Control Method and Related Device of Switching Circuit

Abstract

The present application provides a control method and related device for a switching circuit. The method includes: obtaining the actual value of the input voltage and the actual value of the input current of the switching circuit; converting the actual value of the input voltage into a current limiting coefficient, and the actual value of the input voltage is positively correlated with the current limiting coefficient; multiplying the current limiting coefficient by the current reference value to obtain a reference current limit value; generating a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current. The present application can limit the current reference value based on the magnitude of the actual value of the input voltage, so that the load that the switching circuit can drive decreases as the input voltage decreases under low voltage conditions, enabling the switching circuit to drive a larger load under low voltage, thereby expanding the input voltage range under different loads.

Description

Technical Field

[0001] This application relates to the field of circuit technologies, and in particular, to a control method and related device for a switching circuit. Background Art

[0002] Uninterruptible Power Systems (UPS) are widely used in various occasions with high requirements for power supply reliability, such as data centers, computer rooms, etc. The PFC (Power Factor Correction) circuit is an important component in the UPS, which is used to improve the power factor of the UPS.

[0003] As a switching circuit, the magnitude of the input voltage of the PFC circuit affects the load size that the circuit can drive. In the prior art, the load capacity that can be driven is usually determined based on the voltage range where the input voltage is located. For example, when the input voltage is between 176Vac and 295Vac, the switching circuit allows full-load operation; when the input voltage is between 154Vac and 176Vac, the switching circuit allows a load of less than 75%; when the input voltage is between 120Vac and 154Vac, it allows a load of less than 50%. However, this method can only drive the minimum load capacity within a certain voltage range, resulting in a narrow input voltage range. Summary of the Invention

[0004] This application provides a control method and related device for a switching circuit to solve the problem of the narrow input voltage range of the switching circuit in the prior art.

[0005] In a first aspect, this application provides a control method for a switching circuit, including:

[0006] Obtaining the actual value of the input voltage and the actual value of the input current of the switching circuit;

[0007] Converting the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient;

[0008] Multiplying the current limiting coefficient by a current reference value to obtain a reference current limit value;

[0009] Generating a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current.

[0010] In a second aspect, this application provides a control device for a switching circuit, which is characterized by including:

[0011] An electrical signal acquisition module, configured to acquire the actual value of the input voltage and the actual value of the input current of the switching circuit;

[0012] A current limiting coefficient calculation module is used to convert the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient;

[0013] A current limiting module is used to multiply the current limiting coefficient by a current reference value to obtain a reference current limit value;

[0014] A PWM signal generation module is used to generate a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current.

[0015] In a third aspect, the present application provides a terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the method in any possible implementation manner of the first aspect above are implemented.

[0016] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the method in any possible implementation manner of the first aspect above are implemented.

[0017] In a fifth aspect, an embodiment of the present application provides an uninterruptible power supply, which includes a switching circuit and the terminal described in the third aspect above.

[0018] An embodiment of the present application provides a control method and related device for a switching circuit. The method first obtains the actual value of the input voltage and the actual value of the input current of the switching circuit; then converts the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient; multiplies the current limiting coefficient by a current reference value to obtain a reference current limit value; and finally generates a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current. The present application can limit the current reference value based on the magnitude of the actual value of the input voltage, so that the load rate that the switching circuit allows to drive decreases as the input voltage decreases under low voltage conditions, enabling the switching circuit to drive a larger load under low voltage, thereby expanding the input voltage range under different loads. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1It is the implementation flowchart of the control method of the switching circuit provided by the embodiments of the present application;

[0021] Figure 2 It is a schematic circuit diagram of a switching circuit provided by the embodiments of the present application;

[0022] Figure 3 It is the flow block diagram of the control method of the switching circuit provided by the embodiments of the present application;

[0023] Figure 4 It is the schematic structural diagram of the control device of the switching circuit provided by the embodiments of the present application;

[0024] Figure 5 It is the schematic diagram of the terminal provided by the embodiments of the present application. Detailed implementation manners

[0025] In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are set forth in order to provide a thorough understanding of the embodiments of the present application. However, those skilled in the art should understand that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary details.

[0026] In order to make the objectives, technical solutions, and advantages of the present application clearer, the following will be described through specific embodiments with reference to the accompanying drawings.

