Power supply circuit, energy storage equipment and unmanned aerial vehicle

Abstract

A power supply circuit, an energy storage device and an unmanned aerial vehicle, the power supply circuit comprises a first power supply loop and a second power supply loop, and the first power supply loop is used for providing a first output current for a load based on electric energy provided by a power supply and stopping outputting the first output current when the first output current is greater than a first preset threshold. The second power supply loop is switched on or off based on the first output current; the conduction impedance of the second power supply loop is smaller than that of the first power supply loop; and the second power supply loop is also used for providing a second output current for the load based on the electric energy provided by the power supply when the second power supply loop is switched on, and is switched off when the second output current is greater than a second preset threshold. The first power supply loop and the second power supply loop both have the function of automatic power off when the current is too large, certain short circuit protection is achieved, and meanwhile, by providing the first output current and the second output current for the load, accidents such as fire and explosion caused by the fact that the too large current is output when short circuit occurs at the initial stage of power supply can be avoided.

Description

Technical Field

[0001] This application belongs to the technical field of energy storage devices, and particularly relates to a power supply circuit, an energy storage device, and a drone. Background Art

[0002] Currently, since drones and mobile robots require autonomous mobility, their power supply methods must also be mobile. Therefore, batteries have become essential for drones and mobile robots.

[0003] With the diversification of application scenarios, drones and mobile robots have put forward corresponding requirements for the battery life of batteries. At present, the battery string and parallel connection scheme is usually adopted to increase the battery capacity, but this will cause the battery voltage of the power supply to be continuously increased. As the battery voltage continues to increase, when the positive and negative electrodes are short-circuited, due to the very small output resistance, the battery output current will be extremely large. The instantaneous current during battery short-circuit is even larger, the internal temperature rise of the battery is more rapid, and the battery is more likely to catch fire and explode during short-circuit. Summary of the Utility Model

[0004] The purpose of this application is to provide a power supply circuit, an energy storage device, and a drone, aiming to solve the problem of short circuit existing in traditional energy storage devices.

[0005] In the first aspect of the embodiment of this application, a power supply circuit is provided, including: a first power supply loop, the first end of the first power supply loop is used to connect to a power supply, the second end of the first power supply loop is used to connect to a load, the first power supply loop is used to provide a first output current to the load based on the electric energy provided by the power supply, and stop outputting the first output current when the first output current is greater than a first preset threshold; a second power supply loop, the first end of the second power supply loop is connected to the first end of the first power supply loop, the second end of the second power supply loop is connected to the second end of the first power supply loop, the second power supply loop is used to conduct or turn off based on the first output current; the on-resistance of the second power supply loop is less than the on-resistance of the first power supply loop; the second power supply loop is further used to, when conducting, provide a second output current to the load based on the electric energy provided by the power supply, and turn off when the second output current is greater than a second preset threshold.

[0006] In one embodiment, the first power supply loop includes a first switch unit and a first short-circuit protection unit; the first end of the first switch unit is used to connect to the power supply, the second end of the first switch unit is connected to the first end of the first short-circuit protection unit, and the second end of the first short-circuit protection unit is used to connect to the load; the first switch unit is used to conduct or turn off in response to a switch signal; the first short-circuit protection unit is used to disconnect when the first output current is greater than the first preset threshold to stop outputting the first output current.

[0007] In one embodiment, the first short-circuit protection unit includes a recoverable temperature positive resistance device and a recoverable temperature negative resistance device; the recoverable temperature positive resistance device and the recoverable temperature negative resistance device are connected in series between the first switch unit and the load, and the temperature of the recoverable temperature positive resistance device affects the temperature of the recoverable temperature negative resistance device, and vice versa.

[0008] In one embodiment, the recoverable temperature positive resistance device is configured to turn off when the temperature of the recoverable temperature positive resistance device is greater than a first temperature threshold, and to turn on when the temperature of the recoverable temperature positive resistance device is less than a second temperature threshold after the recoverable temperature positive resistance device turns off, where the first temperature threshold is greater than the second temperature threshold.

[0009] In one embodiment, the temperature coefficient of the recoverable temperature negative resistance device is greater than the temperature coefficient of the recoverable temperature positive resistance device.

