Power supply device and charging control method

Abstract

A power supply device and a charging control method. The power supply device (20) includes: a first-stage conversion circuit (21) and a second-stage conversion circuit (22), wherein the first-stage conversion circuit (21) is configured to convert the received AC voltage into a pulsating DC voltage, and the voltage value of the pulsating DC voltage is higher than the voltage value of the AC voltage; the second-stage conversion circuit (22), connected to the first-stage conversion circuit (21), is configured to convert the pulsating DC voltage and output a constant DC voltage.

Description

Technical Field

[0001] The present disclosure relates to the field of charging technologies, and in particular, to a power supply device and a charging control method. Background Art

[0002] Devices to be charged (such as smart phones, mobile terminals or intelligent devices) are increasingly favored by consumers. However, devices to be charged consume a large amount of power and need to be charged frequently. At present, the volume of power supply devices (such as power adapters) is relatively large, which is not convenient to carry around, resulting in a poor user experience.

[0003] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure, and thus it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0004] The present disclosure provides a power supply device and a charging control method, which can achieve a power supply device with a relatively small volume.

[0005] Other features and advantages of the present disclosure will become apparent through the following detailed description, or will be partially learned through the practice of the present disclosure.

[0006] According to one aspect of the present disclosure, there is provided a power supply device, including: a first-stage conversion circuit configured to convert a received AC voltage into a pulsating DC voltage, where the voltage value of the pulsating DC voltage is higher than the voltage value of the AC voltage; and a second-stage conversion circuit connected to the first-stage conversion circuit and configured to convert the pulsating DC voltage to output a constant DC voltage.

[0007] According to an embodiment of the present disclosure, the first-stage conversion circuit includes at least one filter capacitor, and the capacitance of the filter capacitor is less than a preset value.

[0008] According to an embodiment of the present disclosure, the second-stage conversion circuit includes a first switching unit and a voltage conversion unit. The power supply device further includes: a first detection unit connected to the voltage conversion unit and configured to detect the output voltage and / or current of the voltage conversion unit; and a control unit connected to the detection unit and the first switching unit respectively, and configured to control the first switching unit to turn on or off by outputting a control signal according to the output voltage value and / or current value detected by the first detection unit, and adjust the output voltage of the voltage conversion unit, thereby adjusting the voltage value of the constant DC voltage.

[0009] According to an embodiment of the present disclosure, the control signal includes: a pulse width modulation (PWM) signal and a pulse frequency modulation (PFM) signal; the control unit is configured to output the PWM signal or the PFM signal according to the output voltage value and / or current value detected by the first detection unit, so as to adjust the output voltage of the voltage conversion unit.

[0010] According to an embodiment of the present disclosure, the control unit is configured to output the PWM signal or the PFM signal according to an output gain, so as to adjust the output voltage of the voltage conversion unit, where the output gain is the ratio of the output voltage of the voltage conversion unit

[0011] to the input voltage of the voltage conversion unit, or the output gain is the ratio of the output voltage of the second-stage conversion circuit to the output voltage of the first-stage conversion circuit.

[0012] According to an embodiment of the present disclosure, the control unit is configured to output the PWM signal in the first charging stage to adjust the output voltage of the voltage conversion unit; and output the PFM signal in the second charging stage to adjust the output voltage of the voltage conversion unit; wherein, the output voltage of the power supply device in the first charging stage is lower than that in the second charging stage.

[0013] According to an embodiment of the present disclosure, the control unit is configured to output the PWM signal to adjust the output voltage of the voltage conversion unit when the output voltage of the voltage conversion unit is less than a preset first voltage threshold and / or the output current of the voltage conversion unit is less than a preset first current threshold; and output the PFM signal to adjust the output voltage of the voltage conversion unit when the output voltage of the voltage conversion unit is greater than or equal to the first voltage threshold and / or the output current of the voltage conversion unit is greater than or equal to the first current threshold.

[0014] According to an embodiment of the present disclosure, the second-stage conversion circuit includes a first switch unit and a voltage conversion unit; the power supply device further includes: a first detection unit configured to detect the output voltage and / or current of the power supply device; and a control unit connected to the first detection unit and the first switch unit respectively, and configured to control the first switch unit to be turned on or off by outputting a control signal according to the output voltage value and / or current value detected by the first detection unit, so as to adjust the output voltage of the voltage conversion unit, thereby adjusting the voltage value of the constant DC voltage.

[0015] According to an embodiment of the present disclosure, the control unit is further configured to receive feedback information of a device to be charged connected to the power supply device, and control the control signal of the first switch unit according to the feedback information, so as to adjust the output voltage and / or output current of the power supply device.

[0016] According to an embodiment of the present disclosure, the feedback information includes: the charging voltage and / or charging current desired by the device to be charged, or an adjustment instruction generated by the device to be charged based on the desired charging voltage and / or charging current.

[0017] According to an embodiment of the present disclosure, the first-stage conversion circuit includes: a second switching unit; the power supply device further includes: a second detection unit, connected to the first-stage conversion circuit and the control unit respectively, for detecting the output voltage and / or output current of the first-stage conversion circuit; the control unit is further configured to output a second control signal according to the output voltage and / or output current of the first-stage conversion circuit, and control the conduction or cutoff of the second switching unit to adjust the output voltage and / or output current of the first-stage conversion circuit.

[0018] According to an embodiment of the present disclosure, the second control signal includes: a PWM signal and a PFM signal; the control unit is configured to output the PWM signal or the PFM signal according to the output voltage and / or output current of the first-stage conversion circuit to adjust the output voltage and / or output current of the first-stage conversion circuit, so that the output voltage of the first-stage conversion circuit is equal to a preset reference voltage.

