Circuit control device

Abstract

The present invention provides a circuit control device, including an acquisition module for acquiring the output current and output voltage of a controlled circuit; a current loop for determining a current control quantity according to the output current; a voltage loop for determining a voltage control quantity according to the output voltage; a control module for determining a first control quantity and controlling the controlled circuit according to the first control quantity; wherein, if the first control quantity is the current control quantity, the current loop is the working loop and the voltage loop is the non-working loop; if the first control quantity is the voltage control quantity, the voltage loop is the working loop and the current loop is the non-working loop; an integral limit module for determining the upper limit of the integral value of the non-working loop according to a preset threshold and the current integral value of the working loop. By setting the upper limit of the integral value of the non-working loop according to the integral value of the working loop, integral saturation of the non-working loop can be avoided, thereby shortening the process of integral withdrawal when the non-working loop switches to the working loop, effectively improving the response speed of the control loop, and avoiding faults of the controlled circuit.

Description

Technical Field

[0001] This application belongs to the technical field of circuit control, and particularly relates to a circuit control device. Background Art

[0002] In the application of switched-mode power supplies, LLC resonant converters are widely used in consumer electronics, industry, communications, and other fields. Since an LLC resonant converter is a highly nonlinear system with multiple input variables, it is prone to interference from the load and input during operation. Therefore, it is necessary to control its output current and output voltage.

[0003] In the prior art, an LLC resonant converter is often controlled by a feedback system composed of a current loop and a voltage loop. When one of the current loop and the voltage loop is used as the working loop for control, although the other loop does not participate in control, it still continuously performs integral calculation until integral saturation is reached. When it is necessary to switch the other loop as the working loop for control, it is necessary to first perform de-integration on the other loop and then switch the other loop to the working loop.

[0004] However, due to the slow de-integration process, it is easy to cause untimely control of the LLC resonant converter, resulting in faults such as overcurrent, overvoltage, and undervoltage in the LLC resonant converter. Summary of the Invention

[0005] In view of this, the present invention provides a circuit control device, aiming to solve the problem of faults in the controlled circuit caused by the slow switching process of the control loop in the prior art.

[0006] The first aspect of the embodiment of the present invention provides a circuit control device for controlling a controlled circuit. The circuit control device includes:

[0007] [[ID=2,5]]An acquisition module for acquiring the output current and output voltage of the controlled circuit;

[0008] A current loop for determining a current control amount according to the output current; wherein, the current loop includes a current integration part for calculating an integral value corresponding to the output current;

[0009] A voltage loop for determining a voltage control amount according to the output voltage; wherein, the voltage loop includes a voltage integration part for calculating an integral value corresponding to the output voltage;

[0010] A control module for determining a first control amount and controlling the controlled circuit according to the first control amount; wherein, if the first control amount is a current control amount, the current loop is the working loop and the voltage loop is the non-working loop; if the first control amount is a voltage control amount, the voltage loop is the working loop and the current loop is the non-working loop;

[0011] The integral limit module is used to determine the upper limit of the integral value of the non-working loop according to a preset threshold and the current integral value of the working loop.

[0012] In a possible implementation, the integral limit module is specifically configured to use the sum of the preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop.

[0013] In a possible implementation, the integral limit module is specifically configured to use the product of the preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop.

[0014] In a possible implementation, the control module is further configured to record the integral value of the working loop;

[0015] The integral limit module is further configured to determine the maximum change amount of the integral value of the working loop according to the integral value of the working loop recorded within a historical period, and determine the preset threshold according to the maximum change amount of the integral value of the working loop and the response time of the integral limit module.

[0016] In a possible implementation, the integral limit module is further configured to:

[0017] When the working loop is a voltage loop, determine the voltage change amount according to the output voltage collected by the acquisition module, and adjust the preset threshold according to the voltage change amount;

[0018] When the working loop is a current loop, determine the current change amount according to the output current collected by the acquisition module, and adjust the preset threshold according to the current change amount.

[0019] In a possible implementation, the current loop is specifically configured to determine the current control amount according to the output current and a preset current reference value.