[0010] In one embodiment, the second power supply circuit includes a second switch unit, a current detection unit, and a switch control unit; a first end of the second switch unit is configured to be connected to the power supply, a second end of the second switch unit is connected to a first end of the current detection unit, a second end of the current detection unit is configured to be connected to the load, and the switch control unit is respectively connected to a second end of the first power supply circuit, a controlled end of the second switch unit, and the current detection unit; the current detection unit is configured to detect the second output current and feedback parameters of the second output current to the switch control unit, and the switch control unit is configured to control the second switch unit to turn on when the first output current is detected, and to control the second switch unit to turn off when the second output current is greater than a second preset threshold, where the first preset threshold is less than the second preset threshold.

[0011] In one embodiment, the second power supply circuit further includes a second short-circuit protection unit, the second short-circuit protection unit is connected between a second end of the current detection unit and the load, and the second short-circuit protection unit is configured to disconnect when the second output current is greater than a third preset threshold, where the third preset threshold is greater than or equal to the second preset threshold.

[0012] In one embodiment, the second power supply circuit further includes a unidirectional conduction device, the unidirectional conduction device is connected between a second end of the first power supply circuit and the switch control unit, and is configured to control the unidirectional transmission of the first output current to the switch control unit.

[0013] In a second aspect of the embodiments of the present application, an energy storage device is provided. The energy storage device includes a battery pack, an output port, and the power supply circuit as described above. The power supply circuit is connected between the battery pack and the output port.

[0014] In a third aspect of the embodiments of the present application, a drone is provided, which includes the energy storage device as described above.

[0015] The beneficial effects of the embodiments of the present application compared with the prior art are as follows: on the one hand, the first power supply circuit has the function of automatically cutting off the power when the current is too large, which can achieve a certain short-circuit protection. On the other hand, by separately providing the first output current and the second output current to the load, it is possible to avoid excessive current output and resulting in accidents such as fire and explosion when a short circuit occurs at the initial stage of power supply.

[0016] Through the series connection of a recoverable temperature positive resistance device and a recoverable temperature negative resistance device, automatic periodic conduction and turn-off can be achieved in the case of a load short circuit. When the load short circuit fault is removed, the power supply can be restored automatically. Description of the Drawings

[0017] Figure 1 It is a schematic structural diagram of a power supply circuit provided by an embodiment of the present application;

[0018] Figure 2 It is another schematic structural diagram of a power supply circuit provided by an embodiment of the present application;

[0019] Figure 3 It is a schematic structural diagram of an energy storage device provided by an embodiment of the present application;

[0020] Figure 4 It is a working flow chart of an energy storage device provided by an embodiment of the present application;

[0021] Figure 5 It is a schematic structural diagram of a drone provided by an embodiment of the present application. Detailed Embodiments

[0022] In order to make the technical problems, technical solutions, and beneficial effects to be solved by the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0024] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0025] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0026] Figure 1 The structural schematic diagram of the power supply circuit provided by an embodiment of the present application is shown. For the convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0027] The power supply circuit 10 includes: a first power supply loop 100 and a second power supply loop 200.

[0028] The first end of the first power supply loop 100 is used to connect to the power supply 20, the second end of the first power supply loop 100 is used to connect to the load 30. The first power supply loop 100 is used to provide a first output current to the load 30 based on the electric energy provided by the power supply 20, and stop outputting the first output current when the first output current is greater than a first preset threshold. The first end of the second power supply loop 200 is connected to the first end of the first power supply loop 100, the second end of the second power supply loop 200 is connected to the second end of the first power supply loop 100. The second power supply loop 200 is used to conduct or cut off based on the first output current, and provide a second output current to the load 30 based on the electric energy provided by the power supply 20 when conducting. In some embodiments, the second power supply loop 200 is also used to cut off when the second output current is greater than a second preset threshold to stop outputting the second output current. Among them, the on-resistance of the second power supply loop 200 is less than that of the first power supply loop 100, and the second power supply loop 200 is used to conduct when detecting that the magnitude of the first output current is normal.

