Power conversion device, control device, and switching power supply

Abstract

The application provides a power conversion device, a control device and a switching power supply, which can be used in the technical field of power supply. In the technical scheme of the application, a power-down holding time extension circuit reuses a PFC inductor and a switching unit in a PFC circuit, so that only one capacitor and one switching unit need to be added at least, thereby the number of newly added devices can be reduced, and the cost is reduced.

Description

Technical Field

[0001] This application relates to the field of power supply technology, and in particular to power conversion devices, control devices, and switching power supplies. Background Technology

[0002] In power supply applications, power conversion devices that include alternating current to direct current (AC-DC) converters are typically used to supply power to electrical equipment. Such power conversion devices can be called AC-DC power supply equipment.

[0003] Figure 1 This is a schematic circuit topology diagram of an AC-DC converter. (Example:) Figure 1 As shown, the AC-DC converter may include a rectifier circuit, a bus capacitor C1, a DC converter, and an output capacitor C0. The rectifier circuit converts AC power into a first DC power and outputs the first DC power. The bus capacitor C1 filters the first DC power to obtain a more stable second DC power and outputs the second DC power. The DC converter converts the second DC power into a third DC power corresponding to the voltage required by the electrical equipment and outputs the third DC power. The output capacitor C0 regulates the third DC power to obtain a stable fourth DC power and outputs the fourth DC power to the electrical equipment.

[0004] During the process of supplying power to electrical equipment using a power conversion device containing the AC-DC converter, for a period of time after the AC-DC converter is directly disconnected from the AC power supply, commonly referred to in the art as the power-off period, the bus capacitor C1 can continue to provide energy to the DC converter. This allows the output capacitor to output power to the electrical equipment, enabling the equipment to perform necessary data storage or transmission operations, thus facilitating reliable shutdown of the device. In the art, this period is referred to as the power-off hold-up time.

[0005] Generally speaking, the longer the power-down retention time of an AC-DC converter, the better. Therefore, how to improve the power-down retention time of an AC-DC converter has become an urgent technical problem to be solved. Summary of the Invention

[0006] This application provides a power conversion device, a control device, and a switching power supply. In the power conversion device and power conversion equipment proposed in this application, because the power-down retention circuit reuses the electronic components in the PFC circuit, the power-down retention time of the power conversion device and power conversion equipment can be improved while reducing cost and circuit size.

[0007] In a first aspect, this application provides a power conversion device, the device comprising a rectifier circuit, a power factor correction (PFC) circuit, and a bus capacitor connected in sequence. The rectifier circuit is used to convert received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current.

[0008] Furthermore, the first inductor and the bus capacitor in the PFC circuit are used to form a first current loop, in which the bus capacitor provides electrical energy to the first inductor, and the first inductor stores the electrical energy released by the bus capacitor.

[0009] The device further includes an auxiliary capacitor, the auxiliary capacitor, the bus capacitor, and the first inductor, which are used to form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide power to the auxiliary capacitor. The auxiliary capacitor stores the power released by the bus capacitor and the first inductor. The auxiliary capacitor is also used to provide power to the subsequent circuit.

[0010] In this device, the bus capacitor and the first inductor in the PFC circuit form a first current loop, allowing the bus capacitor to supply power to the first inductor, which in turn stores the energy released by the bus capacitor. Then, the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop, allowing the first inductor and the bus capacitor to supply power to the auxiliary capacitor, which in turn stores the energy released by the first inductor and the bus capacitor.

[0011] Furthermore, the first inductor and the bus capacitor are connected in series. The voltage at which the first inductor and the bus capacitor charge the auxiliary capacitor is the sum of the voltage of the first inductor and the voltage of the bus capacitor. This increases the charging voltage of the auxiliary capacitor, thereby increasing the charge storage capacity of the auxiliary capacitor and thus extending the duration for which the auxiliary capacitor supplies power to the subsequent circuits.

[0012] This device uses the first inductor in the PFC circuit to assist the bus capacitor in boosting the voltage of the auxiliary capacitor. This allows the auxiliary capacitor to extend the power supply time for subsequent circuits during power loss, thereby reducing the number of electronic components required to extend the power-down hold-up time, reducing the board area, and lowering costs. Furthermore, it avoids the problem of reduced power supply efficiency that might arise from adding power devices in existing extended power-down hold-up time circuits.

[0013] In some possible implementations, the first inductor, the bus capacitor, and the auxiliary capacitor are connected by a switching circuit, which is used to: turn on the first current loop or the second current loop after the rectifier circuit is powered off.

[0014] A rectifier circuit losing power can be understood as the rectifier circuit having no current input. For example, the rectifier circuit loses power when it is disconnected from the power supply, or when the power supply stops providing electrical energy.

[0015] Optionally, the switching circuit can turn on either the first current loop or the second current loop.

[0016] In some possible implementations, the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit.

[0017] The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit, the positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor, and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit.

[0018] The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit, and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0019] In some possible implementations, the PFC circuit includes a first switching unit and a second switching unit.

[0020] In this implementation, the switching unit in the PFC circuit is reused to connect the first inductor, the bus capacitor, and the auxiliary capacitor, which can further reduce the number of electronic components required to extend the power-down retention time, reduce the board area, and lower the cost.

[0021] In some possible implementations, the third switching unit includes a MOSFET and a diode, with the cathode of the diode connected to the cathode of the bus capacitor, the anode of the diode connected to the source of the MOSFET, and the drain of the MOSFET connected to the second port of the first inductor.

[0022] This implementation reduces the control complexity of the device because the diode can turn on or off automatically without control.

[0023] In some possible implementations, the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit.

[0024] The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit, the positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit, and the negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor.

[0025] The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit, and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0026] In some possible implementations, the PFC circuit further includes a first switching unit and a second switching unit.

[0027] In this implementation, the switching unit in the PFC circuit is reused to connect the first inductor, the bus capacitor, and the auxiliary capacitor, which can further reduce the number of electronic components required to extend the power-down retention time, reduce the board area, and lower the cost.

[0028] In some possible implementations, the third switching unit includes a MOSFET and a diode, with the anode of the diode connected to the anode of the bus capacitor, the cathode of the diode connected to the drain of the MOSFET, and the source of the MOSFET connected to the second port of the first inductor.

[0029] This implementation reduces the control complexity of the device because the diode can turn on or off automatically without control.

[0030] In some possible implementations, the first switching unit includes a diode, and the anode of the diode in the first switching unit is connected to the first port of the first inductor.

[0031] This implementation reduces the control complexity of the device because the diode can turn on or off automatically without control.

