S14, the increment value is calculated according to formula (1): : , (1) in, To adjust the error, is the adjustment error of the previous stage, is the proportionality coefficient, is the integration coefficient, is the differential coefficient; In step S15, according to the increment value Adjust the current branch.

[0020] The Figure 1 The control method shown in is used to control a multi-way parallel BUCK circuit. The specific connection mode of the multi-way parallel BUCK circuit can be various forms known to those skilled in the art. For example, the input and output ends of multiple BUCK module circuits are connected to form a parallel circuit. In one example of the present invention, considering the design volume of the circuit and the control requirements of the function, the BUCK circuit can be as follows Figure 2 Specifically, in the structure shown in Figure 2In the embodiment, the circuit may include multiple BUCK branches, a capacitor C, a current acquisition module 1, a dynamic election module 2 and a control module 3. Each BUCK branch may include a first controllable switch K1, a second controllable switch K2 and an inductor L. One end of the first controllable switch K1 may be used to connect to a power supply (DC), one end of the second controllable switch K2 may be connected to the other end of the first controllable switch K1, the other end of the second controllable switch K2 may be grounded, and one end of the inductor L may be connected to the other end of the first controllable switch K1. One end of the capacitor C may be connected to the other end of each inductor L, and the other end of the capacitor C may be grounded.

[0021] The current acquisition module 1 can be connected to the other end of each inductor to collect the output current of each inductor. The dynamic election module 2 can be connected to the current acquisition module 1 to determine the BUCK branch that needs to be adjusted based on the current collected by the current acquisition module 1. The control module 3 can be connected to the current acquisition module 1, the dynamic election module 2, the first controllable switch K1 and the second controllable switch K2 to control the duty cycle of each first controllable switch K1 and the second controllable switch K2 based on the output information of the current acquisition module 1 and the dynamic election module 2, thereby adjusting the circuit.

[0022] In one embodiment of the present invention, considering that the control module 3 needs to execute multiple control strategies, Figure 3 As shown, the control module 3 may also include a main controller 31, a current sharing controller 32 and a PWM controller 33. The main controller 31 may be connected to the current acquisition module 1 for scheduling the control signal. The current sharing controller 32 may be connected to the dynamic election module 2 for executing the current sharing control strategy. The PWM controller 33 may be connected to the main controller 31 and the current sharing controller 32 for outputting the PWM control signal. In addition, considering the need to ensure the stable operation of the circuit, in one example of the present invention, as shown in FIG. Figure 4 As shown, the circuit may further include a fault detection module 4. The fault detection module 4 may be connected to the PWM controller 33, and is used to detect the current in the circuit (including but not limited to the current in each branch in the circuit) in real time, and when the current is greater than or equal to a preset maximum difference, the PWM controller 33 stops the operation of the circuit.

[0023] In this Figure 1 In the method shown, step S10 can be used to obtain the output current of each branch connected in parallel. Figure 1 and Figure 3 Taking the circuit in as an example, the step S10 may be to collect the current through the current collection module 1.

[0024] Step S11 is used to determine the average current of each branch according to the current. Step S12 can be used to determine whether current sharing control is currently required. Among them, the method for determining whether current sharing control is required can be a variety of forms known to those skilled in the art. In one example of the present invention, the method for determining whether current sharing control is required can be to first calculate the current error between each (output current of the BUCK branch) current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control. In the case where it is determined that the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control, it can be determined that current sharing control is currently required. Otherwise, step S10 can be continued to obtain the current at the other end of each inductor.

[0025] In the case where it is determined that current sharing control is required, step S13 can be used to calculate the adjustment error according to the current error of the current branch. In this embodiment, since the step of adjusting the branch (BUCK branch) first needs to determine the branch to be adjusted, that is, the current branch. Therefore, in one example of the present invention, step S13 can be to first calculate the current error between each current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset threshold. In the case of judging that the absolute value of the current error is greater than or equal to the threshold, the corresponding branch is used as the branch to be adjusted. In this example, since only one branch is selected as the branch to be adjusted, although the technical effect of feedback regulation can be achieved, considering that more than one BUCK branch may need to be adjusted this time, the efficiency of the adjustment method in this example is limited compared with the prior art. Therefore, in another example of the present invention, step S13 can also be to first calculate the deviation value of the output current and the average current of each BUCK branch, and the deviation value represents the vector difference between each output current and the average current. Then, the BUCK branch corresponding to the maximum positive value and the maximum negative value of the deviation value is selected as the branch to be adjusted. Through this example, before each current sharing control is performed, two branches with the largest deviations in two directions can be selected at the same time, thereby improving control efficiency.

