Method and device for capacitor charging of a voltage conversion circuit, and voltage conversion system
By changing the series and parallel connection of capacitors in the transformer circuit and adjusting the current flow using a switching transistor, the high cost of selecting flyback capacitors for slow charging in existing technologies is solved, achieving a slower and more reliable slow charging solution.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KEHUA DATA CO LTD
- Filing Date
- 2022-07-28
- Publication Date
- 2026-04-14
AI Technical Summary
The selection cost of the current flying capacitor slow charging method is relatively high.
By using a switching transistor in the transformer circuit to change the series-parallel relationship of the capacitors, the charging connection is improved by disconnecting C2, C3 and CfL in parallel and then connecting them in series with C1. This reduces the selection requirements for C2, and the charging progress is determined by the bus capacitor voltage.
This reduces the selection cost of flying capacitor slow charging, saves the cost of additional sensing equipment for voltage acquisition, and improves the reliability and economy of the slow charging solution.
Smart Images
Figure CN115102382B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of charging technology, and more specifically, relates to a method and device for slow charging of a transformer circuit capacitor, and a transformer system. Background Technology
[0002] Before a transformer circuit operates, its flying capacitor typically needs to be slow-charged to prevent inrush current from affecting the electrical components in the transformer circuit. In existing technology, a slow-charge circuit is usually directly added, utilizing the conductivity of each line within the circuit to slow-charge the flying capacitor. For example... Figure 1 As shown, when the transformer circuit is charged using the slow charging circuit 21, the direction of current flow is as follows: Figure 1 As shown by the dashed line, during the slow charging process, it is equivalent to C2 and C. fL After being connected in series with C3, the flying capacitor needs to be slowly charged to a preset voltage. Therefore, the existing slow-charging method requires C2 to be much larger than C. fL And C fL Since C2 is much smaller than C1 after being connected in series, the existing buffer charging method will require a larger C2 capacitance value in the design.
[0003] In other words, the existing flying capacitor slow charging method has a high selection cost. Summary of the Invention
[0004] The purpose of this invention is to provide a method and device for slow charging capacitors in a transformer circuit, as well as a transformer system, to solve the technical problem of high selection cost of the slow charging method for flying capacitors in the prior art.
[0005] To achieve the above objectives, the present invention provides a method for slow-charging a transformer circuit capacitor. This method is used to charge a flying capacitor in a target transformer circuit. The target transformer circuit includes a capacitor circuit formed by two input capacitors connected in series, a switching transistor circuit formed by a first, second, third, and fourth switching transistor connected in series, a diode circuit formed by two diodes connected in series, a flying capacitor, an output inductor, and an output capacitor. The two ends of the capacitor circuit constitute the two input terminals of the target transformer circuit, and the capacitor circuit is connected in parallel with the switching transistor circuit. The common terminal of the capacitor is connected to the common terminal of the two diodes, and the flying capacitor is connected in parallel with the diode circuit; the common terminal of the first switch and the second switch is connected to the first terminal of the flying capacitor, the common terminal of the third switch and the fourth switch is connected to the second terminal of the flying capacitor, and the common terminal of the second switch and the third switch is connected to the first terminal of the output inductor; the two ends of the output capacitor are respectively connected to the second terminal of the output inductor and the low-voltage terminal of the switch circuit, and the two ends of the output capacitor constitute the two output terminals of the transformer circuit; the capacitor slow-charging method of the transformer circuit includes:
[0006] In response to an internal / external slow charge command, the fourth switch is controlled to turn on;
[0007] When the bus capacitor voltage of the target transformer circuit reaches a preset voltage, the fourth switch is controlled to turn off.
[0008] In one possible implementation, the target transformer circuit further includes a slow-charging circuit, which comprises parallel-connected resistive and non-resistive lines; the high-voltage terminal of the switching transistor is connected to an external DC source through the slow-charging circuit; the transformer circuit capacitor slow-charging method further includes:
[0009] When controlling the fourth switch to be turned on, the resistor circuit is also controlled to be turned on;
[0010] When the fourth switch is turned off, the non-resistive circuit is also turned on.