[0032] In some possible implementations, the first switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated-gate bipolar transistor (IGBT).

[0033] Optionally, the first switching unit includes a first MOSFET and a second MOSFET, the first MOSFET and the second MOSFET are connected in series, and the source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET.

[0034] In some possible implementations, the fourth switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated-gate bipolar transistor (IGBT).

[0035] In some possible implementations, the second switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated-gate bipolar transistor (IGBT).

[0036] In some possible implementations, the device further includes a soft-start circuit, which includes the fourth switching unit, and the soft-start circuit is used to control the rising slope and amplitude of the input current of the bus capacitor.

[0037] In this implementation, the switching unit in the soft-start circuit is used to boost the voltage of the auxiliary capacitor, which can further reduce the number of components, reduce costs, and reduce area.

[0038] In some possible implementations, the soft-start circuit further includes a resistor unit connected in parallel with the fourth switching unit.

[0039] In some possible implementations, the rectifier circuit includes a first diode, a second diode, a third diode, and a fourth diode. The anode of the first diode and the cathode of the third diode are connected to a first port of the rectifier circuit, which is used to connect to one electrode of the AC power supply. The anode of the second diode and the cathode of the fourth diode are connected to a second port of the rectified current supply, which is used to connect to the other electrode of the AC power supply. The cathodes of the first diode and the second diode are connected to a third port of the rectifier circuit. The anodes of the third diode and the fourth diode are connected to a fourth port of the rectified current supply. The third port of the rectifier circuit is connected to a first port of the PFC circuit, and the fourth port of the rectifier circuit is connected to a second port of the PFC circuit.

[0040] The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, and the second port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

[0041] The PFC circuit in this implementation can be called a bridged PFC circuit. In other words, the technical solution of this application can extend the power-down retention time in a device containing a bridged PFC circuit using a smaller number of components.

[0042] In some possible implementations, the rectifier circuit includes a first diode and a second diode, the anode of the first diode and the cathode of the second diode being connected to a first port of the rectifier circuit, the cathode of the first diode being connected to a second port of the rectifier circuit, and the anode of the second diode being connected to a third port of the rectifier circuit.

[0043] The first port of the rectifier circuit is used to connect to the negative terminal of the AC power supply, the first port of the PFC circuit is used to connect to the positive terminal of the AC power supply, the second port of the rectifier circuit is connected to the second port of the PFC circuit, and the third port of the rectifier circuit is connected to the third port of the PFC circuit.

[0044] The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, the second port of the PFC circuit is the port connected to the first switching unit in the PFC circuit, and the third port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

[0045] The PFC circuit in this implementation can be called a bridgeless PFC circuit. In other words, the technical solution of this application can extend the power-down retention time in a device containing a bridgeless PFC circuit using a smaller number of components.

[0046] In some possible implementations, the rectifier circuit includes a first diode and a second diode, the cathode of the first diode being connected to a first port of the rectifier circuit, the cathode of the second diode being connected to a second port of the rectifier circuit, and the anodes of the first diode and the second diode being connected to a third port of the rectifier circuit.

[0047] The PFC circuit further includes a second inductor, a fifth switching unit, and a sixth switching unit. The first port of the second inductor is connected to the fourth port of the PFC circuit. The second port of the second inductor, the first port of the fifth switching unit, and the first port of the sixth switching unit are connected. The second port of the fifth switching unit is connected to the second port of the PFC circuit. The second port of the sixth switching unit is connected to the third port of the PFC circuit.

[0048] The first port of the rectifier circuit and the first port of the PFC circuit are used to connect to the positive terminal of the AC power supply, the second port of the rectifier circuit and the fourth port of the PFC circuit are used to connect to the negative terminal of the AC power supply, and the third port of the rectifier circuit and the third port of the PFC circuit are connected.

[0049] The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, the second port of the PFC circuit is the port connected to the first switching unit in the PFC circuit, and the third port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

[0050] The PFC circuit in this implementation can be called a dual-boost bridgeless PFC circuit. In other words, the technical solution of this application can extend the power-down retention time in a device containing a dual-boost bridgeless PFC circuit using a smaller number of components.

[0051] Secondly, this application provides a control method for a power conversion device, wherein the power conversion device can be any of the power conversion devices described in the first aspect. For example, the power conversion device includes a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to provide power to the subsequent circuits.

[0052] The method includes: when the input of the rectifier circuit is de-energized, controlling the power conversion device to be in a first operating state or a second operating state.

[0053] The first operating state includes: the bus capacitor and the first inductor forming a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor.

[0054] The second operating state includes: the auxiliary capacitor, the bus capacitor, and the first inductor forming a second current loop, in which the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor, and the auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

[0055] In this embodiment, in the first operating state, the first inductor can form a circuit with the bus capacitor, so that the bus capacitor charges the first inductor; in the second operating state, the first inductor can form a circuit with the bus capacitor and the auxiliary capacitor, so that the bus capacitor and the first capacitor together charge the auxiliary capacitor, thereby increasing the voltage of the auxiliary capacitor, which in turn allows the auxiliary capacitor to store more charge, thereby extending the time for the auxiliary capacitor to supply power to the subsequent circuit.

[0056] In this embodiment, the power conversion device can be controlled to be in a first working state or a second working state.

[0057] In some possible implementations, the first inductor, the bus capacitor, and the auxiliary capacitor are connected via a switching circuit. Controlling the power conversion device to a first operating state or a second operating state includes: controlling a first portion or a second portion of the switching circuit to be turned on, wherein the first portion of the switching circuit is used to connect the bus capacitor and the first inductor, and the second portion of the switching circuit is used to connect the bus capacitor, the first inductor, and the auxiliary capacitor.

[0058] Optionally, the first part of the switching circuit and the second part of the switching circuit can be controlled to conduct alternately.

[0059] In this implementation, the alternating conduction of the first part of the circuit and the second part of the circuit can be understood as: the first part of the circuit is on and the second part of the circuit is off, then the second part of the circuit is on and the first part of the circuit is off, then the first part of the circuit is on and the second part of the circuit is off, and so on.

[0060] In some possible implementations, the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit; the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit; the positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor; and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit; and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0061] The control of the power conversion device in the first operating state includes: controlling the first switching unit and the third switching unit to be turned on, and controlling the second switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the first operating state; the control of the power conversion device in the second operating state includes: controlling the second switching unit and the third switching unit to be turned on, and controlling the first switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the second operating state.