[0019] According to an embodiment of the present disclosure, the capacitor is at least one of the following capacitors: a thin film capacitor, a multilayer ceramic capacitor, a chip capacitor, or an electrolytic capacitor.

[0020] According to an embodiment of the present disclosure, the first-stage conversion circuit includes: a totem pole boost circuit.

[0021] According to an embodiment of the present disclosure, the first-stage conversion circuit includes: a rectifier circuit and a boost circuit.

[0022] According to an embodiment of the present disclosure, the second-stage conversion circuit includes: an LLC resonant converter.

[0023] According to another aspect of the present disclosure, there is provided a charging control method applied to a power supply device, including: converting an input AC voltage into a pulsating DC voltage with a voltage value higher than that of the AC voltage through a first-stage conversion circuit; and converting the pulsating DC voltage through a second-stage conversion circuit to output a constant DC voltage.

[0024] According to an embodiment of the present disclosure, the first-stage conversion circuit includes at least one filter capacitor, and the capacitance of the filter capacitor is less than a preset value.

[0025] According to an embodiment of the present disclosure, the method further includes: detecting the output voltage and / or output current of the voltage transformation unit in the second-stage transformation circuit; and controlling the conduction or cutoff of the first switch unit in the second-stage transformation circuit by outputting a control signal according to the output voltage and / or output current of the voltage transformation unit, so as to adjust the output voltage of the voltage transformation unit, thereby adjusting the voltage value of the constant DC voltage.

[0026] According to an embodiment of the present disclosure, the control signal includes: a PWM signal and a PFM signal; controlling the conduction or cutoff of the first switch unit in the second-stage transformation circuit by outputting a control signal according to the output voltage and / or output current of the voltage transformation unit, and adjusting the output voltage of the voltage transformation unit, includes: outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit, so as to adjust the output voltage of the voltage transformation unit.

[0027] According to an embodiment of the present disclosure, outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit, so as to adjust the output voltage of the voltage transformation unit, includes: outputting the PWM signal or the PFM signal according to an output gain, so as to adjust the output voltage of the voltage transformation unit; wherein, the output gain is the ratio of the output voltage of the voltage transformation unit to the input voltage of the voltage transformation unit, or the output gain is the ratio of the output voltage of the second-stage transformation circuit to the output voltage of the first-stage transformation circuit.

[0028] According to an embodiment of the present disclosure, outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit, so as to adjust the output voltage of the voltage transformation unit, includes: outputting the PWM signal to adjust the output voltage of the voltage transformation unit in a first charging stage; and outputting the PFM signal to adjust the output voltage of the voltage transformation unit in a second charging stage; wherein, the output voltage of the power supply device in the first charging stage is lower than the output voltage in the second charging stage.

[0029] According to an embodiment of the present disclosure, outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit, so as to adjust the output voltage of the voltage transformation unit, includes: when the output voltage of the voltage transformation unit is less than a preset first voltage threshold, and / or the output current of the voltage transformation unit is less than a preset first current threshold, outputting the PWM signal to adjust the output voltage of the voltage transformation unit; when the output voltage of the voltage transformation unit is greater than or equal to the first voltage threshold, and / or the output current of the voltage transformation unit is greater than or equal to the first current threshold, outputting the PFM signal to adjust the output voltage of the voltage transformation unit.

[0030] According to an embodiment of the present disclosure, the method further includes: detecting the output voltage and / or output current of the power supply device; controlling the conduction or cutoff of a first switch unit in the second-stage conversion circuit by outputting a control signal according to the output voltage and / or output current of the power supply device, and adjusting the output voltage of a voltage conversion unit in the second-stage conversion circuit, so as to adjust the voltage value of the constant DC voltage.

[0031] According to an embodiment of the present disclosure, the method further includes: receiving feedback information of a device to be charged connected to the power supply device; and controlling the control signal of the first switch unit according to the feedback information to adjust the output voltage and / or output current of the power supply device.

[0032] According to an embodiment of the present disclosure, the feedback information includes: the charging voltage and / or charging current desired by the device to be charged, or an adjustment instruction generated by the device to be charged based on the desired charging voltage and / or charging current.

[0033] According to an embodiment of the present disclosure, the method further includes: detecting the output voltage and / or output current of the first-stage conversion circuit; and outputting a second control signal according to the output voltage and / or output current of the first-stage conversion circuit to control the conduction or cutoff of a second switch unit in the first-stage conversion circuit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit.

[0034] According to an embodiment of the present disclosure, the second control signal includes a PWM signal and a PFM signal; outputting a second control signal according to the output voltage and / or output current of the first-stage conversion circuit to control the conduction or cutoff of the second switch unit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit, includes: outputting a PWM signal or a PFM signal according to the output voltage and / or output current of the first-stage conversion circuit to adjust the output voltage and / or output current of the first-stage conversion circuit, so that the output voltage of the first-stage conversion circuit is equal to a preset reference voltage.

[0035] The power supply device provided by an embodiment of the present disclosure adopts a two-stage architecture composed of a first-stage conversion circuit and a second-stage conversion circuit. Since the first-stage conversion circuit boosts the input alternating current, there is a variable bus voltage between the two-stage architectures. The energy storage function can be realized through the change of the bus voltage, so there is no need to use a very large capacitor as an energy storage element. Removing the large electrolytic capacitor can reduce the volume of the power supply device.

[0036] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and other objectives, features, and advantages of the present disclosure will become more apparent by describing its exemplary embodiments in detail with reference to the drawings.

[0038] Figure 1 is a schematic structural diagram of a power supply device in the related art shown according to an example.

[0039] Figure 2 is a schematic structural diagram of a power supply device shown according to an exemplary embodiment.

[0040] Figure 3A is a schematic structural diagram of another power supply device shown according to an exemplary embodiment.

[0041] Figure 3B is a schematic structural diagram of yet another power supply device shown according to an exemplary embodiment.

