Alternating current-direct current conversion circuit, control method and alternating current-direct current conversion system

Abstract

The invention relates to an AC-DC conversion circuit, a control method and an AC-DC conversion system. The AC-DC conversion circuit comprises a voltage reduction module and a control module, the voltage reduction module is used for converting the alternating current voltage of the generator into target direct current voltage and inputting the target direct current voltage to the control module; the control module is used for supplying power to the load according to the supply-demand relationship between the output power of the voltage reduction module and the load demand power, so that automatic distribution can be realized according to the load demand, and when the output energy of the generator is greater than the load consumption, the redundant energy is stored in a standby battery; when the load consumption is greater than the output energy of the generator, the generator and the battery supply power to the load at the same time, so that the generator with unstable output power can also supply power to the load stably, and the stability of the output voltage is improved while the conversion efficiency is maintained.

Description

Technical Field

[0001] This application relates to the field of AC / DC conversion technology, and in particular to an AC / DC conversion circuit, control method, and AC / DC conversion system. Background Technology

[0002] Electrostatic generators, including triboelectric nanogenerators and electret generators, convert mechanical kinetic energy into electrical energy through electrostatic induction. They show great potential in the field of low-frequency and irregular kinetic energy harvesting and are expected to provide a green and sustainable way to solve the energy supply challenges of distributed sensing nodes such as the Internet of Things. However, due to the capacitive characteristics of these generators, their output is characterized by high voltage (hundreds to kilovolts), low current (microamps to milliamps), high impedance, and AC, which is incompatible with the low voltage (1.8-5V), high current (mA-A), low impedance, and DC input requirements of conventional electronic devices. This makes it difficult to efficiently utilize the energy converted by electrostatic generators, thus requiring AC-DC conversion of the output signal.

[0003] Currently, the AC-DC conversion circuit of an electrostatic generator includes a rectifier bridge, an electromagnetic transformer, a capacitor transformer, and a synchronous buck circuit (i.e., a Buck circuit). However, the voltage output of this traditional circuit has low stability. Summary of the Invention

[0004] Therefore, it is necessary to provide an AC / DC conversion circuit, control method, and AC / DC conversion system that can improve the stability of the output voltage while maintaining conversion efficiency, in order to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides an AC / DC conversion circuit, a step-down module and a control module, wherein the control module is connected to the step-down module;

[0006] The step-down module is connected to the generator and is used to convert the generator's AC voltage into a target DC voltage and input the target DC voltage to the control module.

[0007] The control module is used to supply power to the load according to the supply and demand relationship between the output power of the step-down module and the load demand power; the supply and demand relationship includes the output power of the step-down module being higher than the load demand power, or the output power of the step-down module being lower than the load demand power.

[0008] In one embodiment, the control module includes a backup battery, a detection device, and a switching device. The backup battery is connected to the switching device, the detection device is connected to the switching device and the step-down module, and the switching device is connected to the step-down module.

[0009] The detection device is used to generate a control signal based on the output power of the step-down module and the power demand of the load, and send the control signal to the switching device.

[0010] The switching device is used to form an energy storage path between the step-down module and the backup battery when the control signal indicates that the output power is higher than the load demand power, so as to store the energy exceeding the load demand into the backup battery through the energy storage path.

[0011] In one embodiment, the control module includes an undervoltage lockout device connected to the buck module and the switching device.

[0012] The undervoltage lockout device is used to switch the switching state according to the voltage corresponding to the electrical energy stored in the energy storage unit and the threshold voltage of the undervoltage lockout device;

[0013] The switching device is used to form a first power supply path between the energy storage unit in the step-down module and the load when the output power is higher than the load demand power and the undervoltage lockout device is in the open state, and to supply power to the load through the first power supply path.

[0014] In one embodiment, the undervoltage lockout device is configured to be in an open state when the output power is lower than the load demand power and the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, so that the switching device supplies power to the load through the first power supply path via the energy storage unit until the voltage corresponding to the electrical energy stored in the energy storage unit is lower than the lower threshold voltage of the undervoltage lockout device, and then switches from the open state to the closed state.