[0027] Refer to Figure 1 , which shows the implementation flowchart of the control method of the switching circuit provided by the embodiments of the present application. Taking the PFC circuit as an example, the control method is described in detail as follows:

[0028] S101: Obtain the actual value of the input voltage, the actual value of the input current, and the bus voltage of the switching circuit.

[0029] Specifically, Figure 2 It is a three-phase PFC circuit provided by the embodiments of the present application. As Figure 2 shown, the left end of the circuit diagram is the input end, and the right end is the output end. Therefore, the actual value of the input voltage is the three-phase voltage, including u ab , u bc and u ca , and the actual value of the input current is the three-phase current, including i a , i b and i c . The bus voltage U bus is the voltage between PBUS and NBUS.

[0030] It should be noted that Figure 2Only the structure of one kind of switching circuit is shown, which is not used to limit the circuit structure to which the present control method is applied. The control method provided in this embodiment is applicable to any kind of switching circuit structure.

[0031] S102: Convert the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient.

[0032] In a possible embodiment, the specific implementation process of S102 includes:

[0033] Calculate a first voltage threshold according to the full load power and the maximum withstand current of the switching circuit; the first voltage threshold is the minimum input voltage value required when the switching circuit operates at full load;

[0034] If the actual value of the input voltage is less than or equal to the first voltage threshold, then based on the difference between the actual value of the input voltage and the minimum voltage setting value, convert the actual value of the input voltage into a current limiting coefficient greater than the minimum load rate and less than 1, and the actual value of the input voltage is in a direct proportional relationship with the current limiting coefficient; wherein, the minimum load rate is the load rate of the switching circuit when the actual value of the input voltage is the minimum voltage setting value.

[0035] In this embodiment, the full load power Pn is the product of the rated voltage Vn and the rated current In of the PFC circuit. Since the maximum current that the switching circuit can withstand is usually 1.6In, therefore, if you want the PFC circuit to operate at full load, its minimum voltage value is However, in order to ensure the safe operation of the circuit, the input current usually needs to be less than the maximum withstand current. Therefore, in this embodiment, 1.25In is taken as the maximum withstand current, so the first voltage threshold can be 176V.

[0036] Specifically, the minimum voltage setting value can be 120V, then its corresponding minimum load rate is 50%. When the actual value of the input voltage is less than or equal to 176V, convert the actual value of the input voltage into a current limiting coefficient between 100% and 50% based on the difference between the actual value of the input voltage and 120V.

[0037] Specifically, the specific implementation process of S102 further includes:

[0038] If the actual value of the input voltage is less than or equal to the first voltage threshold, then calculate the current limiting coefficient according to the current limiting coefficient calculation formula;

[0039] The current limiting coefficient calculation formula is:

[0040]

[0041] Wherein, k represents the current limiting coefficient, Vin represents the actual value of the input voltage, Vm represents the first voltage threshold, Vmin represents the minimum voltage setting value, and A represents the minimum load ratio.

[0042] In a possible embodiment, the specific implementation process of S102 further includes:

[0043] If the actual value of the input voltage is greater than the rated voltage, based on the difference between the actual value of the input voltage and the rated voltage, the actual value of the input voltage is converted into a current limiting coefficient greater than 1 and less than the maximum load ratio, and the actual value of the input voltage is in a direct proportional relationship with the current limiting coefficient.

[0044] In this embodiment, the rated voltage is 220V. To ensure the safe operation of the circuit under overload conditions, 1.3Vn is used as the maximum voltage value in this embodiment, and its corresponding maximum load ratio is 130%. That is to say, when the actual value of the input voltage is greater than 220V and less than 295V, based on the difference between the actual value of the input voltage and the rated voltage, the actual value of the input voltage is linearly converted into a current limiting coefficient between 100% and 130%.

[0045] Further, if the actual value of the input voltage is greater than the rated voltage, the current limiting coefficient is calculated based on the overload current limiting coefficient calculation formula;

[0046] The overload current limiting coefficient calculation formula can be:

[0047]

[0048] Wherein, k represents the current limiting coefficient, Vin represents the actual value of the input voltage, Vn represents the rated voltage, Vmax represents the maximum voltage value, and B represents the maximum load ratio.

[0049] In a possible embodiment, if the input voltage is greater than the first voltage threshold and less than or equal to the rated voltage, the current limiting coefficient is 1.