[0042] Figure 4 is a circuit structure diagram of an LLC resonant converter shown according to an example.

[0043] Figure 5A is a schematic diagram of a pulsating DC voltage shown according to an example.

[0044] Figure 5B is a schematic diagram of a constant DC voltage shown according to an example.

[0045] Figure 6A is a schematic structural diagram of a boost circuit shown according to an exemplary embodiment.

[0046] Figure 6B is a circuit schematic diagram of a Boost circuit shown according to an example.

[0047] Figure 6C is a schematic diagram of a totem-pole Boost circuit shown according to an example.

[0048] Figure 7 is a schematic structural diagram of yet another power supply device shown according to an example.

[0049] Figure 8 is a flowchart of a charging control method shown according to an exemplary embodiment.

[0050] Figure 9 is a flowchart of another charging control method shown according to an exemplary embodiment.

[0051] Figure 10It is a flowchart of yet another charging control method shown according to an exemplary embodiment.

[0052] Figure 11 It is a flowchart of yet another charging control method shown according to an exemplary embodiment.

[0053] Figure 12 It is a flowchart of yet another charging control method shown according to an exemplary embodiment.

[0054] Figure 13 It is a flowchart of yet another charging control method shown according to an exemplary embodiment.

[0055] Figure 14 It is a flowchart of yet another charging control method shown according to an exemplary embodiment. Detailed implementation manners

[0056] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0057] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus repeated descriptions thereof will be omitted. Some of the block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0058] In the present disclosure, unless otherwise clearly defined and limited, terms such as "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or capable of communicating with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0059] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present disclosure, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, B exists alone, and both A and B exist simultaneously.

[0060] As described above, since the current power supply device requires a large energy storage component for energy storage, its volume is relatively large.

[0061] Figure 1 It is a schematic structural diagram of a power supply device in the related art shown according to an example. As Figure 1 shown, the power supply device 10 includes: a rectification unit 11, a switching unit 12, a transformer 13, a filtering unit 14, and a control unit 15.

[0062] Among them, the rectification unit 11 is used to rectify the received alternating current (such as the commercial power provided by the power grid) and output pulsating direct current as shown by the signal S1 in the figure.

[0063] The switching unit 12, the transformer 13, and the filtering unit further convert the pulsating direct current output by the rectification unit 11, so as to output stable direct current (as shown by the signal S4).

[0064] The control unit 15 samples the voltage output by the power supply device 10 and samples the current of the switching unit 12 respectively, and controls the switching unit 12 according to the voltage sampling signal and the current sampling signal to control the output voltage and / or output current of the power supply device 10.

[0065] As Figure 1 shown, the rectification unit 11 contains a large-volume capacitor for energy storage. This large-volume capacitor is usually a liquid electrolytic capacitor with a relatively large volume, which results in a relatively large volume of the power supply device 10, making it inconvenient to carry and providing a poor user experience.

[0066] Hereinafter, the power supply device in each exemplary embodiment of the present disclosure will be described in more detail with reference to the drawings and embodiments.

[0067] Figure 2 It is a schematic structural diagram of a power supply device shown according to an exemplary embodiment.

[0068] Referring to Figure 2 , the power supply device 20 includes: a first-stage conversion circuit 21 and a second-stage conversion circuit 22.

[0069] Among them, the first-stage conversion circuit 21 can be, for example, a boost circuit, which is used to convert the received AC voltage (such as the mains power received from the power grid) into a pulsating DC voltage, and the voltage value of the pulsating DC voltage is higher than that of the AC voltage.

[0070] The voltage range of the pulsating direct current output by the first-stage conversion circuit 21 is, for example, between 390V and 450V.

[0071] The second-stage conversion circuit 22 is connected to the first-stage conversion circuit 21, and is used to convert the pulsating DC voltage output by the first-stage conversion circuit 21 and output a constant DC voltage as the output voltage of the power supply device 20.

[0072] Those skilled in the art should understand that the constant DC voltage output by the second-stage conversion circuit 22 is a constant DC voltage without a pulsating waveform, but the voltage value of the constant DC voltage is not fixed and can output different voltage values in different charging scenarios or charging stages.

[0073] The power supply device 20 provided by the embodiments of the present disclosure adopts a two-stage architecture composed of a first-stage conversion circuit and a second-stage conversion circuit. Since the first-stage conversion circuit boosts the input AC voltage, there is a variable bus voltage between the two-stage architecture, and the energy storage function can be realized through the change of the bus voltage, so there is no need to use a large-volume capacitor as an energy storage element. Removing the large-volume capacitor can reduce the volume of the power supply device 20.

[0074] In addition, as described above, large-volume capacitors usually use liquid electrolytic capacitors, and the service life of liquid electrolytic capacitors is short and they are prone to bursting. Removing the liquid electrolytic capacitor can also improve the service life and safety of the power supply device 20.

[0075] In some embodiments, the first-stage conversion circuit 21 may further include: at least one capacitor 211 with a relatively small filtering ability (such as a capacitor whose capacitance is less than a preset value or a capacitor whose volume is less than a preset volume threshold), which is used to filter the spikes of the pulsating voltage output by the first-stage conversion circuit 21 to improve the quality of the output current of the power supply device 20. The capacitor 211 can be, for example, a thin film capacitor, a multilayer ceramic capacitor (MLCC), a chip capacitor, or an electrolytic capacitor with a capacitance less than the above preset value. The volume and / or capacitance of the filtering capacitor 211 are both small, so it will not have a great impact on the volume of the power supply device.

[0076] Figure 3A It is a schematic structural diagram of another power supply device shown according to an exemplary embodiment.

[0077] And Figure 2Different from the power supply device 20 shown, in Figure 3A the power supply device 30 shown, the second-stage conversion circuit 22 may further include: a first switch unit 221 and a transformer 222.