[0015] The undervoltage lockout device is used to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, so that the switching device forms a second power supply path between the backup battery and the load, and supplies power to the load through the second power supply path.

[0016] In one embodiment, the undervoltage lockout device is configured to be in a closed state when the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device and the voltage corresponding to the electrical energy not stored in the backup battery meets the opening voltage threshold of the switching device, so that the switching device cuts off the first power supply path and the second power supply path.

[0017] The step-down module is used to obtain electrical energy from the generator and store the obtained electrical energy in the energy storage unit;

[0018] The undervoltage lockout device is activated when the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, so that the switching device can conduct the first power supply path and supply power to the load through the first power supply path via the energy storage unit.

[0019] In one embodiment, the switching device includes: a first switch, a second switch, and a third switch;

[0020] The step-down module is connected to the load via the first switch, the step-down module is connected to the backup battery via the second switch, and the backup battery is connected to the load via the third switch.

[0021] In one embodiment, the first power supply path is formed when the first switch is closed, the energy storage path is formed when the second switch is closed, and the second power supply path is formed when the third switch is closed.

[0022] In one embodiment, the control module further includes a voltage regulator;

[0023] The voltage regulator is used to convert the DC voltage input to the voltage regulator into an output DC voltage that meets a preset requirement; the preset requirement is determined according to the input requirement of the device connected to the output terminal of the voltage regulator.

[0024] Secondly, this application provides a control method for an AC / DC conversion circuit, which is applied to an AC / DC conversion circuit as described in any of the above claims, and the method includes:

[0025] The AC voltage of the generator is converted into the target DC voltage by the step-down module in the AC-DC conversion circuit, and the target DC voltage is input to the control module in the AC-DC conversion circuit.

[0026] The power supply to the load is based on the supply and demand relationship between the output power of the step-down module and the power demand of the load; the supply and demand relationship includes the output power of the step-down module being higher than the power demand of the load, or the output power of the step-down module being lower than the power demand of the load.

[0027] Thirdly, this application provides an AC / DC conversion system, including a generator, a load, and an AC / DC conversion circuit as described in any of the above.

[0028] The aforementioned AC / DC conversion circuit, control method, and AC / DC conversion system include: a step-down module and a control module, with the control module connected to the step-down module; the step-down module is connected to the generator and is used to convert the generator's AC voltage to a target DC voltage, and input the target DC voltage to the control module; the control module is used to supply power to the load according to the supply-demand relationship between the output power of the step-down module and the load's required power; the supply-demand relationship includes the step-down module's output power being higher than the load's required power, or the step-down module's output power being lower than the load's required power, thereby enabling automatic allocation according to load demand. When the generator's output energy is greater than the load consumption, the excess energy is stored in a backup battery; when the load consumption is greater than the generator's output energy, the generator and battery will simultaneously supply power to the load, allowing even a generator with unstable output power to stably supply power to the load, improving the stability of the output voltage while maintaining conversion efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of an AC / DC conversion circuit provided in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of another AC / DC conversion circuit provided in an embodiment of this application;

[0032] Figure 3 This is a waveform diagram of the voltage and current at a key node in an AC / DC conversion circuit provided in an embodiment of this application;

[0033] Figure 4 This is a schematic diagram of the circuit structure of a control module provided in an embodiment of this application;

[0034] Figure 5 This is a schematic diagram of the circuit structure of an undervoltage lockout device provided in an embodiment of this application;

[0035] Figure 6 This is a schematic diagram of the circuit structure of a detection device provided in an embodiment of this application;

[0036] Figure 7 This is a schematic diagram of the circuit structure of a switching device provided in an embodiment of this application;

[0037] Figure 8This is a flowchart illustrating a control method for an AC / DC conversion circuit provided in an embodiment of this application.

