Power supply device, control method, and electric system

Abstract

The present application provides a power supply device, a control method, and an electric system. The power supply device comprises a rectifier, a first branch, a second branch, a DCDC converter, a bus, a ground wire, and a drive controller. The first branch and the second branch are connected in parallel between the bus and the ground wire. A first output end of the rectifier is connected to a first input end of the DCDC converter by means of the bus, and a second output end of the rectifier is connected to a second input end of the DCDC converter by means of the ground wire. The first branch is provided with a first capacitor. The second branch is provided with a switching transistor, a first diode, and a second capacitor. When the second capacitor is discharged, the first diode is turned off; and when the second capacitor is charged, the first diode is turned on. The drive controller is connected to a control electrode of the switching transistor. The drive controller controls a turn-off duration of the switching transistor on the basis of a first voltage of the bus at a start moment when the switching transistor is turned on and the minimum voltage of the bus when the switching transistor is turned on, thereby improving the power supply efficiency.

Description

A power supply device, control method and power consumption system

[0001] Cross-reference of related applications

[0002] This application claims priority to Chinese Patent Application No. 202510237513.2, filed on February 28, 2025, entitled "A power supply device, control method and power consumption system", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of power supply technology, and in particular to a power supply device, control method and power consumption system. Background Technology

[0004] A typical power supply unit includes: a filter cascaded in series, a rectifier, two parallel capacitor branches, and a DC-DC converter. One capacitor branch contains a first capacitor, while the other contains a second capacitor, a bidirectional thyristor, and a Zener diode. The positive terminal of the Zener diode is connected to the second capacitor, and the negative terminal is connected to the control terminal of the bidirectional thyristor. One main electrode of the bidirectional thyristor is connected to the second capacitor, and the other main electrode is connected to the bus. When the bidirectional thyristor is turned on under the control of the Zener diode, it charges the first and second capacitors using the DC voltage output from the rectifier. When the peak voltage of the mains voltage is reached, the Zener diode controls the bidirectional thyristor to turn off, and the first capacitor begins to discharge into the DC-DC converter. After a preset discharge time, the Zener diode controls the bidirectional thyristor to turn on again, causing the second capacitor to discharge until the mains voltage gradually increases and charges both capacitors, at which point the discharge stops. In this process, the preset discharge time is fixed, which means that the preset discharge time is not adjustable. This may lead to a large difference between the voltage at the start of the second capacitor's discharge and the voltage at the end of the discharge. This will result in a "weakest link" effect, leading to large output ripple and reduced power supply efficiency. Summary of the Invention

[0005] This application provides a power supply device, control method, and power system that can reduce output ripple and improve power supply efficiency.

[0006] In a first aspect, embodiments of this application provide a power supply device, which may include: a rectifier, a first branch, a second branch, a DC-DC converter, a bus, and a ground wire. The first branch and the second branch are connected in parallel between the bus and the ground wire. The first output terminal of the rectifier is connected to the first input terminal of the DC-DC converter through the bus, and the second output terminal of the rectifier is connected to the second input terminal of the DC-DC converter through the ground wire. The first branch includes a first capacitor, and the second branch includes a switching transistor and a second capacitor connected in series. The second branch also includes a first diode, which is connected in parallel with the switching transistor. When the second capacitor discharges, the first diode is cut off, and when the second capacitor charges, the first diode is turned on. The power supply device also includes a drive controller, which is connected to the control electrode of the switching transistor. The drive controller is used to: adjust the turn-off time of the switching transistor according to the first voltage of the bus when the switching transistor is at the start of conduction and the minimum voltage of the bus after the switching transistor is turned on.

[0007] Thus, when the capacitance of the first capacitor is small, the voltage in the bus changes in a basically similar trend to the rectified grid voltage during the time the switch is off. Therefore, the voltage in the bus at the moment the switch transitions from the off state to the on state is the first voltage. The first voltage can be adjusted by controlling the off-time of the switch. Changes in the first voltage will affect the minimum voltage, and thus, the first and minimum voltages can be adjusted by controlling the off-time of the switch. Furthermore, by configuring the first diode, it can be kept in the off state when the second capacitor is discharging. Thus, when the switch is off, the second capacitor is not connected to the discharge circuit because the first diode is off, and therefore does not discharge. When the switch is on, even if the first diode is off, the second capacitor can still be connected to the discharge circuit through the switch and discharge. Therefore, the discharge process of the second capacitor can be controlled by turning the switch on and off, thereby achieving controllable discharge of the second capacitor. Furthermore, since the discharge of the second capacitor is controllable, during the design phase of the power supply equipment, the required capacity of the second capacitor under full load can be determined based on the control of the discharge process of the second capacitor and the reference voltage. If the second capacitor is manufactured according to the determined capacity, the capacity of the second capacitor can not only meet the load requirements, but also avoid capacity redundancy. At this time, the first voltage, the minimum voltage, and the reference voltage will be approximately equal. The closer the first voltage and the minimum voltage are, the better the "weakest link" effect can be avoided. However, under non-full load conditions in actual applications, the difference between the first voltage and the minimum voltage may be large. Therefore, by adjusting the turn-off time of the switching transistor to reduce the difference between the first voltage and the minimum voltage, the "weakest link" effect can be eliminated, the output ripple can be reduced, and the power supply efficiency of the power supply equipment can be improved.

[0008] It should be understood that "non-full load" refers to the operating state where the actual output power of the power supply is less than the rated power when the AC voltage input to the power supply is at the lower limit of its range. "Full load" refers to the operating state where the actual output power of the power supply is equal to the rated power when the AC voltage input to the power supply is at the lower limit of its range. The reference voltage corresponds to the minimum operating voltage of the terminal equipment, but the reference voltage is not necessarily equal to the minimum operating voltage of the terminal equipment.

[0009] Optionally, the drive controller is specifically configured to: extend the turn-off time of the switching transistor when the difference between the first voltage and the minimum voltage is greater than the upper limit of a preset range (-20V to 20V); shorten the turn-off time of the switching transistor when the difference between the first voltage and the minimum voltage is less than the lower limit of a preset range; and keep the turn-off time of the switching transistor unchanged when the difference between the first voltage and the minimum voltage is within a preset range. In this way, the turn-off time of the switching transistor can be dynamically adjusted, reducing the difference between the first voltage and the minimum voltage, thereby improving power supply efficiency under non-full load conditions.

[0010] Optionally, the drive controller includes a driver and a controller; the controller is used to: output a control signal to the driver based on a first voltage and a minimum voltage; and control the output of the DC-DC converter; the control signal is used to represent the turn-off duration of the switching transistor; the driver is used to: drive the switching transistor according to the control signal. That is, the controller can be the controller within the DC-DC converter, so the control of the switching transistor's turn-off duration is achieved by the controller within the DC-DC converter. The driver simply converts the control signal output by the controller into a corresponding voltage signal and outputs it to the control electrode of the switching transistor, thereby achieving the control of the switching transistor's turn-off duration. This utilizes the controller within the DC-DC converter to control the switching transistor's turn-off duration, avoiding the need for an additional controller; only the driver needs to be added, thus reducing the manufacturing cost of the power supply equipment.

[0011] Furthermore, the source of the switching transistor is connected to ground. The driver includes a first resistor, a second resistor, a second diode, and a third capacitor. The first terminal of the third capacitor is connected to the controller, and the second terminal of the third capacitor is connected to the anode of the second diode and the first terminal of the first resistor. The cathode of the second diode is connected to ground and the first terminal of the second resistor. The second terminal of the first resistor is connected to the second terminal of the second resistor and the control electrode of the switching transistor. Thus, because the source of the switching transistor is connected to ground, the potential of the source of the switching transistor can be stabilized at the ground potential. At this point, there is no need for excessive control of the source potential of the switching transistor. Therefore, the function of the driver can be realized through a simple combination of components, simplifying the driver structure and reducing costs.

[0012] Furthermore, the DC-DC converter includes a first coil, a second coil, and a voltage detector. The first coil is coupled to the second coil and connected to a bus. The voltage detector is connected to the second coil, a controller, and a ground terminal. The voltage detector is used to detect a first voltage and a minimum voltage coupled from the first coil to the second coil and outputs this information to the controller. Thus, in this embodiment, the voltage detector within the DC-DC converter itself is used to detect the first and minimum voltages, avoiding the need for additional components and reducing costs.