[0020] In a possible implementation, the voltage loop is specifically configured to determine the voltage control amount according to the output voltage and a preset voltage reference value.

[0021] In a possible implementation, the voltage loop further includes a limiting module;

[0022] The limiting module is used to determine the voltage amplitude limit value according to the output current and the average value of the output current;

[0023] The voltage loop is specifically configured to determine the voltage control amount according to the output voltage, the voltage amplitude limit value, and a preset voltage reference value.

[0024] In a possible implementation, the control module includes a selector, a pulse width / frequency modulator, and at least one PWM controller. The selector is connected to the pulse width / frequency modulator; the pulse width / frequency modulator is respectively connected to at least one PWM controller; and at least one PWM controller is connected to the controlled circuit;

[0025] The selector is used to take the larger value of the current control quantity and the voltage control quantity as the first control quantity;

[0026] The width modulation / frequency modulation unit is used to adjust the phase of the first control quantity;

[0027] At least one PWM controller is used to control the controlled circuit.

[0028] In a possible implementation, the controlled circuit is an LLC resonant conversion circuit.

[0029] The circuit control device provided by the embodiment of the present invention is applied to a controlled circuit. The device includes an acquisition module for acquiring the output current and output voltage of the controlled circuit; a current loop for determining a current control quantity according to the output current; a voltage loop for determining a voltage control quantity according to the output voltage; a control module for determining a first control quantity and controlling the controlled circuit according to the first control quantity; wherein, if the first control quantity is the current control quantity, the current loop is the working loop and the voltage loop is the non-working loop; if the first control quantity is the voltage control quantity, the voltage loop is the working loop and the current loop is the non-working loop; an integral limit module for determining the upper limit of the integral value of the non-working loop according to a preset threshold and the current integral value of the working loop. By setting the upper limit of the integral value of the non-working loop according to the current integral value of the working loop, integral saturation of the non-working loop can be avoided, so that the integral of the non-working loop does not exceed the integral value of the working loop too much, thereby shortening the process of integral withdrawal when the non-working loop switches to the working loop, effectively improving the response speed of the control loop, and avoiding faults of the controlled circuit. Description of the Drawings

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0031] Figure 1 is a schematic structural diagram of the circuit control device provided by the embodiment of the present invention;

[0032] Figure 2 is a schematic diagram of a partial control loop provided by the embodiment of the present invention;

[0033] Figure 3 is a schematic structural diagram of the controlled circuit provided by the embodiment of the present invention. Detailed Embodiments

[0034] In the following description, specific details such as specific system architectures and technologies are presented for the purpose of illustration rather than limitation, so as to thoroughly understand the embodiments of the present invention. However, those skilled in the art should clearly understand that the present invention can 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 to avoid unnecessary details from interfering with the description of the present invention.

[0035] Figure 1 It is a schematic structural diagram of a circuit control device provided by an embodiment of the present invention. As Figure 1 shown, in some embodiments, the circuit control device is used to control a controlled circuit. The circuit control device includes: an acquisition module 11, configured to acquire the output current and output voltage of the controlled circuit. A current loop 12, configured to determine a current control quantity according to the output current. Wherein, the current loop 12 includes a current integration part, and the current integration part is configured to calculate an integration value corresponding to the output current. A voltage loop 13, configured to determine a voltage control quantity according to the output voltage. Wherein, the voltage loop 13 includes a voltage integration part, and the voltage integration part is configured to calculate an integration value corresponding to the output voltage. A control module 14, configured to determine a first control quantity and control the controlled circuit according to the first control quantity; wherein, if the first control quantity is a current control quantity, the current loop is the working loop and the voltage loop is the non-working loop; if the first control quantity is a voltage control quantity, the voltage loop is the working loop and the current loop is the non-working loop. An integration limit module 15, configured to determine an upper limit of the integration value of the non-working loop according to a preset threshold and the current integration value of the working loop.

[0036] In the embodiments of the present invention, the controlled circuit may be an LLC resonant conversion circuit, an inverter circuit, a rectifier circuit, a DC-DC conversion circuit, etc., which is not limited herein. The current control quantity and the voltage control quantity are both characterized as frequency values, and the integration values of the voltage loop and the current loop are both characterized as period values.