[0038] Explanation of reference numerals in the attached figures:

[0039] 110: Step-down module; 120: Control module; 121: Backup battery;

[0040] 122: Detection device; 123: Switching device; 124: Undervoltage lockout device;

[0041] 125: Voltage stabilizing device. Detailed Implementation

[0042] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0044] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0045] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0046] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0047] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0048] Electrostatic generators, including triboelectric nanogenerators and electret generators, convert mechanical kinetic energy into electrical energy through electrostatic induction. They show great potential in the field of low-frequency and irregular kinetic energy harvesting and are expected to provide a green and sustainable way to solve the energy supply challenges of distributed sensing nodes such as the Internet of Things. However, due to the capacitive characteristics of these generators, their output is characterized by high voltage (hundreds to kilovolts), low current (microamps to milliamps), high impedance, and AC, which is incompatible with the low voltage (1.8-5V), high current (mA-A), low impedance, and DC input requirements of conventional electronic devices. This makes it difficult to efficiently utilize the energy converted by electrostatic generators, thus requiring AC-DC conversion of the output signal.

[0049] Currently, the AC-DC conversion circuit of an electrostatic generator includes a rectifier bridge, an electromagnetic transformer, a capacitor transformer, and a synchronous buck circuit (i.e., a Buck circuit). However, the voltage output of this traditional circuit has low stability.

[0050] In one embodiment, such as Figure 1 As shown, Figure 1 This is a schematic diagram of an AC / DC conversion circuit provided in an embodiment of this application. The AC / DC conversion circuit includes a step-down module 110 and a control module 120, with the control module 120 connected to the step-down module 110.

[0051] The step-down module 110 is connected to the generator and is used to convert the generator's AC voltage into a target DC voltage and input the target DC voltage to the control module 120.

[0052] For example, the step-down module 110 may include an LC buck circuit, which is mainly used to convert the pulsed high voltage output by the generator into low voltage DC and store the converted electrical energy in an energy storage unit. The energy storage unit may be, for example, an energy storage capacitor CS.

[0053] The control module 120 is used to supply power to the load according to the supply and demand relationship between the output power of the step-down module 110 and the power demand of the load.

[0054] The output power of the step-down module 110 is the power input from the step-down module 110 to the control module 120. The supply and demand relationship includes the output power of the step-down module 110 being higher than the load demand power, or the output power of the step-down module being lower than the load demand power.

[0055] Optionally, since the DC power output of the step-down module 110 has poor stability, the unstable DC power obtained from the energy storage unit can be processed by the control module 120 to obtain stable low-voltage DC power. The converted electrical energy is then dynamically distributed in the AC-DC conversion circuit according to the load demand and the real-time power generation of the generator. For example, if the real-time power generation of the generator is greater than the load demand, that is, the output power of the step-down module 110 is higher than the load demand power, then while supplying power to the load through the generator, the excess electrical energy is stored in the backup battery; if the real-time power generation of the generator is insufficient, that is, the real-time power generation of the generator is lower than the load demand, that is, the output power of the step-down module is lower than the load demand power, then the load is supplied through the generator and / or the backup battery.

[0056] For example, if the output power of the step-down module 110 is higher than the load demand power, that is, the output power of the generator is higher than the load demand, then the excess electrical energy can be stored in the backup battery while the generator supplies power to the load.

[0057] Alternatively, if the output power of the step-down module is lower than the load demand power, that is, the output power of the generator is lower than the load demand, the load can be powered by the generator and / or the backup battery.

[0058] In this embodiment, the AC / DC conversion circuit includes a step-down module and a control module, with the control module connected to the step-down module. The step-down module is connected to the generator and is used to convert the generator's AC voltage into a target DC voltage, and input the target DC voltage to the control module. The control module is used to supply power to the load according to the supply-demand relationship between the output power of the step-down module and the load's required power. The supply-demand relationship includes the step-down module's output power being higher than the load's required power, or the step-down module's output power being lower than the load's required power, thereby enabling automatic allocation according to load demand. When the generator's output energy is greater than the load's consumption, the excess energy is stored in a backup battery. When the load's consumption is greater than the generator's output energy, the generator and battery will simultaneously supply power to the load. This allows even a generator with unstable output power to stably supply power to the load, improving the stability of the output voltage while maintaining conversion efficiency.