[0011] The non-resistive circuit is used to short-circuit the resistive circuit when it is conducting.
[0012] In one possible implementation, the resistor line includes a first switch and a first resistor connected in series; controlling the conduction of the resistor line includes:
[0013] Control the first switch to turn on.
[0014] In one possible implementation, the non-resistive circuit is a circuit consisting of a second switch; controlling the conduction of the non-resistive circuit includes:
[0015] The control turns on the second switch.
[0016] In one possible implementation, C3 ≥ C1, and the preset voltage satisfies |U t -U dc | <e;
[0017] Wherein, C3 is the capacitance value of the capacitor near the low-voltage side in the capacitor circuit, C1 is the capacitance value of the capacitor near the high-voltage side in the capacitor circuit, and U t For the preset voltage, U dc The voltage of the external DC source supplying power to the target transformer circuit is represented by , and e is a preset error.
[0018] In one possible implementation, C3 = C1, and the preset voltage is the voltage of the external DC source.
[0019] In another aspect, the present invention provides a transformer circuit capacitor slow charging device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the transformer circuit capacitor slow charging method described above.
[0020] In another aspect, the present invention provides a transformer system comprising:
[0021] The aforementioned transformer circuit capacitor slow-charging device.
[0022] The beneficial effects of the transformer circuit capacitor slow charging method and equipment, and the transformer system provided by this invention are as follows:
[0023] Unlike existing technologies that directly use a slow-charging circuit to slow down the charging of flying capacitors, this invention also utilizes switching transistors in existing transformer circuits. By turning on the corresponding switching transistors, the series and parallel relationships of the capacitors in the transformer circuit and the current flow direction of the transformer circuit are changed. Based on the technical means of this invention, the existing "C2 and C" can be... fL The charging connection relationship of "connecting C2, C3 and C3 in parallel" is improved to "disconnecting C2, C3 and C3". fL The charging connection relationship of "parallel connection followed by series connection with C1" reduces the selection requirements for C2, thereby saving selection costs and solving the problems existing in the prior art. Based on this, the improved charging connection relationship of this invention eliminates the need for additional sensors to collect the voltage of the flying capacitor when judging the progress of slow charging. The completion of slow charging can be determined solely by the bus capacitor voltage collected by existing sensors, further reducing slow charging costs. Attached Figure Description
[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of the current flow in a capacitor slow-charging scheme for a transformer circuit in the prior art;
[0026] Figure 2 This is a schematic diagram of the current flow direction of a transformer circuit capacitor slow charging method provided in an embodiment of the present invention;
[0027] Figure 3 This is a schematic flowchart of a transformer circuit capacitor slow charging method provided in an embodiment of the present invention;
[0028] Figure 4 This is a structural block diagram of a transformer circuit capacitor slow-charging device provided in an embodiment of the present invention. Detailed Implementation
[0029] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
[0030] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.
[0031] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the current flow direction in a transformer circuit capacitor slow charging method according to an embodiment of the present invention (where the dashed line represents the current flow direction of the target transformer circuit during the slow charging process). Figure 3 This is a schematic flowchart of a transformer circuit capacitor slow-charging method according to an embodiment of the present invention. The present invention provides a transformer circuit capacitor slow-charging method, such as... Figure 2 As shown, this transformer circuit capacitor slow-charging method is used to charge the flying capacitor in the target transformer circuit. The target transformer circuit includes two input capacitors (corresponding to...) Figure 2 The following circuits are described: a capacitor circuit formed by C1 and C3 connected in series; a switching circuit formed by the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 connected in series; a diode circuit formed by two diodes connected in series; and a flying capacitor C. fLOutput inductor L1 and output capacitor C2. The two ends of the capacitor circuit form the two input terminals of the target transformer circuit, and the capacitor circuit is connected in parallel with the switching transistor circuit. The common terminal of the two capacitors is connected to the common terminal of the two diodes, and the flying capacitor C... fL It is connected in parallel with the diode circuit. The common terminal of the first switch Q1 and the second switch Q2 is connected to the flying capacitor C. fL The first terminal is connected, the common terminal of the third switch Q3 and the fourth switch Q4 is connected to the flying capacitor C. fL The second terminal of the output inductor L1 is connected to the common terminal of the second switch Q2 and the third switch Q3. The two ends of the output capacitor C2 are connected to the second terminal of the output inductor L1 and the low-voltage terminal of the switch circuit, respectively. The two ends of the output capacitor C2 form the two output terminals of the transformer circuit.