[0037] In the embodiments of the present invention, the larger the frequency value corresponding to the above control quantity, the smaller the output gain. Therefore, the above selector selects the larger of the output quantity of the above voltage loop and the output quantity of the above current loop as the control quantity output, so that the corresponding output gain is smaller, thereby making the operation of the controlled circuit more stable.

[0038] Since the control module 14 takes the control loop with a large frequency value as the working loop, and at the same time, the period value of the working loop is smaller than the period value of the non-working loop, that is, the integration value of the working loop is smaller than the integration value of the non-working loop. When it is necessary to switch the control loop, it is necessary to first reduce the integration value of the non-working loop until it is less than the integration value of the working loop before the switching can be completed. If the non-working loop is in an integral saturation state, the de-integration process is very slow and is likely to cause overcurrent in the controlled circuit.

[0039] Therefore, in the embodiments of the present invention, an integral limit module 15 is introduced. By setting the upper limit of the integral value of the non-working loop according to the current integral value of the working loop, integral saturation of the non-working loop can be avoided, so that the integral of the non-working loop does not exceed the integral value of the working loop by too much. Thus, the process of integral reduction when the non-working loop switches to the working loop can be shortened, the response speed of the control loop can be effectively improved, and faults of the controlled circuit can be avoided.

[0040] In some embodiments, the integral limit module 15 is specifically configured to use the sum of a preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop.

[0041] In the embodiments of the present invention, for the voltage loop and the current loop, the same preset threshold can be set, or different preset thresholds can be set respectively, which is not limited herein. For example, when working in the voltage loop, the integral upper limit of the current loop = the output of the voltage loop + the first preset threshold; when working in the current loop, the integral upper limit of the voltage loop = the output of the current loop + the second preset threshold.

[0042] In some embodiments, the integral limit module 15 is specifically configured to use the product of a preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop.

[0043] In the embodiments of the present invention, the range of the preset threshold can be [1, 2]. For example, when the preset threshold is 1.2, the upper limit of the integral value of the non-working loop = the current integral value of the working loop * 1.2. Since the current integral value of the working loop changes with the output of the controlled circuit, by multiplying the preset threshold by the current integral value, the upper limit of the integral value of the non-working loop can follow the change of the working loop. Therefore, the calculation method of the upper limit of the integral value provided in this embodiment can further improve the response speed during switching.

[0044] In some embodiments, the control module 14 is further configured to record the integral value of the working loop. Correspondingly, the integral limit module 15 is further configured to determine the maximum change amount of the integral value of the working loop according to the integral value of the working loop recorded within the historical period, and determine the preset threshold according to the maximum change amount of the integral value of the working loop and the response time of the integral limit module.

[0045] In the embodiments of the present invention, the preset threshold cannot be too large. If the preset threshold is too large, the integral values of the working loop and the non-working loop will differ greatly, resulting in a longer control time. Therefore, a relatively small preset threshold should be set as much as possible. However, if the preset threshold is too small, the integral values of the working loop and the non-working loop will be very close. Since the current integral value of the working loop changes with the output of the controlled circuit, if the current integral value of the working loop increases instantaneously and exceeds the integral value of the non-working loop, it will cause an incorrect loop switch and affect the operation of the controlled circuit.

[0046] Therefore, by recording the integral value of the working loop, determining its maximum change per unit time, and then multiplying it by the response time of the integral limit module, the minimum setting value of the preset threshold can be determined, thereby ensuring that the integral value of the working loop does not exceed the working loop during the process of the integral limit module 15 performing the upper limit adjustment.

[0047] In some embodiments, the integral limiting module 15 is further used to: when the working loop is a voltage loop, determine the voltage change according to the output voltage collected by the acquisition module, and adjust the preset threshold according to the voltage change; when the working loop is a current loop, determine the current change according to the output current collected by the acquisition module, and adjust the preset threshold according to the current change.