[0059] In one embodiment, such as Figure 2 As shown, Figure 2This is a schematic diagram of another AC / DC conversion circuit provided in the embodiments of this application. The control module 120 in the AC / DC conversion circuit includes a backup battery 121, a detection device 122 and a switching device 123. The backup battery 121 is connected to the switching device 123, the detection device 122 is connected to the switching device 123 and the step-down module 110, and the switching device 123 is connected to the step-down module 110.

[0060] Optionally, the backup battery 121 may include a lithium battery charging chip and a lithium battery.

[0061] The detection device 122 is used to generate a control signal based on the output power of the step-down module and the power demand of the load, and send the control signal to the switching device 123.

[0062] For example, if the output power of the step-down module is higher than the power required by the load, a control signal can be generated and sent to the switching device 123. This control signal can control the switches in the switching device 123 so that the energy storage unit in the step-down module 110 stores excess electrical energy in the backup battery 121 while supplying power to the load.

[0063] Reference Figure 6 , Figure 6 This is a schematic diagram of the circuit structure of a detection device provided in an embodiment of this application. Optionally, the detection device 122 described above can be configured as follows: Figure 6 Design the structure shown, such as Figure 6 As shown, the detection device 122 is essentially a voltage detection circuit. R2 is a power supply protection resistor, and R1 is a sampling resistor. Together with the reference voltage Vref of the voltage detector and the input resistance RDin of the voltage detector, they determine the operating threshold of the detection device. When the electrical energy generated by the generator cannot be fully consumed by the load, that is, when the output power of the step-down module is higher than the power demand of the load, the voltage of CS in the LC Buck circuit will continue to increase. If the voltage is higher than the operating threshold voltage of the detection device, the detection device outputs a high level, and the control switch SW2 is turned on.

[0064] The switching device 123 is used to form an energy storage path between the step-down module 110 and the backup battery 121 when the control signal indicates that the output power is higher than the load demand power, so as to store the energy exceeding the load demand into the backup battery 121 through the energy storage path.

[0065] Reference Figure 7 , Figure 7 This is a schematic diagram of the circuit structure of a switching device provided in an embodiment of this application. Optionally, the switching device 123 described above can be configured as follows: Figure 7 Design the structure shown, such as Figure 7As shown, the first switch SW1 and the third switch SW3 are mutually exclusive, implemented using a comparator-type PowerMUX chip. That is, the first switch SW1 and the third switch SW3 will not be turned on simultaneously. Based on the working principle of the comparator-type PowerMUX chip, the conduction of the first switch SW1 and the third switch SW3 is determined by the input voltage of SW1 and SW3; the switch with the relatively higher input voltage will turn on. For example, if the input voltage of the first switch SW1 is greater than the input voltage of the third switch SW3, then the first switch SW1 will turn on; if the input voltage of the first switch SW1 is less than the input voltage of the third switch SW3, then the third switch SW3 will turn on.

[0066] In this embodiment, the control module includes a backup battery, a detection device, and a switching device. The backup battery is connected to the switching device, the detection device is connected to both the switching device and the step-down module, and the switching device is also connected to the step-down module. The detection device generates a control signal based on the output power of the step-down module and the load demand power, and sends the control signal to the switching device. The switching device, when the control signal indicates that the output power is higher than the load demand power, forms an energy storage path between the step-down module and the backup battery. This allows excess energy exceeding the load demand to be stored in the backup battery, enabling the generator to supply power to the load while storing excess energy in the backup battery 121, even when the generator's output power exceeds the load demand. This reduces energy waste, facilitates energy reuse, and improves energy utilization. Furthermore, it avoids the efficiency reduction and battery life degradation caused by the electrochemical processes during the charging and discharging of chemical batteries.

[0067] Based on the above embodiments, the control module 120 includes an undervoltage lockout device 124, which is connected to the step-down module 110 and the switching device 123.

[0068] The undervoltage lockout device 124 is used to switch the switching state according to the voltage corresponding to the electrical energy stored in the energy storage unit and the threshold voltage of the undervoltage lockout device.

[0069] The threshold voltage of the undervoltage lockout device (UVLO) includes an upper threshold voltage and a lower threshold voltage. When the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device (UVLO), the undervoltage lockout device (UVLO) will be turned on and remain in the on state. When the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device (UVLO), the undervoltage lockout device (UVLO) will switch to the off state.