[0029] It can be understood that when the load 30 is operating normally, since the conduction impedance of the second power supply circuit 200 is less than that of the first power supply circuit 100, the first power supply circuit 100 will be bypassed by the second power supply circuit 200. When the second power supply circuit 200 is conducting and a short-circuit fault occurs in the load 30, the second output current output by the second power supply circuit 200 will increase until the second output current is greater than the second preset threshold, causing the second power supply circuit 200 to turn off and the first power supply circuit 100 to conduct again. At this time, the first output current output by the first power supply circuit 100 will increase until the first output current is greater than the first preset threshold, causing the first power supply circuit 100 to stop outputting the first output current and disconnect the connection between the power supply 20 and the load 30, realizing short-circuit protection of the power supply circuit 10.

[0030] In the initial stage of power-on of the load 30, the first power supply circuit 100 first provides the first output current to the load 30. At this time, if a short-circuit fault occurs, since the first power supply circuit 100 has the function of automatically cutting off the power when the current is too large, a certain short-circuit protection can be achieved. By first providing the first output current to the load 30 and then providing the second output current, a relatively small first output current can be provided to the load 30 only in the initial stage of power supply. When the load 30 is operating normally based on the first output current, the second output current is provided to the load 30. When a short-circuit fault occurs in the load 30, the short-circuit fault of the load 30 can be judged through the first output current. Thus, before providing the larger second output current, the connection between the power supply 20 and the load 30 is disconnected to avoid outputting an excessive current, resulting in accidents such as fire and explosion.

[0031] In some embodiments, the power supply 20 can be an energy storage device such as a battery, and the load 30 can be a device such as a motor. The second power supply circuit 200 is also used to stop outputting the second output current when the second output current is greater than the second preset threshold. Among them, the conduction impedance of the second power supply circuit 200 is less than that of the first power supply circuit 100, and the second power supply circuit 200 is used to conduct when detecting the first output current.

[0032] In one embodiment, the first power supply circuit 100 includes a first switch unit 110 and a first short-circuit protection unit 120. The first end of the first switch unit 110 is used to connect to the power supply 20, the second end of the first switch unit 110 is connected to the first end of the first short-circuit protection unit 120, and the second end of the first short-circuit protection unit 120 is used to connect to the load 30. The first switch unit 110 is used to conduct or turn off in response to a switch signal. The first short-circuit protection unit 120 is used to disconnect when the first output current is greater than the first preset threshold to stop outputting the first output current.

[0033] It can be understood that the switch signal can be a signal generated by a physical button or a signal provided by a digital circuit. The switch signal and the first switch unit 110 can be specifically set according to actual requirements. The first short-circuit protection unit 120 can use devices such as a circuit breaker to implement the overcurrent protection function. The first preset threshold is set by the specific structure and parameters of the first short-circuit protection unit 120.

[0034] In one embodiment, the first short-circuit protection unit 120 is further configured to re-conduct after every preset duration of disconnection.

[0035] To prevent the power supply circuit 10 from completely stopping working after detecting a short circuit in the primary load 30, by setting it to re-conduct after every preset duration of disconnection, the power supply circuit 10 can resume normal power supply after the short-circuit fault of the load 30 is eliminated. The first short-circuit protection unit 120 can be composed of logic control circuits and devices such as FPGAs, single-chip microcontrollers, and switching tubes.

[0036] In one embodiment, the first short-circuit protection unit 120 includes a recoverable temperature positive resistance device 121 and a recoverable temperature negative resistance device 122. The recoverable temperature positive resistance device 121 and the recoverable temperature negative resistance device 122 are connected in series between the first switch unit 110 and the load 30, and the temperature of the recoverable temperature positive resistance device 121 and the temperature of the recoverable temperature negative resistance device 122 affect each other. In some embodiments, the recoverable temperature positive resistance device 121 and the recoverable temperature negative resistance device 122 can be set closely or at zero distance, for example, mounted closely, so that the heat generated by the devices is transmitted to each other, and the temperature of the recoverable temperature positive resistance device 121 and the temperature of the recoverable temperature negative resistance device 122 are kept consistent.

[0037] It can be understood that when the first switch unit 110 changes from the off state to the on state, since the temperatures of both the recoverable temperature positive resistance device 121 and the recoverable temperature negative resistance device 122 are relatively low, the resistance value of the recoverable temperature negative resistance device 122 is relatively large, and it can be used to absorb the instantaneous large current of the capacitor of the load 30.