[0078] The power supply device 30 may further include a control unit 24 and a first detection unit 25. The first detection unit 25 is connected to the transformer 222 and is used to detect the output voltage and / or output current of the transformer 222. The control unit 24 is respectively connected to the first detection unit 25 and the first switching power supply 221, and is used to output a control signal according to the output voltage and / or output current of the transformer 222 detected by the first detection unit 25, control the conduction or cut-off of the first switch unit 221, adjust the output voltage of the transformer 222, and thus adjust the voltage value of the constant DC voltage output by the power supply device 30.

[0079] The detected output voltage and / or output current may be a sampling signal of the output voltage and / or output current of the transformer 222.

[0080] The transformer 222 can couple electrical energy from the primary side to the secondary side in an electromagnetic coupling manner. The electrical energy coupled to the secondary side can be extracted from the electrical energy output by the first-stage conversion circuit 21. The extraction method of energy can be controlled by the control unit 24 according to the detected output voltage and / or output current of the transformer 222.

[0081] In some embodiments, the first detection unit 25 may also directly detect the output voltage and / or output current of the power supply device 30. The control unit 24 may output a control signal according to the output voltage and / or output current of the power supply device 30, control the conduction or cut-off of the first switch unit 221, adjust the output voltage of the transformer 222, and thus adjust the voltage value of the constant DC voltage output by the power supply device 30. The output voltage and / or output current may be a sampling signal of the output voltage and / or output current of the power supply device 30.

[0082] In some embodiments, the second-stage conversion circuit 22 may be implemented, for example, as Figure 4 the LLC resonant converter shown. Among them, the first switch unit 221 includes MOS transistors Q1 and Q2 before the transformer 222. The first switch unit 221 performs chopping modulation on the pulsating direct current output by the first-stage conversion circuit 21, so that the modulated voltage is transformed by the transformer 222. In addition, as Figure 4 shown, the MOS transistors Q3 and Q4 in the LLC resonant converter are also controlled by the control signal sent by the control unit 24.

[0083] Figure 5AIt is a schematic diagram of a pulsating DC voltage shown according to an example. In the embodiments of the present disclosure, without using a large-volume capacitor, the voltage range of the pulsating DC voltage output by the first-stage conversion circuit is relatively wide. As Figure 5A shown, the voltage range of the pulsating DC voltage (as shown by the dashed line A and the dashed line B in the figure) is, for example, between 390V and 450V. The constant DC voltage is as Figure 5B shown. As described above, the constant DC voltage output by the second-stage conversion circuit 22 is a constant DC voltage without a pulsating waveform, but the voltage value of this constant DC voltage is not fixed and can output different voltage values in different charging scenarios or charging stages.

[0084] It should be noted that Figure 4 the LLC harmonic converter shown is only an example and does not limit the present disclosure. The structure of the LLC resonant converter is well known to those skilled in the art and will not be described in detail here.

[0085] The control unit 24 can be implemented as a micro control unit (MCU) for example. In order to make the power supply device 30 output a constant direct current, the control signal output by the control unit 24 to the first switch unit 221 includes: a Pulse Frequency Modulation (PFM) signal and a Pulse Width Modulation (PWM) signal, to control the on and off of the first switch unit 221.

[0086] Among them, when outputting the PFM signal, keep the duty cycle of the PFM signal unchanged, and control the PFM signal by adjusting the interval (i.e., frequency) of the PFM signal. When outputting the PWM signal, keep the frequency of the PWM signal unchanged, and control the PWM signal by adjusting the duty cycle (i.e., signal width) of the PWM signal.

[0087] The control unit 24 determines whether to output a PWM signal or a PFM signal according to the output voltage and / or output current of the transformer 222, or according to the output voltage and / or output current of the power supply device 30.

[0088] Generally, when the output voltage and / or output current of the power supply device 30 are relatively low, the frequencies of Q1 and Q2 in the first switching unit 221 need to be set very high to ensure the output gain of the power supply device 30. The output gain is the ratio of the output voltage of the power supply device 30 to the input voltage of the second-stage conversion circuit 22 (i.e., the output voltage of the first-stage conversion circuit). However, in practical applications, due to various factors (such as device performance, circuit losses, electromagnetic interference, PCB layout, etc.), it is difficult to ensure that the frequencies of Q1 and Q2 in the first switching unit 221 can be pushed very high, and the maximum frequencies of the MOS transistors Q1 and Q2 need to be limited considering efficiency and heat generation. However, in order to achieve the required output gain, the duty cycle of the input signal must be changed. Therefore, at this stage, the power supply device 30 needs to operate in the PWM mode (i.e., output a PWM signal) to ensure the output gain of the power supply device 30.

[0089] In some embodiments, to ensure the conversion efficiency (i.e., output gain) of the power supply device 30, when the output voltage of the transformer 222 is lower than a preset first voltage threshold, and / or when the output current of the transformer 222 is lower than a preset first current threshold, the control unit 24 outputs a PWM signal, that is, operates in the PWM mode.

[0090] When the output voltage of the transformer 222 is higher than or equal to the first voltage threshold, and / or when the output current of the transformer 222 is higher than or equal to the first current threshold, the control unit 24 outputs a PFM signal, that is, operates in the PFM mode.

[0091] In some embodiments, as described above, the control unit 24 can also determine which control mode to adopt according to the output voltage and / or current of the power supply device 30. When the output voltage of the power supply device 30 is lower than a preset first voltage threshold, and / or when the output current of the power supply device 30 is lower than a preset first current threshold, the control unit 24 outputs a PWM signal, that is, operates in the PWM mode.

[0092] When the output voltage of the power supply device 30 is higher than or equal to the first voltage threshold, and / or when the output current of the power supply device 30 is higher than or equal to the first current threshold, the control unit 24 outputs a PFM signal, that is, operates in the PFM mode.