[0070] The switching device 123 is used to form a first power supply path between the energy storage unit in the step-down module 110 and the load when the output power is higher than the load demand power and the undervoltage lockout device 124 is in the open state, so as to supply power to the load through the first power supply path.

[0071] In this embodiment, when the output power is higher than the load demand power and the undervoltage lockout device 124 is in the open state, the input voltage of the first switch SW1 will be greater than the input voltage of the third switch SW3. Then the first switch SW1 will be turned on, thereby forming a first power supply path between the energy storage unit in the step-down module 110 and the load, so as to supply power to the load through the first power supply path.

[0072] Reference Figure 2-3 , Figure 3 This is a waveform diagram of the voltage and current at a key node in an AC / DC conversion circuit provided in an embodiment of this application. For example,... Figure 2 and Figure 3 As shown in (i), when the output power is higher than the load demand power, the first switch SW1 and the second switch SW2 in the switching device will be closed to form a first power supply path between the energy storage unit and the load, and to form an energy storage path between the step-down module 110 and the backup battery 121, so that the energy storage unit can store excess energy in the backup battery 121 while supplying power to the load.

[0073] Reference Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of an undervoltage lockout device provided in an embodiment of this application. Optionally, the undervoltage lockout device 124 can be configured as follows: Figure 5 Design the structure shown, such as Figure 5As shown, the undervoltage lockout device 124 comprises two parts: i) a UVLO signal control circuit and ii) a switch control circuit. The UVLO signal control circuit consists of sampling resistors R1 and R2, a power supply protection resistor R3, a P-MOSFET, and an integrated voltage detector. The upper threshold voltage of the UVLO is determined by the sampling resistor R2, the input resistance RDin of the voltage detector, and the threshold voltage of the voltage detector (Vupth = Vref*(R2+RDin) / RDin). When the input voltage does not exceed the upper threshold, the voltage detector output is low, all PMOS and NMOS in the circuit remain off, and no current flows through R1 and R4. When the input voltage exceeds the upper threshold, all MOS in the circuit turn on, and the UVLO input and output are connected. Simultaneously, R1 and R2 are connected in parallel, reducing the voltage division ratio, which increases the voltage at the voltage detector input, ensuring that the UVLO input and output remain connected even after the input voltage decreases. When the input voltage of UVLO drops to the lower threshold voltage (Vupth = Vref*(R2 / / R1+RDin) / RDin), the voltage detector outputs a low level, all MOS transistors are turned off, and UVLO is turned off. Essentially, a bistable hysteresis structure is constructed here.

[0074] In this embodiment, the control module includes an undervoltage lockout device connected to the step-down module and a switching device. The undervoltage lockout device switches the switching state based on the voltage corresponding to the electrical energy stored in the energy storage unit and the threshold voltage of the undervoltage lockout device. The switching device forms a first power supply path between the energy storage unit in the step-down module and the load when the output power exceeds the load demand and the undervoltage lockout device is in the open state, and supplies power to the load through the first power supply path. This enables the storage of excess electrical energy in the backup battery 121 while supplying power to the load when the generator's output power exceeds the load demand, reducing energy waste and facilitating energy reuse, thus improving energy utilization. Furthermore, it avoids the efficiency reduction and battery life degradation caused by the electrochemical process during the charging and discharging of chemical batteries.

[0075] In one embodiment, such as Figure 2 As shown, the undervoltage lockout device 124 is used to be in the open state when the output power is lower than the load demand power and the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device 124, so that the switching device 123 supplies power to the load through the first power supply path through the energy storage unit until the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and then switches from the open state to the closed state.

[0076] The undervoltage lockout device 124 is used to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device 124 and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, so that the switching device forms a second power supply path between the backup battery and the load, and supplies power to the load through the second power supply path.

[0077] In one possible implementation, when the output power of the step-down module is lower than the load demand, the power supply mode can be selected according to the electrical energy stored in the energy storage unit. If the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device 124, the undervoltage lockout device 124 is in the open state. At this time, the input voltage of the first switch SW1 is greater than the input voltage of the third switch SW3, so the first switch SW1 is turned on and the third switch SW3 is turned off, so that the energy storage unit can supply power to the load using the first power supply path.