[0050] In a possible embodiment, the specific implementation process of S102 further includes:

[0051] If the actual value of the input voltage is greater than the first voltage threshold, the current limiting coefficient is assigned a value of 1.

[0052] When the actual value of the input voltage is greater than or equal to 176V, the switching circuit can operate at full load, so the current reference value is not current-limited, that is, the current limiting coefficient is 1.

[0053] Through the above method, when the actual value of the input voltage is less than the first voltage threshold and greater than the minimum input voltage value, the load rate linearly decreases from 100% to 50%. When the actual value of the input voltage is greater than the first voltage threshold and less than or equal to the rated voltage value, the load rate is 100%. When the actual value of the input voltage is greater than the rated voltage but less than the maximum voltage value, the load rate linearly increases from 100% to 120%. Compared with the prior art, the method provided in this embodiment can expand the input voltage range when driving the same load, thereby improving the adaptability of the switching circuit.

[0054] S103: Multiply the current limiting coefficient by the current reference value to obtain the reference current limit.

[0055] Specifically, before S103, the method provided in this embodiment further includes: obtaining the current reference value based on the actual value of the bus voltage.

[0056] In this embodiment, as Figure 3 shown, Figure 3 shows the flowchart of the control method of the switching circuit provided in this embodiment. Among them, obtaining the current reference value based on the actual value of the bus voltage is specifically as follows:

[0057] Subtract the actual value of the bus voltage from the given value of the bus voltage to obtain the bus voltage deviation value;

[0058] Input the bus voltage deviation value into the first voltage loop PI controller to obtain the current reference value.

[0059] In this embodiment, as Figure 3 shown, subtract the actual value of the bus voltage U bus_ref from the given value of the bus voltage U bus to obtain the bus voltage deviation value, and input the bus voltage deviation value into the first voltage loop PI controller to obtain the current reference value.

[0060] As Figure 3 shown, after obtaining the current reference value, multiply the current limiting coefficient k by the current reference value to obtain the reference current limit i d_set .

[0061] S104: Generate a PWM signal for controlling the switching circuit according to the reference current limit and the actual value of the input current.

[0062] In a possible embodiment, the specific implementation process of S104 includes:

[0063] S201: Obtain the voltage reference value based on the reference current limit and the actual value of the input current.

[0064] S202: Generate a PWM signal for controlling the switching circuit according to the voltage reference value and the actual input voltage value.

[0065] In a possible embodiment, the voltage reference value includes a d-axis voltage reference value, a q-axis voltage reference value, and a 0-axis voltage reference value; as Figure 3 shown, the specific implementation process of S201 includes:

[0066] Convert the actual input current value from the abc coordinate system to the dq0 coordinate system to obtain the actual d-axis input current value i d , the actual q-axis input current value i q and the actual 0-axis input current value i0;

[0067] Subtract the actual d-axis input current value i d_set from the reference current limit value i d to obtain the d-axis current deviation value, and input the d-axis current deviation value into the first current loop PI controller to obtain the d-axis voltage reference value;

[0068] Subtract the actual q-axis input current value i q_set from the q-axis current given value i q to obtain the q-axis current deviation value, and input the q-axis current deviation value into the second current loop PI controller to obtain the q-axis voltage reference value;

[0069] Obtain the positive and negative bus voltage difference ΔU busPN of the switching circuit, and input the positive and negative bus voltage difference into the second PI controller to obtain the 0-axis current reference value i 0_set ;

[0070] Subtract the actual 0-axis input current value i0 from the 0-axis current reference value i 0_set to obtain the 0-axis current deviation value, and input the 0-axis current deviation value into the third current loop PI controller to obtain the 0-axis voltage reference value.

[0071] In a possible embodiment, as Figure 3 shown, the specific implementation process of S202 includes:

[0072] Convert the actual input voltage value from the abc coordinate system to the dq0 coordinate system to obtain the actual d-axis input voltage value u d , the actual q-axis input voltage value u q and the actual 0-axis input voltage value u0;

[0073] Add the actual d-axis input voltage value u d to the d-axis voltage reference value to obtain the d-axis voltage deviation value;

[0074] Add the actual value u of the q-axis input voltage q to the q-axis voltage reference value to obtain the q-axis voltage deviation value;

[0075] Add the actual value u0 of the 0-axis input voltage to the 0-axis voltage reference value to obtain the 0-axis voltage deviation value;