[0032] The capacitor slow-charging method for this transformer circuit includes:
[0033] S101: In response to an internal / external slow charge command, control the fourth switch to turn on.
[0034] In this embodiment, it should be noted that in the actual slow charging process, the input terminal of the target transformer circuit must be connected to an external DC source, and the output terminal of the target transformer circuit must also be connected to an external load or other circuit equipment to form a complete circuit system, which is common knowledge. Therefore, the transformer circuit capacitor slow charging method provided in this embodiment is designed under the premise that an external DC source and external load are already connected.
[0035] In this embodiment, when the transformer circuit needs to be slowed down (i.e., when a slow-down command is received internally or externally), the fourth switch Q4 can be turned on. At this time, C3 and C fL Equivalent to being connected in parallel, C1, C3, and C fL Simultaneously, a slow charging process is performed. Based on this, due to the conduction of the fourth switch Q4, the diode in the third switch Q3 is cut off, thus causing C2 to be disconnected. In other words, using the solution of this embodiment, C2 does not participate in the slow charging process of the flying capacitor, thus effectively reducing the selection requirements for C2. It should be noted that the transformer circuit can adjust the voltage of C2 by slowing down the duty cycle, therefore pre-charging C2 is unnecessary.
[0036] S102: When the bus capacitor voltage of the target transformer circuit reaches the preset voltage, control the fourth switch to turn off.
[0037] In existing technologies, the conventional method for determining the progress of slow charging is to detect the voltage of the flying capacitor in real time and determine whether slow charging is complete based on the voltage of the flying capacitor. However, this method requires additional sensing equipment to collect the voltage of the flying capacitor, which increases the cost of slow charging. According to the solution of this invention, the voltage of the flying capacitor during slow charging is essentially related to the voltage of the bus capacitor (i.e., it is related to the voltage of the capacitor line). Therefore, the progress of slow charging can be directly determined based on the voltage of the bus capacitor. The bus capacitor voltage is a quantity that must be collected during the transformer circuit control process. The solution of this invention can directly determine whether slow charging is complete based on the collected bus capacitor voltage, thus effectively saving costs.
[0038] In this embodiment, when the bus capacitor voltage reaches the preset voltage, it indicates that the slow charging is over, and the fourth switch Q4 can be turned off after the slow charging is over.
[0039] In this invention, the transformer circuit can be a buck circuit, a boost circuit, or a circuit that combines boost and buck functions; no limitation is made here.
[0040] As described above, unlike existing technologies that directly use a slow-charging circuit to slow-charge flying capacitors, this invention also utilizes switching transistors in existing transformer circuits. By turning on the corresponding switching transistors, the series and parallel relationships of the capacitors in the transformer circuit and the current flow direction of the transformer circuit are changed. Based on the technical means of this invention, the existing "C2 and C" can be... fL The charging connection relationship of "connecting C2, C3 and C3 in parallel" is improved to "disconnecting C2, C3 and C3". fL The charging connection relationship of "parallel connection followed by series connection with C1" reduces the selection requirements for C2, thereby saving selection costs and solving the problems existing in the prior art. Based on this, according to the improved charging connection relationship of the present invention, when judging the progress of slow charging, there is no need to set up additional sensing devices to collect the voltage of the flying capacitor. It is only necessary to judge whether slow charging is complete based on the bus capacitor voltage collected by the existing sensing devices, thus further saving slow charging costs.
[0041] In one possible implementation, please refer to Figure 2 The target transformer circuit also includes a slow-charging circuit 21, which comprises parallel-connected resistive and non-resistive lines. The high-voltage terminal of the switching transistor is connected to an external DC source through the slow-charging circuit 21. The capacitor slow-charging method for the transformer circuit may also include:
[0042] When controlling the fourth switch to turn on, the resistor circuit is also controlled to turn on.
