CN116846039A

CN116846039A - Charging and discharging device, method, apparatus and storage medium

Info

Publication number: CN116846039A
Application number: CN202311099807.0A
Authority: CN
Inventors: 叶强; 张坤; 舒金表; 应小宇; 方勇军; 邓志吉; 周莉
Original assignee: Zhejiang Dahua Technology Co Ltd
Current assignee: Zhejiang Dahua Technology Co Ltd
Priority date: 2023-08-30
Filing date: 2023-08-30
Publication date: 2023-10-03
Anticipated expiration: 2043-08-30
Also published as: CN116846039B

Abstract

The invention discloses a charge and discharge device, a method, equipment and a storage medium, wherein the charge and discharge device comprises at least one charge and discharge unit, and the charge and discharge unit comprises: the power conversion circuit is connected with the first power supply, the energy storage capacitor and the charge-discharge loop are connected with the second power supply. Before the second power supply is charged, the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply; when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge and discharge loop and the second power supply form a charge loop; and/or, before discharging the second power supply, the energy storage capacitor is charged to a second set voltage, and the second set voltage is smaller than the residual voltage of the second power supply; when the second power supply is discharged, the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply form a discharge loop. By the mode, the safety of the charging and discharging device for charging and discharging the second power supply can be improved.

Description

Charging and discharging device, method, apparatus and storage medium

Technical Field

The present invention relates to the field of power management technologies, and in particular, to a charging and discharging device, a charging and discharging method, a charging and discharging device, and a storage medium.

Background

In the case of high-power charge and discharge, the target charge and discharge device is usually charged or discharged by a charge and discharge device. For example, in the field of Vehicle-mounted charging and discharging, a power Grid charges a Vehicle battery, i.e., G2V (Grid-to-Vehicle) through a charging and discharging device of a charging pile, and when the power Grid demand is high, the Vehicle can reversely transfer surplus electric energy, i.e., V2G (Vehicle-to-Grid), to the power Grid through the charging and discharging device. How to improve the safety of the charge-discharge device to charge and discharge the target charge-discharge device becomes a technical problem to be solved.

Disclosure of Invention

The application mainly solves the technical problem of providing a charging and discharging device, a method, equipment and a computer readable storage medium, which can improve the safety of the charging and discharging device for charging and discharging a second power supply.

In order to solve the technical problems, the application adopts a technical scheme that: there is provided a charge and discharge device including at least one charge and discharge unit including: the input end of the power conversion circuit is used for being connected with a first power supply; the first end of the energy storage capacitor is connected with the first output end of the power conversion circuit, and the second end of the energy storage capacitor is connected with the second output end of the power conversion circuit; the first end of the charge-discharge loop is connected with the first end of the energy storage capacitor, and the second end of the charge-discharge loop is connected with the second power supply; before the second power supply is charged, the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply; when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge and discharge loop and the second power supply form a charge loop; and/or, before discharging the second power supply, the energy storage capacitor is charged to a second set voltage, and the second set voltage is smaller than the residual voltage of the second power supply; when the second power supply is discharged, the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply form a discharge loop.

In order to solve the technical problems, the application adopts another technical scheme that: there is provided a charge and discharge method applied to a charge and discharge device including at least one charge and discharge unit including: the power conversion circuit, the energy storage capacitor and the charge-discharge loop are connected with the first power supply; the first end of the energy storage capacitor is connected with the first output end of the power conversion circuit, and the second end of the energy storage capacitor is connected with the second output end of the power conversion circuit; the first end of the charge-discharge loop is connected with the first end of the energy storage capacitor, and the second end of the charge-discharge loop is connected with the second power supply; the method comprises the following steps: before the second power supply is charged, the energy storage capacitor is charged, so that the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply; when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge-discharge loop and the second power supply are controlled to form a charge loop; and/or before discharging the second power supply, charging the energy storage capacitor to enable the energy storage capacitor to be charged to a second set voltage, wherein the second set voltage is smaller than the residual voltage of the second power supply; when the second power supply is discharged, the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply are controlled to form a discharge loop.

In order to solve the technical problems, the application adopts another technical scheme that: there is provided an electronic device comprising a memory and a processor coupled to each other, the memory storing program instructions; the processor is used for executing the program instructions stored in the memory to realize the charge and discharge method.