[0062] In this implementation, the switching unit in the PFC circuit is reused to control the power conversion device to be in the first working state or the second working state, which can further reduce the electronic components required to extend the power-down retention time, reduce the board area, and reduce costs.

[0063] In some possible implementations, the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit. The first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit. The negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The device includes a third switching unit and a fourth switching unit. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit. The positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0064] The control of the power conversion device in the first operating state includes: controlling the second switching unit and the third switching unit to be turned on, and controlling the first switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the first operating state; the control of the power conversion device in the second operating state includes: controlling the first switching unit and the third switching unit to be turned on, and controlling the second switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the second operating state.

[0065] In some possible implementations, the PFC circuit further includes a first switching unit and a second switching unit.

[0066] In this implementation, the switching unit in the PFC circuit is reused to control the power conversion device to be in the first working state or the second working state, which can further reduce the electronic components required to extend the power-down retention time, reduce the board area, and reduce costs.

[0067] Thirdly, this application provides a control device for a power conversion device, wherein the power conversion device can be any of the possible implementations of the first aspect, and the control device is the corresponding control device in the second aspect.

[0068] For example, the power conversion device includes a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to provide power to the subsequent circuits.

[0069] The control device is used to control the power conversion device to be in a first working state or a second working state when the input of the rectifier circuit is de-energized.

[0070] The first operating state includes: the bus capacitor and the first inductor forming a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor.

[0071] The second operating state includes: the auxiliary capacitor, the bus capacitor, and the first inductor forming a second current loop, in which the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor, and the auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

[0072] Optionally, the control device can be used to control the power conversion device to be in a first operating state or a second operating state.

[0073] In some possible implementations, the PFC circuit includes a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor, and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit. The device further includes a third switching unit and a fourth switching unit. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit, and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0074] Specifically, when the power conversion device is controlled to be in a first operating state, the control device is used to: control the first switching unit and the third switching unit to be turned on, and control the second switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the first operating state; when the power conversion device is controlled to be in a second operating state, the control device is used to: control the second switching unit and the third switching unit to be turned on, and control the first switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the second operating state.

[0075] In some possible implementations, the PFC circuit further includes a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit, and the negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The device includes a third switching unit and a fourth switching unit. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit, and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0076] Specifically, when the power conversion device is controlled to be in the first operating state, the control device is used to: control the second switching unit and the third switching unit to be turned on, and control the first switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the first operating state; when the power conversion device is controlled to be in the second operating state, the control device is used to: control the first switching unit and the third switching unit to be turned on, and control the second switching unit and the fourth switching unit to be turned off, so that the power conversion device is in the second operating state.

[0077] The technical effects of the control device in this embodiment can be referred to the control method in the second aspect, and will not be repeated here.

[0078] Fourthly, this application provides a switching power supply, which includes the power conversion device described in any possible implementation of the first aspect and the control device described in any possible implementation of the third aspect.

[0079] The technical effects of the switching power supply in this embodiment can be referred to in the first and second aspects, and will not be repeated here. Attached Figure Description

[0080] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0081] Figure 1 This is a schematic circuit topology diagram of an AC-DC converter;

[0082] Figure 2 This is a schematic diagram of an AC-DC circuit structure;

[0083] Figure 3 This is an exemplary structural diagram of a power conversion device provided in one embodiment of this application;

[0084] Figure 4 This is a schematic structural diagram of a power conversion device 400 according to an embodiment of this application;

[0085] Figure 5(a) is a schematic diagram of current flow when the power conversion device 400 is powered normally;

[0086] Figure 5(b) is a schematic diagram of another current flow when the power conversion device 400 is powered normally;

[0087] Figure 6(a) is a schematic diagram of current flow when the power conversion device 400 is powered off;

[0088] Figure 6(b) is a schematic diagram of another current flow when the power conversion device 400 is powered off;

[0089] Figure 7(a) is an exemplary structural diagram of a switching unit according to an embodiment of this application;

[0090] Figure 7(b) is an exemplary structural diagram of a switching unit according to another embodiment of this application;

[0091] Figure 8 This is an exemplary structural diagram of a power conversion device 400 including a soft-start circuit;

[0092] Figure 9 An exemplary structural diagram of a soft-start circuit provided in one embodiment of this application;

[0093] Figure 10(a) is a schematic structural diagram of a rectifier circuit provided in an embodiment of this application;

[0094] Figure 10(b) is a schematic structural diagram of a rectifier circuit provided in another embodiment of this application;

[0095] Figure 10(c) is a schematic structural diagram of a rectifier circuit provided in another embodiment of this application;

[0096] Figure 11An exemplary structural diagram of a power conversion device 1100 provided in yet another embodiment of this application;

[0097] Figure 12(a) is a schematic diagram of current flow when the power conversion device 1100 is powered off;

[0098] Figure 12(b) is a schematic diagram of another current flow when the power conversion device 1100 is powered off;

[0099] Figure 13 This is an exemplary structural diagram of the power conversion device 1100 including a soft-start circuit in this application;

[0100] Figure 14 An exemplary structural diagram of a soft-start circuit provided in another embodiment of this application;

[0101] Figure 15 This is a schematic structural diagram of a switching power supply according to an embodiment of this application.

[0102] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0103] To better understand the purpose, technical solution, and advantages of this application, further explanation will follow with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained based on the embodiments in this application are within the scope of protection of this application.

[0104] AC-DC converters are generally used in power adapters, commonly known as chargers. For example, power conversion devices that include AC-DC converters can be used as power supplies for servers, network equipment such as routers and switches, communication equipment, uninterruptible power supplies (UPS), and light-emitting diodes (LEDs), providing power to various electronic devices such as monitors, servers, and network equipment.

[0105] When an AC-DC converter experiences a sudden power outage while supplying power to a device, the bus capacitor in the AC-DC converter can continue to provide energy to the DC converter during the power outage hold-up time. This allows the output capacitor to supply power to the device, enabling the device to save or transmit necessary data, thus facilitating a reliable shutdown. Generally, a longer power outage hold-up time for an AC-DC converter is better.

[0106] Figure 2 This is a schematic diagram of an AC-DC circuit structure. (Example) Figure 2 As shown, in this circuit structure, an extended power-down hold-up time circuit is added between the original AC-DC converter bus capacitor C1 and the DC converter. This extended power-down hold-up time circuit may include inductors L2, S4, S5, auxiliary capacitor C2, and power device D5. The power device D5 can be a diode or a MOSFET.