[0013] Optionally, the drive controller includes: a controller, a third resistor, and a fourth resistor; the third resistor is connected between the drain of the switching transistor and the controller; the source of the switching transistor is connected to the bus, and the fourth resistor is connected between the ground wire and the controller; or, the source of the switching transistor is not connected to the bus, and the fourth resistor is connected between the bus and the controller. When the switching transistor is in the on state, and the on state includes the on start time and the on end time, the controller can detect the voltage in the bus and the voltage in the ground wire through the third resistor and the fourth resistor. When the controller is not directly connected to the ground terminal, the voltage in the ground wire can be used as a reference to detect the first voltage and the minimum voltage in the bus. Furthermore, the controller can acquire the voltage at the drain of the switching transistor through the third resistor, realizing that the controller and the source of the switching transistor share a common ground, thereby realizing the control of the switching transistor and the regulation of the off time of the switching transistor. In addition, this can reduce the modification of other components; only the drive controller needs to be added to the original structure, thereby reducing the design cost.

[0014] Optionally, the power supply device further includes a first charging branch and a second charging branch. The first charging branch is connected between the first input terminal of the rectifier and the connection node of the second capacitor and the switching transistor. The second charging branch is connected between the second input terminal of the rectifier and the connection node. The first charging branch is used to transfer the voltage input to the first input terminal of the rectifier to the second capacitor. The second charging branch is used to transfer the voltage input to the second input terminal of the rectifier to the second capacitor. In this way, charging the second capacitor does not require passing through the switching transistor, reducing the impact of the charging current on the switching transistor and thus improving the lightning protection performance of the power supply device.

[0015] Furthermore, the first charging branch includes a third diode, with its cathode connected to the first input terminal of the rectifier and its anode connected to the connection node; alternatively, the second charging branch includes a fourth diode, with its cathode connected to the second input terminal of the rectifier and its anode connected to the connection node. In this way, the third and fourth diodes enable charging of the second capacitor based on AC voltage, and also prevent the first and second charging branches from forming a loop, thereby preventing current backflow and improving the safety of the power supply equipment.

[0016] Secondly, this application also provides a power supply device, which includes: a rectifier, a first branch, a second branch, a DC-DC converter, a bus, and a ground wire. The first branch and the second branch are connected in parallel between the bus and the ground wire. The first output terminal of the rectifier is connected to the first input terminal of the DC-DC converter through the bus, and the second output terminal of the rectifier is connected to the second input terminal of the DC-DC converter through the ground wire. A first capacitor is provided in the first branch, and a switching transistor and a second capacitor are connected in series in the second branch. The power supply device also includes a driver and a controller. The driver is connected to the control electrode of the switching transistor and the controller, respectively. The controller is used to: ensure that the voltage in the bus reaches its peak value. When the voltage is low, a first control signal is output to the driver; when the turn-off time of the switching transistor meets the duration requirement, a second control signal is output to the driver. The driver is used to: drive the switching transistor to turn off according to the first control signal, and drive the switching transistor to turn on according to the second control signal. The source of the switching transistor is connected to ground. The driver includes: a first resistor, a second resistor, a second diode, and a third capacitor. The first terminal of the third capacitor is connected to the controller, and the second terminal of the third capacitor is connected to the positive terminal of the second diode and the first terminal of the first resistor. The negative terminal of the second diode is connected to ground and the first terminal of the second resistor. The second terminal of the first resistor is connected to the second terminal of the second resistor and the control terminal of the switching transistor. In this way, by setting the specific structure of the driver, effective control of the switching transistor can be achieved, thereby ensuring the normal operation of the power supply equipment. Furthermore, since the source of the switching transistor is connected to ground, the potential of the source of the switching transistor can be stabilized at the ground potential. At this time, there is no need to control the source potential of the switching transistor too much. Therefore, the function of the driver can be realized by a simple combination of components, simplifying the structure of the driver and helping to reduce costs.

[0017] It should be understood that the structure of this power supply device is basically similar to that of the power supply device described in the first aspect above. The difference lies in the control logic of the switching transistor. Therefore, the similarity between the structure of this power supply device and the structure of the power supply device described in the first aspect above can be found in the relevant description in the first aspect above. Repeated descriptions will not be repeated.

[0018] Thirdly, embodiments of this application also provide a control method for a power supply device. The power supply device includes: a rectifier, a first branch, a second branch, a DC-DC converter, a bus, a ground wire, and a drive controller. The first branch and the second branch are connected in parallel between the bus and the ground wire. The first output terminal of the rectifier is connected to the first input terminal of the DC-DC converter through the bus, and the second output terminal of the rectifier is connected to the second input terminal of the DC-DC converter through the ground wire. The first branch includes a first capacitor, and the second branch includes a switching transistor and a second capacitor connected in series. The second branch also includes a first diode, which is connected in parallel with the switching transistor. When the second capacitor discharges, the first diode is cut off, and when the second capacitor charges, the first diode is turned on. The drive controller is connected to the control electrode of the switching transistor. The control method includes: acquiring a first voltage of the bus when the switching transistor is at the start of conduction; acquiring a minimum voltage of the bus when the switching transistor is in the conduction state; and adjusting the turn-off time of the switching transistor according to the first voltage and the minimum voltage.

[0019] Optionally, the turn-off time of the switching transistor is adjusted according to the first voltage and the minimum voltage, including: extending the turn-off time of the switching transistor when the difference between the first voltage and the minimum voltage is greater than the upper limit of a preset range; the preset range is -20V to 20V; shortening the turn-off time of the switching transistor when the difference between the first voltage and the minimum voltage is less than the lower limit of the preset range; and keeping the turn-off time of the switching transistor unchanged when the difference between the first voltage and the minimum voltage is within the preset range.

[0020] It should be understood that since the principle of this control method in solving the problem is similar to that of the aforementioned power supply equipment, the implementation and technical effects of this control method can be found in the implementation and technical effects of the aforementioned power supply equipment, and the repetition will not be repeated.

[0021] Fourthly, embodiments of this application also provide an electrical system, which may include: a terminal device and a power supply device as described in the first aspect and any one of the embodiments of the first aspect, or the second aspect and any one of the embodiments of the second aspect, wherein the power supply device is used to supply power to the terminal device.

[0022] It should be understood that since the principle of this power system in solving the problem is similar to that of the aforementioned power supply equipment, the implementation and technical effects of this power system can be found in the implementation and technical effects of the aforementioned power supply equipment, and the repetition will not be repeated. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the structure of an electrical system provided in an embodiment of this application;

[0024] Figure 2 is a schematic diagram of the structure of the driver in the power supply device provided in the embodiment of this application when it is composed of components;

[0025] Figure 3A is a waveform diagram provided in an embodiment of this application;

[0026] Figure 3B is another waveform diagram provided in an embodiment of this application;

[0027] Figure 3C shows another waveform diagram provided in an embodiment of this application;

[0028] Figure 4 is a schematic diagram of the structure of the power supply device provided in the embodiment of this application when the driver is an isolated driver chip;

[0029] Figure 5A is a schematic diagram of a power supply device provided in this application where the controller is set independently.

[0030] Figure 5B is a schematic diagram of another structure when the controller in the power supply device provided in the embodiment of this application is set independently;

[0031] Figure 6 is a schematic diagram of the power supply device provided in the embodiment of this application, which further includes two charging branches.

[0032] Reference numerals: 11-Terminal equipment, 12-Power supply equipment, 121-Filter, 122-Rectifier, 123-DC-DC converter, 123a-Secondary driver, 123b-Voltage detector, 123c-Primary controller, 123d-High voltage detector, 124-Driver controller, 124a-Driver, 124b-Controller, 126a-First charging branch, 126b-Second charging branch, 13-Transmission line, 14-Power grid, m1-Bus, m2-Ground, S-Source, D-Drain, P0-Connection node, GND-Ground terminal, x1-First coil, x2-Second coil, x3-Secondary coil, D11 / D12 / D 13 / D14 - Diodes in the rectifier, C1 - First capacitor, C2 - Second capacitor, C3 - Third capacitor, C4 - Fourth capacitor, C11 - Secondary capacitor, Q0 - Switching transistor, Q1 - Primary switching transistor, Q2 - Secondary switching transistor, R1 - First resistor, R2 - Second resistor, R3 - Third resistor, R4 - Fourth resistor, R5 - Fifth resistor, R6 - Sixth resistor, R7 - Seventh resistor, R11 - Primary resistor, D1 - First diode, D2 - Second diode, D3 - Third diode, D4 ​​- Fourth diode, D5 - Fifth diode, D6 - Sixth diode, D7 - Seventh diode, Output terminal of Vo-DC converter. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the application will now be described in further detail with reference to the accompanying drawings.