[0078] In one implementation, when the energy storage unit supplies power to the load, because the output power of the step-down module is lower than the load demand, the voltage corresponding to the electrical energy stored in the energy storage unit will gradually decrease until the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device. At this time, the undervoltage lockout device switches to the off state. When the undervoltage lockout device is switched to the off state, if the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, the input voltage of the third switch SW3 is greater than the input voltage of the first switch SW1. Therefore, the first switch SW1 is turned off, and the third switch SW3 is turned on, thereby forming a second power supply path between the backup battery and the load, and supplying power to the load through the second power supply path.

[0079] Optionally, such as Figure 2 and Figure 3 As shown in (ii), when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device 124, and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, the undervoltage lockout device stops working, disconnecting the connection between the energy storage unit and the load, allowing the energy storage unit to continue accumulating electrical energy. Simultaneously, the third switch SW3 is turned on to form a second power supply path between the backup battery 121 and the load, supplying power to the load through this second power supply path until the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device 124 again, at which point the power supply to the load is switched back to the energy storage unit.

[0080] In this embodiment, the undervoltage lockout device is configured to be in an open state when the output power is lower than the load demand power and the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, so that the switching device supplies power to the load through the energy storage unit using the first power supply path until the voltage corresponding to the electrical energy stored in the energy storage unit is lower than the lower threshold voltage of the undervoltage lockout device, at which point it switches from the open state to the closed state. The undervoltage lockout device is configured to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is lower than the lower threshold voltage of the undervoltage lockout device and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, so that the switching device forms a second power supply path between the backup battery and the load, and supplies power to the load through the second power supply path. This enables the backup battery to supply power to the load when the generator's output power is insufficient, improving the stability of the power supply.

[0081] In one embodiment, such as Figure 2 As shown, the undervoltage lockout device 124 is used to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device 124, and the voltage corresponding to the electrical energy stored in the backup battery does not meet the opening voltage threshold of the switch device 123, so that the switch device 123 cuts off the first power supply path and the second power supply path.

[0082] The step-down module 110 is used to obtain electrical energy from the generator and store the obtained electrical energy in the energy storage unit.

[0083] The undervoltage lockout device 124 is used to be in the open state when the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device 124, so that the switching device 123 can conduct the first power supply path and supply power to the load through the first power supply path via the energy storage unit.

[0084] In one embodiment, when the energy storage unit supplies power to the load, because the output power of the step-down module is lower than the load demand, the voltage corresponding to the electrical energy stored in the energy storage unit will gradually decrease until the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device. At this time, the undervoltage lockout device switches to the off state. When the undervoltage lockout device switches to the off state, if the voltage corresponding to the electrical energy stored in the backup battery does not meet the opening voltage threshold of the switching device 123, the third switch SW3 cannot be turned on, and the first power supply path and the second power supply path are disconnected. Therefore, neither the generator nor the backup battery can provide power to the load. After the undervoltage lockout device switches to the off state, the generator continues to work, and electrical energy can continue to accumulate in the energy storage unit until the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device 124. The undervoltage lockout device 124 switches to the on state, thereby enabling the first power supply path to be turned on and supplying power to the load through the first power supply path.

[0085] Optionally, such as Figure 2 and Figure 3 As shown in (iii), if the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and the voltage corresponding to the electrical energy stored in the backup battery does not meet the opening voltage threshold of the switching device, neither the generator nor the backup battery can provide electrical energy to the load. In this case, it is necessary to temporarily stop supplying power to the load, that is, to disconnect the first switch SW1 and the third switch SW3 to cut off the first power supply path and the second power supply path. Since the first power supply path is cut off, but the generator continues to output power, the energy storage unit can continue to accumulate electrical energy until the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, and then switch back to supplying power to the load through the energy storage unit.