[0038] Due to the relatively large resistance value of the recoverable temperature negative resistance device 122, the temperature of the recoverable temperature negative resistance device 122 will rise due to the passing of current and affect the temperature of the recoverable temperature positive resistance device 121, causing the resistance value of the recoverable temperature positive resistance device 121 to increase. When the load 30 is working normally, the resistance value of the first short-circuit protection unit 120 will finally stabilize at a fixed value, and the first output current will also remain stable.

[0039] When the load 30 is short-circuited, the series-connected recoverable positive temperature coefficient device 121 and recoverable negative temperature coefficient device 122 can achieve automatic shutdown of the first short-circuit protection unit 120, and re-conduct after the temperature of the recoverable positive temperature coefficient device 121 drops, realizing periodic restart to continuously probe the state of the load 30. When the short-circuit fault of the load 30 is removed, the first short-circuit protection unit 120 can resume power supply by itself.

[0040] In some embodiments, the recoverable positive temperature coefficient device 121 is configured to turn off when the temperature of the recoverable positive temperature coefficient device 121 is greater than a first temperature threshold, and turn on when the temperature of the recoverable positive temperature coefficient device 121 is less than a second temperature threshold after the recoverable positive temperature coefficient device 121 is turned off, where the first temperature threshold is greater than the second temperature threshold.

[0041] When a short-circuit fault of the load 30 causes the first output current to be too large, the temperature of the recoverable positive temperature coefficient device 121 will rise until the temperature of the recoverable positive temperature coefficient device 121 is greater than the first temperature threshold, causing the recoverable positive temperature coefficient device 121 to disconnect, resulting in the first power supply circuit 100 stopping to output the first output current. Stopping the output of the first output current will cause the temperature of the recoverable positive temperature coefficient device 121 to drop until the temperature of the recoverable positive temperature coefficient device 121 is lower than the second temperature threshold, and the recoverable positive temperature coefficient device 121 re-conducts. In the case where the short-circuit fault of the load 30 has not been eliminated, the recoverable positive temperature coefficient device 121 will continuously cycle between conduction and shutdown, and control the first output current within an acceptable range to ensure that the power supply 20 will not have high-temperature faults or accidents. Exemplarily, in some embodiments, the first temperature threshold is 100 °C and the second temperature threshold is 90 °C. It should be noted that different types of recoverable positive temperature coefficient devices 121 can be selected according to actual needs to adjust the first temperature threshold and the second temperature threshold.

[0042] In some embodiments, the recoverable positive temperature coefficient device 121 includes a positive temperature coefficient thermistor, and the recoverable negative temperature coefficient device 122 includes a negative temperature coefficient thermistor.

[0043] In one embodiment, the temperature coefficient of the recoverable negative temperature coefficient device 122 is greater than the temperature coefficient of the recoverable positive temperature coefficient device 121.

[0044] It can be understood that since the temperature of the recoverable positive temperature coefficient device 121 and the temperature of the recoverable negative temperature coefficient device 122 affect each other, when the first switch unit 110 changes from the off state to the on state, the resistance value of the recoverable negative temperature coefficient device 122 begins to gradually decrease, and the resistance value of the recoverable positive temperature coefficient device 121 begins to gradually increase. The temperature coefficient of the recoverable negative temperature coefficient device 122 is greater than that of the recoverable positive temperature coefficient device 121, causing the overall resistance value of the first short-circuit protection unit 120 to gradually decrease, achieving the effect of gradually increasing the first output current.

[0045] In one embodiment, the second power supply circuit 200 includes a second switch unit 210, a current detection unit 220, and a switch control unit 230.

[0046] The first end of the second switch unit 210 is used to connect to the power supply 20, the second end of the second switch unit 210 is connected to the first end of the current detection unit 220, the second end of the current detection unit 220 is used to connect to the load 30, and the switch control unit 230 is respectively connected to the second end of the first power supply circuit 100, the controlled end of the second switch unit 210, and the current detection unit 220. The current detection unit 220 is used to detect the second output current and feedback the parameters of the second output current to the switch control unit 230. The switch control unit 230 is used to control the second switch unit 210 to conduct when the first output current is detected, and is used to control the second switch unit 210 to turn off when the second output current is greater than the second preset threshold.