[0034] It should be noted that the same reference numerals in the accompanying drawings of this application denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms expressing position and direction described in this application are illustrative based on the accompanying drawings, but may be modified as needed, and all such modifications are included within the scope of protection of this application. The accompanying drawings of this application are for illustrating relative positional relationships only and do not represent actual scale.

[0035] It should be noted that, in this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplarily" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner. In the embodiments of this application, the words "first," "second," etc., do not limit the number or order.

[0036] To facilitate understanding of the technical solutions provided in the embodiments of this application, their application scenarios are first described below. The technical solutions provided in the embodiments of this application can be applied to power supply devices. Power supply devices may include adapters and chargers, among other types of power supply devices. An adapter is a device that can convert the voltage and current provided by a power source into voltage and current that meet the operating requirements of a terminal device. It is typically used to power terminal devices. The adapter can be used with various terminal devices that require power; in this case, the system formed by the adapter and the terminal device can be called a power consumption system. A charger is a device that can convert the voltage and current provided by a power source into voltage and current that meet the charging requirements of a terminal device. It is typically used to charge batteries or terminal devices. The charger can be an on-board charger in a vehicle or a charging device used with a terminal device; in this case, the system formed by the charger and the terminal device can be called a power consumption system.

[0037] Figure 1 illustrates an exemplary structural diagram of an electrical system. Referring to Figure 1, the electrical system includes a power supply device 12 and a terminal device 11. The power interface of the terminal device 11 is connected to one end of the power supply device 12 via a transmission line 13. The other end of the power supply device 12 is connected to the power grid 14. The power supply device 12 can convert the voltage provided by the power grid 14 and output it to the terminal device 11 via the transmission line 13, enabling the terminal device 11 to function normally. The terminal device 11 can be any type of electronic device, such as, but not limited to, smartphones, smartwatches, personal computers (PCs), wearable devices, home appliances, network devices, etc., which are not listed here.

[0038] For example, a power supply device generally includes: a filter, a rectifier, two capacitor branches connected in parallel, and a DC-DC converter, all cascaded together. One capacitor branch contains a first capacitor, and the other capacitor branch contains a second capacitor, a bidirectional thyristor, and a Zener diode. The positive terminal of the Zener diode is connected to the second capacitor, and the negative terminal is connected to the control terminal of the bidirectional thyristor. One main electrode of the bidirectional thyristor is connected to the second capacitor, and the other main electrode is connected to the bus. When the bidirectional thyristor is turned on under the control of the Zener diode, the DC voltage output from the rectifier can be used to charge the first and second capacitors. When the peak voltage of the power grid is reached, the Zener diode controls the bidirectional thyristor to turn off, and the first capacitor begins to discharge to the DC-DC converter. When a preset discharge time is reached, the Zener diode controls the bidirectional thyristor to turn on again, causing the second capacitor to begin discharging, until the grid voltage gradually increases and charges the first and second capacitors, at which point the discharge stops. In this process, the preset discharge time is fixed, that is, the discharge time of the first capacitor is fixed. This time actually depends on the Zener diode's voltage regulation point. The voltage regulation point refers to the voltage value that can be kept basically unchanged across the Zener diode within the Zener diode's operating current range. Therefore, the voltage regulation point is generally relatively stable, which leads to the preset discharge time being unadjustable. This may result in a large difference between the voltage at the start of the second capacitor's discharge and the voltage at the end of the discharge. This will cause the "weakest link" effect, resulting in large output ripple and reduced power supply efficiency.

[0039] Based on this, embodiments of this application provide a power supply device that can reduce output ripple and improve power supply efficiency. Exemplarily, the power supply device provided in this application includes: a rectifier, a first branch, a second branch, a DC-DC converter, a bus, and a ground wire. The first branch and the second branch are connected in parallel between the bus and the ground wire. The first output terminal of the rectifier is connected to the first input terminal of the DC-DC converter through the bus, and the second output terminal of the rectifier is connected to the second input terminal of the DC-DC converter through the ground wire. The first branch includes a first capacitor, and the second branch includes a switching transistor and a second capacitor connected in series. The second branch also includes a first diode, which is connected in parallel with the switching transistor. When the second capacitor discharges, the first diode is cut off; when the second capacitor charges, the first diode is turned on. The power supply device also includes a drive controller connected to the control electrode of the switching transistor. The drive controller is used to: adjust the turn-off time of the switching transistor based on the first voltage of the bus when the switching transistor is at the start of conduction and the minimum voltage of the bus after the switching transistor is turned on. Thus, when the capacitance of the first capacitor is small, the voltage in the bus changes in a basically similar trend to the rectified grid voltage during the time the switch is off. Therefore, the voltage in the bus at the moment the switch transitions from the off state to the on state is the first voltage. The first voltage can be adjusted by controlling the off-time of the switch. Changes in the first voltage will affect the minimum voltage, and thus, the first and minimum voltages can be adjusted by controlling the off-time of the switch. Furthermore, by configuring the first diode, it can be kept in the off state when the second capacitor is discharging. Thus, when the switch is off, the second capacitor is not connected to the discharge circuit because the first diode is off, and therefore does not discharge. When the switch is on, even if the first diode is off, the second capacitor can still be connected to the discharge circuit through the switch and discharge. Therefore, the discharge process of the second capacitor can be controlled by turning the switch on and off, thereby achieving controllable discharge of the second capacitor. Furthermore, since the discharge of the second capacitor is controllable, during the design phase of the power supply equipment, the required capacity of the second capacitor under full load can be determined based on the control of the discharge process of the second capacitor and the reference voltage. If the second capacitor is manufactured according to the determined capacity, the capacity of the second capacitor can not only meet the load requirements, but also avoid capacity redundancy. At this time, the first voltage, the minimum voltage, and the reference voltage will be approximately equal. The closer the first voltage and the minimum voltage are, the better the "weakest link" effect can be avoided. However, under non-full load conditions in actual applications, the difference between the first voltage and the minimum voltage may be large. Therefore, by adjusting the turn-off time of the switching transistor to reduce the difference between the first voltage and the minimum voltage, the "weakest link" effect can be eliminated, the output ripple can be reduced, and the power supply efficiency of the power supply equipment can be improved.

[0040] The power supply device in this application will be described in detail below.

[0041] Figure 2 exemplarily illustrates a structural schematic diagram of a power supply device 12 provided in this application. Referring to Figure 2, the power supply device 12 may include: a filter 121, a rectifier 122, a first branch, a second branch, a DC-DC converter 123, a bus m1, a ground wire m2, and a drive controller 124. The first branch and the second branch are connected in parallel between the bus m1 and the ground wire m2. The first branch is provided with a first capacitor C1, and the second branch is provided with a switch Q0 and a second capacitor C2 connected in series. The switch Q0 may be located between the bus m1 and the second capacitor C2 (not shown); or the switch Q0 may be located between the ground wire m2 and the second capacitor C2 (as shown in Figure 2); or the switch Q0 may be located in the ground wire m2, and the source (or drain) of the switch Q0 is connected to the first capacitor C1, and the drain (or source) is connected to the second capacitor C2. No diagram is provided; or, alternatively, the switch Q0 is located in bus m1, and its source (or drain) is connected to the first capacitor C1, and its drain (or source) is connected to the second capacitor C2, no diagram is provided; even if the switch Q0 is located in ground m2, and its source (or drain) is connected to the first capacitor C1, and its drain (or source) is connected to the second capacitor C2, or if the switch Q0 is located in bus m1, and its source (or drain) is connected to the first capacitor C1, and its drain (or source) is connected to the second capacitor C2, then the second capacitor C2 and the switch Q0 are also connected in series, and the second branch including the second capacitor C2 and the switch Q0 and the first branch including the first capacitor C1 are also connected in parallel between bus m1 and ground m2; therefore, this embodiment does not limit the connection order of the switch Q0 and the second capacitor C2.