[0076] Respectively input the d-axis voltage deviation value, the q-axis voltage deviation value, and the 0-axis voltage deviation value into the modulation factor calculation formula to obtain the d-axis modulation factor, the q-axis modulation factor, and the 0-axis modulation factor;

[0077] Respectively convert the d-axis modulation factor, the q-axis modulation factor, and the 0-axis modulation factor from the dq0 coordinate system to the abc coordinate system to obtain the three-phase modulation factors (va, vb, and vc), and generate the PWM signal based on the three-phase modulation factors;

[0078] The modulation factor calculation formula is:

[0079] where u Δ_x represents the x-axis voltage deviation value, x ∈ {d, q, 0}; U bus represents the bus voltage value, and v x represents the x-axis modulation factor.

[0080] Specifically, the difference ΔU between the positive and negative bus voltages busPN is Figure 2 the voltage value U PBUS between PBUS and point O and the voltage value U NBUS between NBUS and point O.

[0081] In this embodiment, after obtaining the three-phase modulation factors, perform SPWM modulation based on the three-phase modulation factors to obtain the PWM signal for controlling the switching tubes in the PWM circuit.

[0082] Through the above method, the present application can perform corresponding current limiting on the current reference value based on the magnitude of the actual input voltage value, so that the load that the switching circuit can drive decreases linearly with the decrease of the input voltage under low voltage conditions. Compared with the existing control methods, the present application can drive a larger load under low voltage, thereby expanding the input voltage range under different loads.

[0083] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0084] The following is the device embodiment of the present application. For the details not described in detail, reference can be made to the corresponding method embodiment above.

[0085] Figure 4 The structure diagram of the control device of the switching circuit provided by the embodiment of the present application is shown. For the convenience of description, only the parts related to the embodiment of the present application are shown and are described in detail as follows:

[0086] As Figure 4 shown, the control device 100 of the switching circuit includes:

[0087] An electrical signal acquisition module 110, configured to acquire the actual value of the input voltage, the actual value of the input current, and the bus voltage of the switching circuit;

[0088] A current limiting coefficient calculation module 120, configured to convert the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient;

[0089] A current limiting module 130, configured to multiply the current limiting coefficient by a current reference value to obtain a reference current limit value;

[0090] A PWM signal generation module 140, configured to generate a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current.

[0091] In a possible embodiment, the current limiting coefficient calculation module 120 includes:

[0092] Calculate a first voltage threshold according to the full-load power and the maximum tolerable current of the switching circuit; the first voltage threshold is the minimum input voltage value required for the switching circuit to operate at full load;

[0093] If the actual value of the input voltage is less than or equal to the first voltage threshold, then based on the difference between the actual value of the input voltage and the minimum voltage setting value, convert the actual value of the input voltage into a current limiting coefficient greater than the minimum load rate and less than 1, and the actual value of the input voltage is in a direct proportional relationship with the current limiting coefficient; wherein, the minimum load rate is the load rate of the switching circuit when the actual value of the input voltage is the minimum voltage setting value.

[0094] In a possible embodiment, the current limiting coefficient calculation module 120 further includes:

[0095] If the actual value of the input voltage is less than or equal to the first voltage threshold, then calculate the current limiting coefficient according to the current limiting coefficient calculation formula;

[0096] The current limiting coefficient calculation formula is:

[0097]

[0098] Wherein, k represents the current limiting coefficient, Vin represents the actual value of the input voltage, Vm represents the first voltage threshold, Vmin represents the minimum voltage setting value, and A represents the minimum load rate.

[0099] In a possible embodiment, the current limiting coefficient calculation module 120 further includes:

[0100] If the actual value of the input voltage is greater than the rated voltage, based on the difference between the actual value of the input voltage and the rated voltage, the actual value of the input voltage is converted into a current limiting coefficient greater than 1 and less than the maximum load rate, and the actual value of the input voltage is in a direct proportional relationship with the current limiting coefficient.

[0101] In a possible embodiment, the current limiting coefficient calculation module 120 further includes:

[0102] If the actual value of the input voltage is greater than the first voltage threshold, the current limiting coefficient is assigned a value of 1.