[0086] In one embodiment, such as Figure 2 As shown, the control module 120 also includes a voltage regulator 125, which is used to convert the DC voltage input to the voltage regulator into an output DC voltage that meets preset requirements; the preset requirements are determined according to the input requirements of the device connected to the output terminal of the voltage regulator.

[0087] For example, the voltage regulator 125 can be a DC-DC step-down device for converting the DC voltage input to the voltage regulator into an output DC voltage that meets preset requirements, so that the output voltage can match the voltage required by the device connected to the output terminal of the voltage regulator.

[0088] Optionally, the specific location of the voltage regulator 125 can be adaptively set according to actual needs. For example, the voltage regulator 125 can be set between the step-down module 110 and the undervoltage lockout device 124; or the voltage regulator 125 can be set between the undervoltage lockout device 124 and the switching device 123; or the voltage regulator 125 can be set between the switching device 123 and the load.

[0089] Reference Figure 4 , Figure 4 This is a circuit structure diagram of a control module provided in an embodiment of this application. Based on the above embodiment, the control module 120 can be... Figure 4 The structure shown is as follows. A is the UVLO circuit, B is the detection device circuit, C is the voltage regulator (DC-DC) circuit, D is the backup battery circuit, and E is the switching device circuit.

[0090] Based on the same inventive concept, this application also provides a control method applied to the AC / DC conversion circuit mentioned above. The solution provided by this control method is similar to the solution described in the AC / DC conversion circuit above. Therefore, the specific limitations in one or more control method embodiments provided below can be found in the limitations of the AC / DC conversion circuit described above, and will not be repeated here.

[0091] In one embodiment, such as Figure 8 As shown, Figure 8 This is a flowchart illustrating a control method for an AC / DC conversion circuit provided in an embodiment of this application. The method includes the following steps:

[0092] S801 converts the generator's AC voltage to the target DC voltage through the step-down module in the AC-DC conversion circuit, and inputs the target DC voltage to the control module in the AC-DC conversion circuit.

[0093] S802 supplies power to the load based on the supply and demand relationship between the output power of the step-down module and the power required by the load.

[0094] The supply and demand relationship includes situations where the output power of the step-down module is higher than the load demand power, or the output power of the step-down module is lower than the load demand power.

[0095] In one embodiment, the method further includes the following steps:

[0096] Based on the output power of the step-down module and the power demand of the load, a control signal is generated and sent to the switching device;

[0097] When the control signal indicates that the output power is higher than the load demand power, an energy storage path is formed between the step-down module and the backup battery to store the excess energy to the backup battery.

[0098] In one embodiment, the method further includes the following steps:

[0099] The switching state is switched based on the voltage corresponding to the electrical energy stored in the energy storage unit and the threshold voltage of the undervoltage lockout device.

[0100] When the output power is higher than the load demand power and the undervoltage lockout device is in the open state, a first power supply path is formed between the energy storage unit in the step-down module and the load, and power is supplied to the load through the first power supply path.

[0101] In one embodiment, the method further includes the following steps:

[0102] When the output power is lower than the load demand power and the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, it is in the open state, so that the switching device supplies power to the load through the first power supply path via the energy storage unit until the voltage corresponding to the electrical energy stored in the energy storage unit is lower than the lower threshold voltage of the undervoltage lockout device, and then switches from the open state to the closed state.

[0103] When the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, the device is in the closed state, so that the switching device forms a second power supply path between the backup battery and the load, and supplies power to the load through the second power supply path.

[0104] In one embodiment, the method further includes the following steps:

[0105] When the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and the voltage corresponding to the electrical energy stored in the backup battery does not meet the opening voltage threshold of the switching device, the device is in the closed state, so that the switching device cuts off the first power supply path and the second power supply path.

[0106] It obtains electrical energy from a generator and stores the obtained electrical energy in an energy storage unit.

[0107] When the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, it is in the open state, so that the switching device can conduct the first power supply path and supply power to the load through the first power supply path via the energy storage unit.

[0108] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An AC / DC conversion circuit, characterized in that, include: A step-down module and a control module, wherein the control module is connected to the step-down module; The step-down module is connected to the generator and is used to convert the AC voltage of the generator into a target DC voltage and input the target DC voltage to the control module. The control module is used to supply power to the load according to the supply and demand relationship between the output power of the step-down module and the load demand power; the supply and demand relationship includes the output power of the step-down module being higher than the load demand power, or the output power of the step-down module being lower than the load demand power.