[0042] The input terminal of filter 121 is connected to the power grid (not shown in Figure 2), and the output terminal of filter 121 is connected to the input terminal of rectifier 122. Filter 121 is used to filter the power grid voltage and output it to rectifier 122. The structure of filter 121 can be any structure known to those skilled in the art that can realize its function, and no specific limitation is made here.

[0043] The first output terminal of rectifier 122 is connected to the first input terminal of DC-DC converter 123 via bus m1, and the second output terminal of rectifier 122 is connected to the second input terminal of DC-DC converter 123 via ground wire m2. Rectifier 122 is used to rectify the filtered grid voltage, i.e., AC voltage, to output DC voltage. Rectifier 122 generally includes four diodes, which are labeled as D11, D12, D13 and D14 in Figure 2. By setting the connection relationship of these four diodes, the rectification function can be realized.

[0044] For the first capacitor C1 and the second capacitor C2, on the one hand, they can filter low-frequency fluctuations in the DC voltage, and on the other hand, they can store electrical energy so that when the mains voltage drops transiently or is low, a stable voltage can be output to the DC-DC converter 123, thereby enabling the power supply device 12 to provide a stable voltage to the terminal device and ensuring the stable operation of the terminal device. As for the switching transistor Q0, the type of switching transistor Q0 can be, but is not limited to, metal-oxide-semiconductor field-effect transistor or junction field-effect transistor, and the type of switching transistor Q0 can be, but is not limited to, a P-type switching transistor or an N-type switching transistor. The active layer of the switching transistor Q0 can be, but is not limited to, gallium nitride, silicon, silicon carbide, and other semiconductor materials. The specific settings can be set according to actual needs, and no specific limitation is made here.

[0045] The second branch may also include a first diode D1, which is connected in parallel with the switch Q0. The function of the first diode D1 is as follows: when the second capacitor C2 is discharging, the first diode D1 is cut off, and when the second capacitor C2 is charging, the first diode D1 is turned on. Therefore, in Figure 2, when the switch Q0 is connected between the second capacitor C2 and the ground line m2, the positive terminal of the first diode D1 is connected to the connection node P0 between the second capacitor C2 and the switch Q0, and the negative terminal of the first diode D1 is connected to the ground line m2. Therefore, by configuring the first diode D1 in the switching transistor Q0, the first diode D1 can always be in the off state when the second capacitor C2 is discharging. Thus, when the switching transistor Q0 is turned off, because the first diode D1 is off, the second capacitor C2 is not connected to the discharge circuit. The discharge circuit refers to the circuit formed by the second capacitor C2, the switching transistor Q0, the first diode D1, the DC-DC converter 123, and the ground terminal GND. Consequently, the second capacitor C2 will not discharge. When the switching transistor Q0 is turned on, even if the first diode D1 is off, the second capacitor C2 can still be connected to the discharge circuit through the switching transistor Q0 and discharge. Therefore, the discharge process of the second capacitor C2 can be controlled by turning the switching transistor Q0 on and off, thereby making the discharge of the second capacitor C2 controllable. Conversely, if the first diode D1 is turned on when the second capacitor C2 is discharging and turned off when the second capacitor C2 is charging, then even if the switch Q0 is turned off, the second capacitor C2 can still be connected to the discharge circuit through the first diode D1, allowing it to discharge. Therefore, the switch Q0 cannot control the discharge process of the second capacitor C2, making it impossible to achieve controllable discharge of the second capacitor C2. Furthermore, when charging the second capacitor C2, the first diode D1 can bypass the switch Q0 and charge the second capacitor C2 directly. This reduces the impact of the large current output by the rectifier 122 on the switch Q0 during a lightning strike, thereby improving the lightning protection performance of the power supply device 12.

[0046] It should be understood that the connection method of the first diode D1 is not limited to that shown in Figure 2. The connection relationship of the first diode D1 is related to the setting position of the switching transistor Q0. Therefore, the connection relationship of the first diode D1 can be adaptively adjusted according to the setting position of the switching transistor Q0. For example, but not limited to: when the switching transistor Q0 is connected between the bus m1 and the second capacitor C2, the positive terminal of the first diode D1 is connected to the bus m1, and the negative terminal of the first diode D1 is connected to the connection node P0; or, when the switching transistor Q0 is located in the ground wire m2, and the source (or drain) of the switching transistor Q0 is connected to the first capacitor C1, and the drain (or source) is connected to the second capacitor C2, the connection relationship of the first and second diodes is adjusted accordingly. The positive terminal of diode D1 is connected to connection node P0, and the negative terminal of the first diode D1 is connected to ground line m2; alternatively, when switching transistor Q0 is located in bus line m1, and the source (or drain) of switching transistor Q0 is connected to the first capacitor C1, and the drain (or source) is connected to the second capacitor C2, the positive terminal of the first diode D1 is connected to bus line m1, and the negative terminal of the first diode D1 is connected to connection node P0; and so on, not all of them will be listed here. As long as the connection relationship of the first diode D1 can satisfy the condition that the first diode D1 is cut off when the second capacitor C2 is discharging and the first diode D1 is conducting when the second capacitor C2 is charging, it falls within the protection scope of the embodiments of this application. For example, the first diode D1 can be a parasitic diode in switching transistor Q0, or it can be an additional diode, both of which are applicable in this embodiment.

[0047] The output terminal Vo of the DC-DC converter 123 is connected to a terminal device (not shown in Figure 2), allowing the voltage output by the DC-DC converter 123 to be transmitted to the terminal device as a power supply voltage to meet the power requirements of the terminal device. The DC-DC converter 123 can be a flyback converter, as shown in Figure 2. The flyback converter includes a first primary side and a secondary side. The first primary side includes a first coil x1, a primary-side switch Q1, a primary-side controller 123c, and a primary-side resistor R11. The secondary side includes a secondary coil x3, a secondary-side switch Q2, a secondary-side capacitor C11, and a secondary-side driver 123a. The first coil x1 is coupled to the secondary coil x3. The control terminal of the primary-side switch Q1 is connected to the primary-side controller 123c. The first terminal of the primary-side switch Q1 is connected to the first terminal of the primary-side resistor R11 and the primary-side controller 123a. In the 3c connection, the second terminal of the primary-side switch Q1 is connected to the first terminal of the first coil x1, the second terminal of the primary-side resistor R11 is connected to the ground terminal GND, and the second terminal of the first coil x1 is connected to the bus m1. The first terminal of the secondary-side coil x3 is connected to the second terminal of the secondary-side switch Q2, the second terminal of the secondary-side coil x3 is connected to the first terminal of the secondary-side capacitor C11, and the second terminal of the secondary-side coil x3 also serves as a signal output terminal. The control terminal of the secondary-side switch Q2 is connected to the secondary-side driver 123a, and the first terminal of the secondary-side switch Q2 is connected to both the second terminal of the secondary-side capacitor C11 and the ground terminal GND. Wherein, when the first terminal is the source, the second terminal is the drain; or, when the first terminal is the drain, the second terminal is the source. The primary-side controller 123c controls the output power of the first primary side by controlling the duty cycle and switching frequency of the primary-side switch Q1. When the corresponding energy is coupled out in the secondary-side coil x3, the secondary-side switch Q2 is turned on under the control of the secondary-side driver 123a, which enables the DC-DC converter 123 to output current, thus realizing the control of the DC-DC converter 123's output current by the primary-side controller 123c. Of course, the DC-DC converter 123 can be other types of converters besides flyback converters, such as, but not limited to, boost converters. When the DC-DC converter 123 is a boost converter, it can also be used in conjunction with a resonant converter to achieve electrical isolation between the input and output, thereby improving the safety of the power supply device 12. Among them, when the DC-DC converter 123 is a flyback converter, the power supply device 12 is suitable for low-power power supply scenarios. When the DC-DC converter 123 is a boost converter and is used in conjunction with a resonant converter, the power supply device 12 is suitable for medium and high-power power supply scenarios. Therefore, the choice of type for DC-DC converter 123 can be set according to actual needs, and no specific restrictions are made here.