[0107] When the AC-DC converter's power conversion equipment is powered normally, controls S4 and S5 in the extended power-down hold-up time circuit to turn off. At this time, power device D5 bypasses the extended power-down hold-up time circuit. When the AC-DC converter's power conversion equipment loses power, controls S4 to turn on and controls S5 to turn off. The bus capacitor C1 transfers energy to the inductor L2. Controls S4 to turn off and controls S5 to turn on. The inductor L2 and the bus capacitor C1 provide energy to the auxiliary capacitor C2, so that the voltage of the auxiliary capacitor C2 can be stabilized within the rated input voltage range of the DC converter, thereby extending the power-down hold-up time.

[0108] However, the newly added power-down hold-up circuit in this circuit structure includes five components. The large number of components results in a larger board area and higher cost for this new power-down hold-up circuit.

[0109] To address this issue, this application proposes a new technical solution that improves the power-down retention time of AC-DC converters while also solving the problem of excessive additional components in existing circuit structures.

[0110] It should be noted that, in the embodiments of this application, the connection between one unit and another unit may include a direct connection or an indirect connection through other units.

[0111] Figure 3 This is an exemplary structural diagram of a power conversion device provided in one embodiment of this application. Figure 3 As shown, the power conversion device 300 may include a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor C1, an auxiliary capacitor C2, and a subsequent circuit. The PFC circuit includes a first inductor L1.

[0112] It is understood that this structure is merely an example, and the power conversion device in this embodiment may include more or fewer circuit units. For example, it may omit the rectifier circuit and / or subsequent stage circuitry.

[0113] In this embodiment, the rectifier circuit, PFC circuit, and bus capacitor are connected in sequence. In this embodiment, the rectifier circuit can be used to: receive alternating current, convert the alternating current into a first direct current, and output the first direct current.

[0114] In this embodiment, the PFC circuit can be used to: receive the first DC power output from the rectifier circuit, compensate for the phase between the current and voltage of the first DC power, and output the compensated second DC power.

[0115] The bus capacitor is used to: receive the second DC power, filter the second DC power, and output the filtered third DC power to the subsequent circuit.

[0116] The subsequent circuit in this embodiment may include a DC-DC converter circuit, which can be used to perform step-down or step-up processing on the received DC signal.

[0117] Optionally, the subsequent circuit may include an output capacitor, which can be used to regulate the received electrical signal. Optionally, the subsequent circuit may include a DC-DC converter and an output capacitor.

[0118] In this embodiment, L1 can be connected in series with C1 to form a first current loop. When the first current loop is formed between C1 and L1, C1 provides electrical energy to L1, and L1, as an energy storage device, stores the electrical energy released by C1.

[0119] In this embodiment, L1, C1, and C2 are used to form a second current loop. When the second current loop is formed between C2, C1, and L1, C1 and L1 are connected in series to provide electrical energy to C2, and C2 acts as an energy storage device to store the electrical energy released by C1 and L1.

[0120] In some implementations of this embodiment, L1, C1 and C2 are connected by a switching circuit, which is used to: conduct the first current loop or the second current loop after the rectifier circuit is powered off.

[0121] As an example, the switching circuit can be divided into two parts: a first part called the first switching circuit and a second part called the second switching circuit. The first switching circuit includes the switching circuit between C1 and L1, and the second switching circuit includes the switching circuit between C2, C1, and L1.

[0122] It is understood that the first and second parts of the switching circuit are divided based on function. Optionally, the first and second parts of the switching circuit may include common electronic components that enable different current loops to be switched into different parts of the switching circuit.

[0123] In some possible implementations, the switching circuit may include a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit.

[0124] When the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit, as an example, the first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit; the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit; the positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor; and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit. Furthermore, the second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit; and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0125] In another example where the switching circuit includes a first switching unit, a second switching unit, a third switching unit, and a fourth switching unit, the first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit; the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit; the positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit; and the negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. Furthermore, the second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit; and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0126] In some implementations, the first switching unit and / or the second switching unit can be switching units in a PFC circuit. The following describes some examples of the power conversion device of this application, assuming that both the first and second switching units are switching units in a PFC circuit.

[0127] Figure 4 This is an exemplary structural diagram of a power conversion device 400 according to an embodiment of this application. Figure 4 As shown, the PFC circuit includes a first switching unit S1 and a second switching unit S2.

[0128] S1 connects the first port of L1 to the positive terminal of C1. The first end of S2 is connected to the first port of L1, and the other end of S2 is connected to the negative terminal of C1. The positive terminal of C1 is connected to the positive terminal of C2, and the negative terminal of C2 is connected to the first port of L1 through S2.

[0129] Optionally, the power conversion device 400 may further include a third switching unit S3 and a fourth switching unit S4. The second port of L1 and the negative terminal of C1 are connected through S3, and the negative terminals of C2 and C1 are connected through S4.

[0130] C2 is also connected to the subsequent circuit to supply power to it, which is to output electrical signals to the subsequent circuit.

[0131] When the device 400 is powered normally, turning on S2 creates a current loop between L1 and the rectifier circuit, as shown in Figure 5(a); turning on S1 creates a current loop between L1, the rectifier circuit, and C1, as shown in Figure 5(b). Alternating between turning on S1 and S2 allows L1 to adjust the phase of the current and voltage of the first DC power output from the rectifier circuit and output the adjusted second DC power to C1. C1 can filter this second DC power to obtain a filtered third DC power, which is then output to the subsequent circuit, enabling the subsequent circuit to supply power to the electrical equipment.

[0132] In this embodiment, alternating S1 and S2 can be understood as: turning off S2 when S1 is turned on, or turning off S2 when S1 is turned on.

[0133] When the input of the power conversion device 400 is de-energized, i.e., when the AC power supply no longer supplies power to the rectifier circuit, the switching unit is controlled to cause the device 400 to alternate between a first operating state and a second operating state. The first operating state includes: a first current loop is formed between L1 and C1, in which C1 provides electrical energy to L1, and L1 stores the energy released by C1. The second operating state includes: a second current loop is formed between L1, C2, and C1, in which C1 and L1 are connected in series to provide electrical energy to C2, and C2 stores the energy released by C1 and L1.

[0134] The device 400 can be put into a first operating state by controlling the closing of S1 and S3 and the turning off of other switching units. When the device 400 is in the first operating state, the current flow between L1 and C1 is shown in Figure 6(a).

[0135] The device 400 can be put into a second operating state by controlling the closing of S2 and S3 and the turning off of other switching units. When the device 400 is in the second operating state, the current flow between L1 and C1 is shown in Figure 6(b).

[0136] Because C1 and L1 together transfer the stored energy to C2, the voltage of C2 can be increased, allowing C2 to store more energy and thus power the subsequent circuits for a longer period of time.