[0026] After selecting the branch to be adjusted, the selected branch to be adjusted can be further subjected to current sharing control, i.e., step S13 to step S15. Specifically, in step S13, in order to improve the control accuracy and maintain the stable operation of the circuit itself, the adjustment error can be first calculated based on the obtained current error. Then, the incremental value can be calculated using the following formula (1): , i.e., step S14. Finally, current sharing control is performed according to the increment value, i.e., step S15.

[0027] The specific method for calculating the adjustment error based on the current error may be in various forms known to those skilled in the art. In one example of the present invention, the following formula (2) may be used for calculation: , (2) in, To adjust the error, is the current error, is the adjustment strength. In this example, the value of the adjustment strength may preferably be 10, 100 or 1000.

[0028] Furthermore, after the current balancing control is completed, considering the fluctuation characteristics of the current value itself over time, a judgment time can be set to determine whether the circuit is adjusted to a stable working state. Specifically, the method can be to determine whether the current balancing control is still needed within a predetermined time length after the current balancing control is completed. In the case where it is determined that current balancing control is required, current balancing control (current regulation) can be performed again at this time. On the contrary, in the case where it is determined that current balancing control is not required, it can be determined that the current balancing control is completed at this time, and in order to be able to adjust the state of the circuit itself in real time, combined with the changes in electronic characteristics of electronic components caused by aging, the duty cycle of the current current balancing control can also be used as the control parameter of the next stage, thereby shortening the time length of the subsequent single round of current balancing control. In addition, after each current balancing control, considering the aging of the device itself, the stability of the current output current of the current circuit can be further determined according to the following formula (3): , (3) in, For this stability, , They are the maximum and minimum output current after current sharing control. It is the average value of the output current after current sharing control.

[0029] Further, on this basis, in order to improve the control progress of the circuit provided by the present invention, the initial amount of control in the next stage can be corrected according to the stability of the current calculation, thereby improving the overall control efficiency. Specifically, the following formula (4) can be used for correction: , (4) in, is the corrected adjustment error, is the adjustment error before correction, is the current adjustment error, For stability.

[0030] In addition, considering that if the circuit itself has a large state fluctuation, corresponding safety measures can also be set to ensure safety. Specifically, in one example of the present invention, when the circuit is working, it can be determined in real time whether the absolute value of the difference between any current and the average current is greater than or equal to the preset maximum difference. If it is determined to be greater than or equal to the maximum difference, the PWM controller can be controlled to stop working, thereby maintaining system safety. As for the specific implementation of this method, it can be, for example, using Figure 4 It is implemented by the fault detection module 4 in.

[0031] On the other hand, the present invention also provides a multi-channel parallel BUCK circuit, which may include multiple BUCK branches, a capacitor C, a current acquisition module 1, a dynamic election module 2 and a control module 3. Each BUCK branch may include a first controllable switch K1, a second controllable switch K2 and an inductor L. One end of the first controllable switch K1 may be used to connect to a power supply (DC), one end of the second controllable switch K2 may be connected to the other end of the first controllable switch K1, the other end of the second controllable switch K2 may be grounded, and one end of the inductor L may be connected to the other end of the first controllable switch K1. One end of the capacitor C may be connected to the other end of each inductor L, and the other end of the capacitor C may be grounded.

[0032] The current acquisition module 1 can be connected to the other end of each inductor to collect the output current of each inductor. The dynamic election module 2 can be connected to the current acquisition module 1 to determine the BUCK branch that needs to be adjusted based on the current collected by the current acquisition module 1. The control module 3 can be connected to the current acquisition module 1, the dynamic election module 2, the first controllable switch K1 and the second controllable switch K2 to control the duty cycle of each first controllable switch K1 and the second controllable switch K2 based on the output information of the current acquisition module 1 and the dynamic election module 2, thereby adjusting the circuit.