[0048] The drive controller 124 is connected to the control electrode of the switch Q0. The drive controller 124 is used to adjust the turn-off time of the switch Q0 based on the first voltage of bus m1 when the switch Q0 is turned on and the minimum voltage of bus m1 after the switch Q0 is turned on. Thus, when the capacitance of the first capacitor C1 is small, the voltage in bus m1 changes in a basically the same trend as the rectified grid voltage during the turn-off time of the switch Q0. Therefore, the voltage in bus m1 at the moment when the switch Q0 changes from the off state to the on state is the first voltage. The first voltage can be adjusted by adjusting the turn-off time of the switch Q0. The change of the first voltage will affect the minimum voltage. Therefore, the first voltage and the minimum voltage can be adjusted by adjusting the turn-off time of the switch Q0. Furthermore, based on the preceding analysis, since the discharge of the second capacitor C2 is controllable, during the design phase of the power supply device 12, the required capacity of the second capacitor C2 under full load conditions can be determined based on the control of the discharge process of the second capacitor C2 and the reference voltage. If the second capacitor C2 is manufactured according to the determined capacity, then the capacity of the second capacitor C2 can not only meet the load requirements, but also avoid capacity redundancy. At this time, the first voltage, the minimum voltage, and the reference voltage will be approximately equal. Furthermore, the closer the first voltage and the minimum voltage are, the better the "weakest link" effect can be avoided. However, under non-full load conditions in actual applications, the difference between the first voltage and the minimum voltage may be large. Therefore, by adjusting the turn-off time of the switching transistor Q0 to reduce the difference between the first voltage and the minimum voltage, the "weakest link" effect can be eliminated, the output ripple can be reduced, and the power supply efficiency of the power supply device 12 can be improved.

[0049] Furthermore, the drive controller 124 can adjust the turn-off duration of the switching transistor Q0 in the following manner:

[0050] Referring to the waveform diagram shown in Figure 3A, if the difference between the first voltage V1 and the minimum voltage Vmin is greater than the upper limit of the preset range, it indicates that the first voltage V1 is greater than the minimum voltage Vmin, and the difference between the first voltage V1 and the minimum voltage Vmin is large. The reasons for this result include: on the one hand, the turn-off time of the switch Q0 may be too short, for example, the turn-off time tooff1 may be too short, causing the switch Q0 to switch from the off state to the on state too early, resulting in a higher first voltage V1; on the other hand, the current may increase when the terminal device acts as a load (e.g., in a heavy-load scenario), causing the second capacitor... Insufficient charge stored in capacitor C2 causes excessive amplification by the second capacitor C2, resulting in a low minimum voltage Vmin. In this case, the off-time of switch Q0 can be extended, i.e., from toff1 toff2, where toff2 is greater than toff1. This delays the transition of switch Q0 from the off state to the on state, causing the first voltage V1 to decrease. This shortens the discharge time of the second capacitor C2, increasing the minimum voltage Vmin. This reduces the difference between the first voltage V1 and the minimum voltage Vmin, helping to ensure both are within a preset range. Furthermore, by adjusting the off-time of switch Q0 in this situation, the fluctuation of the output voltage of the DC-DC converter 123 can be reduced, ensuring the stability of the terminal device under heavy load conditions. It should be understood that heavy load and light load are two different operating states in non-full load scenarios. The difference between these two operating states lies in the required current; the current required under heavy load is greater than that under light load.

[0051] Referring to the waveform diagram shown in Figure 3B, if the difference between the first voltage V1 and the minimum voltage Vmin is less than the lower limit of the preset range, it indicates that the first voltage V1 is less than the minimum voltage Vmin, and the difference between the first voltage V1 and the minimum voltage Vmin is large. The reasons for this result include: on the one hand, the turn-off time of the switch Q0 may be too long, such as the turn-off time tooff1 being too long, causing the switch Q0 to transition from the off state to the on state later, resulting in a lower first voltage V1; on the other hand, the current of the terminal device may be smaller when it acts as a load (such as in a light load scenario), resulting in less discharge of the second capacitor C2, resulting in a higher minimum voltage Vmin. In this case, the turn-off time of the switch Q0 can be shortened, that is, the turn-off time is shortened from tooff1 to tooff2, tooff2 being less than tooff1. This advances the time for the switch Q0 to transition from the off state to the on state, which can increase the first voltage V1. Extending the discharge time of the second capacitor C2 can decrease the minimum voltage Vmin, thereby reducing the difference between the first voltage V1 and the minimum voltage Vmin, which is beneficial to ensuring that both the first voltage V1 and the minimum voltage Vmin are within the preset range.

[0052] Referring to the waveform diagram shown in Figure 3C, if the difference between the first voltage V1 and the minimum voltage Vmin is within the preset range, it indicates that the difference between the first voltage V1 and the minimum voltage Vmin is small. In this case, the turn-off time of the switch Q0 can remain unchanged. Therefore, the turn-off time of the switch Q0 can be toff1 in both the previous and subsequent turn-off times.

[0053] It should be understood that the preset range can be set according to actual needs, such as, but not limited to, -20V to 20V. A further preset range can be set to -10V to 10V; no specific limitation is made here. In Figures 3A, 3B, and 3C, Vh represents the bus m1 voltage corresponding to the minimum operating voltage of the terminal device, which is the reference voltage mentioned earlier. Therefore, when the power supply device 12 supplies power to the terminal device, the voltage in bus m1 is maintained between Vh and Vmax, ensuring the terminal device can operate normally. Vdc represents the DC voltage output by the rectifier 122; Vb represents the voltage in bus m1; and Vmax represents the highest voltage in the bus.

[0054] For example, when the drive controller 124 includes a driver 124a and a controller 124b, if the source S of the switching transistor Q0 is connected to ground m2, then the driver 124a may include: a first resistor R1, a second resistor R2, a second diode D2, and a third capacitor C3; the first terminal of the third capacitor C3 is connected to the controller 124b, and the second terminal of the third capacitor C3 is connected to the positive terminal of the second diode D2 and the first terminal of the first resistor R1; the negative terminal of the second diode D2 is connected to ground m2 and the first terminal of the second resistor R2; the second terminal of the first resistor R1 is connected to the second terminal of the second resistor R2 and the control terminal of the switching transistor Q0. Thus, since the source S of the switching transistor Q0 is connected to ground m2, the potential of the source S of the switching transistor Q0 can be stabilized at the ground potential. At this time, there is no need to perform excessive control on the potential of the source S of the switching transistor Q0. Therefore, the function of the driver 124a can be realized through a simple combination of components, simplifying the structure of the driver 124a and helping to reduce costs. Of course, in this embodiment, the driver 124a is not limited to the above structure, but can be other structures that can realize its function, such as, but not limited to, chips with driving function, etc., which are not specifically limited here.

[0055] Taking the DC-DC converter 123 as a flyback converter as an example, the controller 124b in the drive controller 124 and the primary-side controller 123c in the DC-DC converter 123 can be the same controller. That is, the primary-side controller 123c in the DC-DC converter 123 can not only control the output of the DC-DC converter 123, such as controlling the output current, output voltage or output power of the DC-DC converter 123, but also output a control signal to the driver 124a according to the first voltage and the minimum voltage. This control signal is used to indicate the turn-off time of the switch Q0, so that the driver 124a drives the switch Q0 according to the control signal. In other words, the control of the turn-off time of the switch Q0 is achieved by the primary-side controller 123c. The driver 124a simply converts the control signal output by the primary-side controller 123c into a corresponding voltage signal and outputs it to the control electrode of the switch Q0, thereby realizing the control of the turn-off time of the switch Q0. This utilizes the primary-side controller 123c in the DC-DC converter 123 to control the turn-off time of the switching transistor Q0, which avoids the need to set up an additional controller. Only the driver 124a needs to be added, which helps to reduce the manufacturing cost of the power supply device 12.

[0056] Furthermore, the DC-DC converter 123 may also include a second primary side, which includes a second coil x2 and a voltage detector 123b. The first coil x1 may also be coupled to the second coil x2. The voltage detector 123b is connected to the second coil x2, the primary side controller 123c, and the ground terminal GND. Thus, the voltage in the bus m1 can be coupled to the second coil x2 through the first coil x1, and the voltage detector 123b can detect the voltage of the bus m1 coupled to the second coil x2. Since the voltage detector 123b is connected to the ground terminal GND, the voltage detector 123b can use the ground potential reference. Since the first voltage and the minimum voltage are both voltages in the bus m1 at a certain moment, the voltage detector 123b can detect the first voltage and the minimum voltage and output them to the primary side controller 123c. That is, the voltage detector 123b is used to detect the first voltage and the minimum voltage coupled from the first coil x1 to the second coil x2 and output them to the primary side controller 123c, thereby realizing the control of the turn-off time of the switching transistor Q0. Furthermore, in this embodiment, the voltage detector 123b of the DC-DC converter 123 itself is used to detect the first voltage and the minimum voltage, which avoids the need for additional components and thus reduces costs.