[0043] When the fourth switch is turned off, the non-resistive circuit is also turned on.
[0044] Non-resistive circuits are used to short-circuit resistive circuits when they are conducting.
[0045] In this embodiment, when a slow charging of the transformer circuit is required (i.e., when a slow charging command is received internally or externally), the resistor line and the fourth switch Q4 can be turned on. After the resistor line is turned on, current begins to flow into the transformer circuit. After the fourth switch Q4 is turned on, C3 and C... fL Equivalent to being connected in parallel, C1, C3, and C fL Simultaneously, slow charging is performed. The solution applied in this embodiment of the invention can effectively avoid C3 and C. fL The current surge caused by direct parallel connection when there is a pressure difference is eliminated, thus ensuring the reliability of the slow charging scheme in this embodiment of the invention.
[0046] In this embodiment, when the fourth switch is turned off at the end of the slow charging control, the non-resistive circuit in the slow charging circuit 21 can also be turned on (equivalent to ending the slow charging effect of the slow charging circuit 21) to complete the slow charging of the flying capacitor.
[0047] In one possible implementation, such as Figure 2 As shown, the resistor circuit includes a first switch K2 and a first resistor R1 connected in series. Controlling the conduction of the resistor circuit in the slow-charge circuit can be described in detail as follows:
[0048] Control the first switch K2 to turn on.
[0049] In this embodiment, the resistor circuit can be a diode resistor circuit, that is, the resistor circuit can include a first switch K2, a first resistor R1, and a first diode D1 connected in series. Based on this, controlling the conduction of the resistor circuit is also controlling the conduction of the second switch K2.
[0050] In one possible implementation, please refer to Figure 2 The non-resistive circuit is the circuit formed by the second switch K1A. Controlling the conduction of the non-resistive circuit in the slow-charge circuit includes:
[0051] Control the second switch to turn on.
[0052] In this embodiment, after the second switch K1A is turned on, the resistor line can be short-circuited, so that the voltage of the external DC source can be directly input to the target transformer circuit.
[0053] In one possible implementation, C3 ≥ C1, and the preset voltage satisfies |U t -U dc | <e;
[0054] Where C3 is the capacitance value of the capacitor near the low-voltage side in the capacitor circuit, C1 is the capacitance value of the capacitor near the high-voltage side in the capacitor circuit, and U t U is the preset voltage.dc V represents the voltage of an external DC source that powers the target voltage conversion circuit, and e is a preset error.
[0055] In this embodiment, it is possible to set C3 ≥ C1. At this time, the range of the preset voltage can be |U t -U dc |< e. Correspondingly, the voltage U fL after the flying capacitor is fully charged is within the range of That is, the voltage U fL after the flying capacitor is fully charged should not be greater than the maximum voltage that C3 can reach.
[0056] In a possible implementation, C3 = C1, and the preset voltage is the voltage of the external DC source.
[0057] In this embodiment, when C3 = C1, the preset voltage can directly be the external DC source voltage. At this time, the voltage U fL after the flying capacitor is fully charged satisfies U fL = U dc × 1 / 2.
[0058] Please refer to Figure 4In another aspect, the present invention provides a transformer circuit capacitor slow-charging device 400, comprising: one or more processors 401, one or more input devices 402, one or more output devices 403, and one or more memories 404. The processors 401, input devices 402, output devices 403, and memories 404 communicate with each other via a communication bus 405. The memories 404 store computer programs, including program instructions. The processors 401 execute the program instructions stored in the memories 404. The processors 401 are configured to invoke the program instructions to execute the steps of the above-described method embodiments. It should be understood that in the embodiments of the present invention, the processor 401 may be a central processing unit (CPU). The processor 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 can be a microprocessor or any conventional processor. Input device 402 may include a touchpad, a fingerprint sensor (for collecting the user's fingerprint information and fingerprint orientation information), a microphone, etc., and output device 403 may include a display (LCD, etc.), a speaker, etc. The memory 404 may include read-only memory and random access memory, and provides instructions and data to processor 401. A portion of memory 404 may also include non-volatile random access memory. For example, memory 404 may also store device type information. In specific implementations, the processor 401, input device 402, and output device 403 described in the embodiments of the present invention can execute the implementation methods described in the first and second embodiments of the transformer circuit capacitor slow-charging method provided in the embodiments of the present invention.