[0137] In this embodiment, as an example, S3 may include a first field-effect MOSFET and a second MOSFET, wherein the first MOSFET is connected in series with the second MOSFET, and the source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET.

[0138] In this embodiment, as another example, S3 may include a MOS transistor and a diode, the negative terminal of the diode is connected to the negative terminal of C1, the positive terminal of the diode is connected to the source of the MOS transistor, and the drain of the MOS transistor is connected to the second port of L1.

[0139] In this embodiment, as an example, S4 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0140] In this embodiment, as an example, S1 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0141] Optionally, in some possible implementations, S1 may include a diode, and the positive terminal of the diode in the first switching unit is connected to the first port of the first inductor.

[0142] Optionally, in some possible implementations, S1 may include a first MOS transistor and a second MOS transistor, wherein the first MOS transistor is connected in series with the second MOS transistor, and the source of the first MOS transistor is connected to the source of the second MOS transistor, or the drain of the first MOS transistor is connected to the drain of the second MOS transistor.

[0143] In this embodiment, as another example, S2 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0144] When S3 includes a MOSFET and a diode, and S1, S2 and S4 each include a MOSFET, a schematic diagram of one structure of device 400 is shown in Figure 7(a).

[0145] When S3 includes two opposing MOSFETs, S2 includes a MOSFET, S4 includes a relay, and S1 includes a diode, a schematic diagram of one structure of device 400 is shown in Figure 7(b).

[0146] In this embodiment, optionally, as follows: Figure 8 As shown, the power conversion device 400 may also include a soft-start circuit, which may include S4. The soft-start circuit is used to control the rising slope and amplitude of the input current of C1.

[0147] The soft-start circuit can be used to soft-start C1 when the PFC circuit initially receives the first DC current. This prevents C1 from being damaged by a strong current surge due to excessive current or voltage from the first DC current, thus achieving the purpose of circuit protection.

[0148] Optionally, such as Figure 9 As shown, the soft-start circuit may also include a positive temperature coefficient (PTC) thermistor, which is connected in parallel with S4.

[0149] The resistance of a PTC thermistor increases dramatically with its temperature; the higher the temperature, the greater the resistance. For example, when a PFC circuit initially receives its first DC current, or when an AC power source is initially input into the power converter, a large inrush current can easily be generated in the power converter, leading to overcurrent in the soft-start circuit. At this time, the PTC thermistor's temperature rises due to increased heating power. When the temperature exceeds a certain threshold, the resistance increases dramatically, and the current in the circuit rapidly decreases to a safe value.

[0150] In this embodiment, a PTC thermistor is added to the soft-start circuit. This can prevent the power loss from being increased when a single switching device is used as a soft-start circuit, thereby affecting the power efficiency.

[0151] In this application, the rectifier circuit can be implemented using various circuit structures, such as a bridged structure and a bridgeless structure. The bridged structure refers to a rectifier circuit that includes four diodes connected in a bridge configuration, converting alternating current (AC) into unidirectional direct current (DC). The bridgeless structure refers to a rectifier circuit that includes only two diodes, two fewer than a bridged rectifier circuit, which reduces conduction losses and improves power efficiency.

[0152] The PFC circuit in a power converter differs depending on the structure of the rectifier circuit. For example, when the rectifier circuit has a bridged structure, the PFC circuit in the power converter can be called a bridged PFC circuit. Similarly, when the rectifier circuit has a bridgeless structure and the PFC circuit includes one inductor, the PFC circuit in the power converter can be called a bridgeless PFC circuit. Furthermore, when the rectifier circuit has a bridgeless structure and the PFC circuit includes two inductors, the PFC circuit in the power converter can be called a dual-drive (boost) bridgeless PFC circuit.

[0153] When the rectifier circuit is a bridge rectifier circuit, an exemplary structural diagram of the device 400 is shown in Figure 10(a).

[0154] When the rectifier circuit is a bridgeless rectifier circuit and the PFC circuit includes a PFC inductor, an exemplary structural diagram of the device 400 is shown in Figure 10(b).

[0155] When the rectifier circuit is a bridgeless rectifier circuit and the PFC circuit includes two PFC inductors, an exemplary structural diagram of the device 400 is shown in Figure 10(c).

[0156] An exemplary structural diagram of a power conversion device according to another embodiment of this application is shown below. Figure 11 As shown. The power conversion device 1100 may include a rectifier circuit, a PFC circuit, capacitors C1, S1, S2, S3, S4 and an auxiliary capacitor C2.

[0157] The difference between device 1100 and device 300 in this embodiment is that: S3 is connected to the second port of L1 and the positive terminal of C1, one end of S1 is connected to the first port of L1, the other end of S1 is connected to the positive terminal of C1 through S4, the other end of S1 is connected to the positive terminal of C2, and the negative terminal of C2 is connected to the negative terminal of C1.

[0158] When the input of the power conversion device 1100 is de-energized, that is, when the AC power supply no longer supplies power to the rectifier circuit, the switching unit is controlled so that the device 1100 alternates between the first operating state and the second operating state.

[0159] The device 1100 can be put into its first operating state by controlling S2 and S3 to close and other switching units to turn off. When the device 1100 is in its first operating state, the current flow between L1 and C1 is shown in Figure 12(a).

[0160] The device 1100 can be put into a second operating state by controlling the closing of S1 and S3 and the turning off of other switching units. When the device 1100 is in the second operating state, the current flow between L1 and C1 is shown in Figure 12(b).

[0161] Because C1 and L1 together transfer the stored energy to C2, the voltage of C2 can be increased, allowing C2 to store more energy and thus power the subsequent circuits for a longer period of time.

[0162] In this embodiment, as an example, S3 may include a first field-effect MOSFET and a second MOSFET, wherein the first MOSFET is connected in series with the second MOSFET, and the source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET.

[0163] In this embodiment, as another example, S3 may include a MOSFET and a diode, with the anode of the diode connected to the anode of the bus capacitor, the cathode of the diode connected to the drain of the MOSFET, and the source of the MOSFET connected to the first port of the PFC circuit.

[0164] In this embodiment, as an example, S4 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0165] In this embodiment, as an example, S2 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0166] In this embodiment, as another example, S1 may include a diode, and the positive terminal of the diode is connected to the first port of L1.

[0167] In this embodiment, as an example, S3 may include a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

[0168] In this embodiment, optionally, as follows: Figure 13 As shown, the power conversion device 1100 may also include a soft-start circuit, which may include S4.