[0057] The voltage detector 123b includes a fifth resistor R5, a sixth resistor R6, a fifth diode D5, and a fourth capacitor C4. The fifth resistor R5 and the sixth resistor R6 are connected in series and then in parallel with the second coil x2. One end of the fifth resistor R5 is also connected to the positive terminal of the fifth diode D5. One end of the sixth resistor R6 is also connected to the ground terminal GND and one end of the fourth capacitor C4. The fourth capacitor C4 is connected between the ground terminal GND and the negative terminal of the fifth diode D5. The connection between the fifth resistor R5 and the sixth resistor R6 is connected to the primary-side controller 123c. Thus, when a voltage is coupled into the second coil x2, the fifth diode D5 can act as a unidirectional conductor, the fourth capacitor C4 is used to store electrical energy, and the fifth resistor R5 and the sixth resistor R6 can act as a voltage divider. The potential change at the connection between the fifth resistor R5 and the sixth resistor R6 reflects the voltage change in the bus m1, thereby detecting the first voltage and the minimum voltage in the bus m1.

[0058] Of course, the structure of voltage detector 123b is not limited to the above description, and can be any structure known in the art that can realize its function. For example, but not limited to, voltage detector 123b is connected between bus m1 and controller 124b, and voltage detector 123b includes a first sampling resistor. When controller 124b is connected to ground terminal GND, controller 124b can use ground potential as a reference and directly detect the voltage in bus m1 through the first sampling resistor, thereby detecting the first voltage and minimum voltage in bus m1.

[0059] For example, the DC-DC converter 123 may also include a high-voltage detector 123d. The high-voltage detector 123d is connected to the primary-side controller 123c and the two output terminals of the filter 121 (i.e., the two input terminals of the rectifier 122), respectively. The high-voltage detector 123d can be used to detect the peak voltage of the power grid, thereby determining the peak voltage in bus m1 and outputting it to the controller 124b, so that the controller 124b can determine the turn-off start time of the switch Q0, thereby realizing the control of the switch Q0. The high-voltage detector 123d may include: a sixth diode D6, a seventh diode D7, and a seventh resistor R7. The negative terminals of the sixth diode D6 and the seventh diode D7 are both connected to one end of the seventh resistor R7. The positive terminal of the sixth diode D6 is connected to the first output terminal of the filter 121, the positive terminal of the seventh diode D7 is connected to the second output terminal of the filter 121, and the other end of the fifth resistor R5 is connected to the controller 124b. In this way, the controller 124b can detect the power grid voltage and thus determine the peak voltage in bus m1. Furthermore, in this embodiment, the high voltage detector 123d built into the DC-DC converter 123 is used to detect the peak voltage, which avoids the need for additional components and thus reduces costs.

[0060] Of course, the structure of the high voltage detector 123d is not limited to the above description, and can be any structure known in the art that can realize its function. For example, but not limited to, the high voltage detector 123d can be connected between the controller 124b and the bus m1, and the high voltage detector 123d can include a second sampling resistor. When the controller 124b is connected to the ground terminal GND, the controller 124b can use the ground potential as a reference and directly detect the voltage in the bus m1 through the second sampling resistor, thereby detecting the peak voltage in the bus m1. Since the voltage in the bus m1 comes from the power grid, the peak voltage in the bus m1 can be regarded as the peak voltage of the power grid.

[0061] The working process of power supply device 12 is described below.

[0062] Refer to the waveform diagram shown in Figure 3A.

[0063] At time t1, the switch Q0 is in the on state, and the first capacitor C1 and the second capacitor C2 enter the charging state. This continues until the voltage Vdc of the rectified power grid reaches the peak voltage Vmax at time t2, which is also the time when the voltage Vb in bus m1 reaches the peak voltage Vmax. At time t2, the controller 124b controls the switch Q0 to turn off, the first capacitor C1 and the second capacitor C2 stop charging, and the first capacitor C1 begins to discharge. Since the first capacitor C1 is a small-capacity capacitor and the second capacitor C2 is a large-capacity capacitor, and the capacitance of the second capacitor C2 is greater than that of the first capacitor C1, the change in voltage Vb in bus m1 after the first capacitor C1 discharges is basically consistent with the change in voltage Vdc of the rectified power grid. Therefore, from time t2 to time t3, the voltage Vb in bus m1 decreases non-linearly.

[0064] At time t3, the turn-off time of switch Q0 meets the duration requirement, which refers to the most recently determined turn-off duration. Controller 124b controls switch Q0 to turn on and obtains the voltage Vb in bus m1 at this time, i.e., the first voltage V1. Since switch Q0 is turned on, the second capacitor C2 begins to discharge, so the voltage Vb in bus m1 increases suddenly. As the second capacitor C2 discharges, the voltage Vb in bus m1 gradually decreases. Because the capacitance of the second capacitor C2 is large, the voltage Vb in bus m1 decreases linearly during discharge until it reaches its minimum at time t4. Controller 124b obtains the voltage Vb in bus m1 at this time, i.e., the minimum voltage Vmin. Furthermore, starting from time t4, the first capacitor C1 and the second capacitor C2 re-enter the charging state and continue the above process.

[0065] It is important to note that when the controller 124b controls the first turn-off of the switch Q0, it can control the turn-off duration of the switch Q0 based on a pre-configured time such as toff1. Then, it obtains the first voltage V1 and the minimum voltage Vmin in the bus m1. If it finds that the first voltage V1 and the minimum voltage Vmin are not within the preset range, it uses, but is not limited to, a Proportion Integral Differential (PID) algorithm to calculate the turn-off duration of the switch Q0 for the second turn-off, such as toff2, so that the controller 124b controls the turn-off duration of the switch Q0 for toff2 during the second turn-off. Then, it repeats the above process to achieve dynamic control of the turn-off duration of the switch Q0, reduce the difference between the first voltage V1 and the minimum voltage Vmin, and thus improve the power supply efficiency under non-full load conditions.

[0066] Furthermore, time t1 can be considered as the power-on time of power supply device 12, and toff1 can be considered as the duration of the first turn-off of switching transistor Q0. In other words, after power supply device 12 is powered on, the turn-off duration of switching transistor Q0 will be continuously adjusted. That is to say, when power supply device 12 is operating in steady state, the turn-off duration of switching transistor Q0 will be continuously adjusted to ensure that the difference between the first voltage V1 and the minimum voltage Vmin is stable within a preset range.

[0067] Figure 4 exemplarily illustrates a structural schematic diagram of a power supply device 12 provided in this application. Referring to Figure 4, the structure of the power supply device 12 in this embodiment is basically similar to that in the embodiment described in Figure 2 above, except that the structure of the driver 124a is different. For example, when the source S of the switching transistor Q0 is not connected to the ground line m2, the potential of the source S of the switching transistor Q0 is in a floating state, so the source S is not grounded, which may lead to the switching transistor Q0 being unable to be effectively controlled. At this time, the driver 124a can be an isolated driver chip, enabling the driver 124a to have certain logic processing functions. This can effectively control the potential of the control electrode of the switching transistor Q0, achieving effective control of the switching transistor Q0, ensuring that the voltage difference between the control electrode and the source of the switching transistor Q0 meets the voltage requirements, thereby controlling the conduction and turn-off of the switching transistor Q0.

[0068] It should be understood that the power supply device 12 structure in this embodiment is similar to the power supply device 12 structure in the embodiment described in FIG2 above. For details, please refer to the relevant descriptions in the above embodiments. Repeated descriptions will not be repeated.

[0069] Figures 5A and 5B exemplarily illustrate a structural schematic diagram of a power supply device 12 provided in this application. Referring to Figures 5A and 5B, the structure of the power supply device 12 in this embodiment is basically similar to that of the power supply device 12 in the embodiments described in Figures 2 or 4 above. The difference is that the drive controller 124 does not include a driver 124a, and the controller 124b in the drive controller 124 is a chip with drive control function and is independently set. Exemplarily, the drive controller 124 may include: a controller 124b, a third resistor R3, and a fourth resistor R4; the third resistor R3 is connected between the drain D of the switching transistor Q0 and the controller 124b; the source S of the switching transistor Q0 is connected to the bus m1, and the fourth resistor R4 is connected between the ground line m2 and the controller 124b, as shown in Figure 5A; or, the source S of the switching transistor Q0 is not connected to the bus m1, and the fourth resistor R4 is connected between the bus m1 and the controller 124b, as shown in Figure 5B.