[0093] The above-mentioned first voltage threshold and first current threshold can be set according to the battery charging condition of the device to be charged connected to the power supply device 30. Taking the battery in the device to be charged as a two-cell series lithium battery as an example, if the desired charging voltage of the device to be charged is 10V, and in the initial stage of charging, when the output voltage is lower than 10V (such as 8V or 9V), the above-mentioned PWM mode can be adopted. When the output voltage is 10V, it can be switched to the PFM mode to control the input signal so as to adjust the output voltage and / or output current of the power supply device 30.

[0094] In some embodiments, the control unit 24 is configured to, in the first charging stage, adjust the output voltage of the transformer 222 by outputting a PWM signal; in the second charging stage, adjust the output voltage of the transformer 222 by outputting a PFM signal; wherein, the output voltage of the power supply device 30 in the first charging stage is lower than that in the second charging stage. The first charging stage is, for example, the stage at the start of charging, such as the trickle charging stage and / or the constant voltage charging stage. The second charging stage can be, for example, the subsequent constant current charging stage.

[0095] In some embodiments, the control unit 24 is configured to output a PWM signal or a PFM signal according to the output gain to adjust the output voltage of the transformer 222. Wherein, the output gain can be, for example, the ratio of the output voltage of the transformer 222 to the input voltage of the transformer 222, or the output gain can be the ratio of the output voltage of the second-stage conversion circuit 22 to the output voltage of the first-stage conversion circuit 21. In addition, the output gain can also be, for example, the ratio of the output voltage of the power supply device 30 to the input voltage of the transformer 222.

[0096] In some embodiments, the control unit 24 can also be configured to receive the feedback information of the device to be charged connected to the power supply device 30, and according to the feedback information, control the control signal input to the first switch unit 211 to adjust the output voltage and / or output current of the power supply device 30.

[0097] For example, when it is determined to adopt the PWM mode (i.e., output a PWM signal), according to the feedback information, adjust the duty cycle of the control signal input to the first switch unit 211 to adjust the output voltage and / or output current of the power supply device 30. When it is determined to adopt the PFM mode (i.e., output a PFM signal), according to the feedback information, adjust the frequency of the control signal input to the first switch unit 211 to adjust the output voltage and / or output current of the power supply device 30.

[0098] The feedback information can include, for example: the desired charging voltage and / or charging current of the device to be charged. Or, the feedback information can also include: the adjustment instruction generated by the device to be charged based on the desired charging voltage and / or charging current.

[0099] In the embodiments of the present disclosure, a first-stage conversion circuit is adopted in the first-stage architecture to rectify and boost the AC voltage, so that there is no need to use large-size capacitors (such as liquid electrolytic capacitors). However, since the output of the first-stage conversion circuit is unstable, the PFM mode or the PWM mode can also be used to control the input signal of the switching unit in the first-stage conversion circuit to ensure the stability of the output gain and output voltage of the first-stage conversion circuit.

[0100] The first-stage conversion circuit 21 may include a second switching unit. In addition, the power supply device 30 may also Figure 3A as shown, include a second detection unit 26 for detecting the output voltage and / or output current of the first-stage conversion circuit 21. The control unit 24 controls the on and off of the second switching unit by outputting a control signal according to the output voltage and / or output current detected by the second detection unit 26 to adjust the output voltage and / or output current of the first-stage conversion circuit 21.

[0101] The first-stage conversion circuit 21 may, for example, Figure 6A as shown, include a rectification circuit 211 and a boost circuit 212. Among them, the rectification circuit 211 is used to rectify the received alternating current. The rectification circuit 211 may, for example, be a full-bridge rectification circuit. The boost circuit 212 is used to boost the rectified direct current. The boost circuit 212 may, for example, Figure 6B as shown, the second switching unit is, for example, Figure 6B the switching transistor S1 in the boost circuit 212 in. It should be noted that the boost circuit shown in the figure is only an example and does not limit the present disclosure.

[0102] The first-stage conversion circuit 21 may also, for example, be implemented as Figure 6C the shown totem-pole boost circuit. The second switching unit may, for example, Figure 6C the switching transistors S1 and S2 in.

[0103] It should be noted that Figure 6C the shown totem-pole boost circuit is only an example and does not limit the present disclosure. The structure of the totem-pole boost circuit is well known to those skilled in the art and will not be elaborated here.

[0104] The control unit 24 determines to output a PWM signal or a PFM signal according to the output voltage and / or output current of the first-stage conversion circuit 21, and adjusts the output voltage and / or output current of the first-stage conversion circuit 21 so that the output voltage of the first-stage conversion circuit 21 is equal to a preset reference voltage.

[0105] Figure 3BIt is a schematic structural diagram of yet another power supply device shown according to an example. Different from Figure 3A the power supply device 30 shown, Figure 3B the power supply device 30' in

[0106] includes a first control unit 241 and a second control unit 242, which are respectively used to control the first-stage conversion circuit 21 and the second-stage conversion circuit 22.

[0107] The second control unit 242 is used to determine that the control signal output to the first switch unit 221 is a PWM signal or a PFM signal according to the voltage and / or current output by the transformer 222 or the power supply device 30', so as to adjust the output voltage of the transformer 222. The second control unit 242 can also be used to adjust the output voltage and / or output current of the power supply device 30' according to the received feedback information.

[0108] The first control unit 241 is used to determine that the control signal output to the second switch unit is a PWM signal or a PFM signal according to the voltage and / or current output by the first-stage conversion circuit 21, and adjust the output voltage and / or output current of the first-stage conversion circuit 21 so that the output voltage of the first-stage conversion circuit 21 is equal to a preset reference voltage.