[0033] In one embodiment of the present invention, considering that the control module 3 needs to execute multiple control strategies, Figure 3 As shown, the control module 3 may also include a main controller 31, a current sharing controller 32 and a PWM controller 33. The main controller 31 may be connected to the current acquisition module 1 for scheduling the control signal. The current sharing controller 32 may be connected to the dynamic election module 2 for executing the current sharing control strategy. The PWM controller 33 may be connected to the main controller 31 and the current sharing controller 32 for outputting the PWM control signal. In addition, considering the need to ensure the stable operation of the circuit, in one example of the present invention, as shown in FIG. Figure 4As shown, the circuit may further include a fault detection module 4. The fault detection module 4 may be connected to the PWM controller 33 and used to detect the current in the circuit (including but not limited to the current in each branch of the circuit) in real time. When the current is greater than or equal to the preset maximum difference, the PWM controller 33 stops the operation of the circuit. The control module may be used to perform the following steps: Figure 1 Specifically, in the control method shown in Figure 1 In the control method, the control method may include the following steps: In step S10, the output current of each branch connected in parallel is obtained; In step S11, the average current of each branch is determined according to the current; In step S12, it is determined whether current sharing control is currently required; In step S13, when it is determined that current sharing control is required, the adjustment error is calculated according to the current error of the current branch; In step S14, the increment value is calculated according to formula (1): : , (1) in, To adjust the error, is the adjustment error of the previous stage, is the proportionality coefficient, is the integration coefficient, is the differential coefficient; In step S15, according to the increment value Adjust the current branch.

[0034] In this Figure 1 In the method shown, step S10 can be used to obtain the output current of each branch connected in parallel. Figure 1 and Figure 3 Taking the circuit in as an example, step S10 may be to collect the current through the current collection module 1.

[0035] Step S11 is used to determine the average current of each branch according to the current. Step S12 can be used to determine whether current sharing control is currently required. Among them, the method for determining whether current sharing control is required can be a variety of forms known to those skilled in the art. In one example of the present invention, the method for determining whether current sharing control is required can be to first calculate the current error between each (output current of the BUCK branch) current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control. In the case where it is determined that the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control, it can be determined that current sharing control is currently required. Otherwise, step S10 can be continued to obtain the current at the other end of each inductor.

[0036] In the case where it is determined that current sharing control is required, step S13 can be used to calculate the adjustment error according to the current error of the current branch. In this embodiment, since the step of adjusting the branch (BUCK branch) first needs to determine the branch to be adjusted, that is, the current branch. Therefore, in one example of the present invention, step S13 can be to first calculate the current error between each current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset threshold. In the case of judging that the absolute value of the current error is greater than or equal to the threshold, the corresponding branch is used as the branch to be adjusted. In this example, since only one branch is selected as the branch to be adjusted, although the technical effect of feedback regulation can be achieved, considering that more than one BUCK branch may need to be adjusted this time, the efficiency of the adjustment method in this example is limited compared with the prior art. Therefore, in another example of the present invention, step S13 can also be to first calculate the deviation value of the output current and the average current of each BUCK branch, and the deviation value represents the vector difference between each output current and the average current. Then, the BUCK branch corresponding to the maximum positive value and the maximum negative value of the deviation value is selected as the branch to be adjusted. Through this example, before each current sharing control is performed, two branches with the largest deviations in two directions can be selected at the same time, thereby improving control efficiency.

[0037] After selecting the branch to be adjusted, the selected branch to be adjusted can be further subjected to current sharing control, i.e., step S13 to step S15. Specifically, in step S13, in order to improve the control accuracy and maintain the stable operation of the circuit itself, the adjustment error can be first calculated based on the obtained current error. Then, the incremental value can be calculated using the following formula (1): , i.e., step S14. Finally, current sharing control is performed according to the increment value, i.e., step S15.