[0048] In an embodiment of the present invention, in order to enable the controlled circuit to stabilize the voltage and current, when the voltage change is large, the control loop will definitely output a larger adjustment amount, and the preset threshold should be correspondingly increased to avoid incorrect switching of the working loop. When the voltage change is relatively small, the control loop will definitely output a smaller adjustment amount, and the preset threshold should be correspondingly lowered to reduce the corresponding time during switching.

[0049] It should be noted that by determining the upper limit of the non-operating loop's integral value based on the integral value of the operating loop, changes in the upper limit of the non-operating loop's integral value lag behind those of the operating loop. Adjusting the upper limit based on the output of the controlled circuit involves at least a difference calculation and a PI operation. However, in this embodiment, only the change calculation—that is, only the difference calculation—is required. Therefore, in this embodiment, the upper limit of the non-operating loop must be adjusted ahead of that of the operating loop.

[0050] Figure 2 This is a schematic diagram of a partial control loop provided by an embodiment of the present invention. Figure 2 As shown, in some embodiments, the current loop 12 is specifically used to determine the current control amount according to the output current and the preset current reference value.

[0051] In the embodiment of the present invention, the output current I0 and the preset current reference value I 0_ref After making the difference, input the difference into the PI controller to get the current control value f i .

[0052] In some embodiments, the voltage loop 13 is specifically configured to determine a voltage control variable based on the output voltage and a preset voltage reference value. The voltage loop 13 also includes a limiting module. The limiting module is configured to determine a voltage amplitude limit based on the output current and its average value. Accordingly, the voltage loop 13 is specifically configured to determine the voltage control variable based on the output voltage, the voltage amplitude limit, and the preset voltage reference value.

[0053] In the embodiment of the present invention, the output current U0 and the preset current reference value U 0_refAfter taking the difference, input the obtained difference value into the PI controller, and the current control quantity f can be obtained. u .

[0054] In the embodiment of the present invention, as Figure 2 shown, when the limiting module is closed, the selection switch is at 0. When the limiting module is turned on, the selection switch is connected to the limiter. At this time, the output current I0 and the preset current reference value I 0_ref are subtracted, and the obtained difference value is input into the PI controller, and then the output of the PI controller is input into the limiter, and the voltage amplitude limit value can be obtained.

[0055] In some embodiments, the control module 14 includes a selector, a pulse width / frequency modulator, and at least one PWM controller. The selector is connected to the pulse width / frequency modulator; the pulse width / frequency modulator is respectively connected to at least one PWM controller; at least one PWM controller is connected to the controlled circuit; the selector is used to use the larger value of the current control quantity and the voltage control quantity as the first control quantity; the pulse width / frequency modulator is used to adjust the phase of the first control quantity; at least one PWM controller is used to control the controlled circuit.

[0056] In the embodiment of the present invention, the selector is a MAX selector, which is used to select the control loop with a larger frequency from the current loop and the voltage loop as the working loop. The pulse width / frequency modulator G f / G d is used to adjust the phase of the control quantity input to the PWM controller. The specific adjustment method is determined according to the requirements of the controlled circuit and is not limited here. The PWM controller can be connected to controller devices such as thyristor relays in the controlled circuit, and by adjusting its own duty cycle according to the first control quantity, the control of the controlled circuit is realized.

[0057] Figure 3 is the structural schematic diagram of the controlled circuit provided by the embodiment of the present invention. As Figure 3 shown, in some embodiments, the controlled circuit is an LLC resonant conversion circuit.

[0058] In the embodiment of the present invention, the LLC resonant conversion circuit includes a power supply U c , a bridge inverter circuit composed of thyristors Q1-Q4, a resonant inductor L r , an exciting inductor L m , a resonant capacitor C r , an isolation transformer T r , a bridge rectifier circuit composed of diodes D1-D4, and an output capacitor C f .

[0059] In summary, the beneficial effects of the present invention are as follows: By setting the upper limit of the integral value of the non-working loop according to the current integral value of the working loop, it is possible to avoid the integral saturation of the non-working loop, prevent the integral of the non-working loop from being excessively higher than that of the working loop, thereby shortening the process of integral reduction when the non-working loop switches to the working loop, effectively improving the response speed of the control loop, and avoiding failures of the controlled circuit.