[0169] Optionally, such as Figure 14 As shown, the soft-start circuit may also include a positive temperature coefficient (PTC) thermistor, which is connected in parallel with S4.

[0170] It is understood that the specific implementation of the rectifier circuit and / or subsequent circuit in device 1100 can be referred to the relevant content in device 300, and will not be repeated here.

[0171] The apparatus in the foregoing embodiments of this application may further include subsequent circuitry.

[0172] One embodiment of this application also provides a control method for the aforementioned power conversion device. The power conversion device may include a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to release the electrical energy stored in the auxiliary capacitor for subsequent circuits.

[0173] The control method for the power conversion device may include: when the input of the rectifier circuit is de-energized, controlling the power conversion device to be in a first operating state or a second operating state.

[0174] The first operating state includes: the bus capacitor and the first inductor form a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor.

[0175] The second operating state includes: the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor, and the auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

[0176] In some possible implementations, the PFC circuit may include a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the bus capacitor is connected to the positive terminal of an auxiliary capacitor, and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit. The power conversion device may also include a third switching unit and a fourth switching unit. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit, and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0177] Controlling the power conversion device to be in a first operating state or a second operating state includes: controlling the first and third switching units to be turned on, and controlling the second and fourth switching units to be turned off, so that the power conversion device is in the first operating state; controlling the second and third switching units to be turned on, and controlling the first and fourth switching units to be turned off, so that the power conversion device is in the second operating state.

[0178] In other possible implementations, the PFC circuit may include a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit, and the negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The power conversion device may also include a third switching unit and a fourth switching unit. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit, and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0179] Controlling the power conversion device to be in a first operating state or a second operating state includes: controlling the second and third switching units to be turned on, and controlling the first and fourth switching units to be turned off, so that the power conversion device is in a first operating state; controlling the first and third switching units to be turned on, and controlling the second and fourth switching units to be turned off, so that the power conversion device is in a second operating state.

[0180] In this embodiment, the control method is used to control each switching unit in the power conversion device, so that the power conversion device can be in a first working state or a second working state.

[0181] For example, the switching unit can be controlled to be in a closed state by transmitting a signal to the switching unit. Optionally, in some embodiments, when the switching unit is a diode, the diode can be turned on or off by controlling the closing or opening of other switching units.

[0182] In one embodiment of this application, a control device for a power conversion device is also provided to implement the above-described control method. This control device can be implemented by software and / or hardware.

[0183] The power conversion device may include a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to release the electrical energy stored in the auxiliary capacitor for the subsequent circuit.

[0184] The control device of the power conversion device can be used to control the power conversion device to be in a first working state or a second working state when the input of the rectifier circuit is de-energized.

[0185] The first operating state includes: the bus capacitor and the first inductor form a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor.

[0186] The second operating state includes: the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor, and the auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

[0187] In one example, the PFC circuit may include a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the bus capacitor is connected to the positive terminal of an auxiliary capacitor, and the negative terminal of the auxiliary capacitor is connected to the first port of the first inductor through the second switching unit. The power conversion device may also include a third switching unit and a fourth switching unit. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit, and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

[0188] Specifically, the control device of the power conversion device can be used to: control the first and third switching units to be turned on, and control the second and fourth switching units to be turned off, so that the power conversion device is in a first working state; control the second and third switching units to be turned on, and control the first and fourth switching units to be turned off, so that the power conversion device is in a second working state.

[0189] In another example, the PFC circuit may include a first switching unit and a second switching unit. The first port of the first inductor and the positive terminal of the bus capacitor are connected through the first switching unit, and the first port of the first inductor and the negative terminal of the bus capacitor are connected through the second switching unit. The positive terminal of the auxiliary capacitor is connected to the first port of the first inductor through the first switching unit, and the negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The power conversion device may also include a third switching unit and a fourth switching unit. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit, and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

[0190] Specifically, the control device of the power conversion device can be used to: control the second and third switching units to be turned on, and control the first and fourth switching units to be turned off, so that the power conversion device is in a first working state; control the first and third switching units to be turned on, and control the second and fourth switching units to be turned off, so that the power conversion device is in a second working state.

[0191] As an example, the control device may include a controller and a drive circuit. The controller can execute instructions, and when the controller specifies the instructions, it can cause the drive circuit to transmit an on or off signal to the corresponding switching unit in the power conversion device, thereby enabling the power conversion device to operate in the aforementioned first operating state or second operating state.

[0192] Figure 15This is a schematic structural diagram of a switching power supply according to an embodiment of this application. The switching power supply may include a power adapter (commonly known as a charger). As an example, the switching power supply can be used as a server power supply, a network device power supply such as routers and switches, a communication power supply, an uninterruptible power supply (UPS), and a light-emitting diode (LED) lighting power supply, providing power to various electronic devices such as displays, servers, and network devices.

[0193] like Figure 15 As shown, the switching power supply 1500 may include a power conversion device 1501 and a control device 1502. Optionally, the power supply 1500 may also include a first interface and a second interface.

[0194] The first interface, the power conversion device 1501, the control device 1502, and the second interface are connected in sequence.

[0195] The first interface can be used to connect a power supply device (or power source) and transmit the current signal output by the power supply device to the power conversion device 1501. The power supply device can be a DC power source or an AC power source. Typically, the power supply device is an AC power source.

[0196] The power conversion device 1501 can be any of the power conversion devices described in the foregoing embodiments.

[0197] The control device 1502 can be used to control the aforementioned power conversion device 1501 to operate in the aforementioned first operating state or second operating state.

[0198] The second interface is used to connect electrical equipment and output DC current signals to the electrical equipment.

[0199] In the various embodiments of this application, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments are consistent and can be referenced mutually. Technical features in different embodiments can be combined to form new embodiments based on their inherent logical relationships. The term "multiple" in this document refers to two or more. The term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the preceding and following related objects; in formulas, the character " / " indicates a "division" relationship between the preceding and following related objects.

[0200] It is understood that the connection methods of the positive and negative terminals of the AC power supply and the connection methods between various circuit units involved in the embodiments of this application are simple examples and are not intended to limit the scope of the embodiments of this application.

[0201] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application.