[0038] The specific method for calculating the adjustment error based on the current error may be in various forms known to those skilled in the art. In one example of the present invention, the following formula (2) may be used for calculation: , (2) in, To adjust the error, is the current error, is the adjustment strength. In this example, the value of the adjustment strength may preferably be 10, 100 or 1000.

[0039] Furthermore, after the current balancing control is completed, considering the fluctuation characteristics of the current value itself over time, a judgment time can be set to determine whether the circuit is adjusted to a stable working state. Specifically, the method can be to determine whether the current balancing control is still needed within a predetermined time length after the current balancing control is completed. In the case where it is determined that current balancing control is required, current balancing control (current regulation) can be performed again at this time. On the contrary, in the case where it is determined that current balancing control is not required, it can be determined that the current balancing control is completed at this time, and in order to be able to adjust the state of the circuit itself in real time, combined with the changes in electronic characteristics of electronic components caused by aging, the duty cycle of the current current balancing control can also be used as the control parameter of the next stage, thereby shortening the time length of the subsequent single round of current balancing control. In addition, after each current balancing control, considering the aging of the device itself, the stability of the current output current of the current circuit can be further determined according to the following formula (3): , (3) in, For this stability, , They are the maximum and minimum output current after current sharing control. It is the average value of the output current after current sharing control.

[0040] Further, on this basis, in order to improve the control progress of the circuit provided by the present invention, the initial amount of control in the next stage can be corrected according to the stability of the current calculation, thereby improving the overall control efficiency. Specifically, the following formula (4) can be used for correction: , (4) in, is the corrected adjustment error, is the adjustment error before correction, is the current adjustment error, For stability.

[0041] On the other hand, the present invention also provides a power supply, which includes a multi-channel parallel BUCK circuit and a DC source component as described above. The DC source component is used to output a source current, and the circuit is used to process the source current to further obtain an output current. Specifically, the multi-channel parallel BUCK circuit may include a plurality of BUCK branches, a capacitor C, a current acquisition module 1, a dynamic election module 2, and a control module 3. Each BUCK branch may include a first controllable switch K1, a second controllable switch K2, and an inductor L. One end of the first controllable switch K1 may be used to connect to a power supply (DC), one end of the second controllable switch K2 may be connected to the other end of the first controllable switch K1, the other end of the second controllable switch K2 may be grounded, and one end of the inductor L may be connected to the other end of the first controllable switch K1. One end of the capacitor C may be connected to the other end of each inductor L, and the other end of the capacitor C may be grounded.

[0042] The current acquisition module 1 can be connected to the other end of each inductor to collect the output current of each inductor. The dynamic election module 2 can be connected to the current acquisition module 1 to determine the BUCK branch that needs to be adjusted based on the current collected by the current acquisition module 1. The control module 3 can be connected to the current acquisition module 1, the dynamic election module 2, the first controllable switch K1 and the second controllable switch K2 to control the duty cycle of each first controllable switch K1 and the second controllable switch K2 based on the output information of the current acquisition module 1 and the dynamic election module 2, thereby adjusting the circuit.

[0043] In one embodiment of the present invention, considering that the control module 3 needs to execute multiple control strategies, Figure 3 As shown, the control module 3 may also include a main controller 31, a current sharing controller 32 and a PWM controller 33. The main controller 31 may be connected to the current acquisition module 1 for scheduling the control signal. The current sharing controller 32 may be connected to the dynamic election module 2 for executing the current sharing control strategy. The PWM controller 33 may be connected to the main controller 31 and the current sharing controller 32 for outputting the PWM control signal. In addition, considering the need to ensure the stable operation of the circuit, in one example of the present invention, as shown in FIG. Figure 4 As shown, the circuit may further include a fault detection module 4. The fault detection module 4 may be connected to the PWM controller 33 and used to detect the current in the circuit (including but not limited to the current in each branch of the circuit) in real time. When the current is greater than or equal to the preset maximum difference, the PWM controller 33 stops the operation of the circuit. The control module may be used to perform the following steps: Figure 1 Specifically, in the control method shown in Figure 1 In the control method, the control method may include the following steps: In step S10, the output current of each branch connected in parallel is obtained; In step S11, the average current of each branch is determined according to the current; In step S12, it is determined whether current sharing control is currently required; In step S13, when it is determined that current sharing control is required, the adjustment error is calculated according to the current error of the current branch; In step S14, the increment value is calculated according to formula (1): : , (1) in, To adjust the error, is the adjustment error of the previous stage, is the proportionality coefficient, is the integration coefficient, is the differential coefficient; In step S15, according to the increment value Adjust the current branch.