[0109] Figure 7 It is a schematic structural diagram of yet another power supply device shown according to an example. As Figure 7 shown, the first-stage conversion circuit 21 in the power supply device takes the totem-pole boost circuit as an example, and the second-stage conversion circuit 22 takes the LLC resonant converter as an example.

[0110] The following are method embodiments of the present disclosure, which can be applied to the device embodiments of the present disclosure. For details not disclosed in the method embodiments of the present disclosure, please refer to the device embodiments of the present disclosure.

[0111] Figure 8 It is a flowchart of a charging control method shown according to an exemplary embodiment. The charging control method can be applied to the above power supply device 20 or 30 or 30'.

[0112] Refer to Figure 8 , the charging control method 40 includes:

[0113] In step S402, the received AC voltage is converted into a pulsating DC voltage through the first-stage conversion circuit.

[0114] Among them, the voltage value of the pulsating DC voltage is higher than that of the AC voltage.

[0115] In step S404, the pulsating direct current is transformed by the second-stage transformation circuit to output a constant DC voltage.

[0116] In some embodiments, the first-stage transformation circuit includes at least one filter capacitor, and the capacitance of the filter capacitor is less than a preset value.

[0117] In some embodiments, as Figure 9 shown, the charging control method 40 further includes:

[0118] In step S406, the output voltage and / or output current of the power supply providing device is detected.

[0119] In step S408, according to the output voltage and / or output current of the power supply providing device, a control signal is output to control the on or off of the first switch unit in the second-stage transformation circuit, and the output voltage of the voltage transformation unit in the second-stage transformation circuit is adjusted, so as to adjust the voltage value of the constant DC voltage.

[0120] In some embodiments, as [[ID=H]]Figure 1 shown, step S408 may include: in step S4082, according to the output voltage and / or output current of the power supply providing device, a PWM signal or a PFM signal is output to adjust the output voltage of the voltage transformation unit.

[0121] In some embodiments, step 4082 may be specifically implemented as: when the output voltage of the power supply providing device is less than a preset first voltage threshold, and / or the output current of the power supply providing device is less than a preset first current threshold, a PWM signal is output to adjust the output voltage of the voltage transformation unit; when the output voltage of the power supply providing device is greater than or equal to the first voltage threshold, and / or the output current of the power supply providing device is greater than or equal to the first current threshold, a PFM signal is output to adjust the output voltage of the voltage transformation unit.

[0122] In some embodiments, in some embodiments, as Figure 10 shown, the charging control method 40 further includes:

[0123] In step S406’, the output voltage and / or output current of the voltage transformation unit in the second-stage transformation circuit is detected.

[0124] In step S408’, according to the output voltage and / or output current of the voltage transformation unit, a control signal is output to control the on or off of the first switch unit in the second-stage transformation circuit, and the output voltage of the voltage transformation unit is adjusted, so as to adjust the voltage value of the constant DC voltage.

[0125] In some embodiments, asFigure 11 As shown, step S408' may include: in step S4082', output a PWM signal or a PFM signal according to the output voltage and / or output current of the voltage conversion unit to adjust the output voltage of the voltage conversion unit.

[0126] In some embodiments, step 4082' may be specifically implemented as follows: when the output voltage of the voltage conversion unit is less than a preset first voltage threshold and / or the output current of the voltage conversion unit is less than a preset first current threshold, output a PWM signal to adjust the output voltage of the voltage conversion unit; when the output voltage of the voltage conversion unit is greater than or equal to the first voltage threshold and / or the output current of the voltage conversion unit is greater than or equal to the first current threshold, output a PFM signal to adjust the output voltage of the voltage conversion unit.

[0127] In some embodiments, step 4082' may also be specifically implemented as follows: in the first charging stage, adjust the output voltage of the voltage conversion unit by outputting a PWM signal; and in the second charging stage, adjust the output voltage of the voltage conversion unit by outputting a PFM signal; wherein, the output voltage of the power supply device in the first charging stage is lower than the output voltage in the second charging stage.

[0128] In some embodiments, step 4082' may also be specifically implemented as follows: adjust the output voltage of the voltage conversion unit by outputting a PWM signal or a PFM signal according to the output gain; wherein, the output gain is the ratio of the output voltage of the voltage conversion unit to the input voltage of the voltage conversion unit, or the output gain is the ratio of the output voltage of the second-stage conversion circuit to the output voltage of the first-stage conversion circuit.

[0129] In some embodiments, as Figure 12 or Figure 9 shown, the charging control method 40 further includes: in step 410, receiving feedback information of a device to be charged connected to the power supply device. In step S412, according to the feedback information, control a control signal that is a PFM signal or a PWM signal to adjust the output voltage and / or output current of the power supply device.

[0130] In some embodiments, the feedback information includes: the charging voltage and / or charging current expected by the device to be charged, or an adjustment instruction generated by the device to be charged based on the expected charging voltage and / or charging current.

[0131] The charging control method provided by the embodiments of the present disclosure enables a variable bus voltage to exist between the two-stage architecture formed by the first-stage conversion circuit and the second-stage conversion circuit because the first-stage conversion circuit boosts the input AC voltage. The energy storage function can be achieved through the change of the bus voltage, so that the power supply device executing this method does not need to use a large-sized capacitor as an energy storage element. Removing the large-sized capacitor can reduce the volume of the power supply device.

[0132] Figure 11 is a flowchart of another charging control method shown according to an exemplary embodiment. Different from Figure 13 the charging control method 40 shown, Figure 8 the charging control method 50 shown further includes:

[0133] In step S502, detect the output voltage and / or output current of the first-stage conversion circuit.

[0134] In step S504, according to the output voltage and / or output current of the first-stage conversion circuit, output a control signal to control the conduction or cutoff of the second switch unit in the first-stage conversion circuit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit.