[0202] It is understood that, in the embodiments of this application, the order of the above-mentioned process numbers does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

Claims

1. A power conversion device, characterized in that: The device includes a rectifier circuit, a power factor correction (PFC) circuit, an auxiliary capacitor, and a bus capacitor. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The PFC circuit includes a first inductor, a first switching unit, and a second switching unit. The first port of the first inductor is connected to the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor through the first switching unit. The first port of the first inductor is connected to the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor through the second switching unit. The device further includes a third switching unit and a fourth switching unit. The third switching unit is used to connect the second port of the first inductor to one of the positive or negative terminals of the bus capacitor, and the fourth switching unit is used to connect the other of the positive or negative terminals of the bus capacitor to the auxiliary capacitor. When the input of the device is de-energized, one of the first or second switch units closes, the other of the first or second switch units turns off, the third switch unit closes, and the fourth switch unit turns off. The first inductor and the bus capacitor in the PFC circuit are used to form a first current loop. The bus capacitor provides electrical energy to the first inductor, and the first inductor stores the electrical energy released by the bus capacitor. One of the first or second switching units is turned off, the other of the first or second switching units is closed, the third switching unit is closed, and the fourth switching unit is turned off. The auxiliary capacitor, the bus capacitor, and the first inductor are used to form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor. The auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor. Furthermore, the auxiliary capacitor is also used to provide power to the subsequent circuitry.

2. The apparatus according to claim 1, characterized in that, When the input of the rectifier circuit is de-energized, the power conversion device is in either the first operating state or the second operating state. The first operating state includes: one of the first switch unit or the second switch unit is closed, the other of the first switch unit or the second switch unit is closed, the third switch unit is closed, the fourth switch unit is closed, the bus capacitor and the first inductor form a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor; The second operating state includes: one of the first or second switching units is off, the other of the first or second switching units is closed, the third switching unit is closed, the fourth switching unit is off, the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop, in which the bus capacitor and the first inductor are connected in series to provide power to the auxiliary capacitor, and the auxiliary capacitor stores the power released by the bus capacitor and the first inductor.

3. The apparatus according to claim 2, characterized in that, The positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor; The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit, and the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit.

4. The apparatus according to claim 3, characterized in that, When the input of the device is de-energized, the first switch unit closes, the second switch unit closes, the third switch unit closes, and the fourth switch unit closes. The first inductor and the bus capacitor in the PFC circuit are used to form a first current loop. The bus capacitor provides electrical energy to the first inductor, and the first inductor stores the electrical energy released by the bus capacitor. The first switch unit is turned off, the second switch unit is closed, the third switch unit is closed, and the fourth switch unit is turned off. The auxiliary capacitor, the bus capacitor, and the first inductor are used to form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor. The auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

5. The apparatus according to claim 3 or 4, characterized in that, The third switching unit includes a MOSFET and a diode. The cathode of the diode is connected to the cathode of the bus capacitor, the anode of the diode is connected to the source of the MOSFET, and the drain of the MOSFET is connected to the second port of the first inductor.

6. The apparatus according to claim 2, characterized in that, The negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor; The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit, and the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit.

7. The apparatus according to claim 6, characterized in that, When the input of the device is de-energized, the second switch unit closes, the first switch unit closes, the third switch unit closes, and the fourth switch unit closes. The first inductor and the bus capacitor in the PFC circuit are used to form a first current loop. The bus capacitor provides electrical energy to the first inductor, and the first inductor stores the electrical energy released by the bus capacitor. The second switch unit is turned off, the first switch unit is closed, the third switch unit is closed, and the fourth switch unit is turned off. The auxiliary capacitor, the bus capacitor, and the first inductor are used to form a second current loop. In the second current loop, the bus capacitor and the first inductor are connected in series to provide electrical energy to the auxiliary capacitor. The auxiliary capacitor stores the electrical energy released by the bus capacitor and the first inductor.

8. The apparatus according to claim 6 or 7, characterized in that, The third switching unit includes a MOSFET and a diode. The anode of the diode is connected to the anode of the bus capacitor, the cathode of the diode is connected to the drain of the MOSFET, and the source of the MOSFET is connected to the second port of the first inductor.

9. The apparatus according to claim 7, characterized in that, The first switching unit includes a diode, and the anode of the diode in the first switching unit is connected to the first port of the first inductor.

10. The apparatus according to any one of claims 3-4 and 6-7, characterized in that, The first switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

11. The apparatus according to claim 10, characterized in that, The first switching unit includes a first field-effect MOSFET and a second MOSFET. The first MOSFET and the second MOSFET are connected in series, and the source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET.

12. The apparatus according to any one of claims 3-4 and 6-7, characterized in that, The fourth switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated gate bipolar transistor (IGBT).

13. The apparatus according to any one of claims 3-4 and 6-7, characterized in that, The second switching unit includes a field-effect MOSFET, a gallium nitride transistor (GaN), a silicon carbide transistor (SiC), or an insulated-gate bipolar transistor (IGBT).

14. The apparatus according to any one of claims 3-4 and 6-7, characterized in that, The device further includes a soft-start circuit, which includes the fourth switching unit. The soft-start circuit is used to control the rising slope and amplitude of the input current of the bus capacitor.

15. The apparatus according to claim 14, characterized in that, The soft-start circuit also includes a resistor unit, which is connected in parallel with the fourth switch unit.

16. The apparatus according to any one of claims 3-4 and 6-7, characterized in that, The rectifier circuit includes a first diode, a second diode, a third diode, and a fourth diode, wherein the anode of the first diode and the cathode of the third diode are connected to the first port of the rectifier circuit. The first port of the rectifier circuit is used to connect to one electrode of the AC power supply. The positive terminal of the second diode and the negative terminal of the fourth diode are connected to the second port of the rectifier circuit. The second port of the rectifier circuit is used to connect to the other electrode of the AC power supply. The negative terminals of the first diode and the second diode are connected to the third port of the rectifier circuit. The positive terminals of the third diode and the fourth diode are connected to the fourth port of the rectifier circuit. The third port of the rectifier circuit is connected to the first port of the PFC circuit. The fourth port of the rectifier circuit is connected to the second port of the PFC circuit. The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, and the second port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

17. The apparatus according to any one of claims 4, 6-7, characterized in that, The rectifier circuit includes a first diode and a second diode. The anode of the first diode and the cathode of the second diode are connected to a first port of the rectifier circuit, the cathode of the first diode is connected to a second port of the rectifier circuit, and the anode of the second diode is connected to a third port of the rectifier circuit. The first port of the rectifier circuit is used to connect to the negative terminal of the AC power supply, the first port of the PFC circuit is used to connect to the positive terminal of the AC power supply, the second port of the rectifier circuit is connected to the second port of the PFC circuit, and the third port of the rectifier circuit is connected to the third port of the PFC circuit. The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, the second port of the PFC circuit is the port connected to the first switching unit in the PFC circuit, and the third port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