[0044] In this Figure 1 In the method shown, step S10 can be used to obtain the output current of each branch connected in parallel. Figure 1 and Figure 3 Taking the circuit in as an example, the step S10 may be to collect the current through the current collection module 1.

[0045] Step S11 is used to determine the average current of each branch according to the current. Step S12 can be used to determine whether current sharing control is currently required. Among them, the method for determining whether current sharing control is required can be a variety of forms known to those skilled in the art. In one example of the present invention, the method for determining whether current sharing control is required can be to first calculate the current error between each (output current of the BUCK branch) current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control. In the case where it is determined that the absolute value of the current error is greater than or equal to the preset start threshold of current sharing control, it can be determined that current sharing control is currently required. Otherwise, step S10 can be continued to obtain the current at the other end of each inductor.

[0046] In the case where it is determined that current sharing control is required, step S13 can be used to calculate the adjustment error according to the current error of the current branch. In this embodiment, since the step of adjusting the branch (BUCK branch) first needs to determine the branch to be adjusted, that is, the current branch. Therefore, in one example of the present invention, step S13 can be to first calculate the current error between each current and the average current, and then determine whether the absolute value of the current error is greater than or equal to the preset threshold. In the case of judging that the absolute value of the current error is greater than or equal to the threshold, the corresponding branch is used as the branch to be adjusted. In this example, since only one branch is selected as the branch to be adjusted, although the technical effect of feedback regulation can be achieved, considering that more than one BUCK branch may need to be adjusted this time, the efficiency of the adjustment method in this example is limited compared with the prior art. Therefore, in another example of the present invention, step S13 can also be to first calculate the deviation value of the output current and the average current of each BUCK branch, and the deviation value represents the vector difference between each output current and the average current. Then, the BUCK branch corresponding to the maximum positive value and the maximum negative value of the deviation value is selected as the branch to be adjusted. Through this example, before each current sharing control is performed, two branches with the largest deviations in two directions can be selected at the same time, thereby improving control efficiency.

[0047] After selecting the branch to be adjusted, the selected branch to be adjusted can be further subjected to current sharing control, i.e., step S13 to step S15. Specifically, in step S13, in order to improve the control accuracy and maintain the stable operation of the circuit itself, the adjustment error can be first calculated based on the obtained current error. Then, the incremental value can be calculated using the following formula (1): , i.e., step S14. Finally, current sharing control is performed according to the increment value, i.e., step S15.

[0048] The specific method for calculating the adjustment error based on the current error may be in various forms known to those skilled in the art. In one example of the present invention, the following formula (2) may be used for calculation: , (2) in, To adjust the error, is the current error, is the adjustment strength. In this example, the value of the adjustment strength may preferably be 10, 100 or 1000.

[0049] Furthermore, after the current balancing control is completed, considering the fluctuation characteristics of the current value itself over time, a judgment time can be set to determine whether the circuit is adjusted to a stable working state. Specifically, the method can be to determine whether the current balancing control is still needed within a predetermined time length after the current balancing control is completed. In the case where it is determined that current balancing control is required, current balancing control (current regulation) can be performed again at this time. On the contrary, in the case where it is determined that current balancing control is not required, it can be determined that the current balancing control is completed at this time, and in order to be able to adjust the state of the circuit itself in real time, combined with the changes in electronic characteristics of electronic components caused by aging, the duty cycle of the current current balancing control can also be used as the control parameter of the next stage, thereby shortening the time length of the subsequent single round of current balancing control. In addition, after each current balancing control, considering the aging of the device itself, the stability of the current output current of the current circuit can be further determined according to the following formula (3): , (3) in, For this stability, , They are the maximum and minimum output current after current sharing control. It is the average value of the output current after current sharing control.