2. The AC / DC conversion circuit according to claim 1, characterized in that, The control module includes a backup battery, a detection device, and a switching device. The backup battery is connected to the switching device, the detection device is connected to the switching device and the step-down module, and the switching device is connected to the step-down module. The detection device is used to generate a control signal based on the output power of the step-down module and the load demand power, and send the control signal to the switching device. The switching device is configured to form an energy storage path between the step-down module and the backup battery when the control signal indicates that the output power is higher than the load demand power, so as to store the energy exceeding the load demand into the backup battery through the energy storage path.

3. The AC / DC conversion circuit according to claim 2, characterized in that, The control module includes an undervoltage lockout device, which is connected to the step-down module and the switching device. The undervoltage lockout device is used to switch the switching state according to the voltage corresponding to the electrical energy stored in the energy storage unit in the step-down module and the threshold voltage of the undervoltage lockout device. The switching device is used to form a first power supply path between the energy storage unit and the load when the output power is higher than the load demand power and the undervoltage lockout device is in the open state, and to supply power to the load through the first power supply path.

4. The AC / DC conversion circuit according to claim 3, characterized in that, The undervoltage lockout device is used to be in the open state when the output power is lower than the load demand power and the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, so that the switching device supplies power to the load through the first power supply path via the energy storage unit until the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and then switches from the open state to the closed state. The undervoltage lockout device is configured to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and the voltage corresponding to the electrical energy stored in the backup battery meets the opening voltage threshold of the switching device, so that the switching device forms a second power supply path between the backup battery and the load, and supplies power to the load through the second power supply path.

5. The AC / DC conversion circuit according to claim 4, characterized in that, The undervoltage lockout device is used to be in a closed state when the voltage corresponding to the electrical energy stored in the energy storage unit is less than the lower threshold voltage of the undervoltage lockout device, and the voltage corresponding to the electrical energy stored in the backup battery does not meet the opening voltage threshold of the switching device, so that the switching device cuts off the first power supply path and the second power supply path. The step-down module is used to obtain electrical energy from the generator and store the obtained electrical energy in the energy storage unit; The undervoltage lockout device is configured to be in an open state when the voltage corresponding to the electrical energy stored in the energy storage unit reaches the upper threshold voltage of the undervoltage lockout device, so as to enable the switching device to conduct the first power supply path and supply power to the load through the first power supply path via the energy storage unit.

6. The AC / DC conversion circuit according to claim 5, characterized in that, The switching device includes: a first switch, a second switch, and a third switch; The step-down module is connected to the load via the first switch, the step-down module is connected to the backup battery via the second switch, and the backup battery is connected to the load via the third switch.

7. The AC / DC conversion circuit according to claim 6, characterized in that, When the first switch is closed, the first power supply path is formed; when the second switch is closed, the energy storage path is formed; and when the third switch is closed, the second power supply path is formed.

8. The AC / DC conversion circuit according to any one of claims 3-7, characterized in that, The control module also includes a voltage regulator; The voltage regulator is used to convert the DC voltage input to the voltage regulator into an output DC voltage that meets a preset requirement; the preset requirement is determined according to the input requirement of the device connected to the output terminal of the voltage regulator.

9. A control method for an AC / DC conversion circuit, characterized in that, The method is applied to the AC / DC conversion circuit as described in any one of claims 1-8, and the method includes: The AC voltage of the generator is converted into the target DC voltage by the step-down module in the AC-DC conversion circuit, and the target DC voltage is input to the control module in the AC-DC conversion circuit. The power supply to the load is based on the supply and demand relationship between the output power of the step-down module and the power demand of the load; the supply and demand relationship includes the output power of the step-down module being higher than the power demand of the load, or the output power of the step-down module being lower than the power demand of the load.

10. An AC / DC conversion system, characterized in that, It includes a generator, a load, and an AC / DC conversion circuit as described in any one of claims 1-8.

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