[0060] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0061] 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 according to needs, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. 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 the present 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.

[0062] In the above embodiments, the descriptions of the various embodiments have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0063] Those of ordinary skill in the art can realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or by a combination of computer software and electronic hardware. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled professionals 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 the present invention.

[0064] In the embodiments provided by the present invention, 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 modules or units is only a logical function division. In actual implementation, there may be other division methods. 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 coupling, direct coupling, or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of devices or units can be in electrical, mechanical, or other forms.

[0065] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or 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.

[0066] In addition, in each embodiment of the present invention, the functional units can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated units can be implemented in the form of hardware or in the form of software functional units.

[0067] If 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-mentioned embodiment methods of the present invention, it can also be completed by instructing relevant hardware through a computer program. 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 above-mentioned various method embodiments 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 that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), 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.

[0068] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention 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 on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A circuit control device, characterized in that, The circuit control device is used to control a controlled circuit, and the circuit control device includes: An acquisition module, configured to acquire the output current and output voltage of the controlled circuit; A current loop, configured to determine a current control quantity according to the output current; wherein, the current loop includes a current integration part, and the current integration part is configured to calculate an integral value corresponding to the output current; A voltage loop, configured to determine a voltage control quantity according to the output voltage; wherein, the voltage loop includes a voltage integration part, and the voltage integration part is configured to calculate an integral value corresponding to the output voltage; A control module, configured to determine a first control quantity and control the controlled circuit according to the first control quantity; wherein, if the first control quantity is a current control quantity, the current loop is the working loop and the voltage loop is the non-working loop; if the first control quantity is a voltage control quantity, the voltage loop is the working loop and the current loop is the non-working loop; An integral limiting module, configured to determine an upper limit of the integral value of the non-working loop according to a preset threshold and the current integral value of the working loop; The control module is further configured to record the integral value of the working loop; The integral limiting module is further configured to determine a maximum change amount of the integral value of the working loop according to the integral value of the working loop recorded within a historical period, and determine the preset threshold according to the maximum change amount of the integral value of the working loop and the response time of the integral limiting module; 2. The circuit control device according to claim 1, characterized in that Specifically, the integral limiting module uses the sum value of the preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop; 3. The circuit control device according to claim 1, wherein, Specifically, the integral limiting module uses the product value of the preset threshold and the current integral value of the working loop as the upper limit of the integral value of the non-working loop; 4. The circuit control device according to claim 1, characterized in that, The integral limiting module is further configured to: When the working loop is a voltage loop, determine a voltage change amount according to the output voltage acquired by the acquisition module, and adjust the preset threshold according to the voltage change amount; When the working loop is a current loop, determine a current change amount according to the output current acquired by the acquisition module, and adjust the preset threshold according to the current change amount; 5. The circuit control device according to claim 1, wherein Specifically, the current loop is configured to determine a current control quantity according to the output current and a preset current reference value; 6. The circuit control device according to claim 1, characterized in that, Specifically, the voltage loop is configured to determine a voltage control quantity according to the output voltage and a preset voltage reference value; 7. The circuit control device according to claim 6, characterized in that, The voltage loop further includes a limiting module; The limiting module is configured to determine a voltage amplitude limit value according to the output current and the average value of the output current; Specifically, the voltage loop is configured to determine a voltage control quantity according to the output voltage, the voltage amplitude limit value, and a preset voltage reference value; 8. The circuit control device according to any one of claims 1 to 7, characterized in that, The control module includes a selector, a pulse width / frequency modulator, and at least one PWM controller. The selector is connected to the pulse width / frequency modulator; the pulse width / frequency modulator is respectively connected to the at least one PWM controller; the at least one PWM controller is connected to the controlled circuit; The selector is configured to use the larger value of the current control quantity and the voltage control quantity as the first control quantity; The pulse width / frequency modulator is configured to adjust the phase of the first control quantity; The at least one PWM controller is used to control the controlled circuit.

9. The circuit control device according to any one of claims 1-7, characterized in that, The controlled circuit is an LLC resonant conversion circuit.

Images