[0047] The first output current is relatively small and can drive a partial system of the load 30 to operate. For example, it can be used to drive the control system of the load 30 to operate. When the first output current is normally output, it indicates that there is no short-circuit fault in the currently started part of the load 30. When the power demand of the load 30 increases, the second output current needs to be provided to the load 30.

[0048] The second power supply circuit 200 can provide the second output current to the load 30 to drive the load 30 to perform high-power operations when the first output current is detected. The switch control unit 230 can control the second switch unit 210 based on the second output current and turn off the second switch unit 210 in a timely manner when the second output current is too large and there is a risk of a short-circuit fault in the load 30.

[0049] In one embodiment, the second power supply circuit 200 further includes a second short-circuit protection unit 240. The second short-circuit protection unit 240 is connected between the second end of the current detection unit 220 and the load 30. The second short-circuit protection unit 240 is configured to disconnect when the second output current is greater than a third preset threshold, so as to stop the output of the second output current. Wherein, the third preset threshold is greater than or equal to the second preset threshold.

[0050] It can be understood that the second short-circuit protection unit 240 can perform short-circuit protection on the second power supply circuit 200 and the load 30 when the control of the second switch unit 210 by the switch control unit 230 fails, causing the second output current to continuously increase.

[0051] In some embodiments, the third preset threshold is greater than the second preset threshold. The second short-circuit protection unit 240 can perform short-circuit protection on the second power supply circuit 200, further improving the safety of the power supply circuit 10.

[0052] The second short-circuit protection unit 240 may specifically be a non-recoverable thermal disconnect device.

[0053] In one embodiment, the second power supply circuit 200 further includes a unidirectional conduction device 250. The unidirectional conduction device 250 is connected between the second end of the first power supply circuit 100 and the switch control unit 230, and is configured to control the unidirectional transmission of the first output current to the switch control unit 230.

[0054] It can be understood that since the second output current is relatively large, the unidirectional conduction device 250 can prevent the current in the second power supply circuit 200 from being transmitted to the first power supply circuit 100, affecting the operation of the load 30 and the first power supply circuit 100.

[0055] In some embodiments, the unidirectional conduction device 250 includes a diode.

[0056] Figure 3 The structural schematic diagram of an energy storage device provided by an embodiment of the present application is shown. For the sake of convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0057] As Figures 1 to 3 shown, the energy storage device 40 includes a battery pack 50, an output port 60, and the power supply circuit 10 according to any one of the above embodiments. The power supply circuit 10 is connected between the battery pack 50 and the output port 60. The output port 60 is used to connect to the load 30, and the power supply circuit 10 is used to control the current transmitted from the battery pack 50 to the output port 60.

[0058] In one embodiment, the energy storage device 40 further includes a mechanical signal switch 70. The mechanical signal switch 70 can output a switch signal after being triggered.

[0059] In one embodiment, the specific working process of the energy storage device 40 is as follows Figure 4 As shown, after the first power supply circuit 100 receives a switch signal, the first power supply circuit 100 can provide a first output current, and the second power supply circuit 200 provides a second output current after detecting the first output current. Once a short circuit fault occurs in the load 30, causing the first output current to be greater than the first preset threshold or the second output current to be greater than the second preset threshold, both the first power supply circuit 100 and the second power supply circuit 200 can be disconnected in a timely manner to reduce the risks of overheating, combustion, and explosion of the battery pack 50.

[0060] Figure 5 The following shows a schematic structural diagram of a drone provided by an embodiment of the present application. For the convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0061] The drone 80 includes an energy storage device 40 and a motor 90 as described in any of the above embodiments. The energy storage device 40 is connected to the motor 90 to supply electrical energy to the motor 90.

[0062] Those skilled in the art can clearly understand that for the convenience and conciseness of description, only the above-mentioned division of each functional unit and module is used as an example. In actual applications, the above functions can be allocated to different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated into a processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. In addition, the specific names of each functional unit and module are only for the convenience of mutual distinction and do not limit the protection scope of the present application. The specific working processes of the units and modules in the above system can refer to the corresponding processes in the foregoing method embodiments and will not be repeated here.