[0059] In another aspect, the present invention provides a transformer system comprising:
[0060] The transformer circuit capacitor slow-charging device described above.
[0061] In this embodiment, the transformer system may further include the target transformer circuit described above.
[0062] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for slow charging of a transformer circuit capacitor, characterized in that, The transformer circuit capacitor slow-charging method is used to pre-charge the flying capacitor in the target transformer circuit. The target transformer circuit includes a capacitor circuit formed by two input capacitors connected in series, a switching circuit formed by a first switch, a second switch, a third switch, and a fourth switch connected in series, a diode circuit formed by two diodes connected in series, a flying capacitor, an output inductor, and an output capacitor. The two ends of the capacitor circuit constitute the two input terminals of the target transformer circuit, and the capacitor circuit is connected in parallel with the switching circuit. The common terminal of the two input capacitors is connected to the common terminal of the two diodes, and the flying capacitor is connected in parallel with the diode circuit. The common terminal of the first switch and the second switch is connected to the first terminal of the flying capacitor, the common terminal of the third switch and the fourth switch is connected to the second terminal of the flying capacitor, and the common terminal of the second switch and the third switch is connected to the first terminal of the output inductor. The two ends of the output capacitor are respectively connected to the second terminal of the output inductor and the low-voltage terminal of the switching circuit, and the two ends of the output capacitor constitute the two output terminals of the transformer circuit. The transformer circuit capacitor slow charging method includes: In response to an internal / external slow charge command, the fourth switch is turned on. The current path is as follows: from the input terminal of the high-voltage side of the target transformer circuit, through the input capacitor near the high-voltage side, the diode with the common terminal of the two diodes as the anode, the flying capacitor, and the fourth switch, it returns to the input terminal of the low-voltage side of the target transformer circuit; and from the input terminal of the high-voltage side of the target transformer circuit, through the input capacitor near the high-voltage side and the input capacitor near the low-voltage side, it returns to the input terminal of the low-voltage side of the target transformer circuit. When the bus capacitor voltage of the target transformer circuit reaches a preset voltage, the fourth switch is controlled to turn off.
2. The transformer circuit capacitor slow charging method as described in claim 1, characterized in that, The target transformer circuit is also provided with a slow charging circuit, which includes parallel-connected resistive lines and non-resistive lines; the high-voltage end of the switching transistor line is connected to an external DC source through the slow charging circuit. The transformer circuit capacitor slow charging method further includes: When controlling the fourth switch to be turned on, the resistor circuit is also controlled to be turned on; When the fourth switch is turned off, the non-resistive circuit is also turned on. The non-resistive circuit is used to short-circuit the resistive circuit when it is conducting.
3. The transformer circuit capacitor slow charging method as described in claim 2, characterized in that, The resistor circuit includes a first switch and a first resistor connected in series; controlling the conduction of the resistor circuit includes: Control the first switch to turn on.
4. The transformer circuit capacitor slow charging method as described in claim 2, characterized in that, The non-resistive circuit is a circuit consisting of a second switch; The control of the non-resistive circuit to conduct includes: The control turns on the second switch.
5. The transformer circuit capacitor slow-charging method according to any one of claims 1 to 4, characterized in that, C3≥C1, the preset voltage satisfies | U t - U dc |< e ; Wherein, C3 is the capacitance value of the capacitor near the low-voltage side in the capacitor circuit, and C1 is the capacitance value of the capacitor near the high-voltage side in the capacitor circuit. U t The preset voltage, U dc This represents the voltage of the external DC source that powers the target transformer circuit. e This is the preset error.
6. The transformer circuit capacitor slow charging method as described in claim 5, characterized in that, C3 = C1, and the preset voltage is the voltage of the external DC source.
7. A transformer circuit capacitor slow-charging device, 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 method as described in any one of claims 1 to 6.
8. A transformer system, characterized in that, Includes the transformer circuit capacitor slow charging device as described in claim 7.
Citation Information
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