[0070] Thus, when the switch Q0 is in the ON state, and the ON state includes the ON start and ON end times, in the structure shown in Figure 5A, the controller 124b can detect the voltage in bus m1 through the third resistor R3 and the voltage in ground m2 through the fourth resistor R4; or, in the structure shown in Figure 5B, the controller 124b can detect the voltage in bus m1 through the fourth resistor R4 and the voltage in ground m2 through the third resistor R3. When the controller 124b is not directly connected to the ground terminal GND, the voltage in ground m2 can be used as a reference to detect the first voltage, minimum voltage, and peak voltage in bus m1. Furthermore, the controller 124b can acquire the drain voltage of the switch Q0 through the third resistor R3, realizing that the controller 124b and the source of the switch Q0 share a common ground, thereby realizing the control of the switch Q0 and the regulation of the turn-off time of the switch Q0. In addition, this can reduce the modification of other components; only the drive controller 124 needs to be added to the original structure, thereby reducing the design cost.

[0071] It should be understood that the power supply device 12 structure in this embodiment is similar to the power supply device 12 structure in the embodiments described in FIG2 or FIG4 above. For details, please refer to the relevant descriptions in the aforementioned embodiments. Repeated descriptions will not be repeated.

[0072] Figure 6 exemplarily illustrates a structural schematic diagram of a power supply device 12 provided in this application. Referring to Figure 6, the structure of the power supply device 12 in this embodiment is basically similar to the structure of the power supply device 12 in any of the embodiments described in Figures 2, 4, 5A, and 5B, except that the power supply device 12 further includes a first charging branch 126a and a second charging branch 126b. For example, if the node between the second capacitor C2 and the switching transistor Q0 in the second branch is referred to as the connection node P0, the first charging branch 126a is connected between the first input terminal of the rectifier 122 and the connection node P0, and the second charging branch 126b is connected between the second input terminal of the rectifier 122 and the connection node P0. In this case, the first charging branch 126a is used to transmit the voltage input to the first input terminal of the rectifier 122 to the second capacitor C2; the second charging branch 126b is used to transmit the voltage input to the second input terminal of the rectifier 122 to the second capacitor C2.

[0073] Therefore, since the current at the output of rectifier 122 may be large during a lightning strike, if the second capacitor C2 is charged through the switching transistor Q0 at this time, the large current will cause a significant impact on the switching transistor Q0, potentially damaging it. Although the first diode D1 provides lightning protection, its performance will be weakened if it malfunctions. Therefore, by using the first charging branch 126a and the second charging branch 126b, the second capacitor C2 can be charged directly without passing through the switching transistor Q0. This further reduces the impact of the large current on the switching transistor Q0, further improving the lightning protection performance of the power supply device 12. Furthermore, since the input side of rectifier 122 uses AC voltage, the second capacitor C2 can be charged using AC voltage through the first charging branch 126a and the second charging branch 126b, ensuring the normal operation of the power supply device 12.

[0074] The first charging branch 126a includes a third diode D3, with its cathode connected to the first input terminal of the rectifier 122 and its anode connected to the connection node P0. The second charging branch 126b includes a fourth diode D4, with its cathode connected to the second input terminal of the rectifier 122 and its anode connected to the connection node P0. Thus, the third diode D3 and the fourth diode D4 enable charging of the second capacitor C2 based on AC voltage, preventing the first charging branch 126a and the second charging branch 126b from forming a loop, thereby preventing current backflow and improving the safety of the power supply device 12.

[0075] Of course, the first charging branch 126a and the second charging branch 126b are not limited to the positions shown in Figure 6. The positions of the first charging branch 126a and the second charging branch 126b can also be adaptively adjusted according to the position of the switching transistor Q0. For example, but not limited to: when the switching transistor Q0 is located in the ground wire m2, and the source (or drain) of the switching transistor Q0 is connected to the first capacitor C1, and the drain (or source) is connected to the second capacitor C2, the connection node P0 will also be connected to the second output terminal of the rectifier 122. That is, the second capacitor C2 is connected to the rectifier 122 respectively. The first output terminal of the rectifier 122 is connected to the second output terminal of the rectifier 122. When charging the second capacitor C2, the power output from the rectifier 122 can be used directly without passing through the switching transistor Q0. However, when charging the first capacitor C1, the power output from the switching transistor Q0 is required. If the node between the first capacitor C1 and the switching transistor Q0 is called the second node, then the first charging branch 126a can be connected between the first input terminal of the rectifier 122 and the second node, and the second charging branch 126b can be connected between the second input terminal of the rectifier 122 and the second node. (The specific details are not provided.) As shown in the diagram, if a lightning strike occurs during the charging process of the first capacitor C1 and the second capacitor C2, the switching transistor Q0 can be bypassed, and the lightning protection performance can be improved through the first charging branch 126a and the second charging branch 126b. Similarly, when the switching transistor Q0 is located in the bus m1, and its source (or drain) is connected to the first capacitor C1, and its drain (or source) is connected to the second capacitor C2, the connection node P0 is also connected to the first output terminal of the rectifier 122. That is, the second capacitor C2 is connected to both the first output terminal and the second output terminal of the rectifier 122. When the second capacitor C2 is charged, the power output from the rectifier 122 can be used directly without going through the switching transistor Q0. However, when the first capacitor C1 is charged, it needs to go through the switching transistor Q0. In this case, the first charging branch 126a can be connected between the first input terminal and the second node of the rectifier 122, and the second charging branch 126b can be connected between the second input terminal and the second node of the rectifier 122 (not shown in the figure). The first charging branch 126a and the second charging branch 126b improve the lightning protection performance; and so on, which will not be listed here.

[0076] It should be understood that the power supply device 12 structure in this embodiment is similar to the power supply device 12 structure in any of the embodiments described in Figures 2, 4, 5A, and 5B. For details, please refer to the relevant descriptions in the aforementioned embodiments. Repeated descriptions will not be repeated.

[0077] In another embodiment of the power supply device 12 provided in this application, the structure of the power supply device 12 in this embodiment is basically similar to that of the power supply device 12 in any of the embodiments described in Figures 2, 4, 5A, and 5B, except that the control logic of the drive controller 124 for the switching transistor Q0 is different. For example, the drive controller 124 controls the switching transistor Q0 according to a fixed turn-off duration, such as, but not limited to, the turn-off duration of the switching transistor Q0 can be pre-configured according to actual needs, or the turn-off end time can be determined according to the first voltage obtained by looking up a table, etc., which will not be listed here. Thus, by setting the specific structure of the drive controller 124, effective control of the switching transistor Q0 can be achieved, thereby ensuring the normal operation of the power supply device 12. Furthermore, since the source S of the switching transistor Q0 is connected to the ground line m2, the potential of the source S of the switching transistor Q0 can be stabilized at the ground potential. At this time, there is no need to perform excessive control on the source potential of the switching transistor Q0. Therefore, the function of the driver 124a can be realized through a simple combination of components, simplifying the structure of the driver 124a and helping to reduce costs.

[0078] It should be understood that the power supply device 12 structure in this embodiment is similar to the power supply device 12 structure in any of the embodiments described in Figures 2, 4, 5A, and 5B. For details, please refer to the relevant descriptions in the aforementioned embodiments. Repeated descriptions will not be repeated.

[0079] In this application, when the switching transistor is a metal-oxide-semiconductor field-effect transistor or a junction field-effect transistor, the three electrodes of the switching transistor are the source, drain, and gate, respectively. The control electrode mentioned above is the gate, and the above embodiments are all described using this as an example. Alternatively, the switching transistor can also be other types of devices, such as, but not limited to, transistors. In this case, the three electrodes of the switching transistor are the collector, emitter, and base, respectively. The control electrode mentioned above is the base, and the source of the switching transistor mentioned above can be replaced with the emitter, and the drain of the switching transistor mentioned above can be replaced with the collector.