[0103] In a possible embodiment, the PWM signal generation module 140 includes:

[0104] A voltage reference value calculation unit, configured to obtain a voltage reference value based on the reference current limit value and the actual value of the input current;

[0105] A PWM signal generation unit, configured to generate a PWM signal for controlling the switching circuit according to the voltage reference value and the actual value of the input voltage.

[0106] The control device for the switching circuit provided by the present application first obtains the actual value of the input voltage, the actual value of the input current, and the bus voltage of the switching circuit; then converts the actual value of the input voltage into a current limiting coefficient; and the actual value of the input voltage is positively correlated with the current limiting coefficient; multiplies the current limiting coefficient by the current reference value to obtain a reference current limit value; and finally generates a PWM signal for controlling the switching circuit according to the reference current limit value and the actual value of the input current. The present application can limit the current reference value based on the magnitude of the actual value of the input voltage, so that the load rate that the switching circuit allows to drive decreases linearly with the decrease of the input voltage under low voltage conditions, enabling the switching circuit to drive a larger load under low voltage, thereby expanding the input voltage range under different loads.

[0107] The embodiment of the present application further provides a computer program product, which has program codes, and when the program codes run in a corresponding processor, controller, computing device or terminal, they execute the steps in any one of the above method embodiments of the control method for the switching circuit, for example Figure 1Steps 101 to 104 shown. Those skilled in the art should understand that the methods and the devices belonging thereto proposed in the embodiments of the present application can be implemented in various forms of hardware, software, firmware, a dedicated processor, or a combination thereof. The dedicated processor may include an application specific integrated circuit (ASIC), a reduced instruction set computer (RISC), and / or a field programmable gate array (FPGA). The proposed methods and devices are preferably implemented as a combination of hardware and software. The software is preferably installed as an application program on a program storage device. It is typically a machine based on a computer platform with hardware, such as one or more central processing units (CPUs), random access memory (RAM), and one or more input / output (I / O) interfaces. An operating system is typically also installed on the computer platform. The various processes and functions described herein may be part of an application program, or a part of it may be executed by the operating system.

[0108] Figure 5 is a schematic diagram of a terminal provided by an embodiment of the present application. As Figure 5 shown, the terminal 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, it implements the steps in the embodiments of the control method of each of the above switching circuits, such as Figure 1 the steps 101 to 104 shown. Alternatively, when the processor 50 executes the computer program 52, it implements the functions of each module / unit in the above device embodiments, such as Figure 4 the functions of the modules 110 to 140 shown.

[0109] Exemplarily, the computer program 52 may be divided into one or more modules / units. The one or more modules / units are stored in the memory 51 and executed by the processor 50 to complete / implement the solution provided by the present application. The one or more modules / units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 52 in the terminal 5. For example, the computer program 52 may be divided into Figure 4 the modules 110 to 140 shown.

[0110] The terminal 5 may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The terminal 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art can understand that Figure 5 merely examples of the terminal 5 do not constitute a limitation on the terminal 5, and it may include more or fewer components than shown in the figure, or combine certain components, or different components. For example, the terminal may further include input / output devices, network access devices, a bus, etc.

[0111] The so-called processor 50 may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0112] The memory 51 may be an internal storage unit of the terminal 5, such as the hard disk or memory of the terminal 5. The memory 51 may also be an external storage device of the terminal 5, such as a plug-in hard disk, Smart Media Card (SMC), Secure Digital (SD) card, Flash Card, etc. equipped on the terminal 5. Further, the memory 51 may also include both the internal storage unit of the terminal 5 and the external storage device. The memory 51 is used to store the computer program and other programs and data required by the terminal. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0113] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules as needed, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiments can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of this application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0114] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0115] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional technician can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0116] In the embodiments provided in this application, it should be understood that the disclosed device / terminal and method can be implemented in other ways. For example, the device / terminal embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the devices or units can be in electrical, mechanical or other forms.

[0117] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0118] In addition, the functional units in each embodiment of this application can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0119] When the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, to implement all or part of the processes in the above-described embodiment methods of the present application, it can also be completed by a computer program instructing relevant hardware. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, the steps of the control method embodiments of the above-described various switching circuits can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disc, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content included in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, the computer-readable medium does not include electrical carrier signals and telecommunication signals.

[0120] In addition, the features of the embodiments shown in the drawings of the present application or various embodiments mentioned in this specification do not have to be understood as independent embodiments from each other. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments, thereby generating other embodiments not described in words or with reference to the drawings.