18. The apparatus according to any one of claims 4, 6-7, characterized in that, The rectifier circuit includes a first diode and a second diode. The cathode of the first diode is connected to a first port of the rectifier circuit, the cathode of the second diode is connected to a second port of the rectifier circuit, and the anodes of the first diode and the second diode are connected to a third port of the rectifier circuit. The PFC circuit further includes a second inductor, a fifth switching unit, and a sixth switching unit. The first port of the second inductor is connected to the fourth port of the PFC circuit. The second port of the second inductor, the first port of the fifth switching unit, and the first port of the sixth switching unit are connected. The second port of the fifth switching unit is connected to the second port of the PFC circuit. The second port of the sixth switching unit is connected to the third port of the PFC circuit. The first port of the rectifier circuit and the first port of the PFC circuit are used to connect to the positive terminal of the AC power supply, the second port of the rectifier circuit and the fourth port of the PFC circuit are used to connect to the negative terminal of the AC power supply, and the third port of the rectifier circuit and the third port of the PFC circuit are connected. The first port of the PFC circuit is the port connected to the first inductor in the PFC circuit, the second port of the PFC circuit is the port connected to the first switching unit in the PFC circuit, and the third port of the PFC circuit is the port connected to the second switching unit in the PFC circuit.

19. A control method for a power conversion device, characterized in that, The power conversion device includes a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to provide power to the subsequent circuits. The PFC circuit includes a first inductor, a first switching unit, and a second switching unit. The first port of the first inductor is connected to the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor through the first switching unit. The first port of the first inductor is connected to the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor through the second switching unit. The device further includes a third switching unit and a fourth switching unit. The third switching unit is used to connect the second port of the first inductor to one of the positive or negative terminals of the bus capacitor, and the fourth switching unit is used to connect the other of the positive or negative terminals of the bus capacitor to the auxiliary capacitor. The method includes: When the input of the rectifier circuit is de-energized, the power conversion device is controlled to be in a first working state or a second working state. The first operating state includes: one of the first switch unit or the second switch unit is closed, the other of the first switch unit or the second switch unit is closed, the third switch unit is closed, the fourth switch unit is closed, the bus capacitor and the first inductor form a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor; The second operating state includes: one of the first or second switching units is off, the other of the first or second switching units is closed, the third switching unit is closed, the fourth switching unit is off, the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop, in which the bus capacitor and the first inductor are connected in series to provide power to the auxiliary capacitor, and the auxiliary capacitor stores the power released by the bus capacitor and the first inductor.

20. The method according to claim 19, characterized in that, The positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit. The negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit. The control of the power conversion device to be in a first operating state includes: The first and third switching units are turned on, and the second and fourth switching units are turned off, so that the power conversion device is in the first working state. The control of the power conversion device to a second operating state includes: The second and third switching units are controlled to be turned on, and the first and fourth switching units are controlled to be turned off, so that the power conversion device is in the second working state.

21. The method according to claim 19, characterized in that, The negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit. The positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit. The control of the power conversion device to be in a first operating state includes: The second and third switching units are controlled to be turned on, and the first and fourth switching units are controlled to be turned off, so that the power conversion device is in the first working state. The control of the power conversion device to a second operating state includes: The first and third switching units are controlled to be turned on, and the second and fourth switching units are controlled to be turned off, so that the power conversion device is in the second working state.

22. A control device for a power conversion device, characterized in that, The power conversion device includes a rectifier circuit, a power factor correction (PFC) circuit, a bus capacitor, and an auxiliary capacitor. The rectifier circuit, the PFC circuit, the bus capacitor, and the auxiliary capacitor are connected in sequence. The rectifier circuit is used to convert the received alternating current into a first direct current. The PFC circuit is used to compensate the phase between the current and voltage of the received first direct current to obtain a second direct current. The bus capacitor is used to filter the second direct current to obtain a third direct current. The auxiliary capacitor is used to provide power to the subsequent circuits. The PFC circuit includes a first inductor, a first switching unit, and a second switching unit. The first port of the first inductor is connected to the positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor through the first switching unit. The first port of the first inductor is connected to the negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor through the second switching unit. The device further includes a third switching unit and a fourth switching unit. The third switching unit is used to connect the second port of the first inductor to one of the positive or negative terminals of the bus capacitor, and the fourth switching unit is used to connect the other of the positive or negative terminals of the bus capacitor to the auxiliary capacitor. The control device is used to: control the power conversion device to be in a first working state or a second working state when the input of the rectifier circuit is de-energized; The first operating state includes: one of the first switch unit or the second switch unit is closed, the other of the first switch unit or the second switch unit is closed, the third switch unit is closed, the fourth switch unit is closed, the bus capacitor and the first inductor form a first current loop, in which the bus capacitor provides electrical energy to the first inductor and the first inductor stores the electrical energy released by the bus capacitor; The second operating state includes: one of the first or second switching units is off, the other of the first or second switching units is closed, the third switching unit is closed, the fourth switching unit is off, the auxiliary capacitor, the bus capacitor, and the first inductor form a second current loop, in which the bus capacitor and the first inductor are connected in series to provide power to the auxiliary capacitor, and the auxiliary capacitor stores the power released by the bus capacitor and the first inductor.

23. The control device according to claim 22, characterized in that, The positive terminal of the bus capacitor is connected to the positive terminal of the auxiliary capacitor. The second port of the first inductor and the negative terminal of the bus capacitor are connected through the third switching unit. The negative terminal of the auxiliary capacitor and the negative terminal of the bus capacitor are connected through the fourth switching unit. Specifically, the control device is used for: The first and third switching units are turned on, and the second and fourth switching units are turned off, so that the power conversion device is in the first working state. The second and third switching units are controlled to be turned on, and the first and fourth switching units are controlled to be turned off, so that the power conversion device is in the second working state.

24. The control device according to claim 22, characterized in that, The negative terminal of the bus capacitor is connected to the negative terminal of the auxiliary capacitor. The second port of the first inductor and the positive terminal of the bus capacitor are connected through the third switching unit. The positive terminal of the auxiliary capacitor and the positive terminal of the bus capacitor are connected through the fourth switching unit. Specifically, the control device is used for: The second and third switching units are controlled to be turned on, and the first and fourth switching units are controlled to be turned off, so that the power conversion device is in the first working state. The first and third switching units are controlled to be turned on, and the second and fourth switching units are controlled to be turned off, so that the power conversion device is in the second working state.

25. A switching power supply, characterized in that, The switching power supply includes a power conversion device as described in any one of claims 1 to 18 and a control device as described in any one of claims 22 to 24.

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