[0135] In some embodiments, the input signal of the second switch unit is a pulse width modulation signal; as Figure 13 Figure 14 shown, step S504 may include: in step S5042, according to the output voltage and / or output current of the first-stage conversion circuit, adjust the output voltage and / or output current of the first-stage conversion circuit by outputting a PWM signal or a PFM signal, so that the output voltage of the first-stage conversion circuit is equal to a preset reference voltage.

[0136] It should be noted that the above drawings are only schematic illustrations of the processes included in the method according to the exemplary embodiments of the present disclosure, rather than for limiting purposes. It is easy to understand that the processes shown in the above drawings do not indicate or limit the time sequence of these processes. Additionally, it is also easy to understand that these processes can be executed synchronously or asynchronously in, for example, multiple modules.

[0137] The exemplary embodiments of the present disclosure have been specifically shown and described above. It should be understood that the present disclosure is not limited to the detailed structures, setting manners, or implementation methods described herein; on the contrary, the present disclosure is intended to cover various modifications and equivalent settings included within the spirit and scope of the appended claims.

Claims

1. A power supply device, characterized in that, Comprising: A first-stage conversion circuit for converting the received AC voltage into a pulsating DC voltage, the voltage value of the pulsating DC voltage being higher than that of the AC voltage; And A second-stage conversion circuit connected to the first-stage conversion circuit for converting the pulsating DC voltage and outputting a constant DC voltage, the constant DC voltage being a constant DC voltage without a pulsating waveform, and the voltage value of the constant DC voltage being different in different charging scenarios or charging stages; The second-stage conversion circuit includes a first switching unit and a voltage conversion unit; The power supply device further includes: A first detection unit connected to the voltage conversion unit for detecting the output voltage and / or current of the voltage conversion unit, wherein the voltage conversion unit magnetically couples electrical energy from the primary side to the secondary side, and the electrical energy coupled to the secondary side is extracted from the electrical energy output by the first-stage conversion circuit, and the extraction method of energy is controlled by the control unit according to the detected output voltage and / or output current of the voltage conversion unit; and A control unit connected to the first detection unit and the first switching unit respectively, for controlling the first switching unit to conduct or turn off by outputting a control signal according to the output voltage value and / or current value detected by the first detection unit, and adjusting the output voltage of the voltage conversion unit, thereby adjusting the voltage value of the constant DC voltage, wherein the first switching unit performs chopper modulation on the pulsating direct current output by the first-stage conversion circuit, so that the modulated voltage is transformed by the voltage conversion unit.

2. The power supply device according to claim 1, wherein The first-stage conversion circuit includes at least one filter capacitor, and the capacitance of the filter capacitor is less than a preset value.

3. The power supply device according to claim 1, characterized in that, The control signal includes: a pulse width modulation (PWM) signal and a pulse frequency modulation (PFM) signal; the control unit is configured to output the PWM signal or the PFM signal according to the output voltage value and / or current value detected by the first detection unit to adjust the output voltage of the voltage conversion unit.

4. The power supply device according to claim 3, characterized in that, The control unit is configured to output the PWM signal or the PFM signal according to an output gain to adjust the output voltage of the voltage conversion unit, wherein the output gain is the ratio of the output voltage of the voltage conversion unit to the input voltage of the voltage conversion unit, or the output gain is the ratio of the output voltage of the second-stage conversion circuit to the output voltage of the first-stage conversion circuit.

5. The power supply device according to claim 3, characterized in that The control unit is configured to output the PWM signal to adjust the output voltage of the voltage conversion unit in the first charging stage; and output the PFM signal to adjust the output voltage of the voltage conversion unit in the second charging stage; wherein the output voltage of the power supply device in the first charging stage is lower than that in the second charging stage.

6. The power supply device according to claim 3, wherein The control unit is configured to output the PWM signal to adjust the output voltage of the voltage conversion unit when the output voltage of the voltage conversion unit is less than a preset first voltage threshold and / or the output current of the voltage conversion unit is less than a preset first current threshold; When the output voltage of the voltage conversion unit is greater than or equal to the first voltage threshold, and / or the output current of the voltage conversion unit is greater than or equal to the first current threshold, output the PFM signal to adjust the output voltage of the voltage conversion unit.

7. The power supply device according to claim 1, characterized in that, The second-stage conversion circuit includes a first switching unit and a voltage conversion unit; The power supply device further includes: A first detection unit for detecting the output voltage and / or current of the power supply device; and A control unit, connected to the first detection unit and the first switching unit respectively, for controlling the first switching unit to conduct or turn off according to the output voltage value and / or current value detected by the first detection unit, by outputting a control signal, to adjust the output voltage of the voltage conversion unit, thereby adjusting the voltage value of the constant DC voltage.

8. The power supply device according to any one of claims 3-7, characterized in that, The control unit is further configured to receive feedback information of a device to be charged connected to the power supply device, and control the control signal of the first switching unit according to the feedback information to adjust the output voltage and / or output current of the power supply device.

9. The power supply device according to claim 8, wherein The feedback information includes: the charging voltage and / or charging current expected by the device to be charged, or an adjustment instruction generated by the device to be charged based on the expected charging voltage and / or charging current.

10. The power supply device according to any one of claims 3-7, characterized in that, The first-stage conversion circuit includes: a second switching unit; The power supply device further includes: A second detection unit, connected to the first-stage conversion circuit and the control unit respectively, for detecting the output voltage and / or output current of the first-stage conversion circuit; The control unit is further configured to output a second control signal according to the output voltage and / or output current of the first-stage conversion circuit to control the conduction or turn-off of the second switching unit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit.