[0121] The embodiment of the present application also provides an uninterruptible power supply, which includes a switching circuit and a terminal as described above.

[0122] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A control method for a switching circuit, characterized in that, Including: Obtain the actual input voltage value and the actual input current value of the switching circuit; Convert the actual input voltage value into a current limiting coefficient; and the actual input voltage value is positively correlated with the current limiting coefficient; Multiply the current limiting coefficient by the current reference value to obtain a reference current limit value; Generate a PWM signal for controlling the switching circuit according to the reference current limit value and the actual input current value; The converting the actual input voltage value into a current limiting coefficient includes: Calculate a first voltage threshold according to the full-load power and the maximum tolerable current of the switching circuit; the first voltage threshold is the minimum input voltage value required for the switching circuit to operate at full load; If the actual input voltage value is less than or equal to the first voltage threshold, convert the actual input voltage value into a current limiting coefficient greater than the minimum load rate and less than 1 based on the difference between the actual input voltage value and the minimum voltage setting value, and the actual input voltage value is in a proportional relationship with the current limiting coefficient; wherein, the minimum load rate is the load rate of the switching circuit when the actual input voltage value is the minimum voltage setting value.

2. The control method for a switching circuit according to claim 1, characterized in that, The converting the actual input voltage value into a current limiting coefficient further includes: If the actual input voltage value is greater than the rated voltage, convert the actual input voltage value into a current limiting coefficient greater than 1 and less than the maximum load rate based on the difference between the actual input voltage value and the rated voltage, and the actual input voltage value is in a proportional relationship with the current limiting coefficient.

3. The control method for a switching circuit according to claim 1, characterized in that, The if the actual input voltage value is less than or equal to the first voltage threshold, convert the actual input voltage value into a current limiting coefficient greater than the minimum load rate and less than 1 based on the difference between the actual input voltage value and the minimum voltage setting value includes: If the actual input voltage value is less than or equal to the first voltage threshold, calculate the current limiting coefficient according to the current limiting coefficient calculation formula; The current limiting coefficient calculation formula is: wherein, k represents the current limiting coefficient, Vin represents the actual input voltage value, Vm represents the first voltage threshold, Vmin represents the minimum voltage setting value, and A represents the minimum load rate.

4. The control method for a switching circuit according to claim 1, characterized in that, The converting the actual input voltage value into a current limiting coefficient further includes: If the actual input voltage value is greater than the first voltage threshold, assign the current limiting coefficient as 1.

5. The control method for a switching circuit according to claim 1, characterized in that, The generating a PWM signal for controlling the switching circuit according to the reference current limit value and the actual input current value includes: Obtain a voltage reference value based on the reference current limit value and the actual input current value; Generate a PWM signal for controlling the switching circuit according to the voltage reference value and the actual input voltage value.

6. A control device for a switching circuit, characterized in that, Including: An electrical signal acquisition module for obtaining the actual input voltage value and the actual input current value of the switching circuit; A current limiting coefficient calculation module for converting the actual input voltage value into a current limiting coefficient; and the actual input voltage value is positively correlated with the current limiting coefficient; A current limiting module for multiplying the current limiting coefficient by the current reference value to obtain a reference current limit value; A PWM signal generation module, configured to generate a PWM signal for controlling the switching circuit according to the reference current limit value and the actual input current value; The current limiting coefficient calculation module includes: Calculating a first voltage threshold according to the full-load power and the maximum withstand current of the switching circuit; the first voltage threshold is the minimum input voltage value required for the switching circuit to operate at full load; If the actual input voltage value is less than or equal to the first voltage threshold, based on the difference between the actual input voltage value and the minimum voltage setting value, the actual input voltage value is converted into a current limiting coefficient greater than the minimum load rate and less than 1, and the actual input voltage value is in a direct proportional relationship with the current limiting coefficient; wherein, the minimum load rate is the load rate of the switching circuit when the actual input voltage value is the minimum voltage setting value.

7. A terminal, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the control method of the switching circuit according to any one of claims 1 to 5 above.

8. A computer-readable storage medium storing a computer program, characterized in that,When the computer program is executed by the processor, it implements the steps of the control method of the switching circuit according to any one of claims 1 to 5 above.

9. An uninterruptible power supply, characterized in that, It includes a switching circuit and a terminal according to claim 7.

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