[0050] Further, on this basis, in order to improve the control progress of the circuit provided by the present invention, the initial amount of control in the next stage can be corrected according to the stability of the current calculation, thereby improving the overall control efficiency. Specifically, the following formula (4) can be used for correction: , (4) in, is the corrected adjustment error, is the adjustment error before correction, is the current adjustment error, For stability.

[0051] Through the above technical solution, the embodiment of the present invention provides a multi-channel parallel BUCK circuit and a control method, which realizes the parallel connection of multiple BUCK units by sharing the capacitance of multiple BUCK units, thereby reducing the design volume of the device. The control method realizes comprehensive monitoring of the circuit by sampling and calculating the current of each output, and finally, realizes feedback control of the circuit in combination with the calculation of the current, thereby improving the control efficiency.

[0052] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0053] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0054] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0055] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0056] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0057] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0058] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0059] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0060] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A control method for a multi-channel parallel BUCK circuit, characterized in that: include: Obtain the output current of each branch connected in parallel; Determine the average current of each branch based on the current; Determine whether current sharing control is currently required; When it is determined that current sharing control is required, the regulation error is calculated based on the current error of the current branch; Calculate the increment value according to formula (1) : ，（1） in, To adjust the error, is the adjustment error of the previous stage, is the proportionality coefficient, is the integration coefficient, is the differential coefficient; According to the increment value Adjust the current branch.

2. The control method according to claim 1, characterized in that: Determine whether current sharing control is required, including: Calculate the current error between each current and the average current respectively; Determining whether the absolute value of the current error is greater than or equal to a preset threshold; When it is determined that the absolute value is greater than or equal to the threshold, it is determined that the current branch requires current sharing control.

3. The control method according to claim 1, characterized in that: The regulation error is calculated based on the current error of the current branch, including: Calculate the current error between each current and the average current respectively; The branch with the largest absolute value of the current error is selected as the current branch.

4. The control method according to claim 1, characterized in that: The regulation error is calculated based on the current error of the current branch, including: Calculate the deviation value of each current and the average current respectively; The maximum positive value and the maximum negative value of the deviation value are selected as the current branch.

5. The control method according to claim 3 or 4, characterized in that: The regulation error is calculated based on the current error of the current branch, including: The adjustment error is calculated according to formula (2): ，（2） in, To adjust the error, is the current error, To adjust the intensity.

6. The control method according to claim 1, characterized in that: Also includes: After the current sharing control is completed, it is determined whether the current sharing control is still needed within a predetermined time length; When it is determined that current sharing control is not required, it is determined that current sharing control is completed, and the duty cycle of the current current sharing control is used as a control parameter for the next stage.

7. The control method according to claim 1, characterized in that: Also includes: Determine whether the absolute value of the current error of any branch is greater than or equal to a preset maximum difference; When it is determined that the absolute value is greater than or equal to the maximum difference, the PWM controller is controlled to stop working.

8. A multi-channel parallel BUCK circuit, characterized in that: include: A plurality of branches, each branch comprising a first controllable switch, a second controllable switch and an inductor, wherein one end of the first controllable switch is used to be connected to a power source, one end of the second controllable switch is connected to the other end of the first controllable switch, and one end of the inductor is connected to the other end of the first controllable switch; A capacitor, one end of which is connected to the other end of each inductor; A current acquisition module is connected to the other end of each inductor; A dynamic election module is connected to the current acquisition module; A control module is connected to the current acquisition module, the dynamic election module, the first controllable switch and the second controllable switch, and is used to execute the control method according to any one of claims 1 to 7.

9. The circuit according to claim 8, characterized in that The control module comprises: A main controller connected to the current acquisition module; A current sharing controller connected to a dynamic election module; The PWM controller is connected to the main controller and the current sharing controller.

10. A power supply, characterized in that: The power supply comprises a multi-channel parallel BUCK circuit and a DC source component as described in claim 8 or 9, wherein the DC source component is used to output a source current, and the circuit is used to process the source current to further obtain an output current.

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