[0080] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of the embodiments of this application. Therefore, if these modifications and variations to the embodiments of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A power supply device, characterized in that, include: The system includes a rectifier (122), a first branch, a second branch, a DC-DC converter (123), a bus (m1), and a ground wire (m2). The first branch and the second branch are connected in parallel between the bus (m1) and the ground wire (m2). The first output terminal of the rectifier (122) is connected to the first input terminal of the DC-DC converter (123) through the bus (m1), and the second output terminal of the rectifier (122) is connected to the second input terminal of the DC-DC converter (123) through the ground wire (m2). The first branch has a first capacitor (C1), and the second branch has a series-connected switch (Q0) and a second capacitor (C2). The second branch also has a first diode (D1), which is connected in parallel with the switch (Q0). When the second capacitor (C2) is discharging, the first diode (D1) is cut off, and when the second capacitor (C2) is charging, the first diode (D1) is turned on. The power supply device further includes a drive controller (124), which is connected to the control electrode of the switch (Q0). The drive controller (124) is used to: adjust the turn-off time of the switch (Q0) according to the first voltage of the bus (m1) when the switch (Q0) is at the start of conduction and the minimum voltage of the bus (m1) after the switch (Q0) is turned on.

2. The power supply device as described in claim 1, characterized in that, The drive controller (124) is specifically used for: When the difference between the first voltage and the minimum voltage is greater than the upper limit of the preset range, the turn-off time of the switching transistor (Q0) is extended; the preset range is -20V to 20V. When the difference between the first voltage and the minimum voltage is less than the lower limit of the preset range, the turn-off time of the switching transistor (Q0) is shortened. When the difference between the first voltage and the minimum voltage is within the preset range, the off-time of the switching transistor (Q0) remains unchanged.

3. The power supply device as described in claim 1 or 2, characterized in that, The drive controller (124) includes a driver (124a) and a controller (124b); The controller (124b) is configured to: output a control signal to the driver (124a) based on the first voltage and the minimum voltage; and control the output of the DC-DC converter (123); the control signal is used to indicate the off-time of the switching transistor (Q0); The driver (124a) is used to drive the switch (Q0) according to the control signal.

4. The power supply device as described in claim 3, characterized in that, The source of the switching transistor (Q0) is connected to the ground wire (m2), and the driver (124a) includes: a first resistor (R1), a second resistor (R2), a second diode (D2), and a third capacitor (C3); The first terminal of the third capacitor (C3) is connected to the controller (124b), and the second terminal of the third capacitor (C3) is connected to the positive terminal of the second diode (D2) and the first terminal of the first resistor (R1), respectively. The negative terminal of the second diode (D2) is connected to the ground wire (m2) and the first terminal of the second resistor (R2), respectively; The second end of the first resistor (R1) is connected to the second end of the second resistor (R2) and the control electrode of the switching transistor (Q0).

5. The power supply device as described in claim 3 or 4, characterized in that, The DC-DC converter (123) includes: a first coil (x1), a second coil (x2), and a voltage detector (123b). The first coil (x1) is coupled to the second coil (x2) and is connected to the bus (m1). The voltage detector (123b) is connected to the second coil (x2), the controller (124b), and the ground terminal, respectively. The voltage detector (123b) is used to detect the first voltage and the minimum voltage coupled from the first coil (x1) to the second coil (x2) and output the result to the controller (124b).

6. The power supply device as described in claim 1 or 2, characterized in that, The drive controller (124) includes: a controller (124b), a third resistor (R3), and a fourth resistor (R4); The third resistor (R3) is connected between the drain of the switching transistor (Q0) and the controller (124b); The source of the switching transistor (Q0) is connected to the bus (m1), and the fourth resistor (R4) is connected between the ground wire (m2) and the controller (124b); or, the source of the switching transistor (Q0) is not connected to the bus (m1), and the fourth resistor (R4) is connected between the bus (m1) and the controller (124b).

7. The power supply device according to any one of claims 1-6, characterized in that, The power supply device further includes a first charging branch (126a) and a second charging branch (126b). The first charging branch (126a) is connected between the first input terminal of the rectifier (122) and the connection node (P0) of the second capacitor (C2) and the switching transistor (Q0). The second charging branch (126b) is connected between the second input terminal of the rectifier (122) and the connection node (P0). The first charging branch (126a) is used to: transfer the voltage input to the first input terminal of the rectifier (122) to the second capacitor (C2); The second charging branch (126b) is used to: transmit the voltage input to the second input terminal of the rectifier (122) to the second capacitor (C2).

8. The power supply device as described in claim 7, characterized in that, The first charging branch (126a) is provided with a third diode (D3), the negative terminal of the third diode (D3) is connected to the first input terminal of the rectifier (122), and the positive terminal of the third diode (D3) is connected to the connection node (P0). Alternatively, the second charging branch (126b) may include a fourth diode (D4), the negative terminal of which is connected to the second input terminal of the rectifier (122), and the positive terminal of which is connected to the connection node (P0).

9. A power supply device, characterized in that, include: The system includes a rectifier (122), a first branch, a second branch, a DC-DC converter (123), a bus (m1), and a ground wire (m2). The first branch and the second branch are connected in parallel between the bus (m1) and the ground wire (m2). The first output terminal of the rectifier (122) is connected to the first input terminal of the DC-DC converter (123) through the bus (m1), and the second output terminal of the rectifier (122) is connected to the second input terminal of the DC-DC converter (123) through the ground wire (m2). The first branch has a first capacitor (C1), and the second branch has a series-connected switching transistor (Q0) and a second capacitor (C2). The power supply device further includes a driver (124a) and a controller (124b). The driver (124a) is connected to the control electrode of the switching transistor (Q0) and the controller (124b), respectively. The controller (124b) is used to: output a first control signal to the driver (124a) when the voltage in the bus (m1) reaches the peak voltage; and output a second control signal to the driver (124a) when the turn-off time of the switching transistor (Q0) meets the duration requirement. The driver (124a) is used to: drive the switching transistor (Q0) to turn off according to the first control signal, and drive the switching transistor (Q0) to turn on according to the second control signal. The source of the switching transistor (Q0) is connected to the ground line (m2). The driver (124a) includes a first resistor (R1), a second resistor (R2), a second diode (D2), and a third capacitor (C3). The first terminal of the third capacitor (C3) is connected to the controller (124b), and the second terminal of the third capacitor (C3) is connected to the positive terminal of the second diode (D2) and the first terminal of the first resistor (R1). The negative terminal of the second diode (D2) is connected to the ground line (m2) and the first terminal of the second resistor (R2). The second terminal of the first resistor (R1) is connected to the second terminal of the second resistor (R2) and the control terminal of the switching transistor (Q0).

10. A control method for a power supply device, characterized in that, The power supply device includes: a rectifier, a first branch, a second branch, a DC-DC converter, a bus, a ground wire, and a drive controller. The first branch and the second branch are connected in parallel between the bus and the ground wire. The first output terminal of the rectifier is connected to the first input terminal of the DC-DC converter through the bus, and the second output terminal of the rectifier is connected to the second input terminal of the DC-DC converter through the ground wire. The first branch includes a first capacitor, and the second branch includes a switching transistor and a second capacitor connected in series. The second branch also includes a first diode connected in parallel with the switching transistor. When the second capacitor discharges, the first diode is cut off, and when the second capacitor charges, the first diode is turned on. The drive controller is connected to the control electrode of the switching transistor. The control method includes: Obtain the first voltage of the bus when the switching transistor is at the start of conduction; Obtain the minimum voltage of the bus when the switch is in the ON state; The turn-off duration of the switching transistor is adjusted based on the first voltage and the minimum voltage.

11. The control method as described in claim 10, characterized in that, Adjusting the turn-off duration of the switching transistor based on the first voltage and the minimum voltage includes: When the difference between the first voltage and the minimum voltage is greater than the upper limit of the preset range, the turn-off time of the switching transistor is extended; the preset range is -20V to 20V. When the difference between the first voltage and the minimum voltage is less than the lower limit of the preset range, the turn-off time of the switching transistor is shortened. When the difference between the first voltage and the minimum voltage is within the preset range, the off-time of the switching transistor remains unchanged.

12. An electrical system, characterized in that, include: The terminal device and the power supply device as described in any one of claims 1-9, wherein the power supply device is used to supply power to the terminal device.

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