[0063] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed or recorded in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0064] The above-mentioned embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of each embodiment of the present application and should all be included in the protection scope of the present application.

Claims

1. A power supply circuit, characterized in that: include: a first power supply circuit, wherein a first end of the first power supply circuit is used to be connected to a power source, a second end of the first power supply circuit is used to be connected to a load, the first power supply circuit is used to provide a first output current to the load based on the electric energy provided by the power source, and stops outputting the first output current when the first output current is greater than a first preset threshold; a second power supply circuit, wherein a first end of the second power supply circuit is connected to a first end of the first power supply circuit, a second end of the second power supply circuit is connected to a second end of the first power supply circuit, and the second power supply circuit is used to be turned on or off based on the first output current; an on-impedance of the second power supply circuit is smaller than an on-impedance of the first power supply circuit; The second power supply circuit is also used for providing a second output current to the load based on the electric energy provided by the power supply when it is turned on, and is turned off when the second output current is greater than a second preset threshold.

2. The power supply circuit according to claim 1, characterized in that: The first power supply circuit includes a first switch unit and a first short-circuit protection unit; The first end of the first switch unit is used to connect to the power supply, the second end of the first switch unit is connected to the first end of the first short-circuit protection unit, and the second end of the first short-circuit protection unit is used to connect to the load; The first switch unit is used to be turned on or off in response to a switch signal; The first short-circuit protection unit is used to disconnect when the first output current is greater than the first preset threshold value, so as to stop outputting the first output current.

3. The power supply circuit according to claim 2, characterized in that: The first short circuit protection unit includes a recoverable temperature positive resistance device and a recoverable temperature negative resistance device; The recoverable temperature positive resistance device and the recoverable temperature negative resistance device are connected in series between the first switch unit and the load, and the temperature of the recoverable temperature positive resistance device and the temperature of the recoverable temperature negative resistance device affect each other.

4. The power supply circuit according to claim 3, characterized in that: The recoverable temperature positive resistance device is used to shut down when the temperature of the recoverable temperature positive resistance device is greater than a first temperature threshold, and to turn on when the temperature of the recoverable temperature positive resistance device is less than a second temperature threshold after the recoverable temperature positive resistance device is shut down, wherein the first temperature threshold is greater than the second temperature threshold.

5. The power supply circuit according to claim 4, characterized in that: The temperature coefficient of the recoverable temperature negative resistance device is greater than the temperature coefficient of the recoverable temperature positive resistance device.

6. The power supply circuit according to any one of claims 1 to 5, characterized in that: The second power supply circuit includes a second switch unit, a current detection unit and a switch control unit; The first end of the second switch unit is used to be connected to the power supply, the second end of the second switch unit is connected to the first end of the current detection unit, the second end of the current detection unit is used to be connected to the load, and the switch control unit is respectively connected to the second end of the first power supply circuit, the controlled end of the second switch unit and the current detection unit; The current detection unit is used to detect the second output current and to feed back the parameters of the second output current to the switch control unit. The switch control unit is used to control the second switch unit to turn on when the first output current is detected, and to control the second switch unit to turn off when the second output current is greater than the second preset threshold, wherein the first preset threshold is less than the second preset threshold.

7. The power supply circuit according to claim 6, characterized in that: The second power supply circuit also includes a second short-circuit protection unit, which is connected between the second end of the current detection unit and the load, and the second short-circuit protection unit is used to disconnect when the second output current is greater than a third preset threshold, and the third preset threshold is greater than or equal to the second preset threshold.

8. The power supply circuit according to claim 6, characterized in that: The second power supply circuit further includes a unidirectional conductive device, which is connected between the second end of the first power supply circuit and the switch control unit and is used to control the first output current to be transmitted unidirectionally to the switch control unit.

9. An energy storage device, characterized in that: The energy storage device comprises a battery pack, an output port and a power supply circuit as claimed in any one of claims 1 to 8, wherein the power supply circuit is connected between the battery pack and the output port.

10. A drone, characterized in that: Comprising the energy storage device as claimed in claim 9.

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