11. The power supply device according to claim 10, wherein The second control signal includes: a PWM signal and a PFM signal; the control unit is configured to output the PWM signal or the PFM signal according to the output voltage and / or output current of the first-stage conversion circuit to adjust the output voltage and / or output current of the first-stage conversion circuit, so that the output voltage of the first-stage conversion circuit is equal to a preset reference voltage.

12. The power supply device according to claim 2, characterized in that, The capacitor includes at least one of the following capacitors: a thin film capacitor, a multilayer ceramic capacitor, a chip capacitor or an electrolytic capacitor.

13. The power supply device according to any one of claims 1-7, characterized in that, The first-stage conversion circuit includes: a totem pole boost circuit.

14. The power supply device according to any one of claims 1-7, characterized in that, The first-stage conversion circuit includes: a rectification circuit and a boost circuit.

15. The power supply device according to any one of claims 1-7, characterized in that, The second-stage conversion circuit includes: an LLC resonant converter.

16. A charging control method, applied to a power supply device, characterized in that Including: Converting the received AC voltage into a pulsating DC voltage through a first-stage conversion circuit, the voltage value of the pulsating DC voltage being higher than the voltage value of the AC voltage; And Converting the pulsating DC voltage through a second-stage conversion circuit to output a constant DC voltage, the constant DC voltage being a constant DC voltage without a pulsating waveform, and the voltage value of the constant DC voltage being different in different charging scenarios or charging stages; The method further includes: detecting the output voltage and / or output current of the voltage transformation unit in the second-stage transformation circuit, wherein the voltage transformation unit couples electrical energy from the primary side to the secondary side in an electromagnetic coupling manner, and the electrical energy coupled to the secondary side is extracted from the electrical energy output by the first-stage transformation circuit, and the extraction manner of the energy is controlled by the control unit according to the detected output voltage and / or output current of the voltage transformation unit; According to the output voltage and / or output current of the voltage transformation unit, by outputting a control signal, controlling the conduction or cutoff of the first switching unit in the second-stage transformation circuit, and adjusting the output voltage of the voltage transformation unit, so as to adjust the voltage value of the constant DC voltage, wherein the first switching unit performs chopping modulation on the pulsating direct current output by the first-stage transformation circuit, so that the modulated voltage is transformed by the voltage transformation unit.

17. The method according to claim 16, wherein The first-stage transformation circuit includes at least one filter capacitor, and the capacitance of the filter capacitor is less than a preset value.

18. The method according to claim 16, wherein The control signal includes: a PWM signal and a PFM signal; according to the output voltage and / or output current of the voltage transformation unit, by outputting a control signal, controlling the conduction or cutoff of the first switching unit in the second-stage transformation circuit, and adjusting the output voltage of the voltage transformation unit, includes: Outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit to adjust the output voltage of the voltage transformation unit.

19. The method according to claim 18, wherein Outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit to adjust the output voltage of the voltage transformation unit, includes: Outputting the PWM signal or the PFM signal according to the output gain to adjust the output voltage of the voltage transformation unit; Wherein, the output gain is the ratio of the output voltage of the voltage transformation unit to the input voltage of the voltage transformation unit, or the output gain is the ratio of the output voltage of the second-stage transformation circuit to the output voltage of the first-stage transformation circuit.

20. The method according to claim 18, wherein Outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit to adjust the output voltage of the voltage transformation unit, includes: In the first charging stage, outputting the PWM signal to adjust the output voltage of the voltage transformation unit; and In the second charging stage, outputting the PFM signal to adjust the output voltage of the voltage transformation unit; Wherein, the output voltage of the power supply device in the first charging stage is lower than the output voltage in the second charging stage.

21. The method according to claim 18, wherein Outputting the PWM signal or the PFM signal according to the output voltage value and / or current value of the voltage transformation unit to adjust the output voltage of the voltage transformation unit, includes: When the output voltage of the voltage transformation unit is less than a preset first voltage threshold, and / or the output current of the voltage transformation unit is less than a preset first current threshold, outputting the PWM signal to adjust the output voltage of the voltage transformation unit; When the output voltage of the voltage conversion unit is greater than or equal to the first voltage threshold, and / or the output current of the voltage conversion unit is greater than or equal to the first current threshold, output the PFM signal to adjust the output voltage of the voltage conversion unit.

22. The method according to claim 16, wherein It further includes: Detect the output voltage and / or output current of the power supply device; According to the output voltage and / or output current of the power supply device, control the conduction or cutoff of the first switching unit in the second-stage conversion circuit by outputting a control signal, and adjust the output voltage of the voltage conversion unit in the second-stage conversion circuit, so as to adjust the voltage value of the constant DC voltage.

23. The method according to any one of claims 19-22, characterized in that, It further includes: Receive the feedback information of the device to be charged connected to the power supply device; And According to the feedback information, control the control signal of the first switching unit to adjust the output voltage and / or output current of the power supply device.

24. The method according to claim 23, characterized in that The feedback information includes: the charging voltage and / or charging current expected by the device to be charged, or the adjustment instruction generated by the device to be charged based on the expected charging voltage and / or charging current.

25. The method according to any one of claims 19 - 22, characterized in that, It further includes: Detect the output voltage and / or output current of the first-stage conversion circuit; And According to the output voltage and / or output current of the first-stage conversion circuit, output a second control signal to control the conduction or cutoff of the second switching unit in the first-stage conversion circuit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit.

26. The method according to claim 25, wherein The second control signal includes: PWM signal and PFM signal; according to the output voltage and / or output current of the first-stage conversion circuit, output a second control signal to control the conduction or cutoff of the second switching unit, so as to adjust the output voltage and / or output current of the first-stage conversion circuit, including: According to the output voltage and / or output current of the first-stage conversion circuit, output a PWM signal or a PFM signal to adjust the output voltage and / or output current of the first-stage conversion circuit, so that the output voltage of the first-stage conversion circuit is equal to a preset reference voltage.

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