In order to solve the technical problems, the application adopts another technical scheme that: there is provided a computer readable storage medium for storing program instructions executable by a processor to implement the charge and discharge method described above.

According to the scheme, on one hand, before the second power supply is charged, the second power supply is charged to the first set voltage which is larger than the residual voltage of the second power supply, so that a current path from the first power supply to the second power supply can be formed when the second power supply is connected for charging, and the residual voltage of the second power supply is prevented from flowing backwards to the charging and discharging circuit to damage components in the charging and discharging circuit. On the other hand, before discharging the second power supply, the energy storage capacitor is charged to a second set voltage smaller than the residual voltage of the second power supply, so that a current path from the second power supply to the first power supply can be formed when the second power supply is connected for discharging, and the voltage of the energy storage capacitor is prevented from flowing backwards to the charge and discharge loop to damage components in the charge and discharge loop. By the mode, the safety of the charging and discharging device for charging and discharging the second power supply can be improved.

Drawings

FIG. 1 is a schematic diagram of a charge/discharge device according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of another embodiment of the charge-discharge device provided by the present application;

fig. 3 is a schematic structural diagram of a charge-discharge device according to another embodiment of the present application;

fig. 4 is a schematic structural diagram of a charge and discharge device according to another embodiment of the present application;

FIG. 5 is a schematic diagram of a charge and discharge system according to an embodiment of the present application;

FIG. 6 is a schematic flow chart of an embodiment of a charge/discharge method according to the present application;

FIG. 7 is a schematic flow chart of another embodiment of a charge/discharge method according to the present application;

FIG. 8 is a schematic flow chart of another embodiment of a charge/discharge method according to the present application;

FIG. 9 is a schematic flow chart of an embodiment of a charge/discharge method according to the present application;

FIG. 10 is a schematic flow chart of another embodiment of a charge/discharge method according to the present application;

FIG. 11 is a schematic flow chart of another embodiment of a charge/discharge method according to the present application;

FIG. 12 is a schematic diagram of a frame of an embodiment of an electronic device provided by the present application;

FIG. 13 is a schematic diagram of a computer-readable storage medium according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and effects of the present application clearer and more specific, the present application will be described in further detail below with reference to the accompanying drawings and examples.

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, interfaces, techniques, etc., in order to provide a thorough understanding of the present application.

The term "and/or" is herein merely an association relation describing an associated object, meaning that three relations may exist, e.g., a and/or B may represent: a exists alone, A and B exist together, and B exists alone. The term "multiple" means two or more than two. In addition, the terms "first," "second," etc. are used to distinguish similar objects and not necessarily to describe a particular order or precedence.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a charge-discharge device according to an embodiment of the application. As shown in fig. 1, the charge and discharge device includes at least one charge and discharge cell 10 (one charge and discharge cell 10 is exemplified in fig. 1). The charge-discharge unit 10 includes a power conversion circuit 11, an energy storage capacitor 12, and a charge-discharge circuit 13.

Wherein an input of the power conversion circuit 11 is adapted to be connected to a first power supply 20. In an example, the first power source 20 is an alternating current power source (e.g., a three-phase alternating current grid), and the power conversion circuit 11 may include a bidirectional AC/DC (Alternating Current to Direct Current ) conversion sub-circuit and a bidirectional DC/DC (Direct Current to Direct Current, alternating current to direct current) conversion sub-circuit, one end of the bidirectional AC/DC conversion sub-circuit being connected to the first power source 20, and the other end of the bidirectional AC/DC conversion sub-circuit being connected to the bidirectional DC/DC conversion sub-circuit. In yet another example, the first power source 20 is a direct current power source (e.g., a battery), and the power conversion circuit 11 may include a bi-directional DC/DC conversion sub-circuit. The specific circuit topology of the power conversion circuit 11 can be designed according to practical situations, and this embodiment is not particularly limited.

The first end of the energy storage capacitor 12 is connected with the first output end of the power conversion circuit 11, the second end of the energy storage capacitor 12 is connected with the second output end of the power conversion circuit 11, and the second end of the energy storage capacitor 12 is grounded.

The first end of the charge-discharge loop 13 is connected to the first end of the energy storage capacitor 12, the second end of the charge-discharge loop 13 is connected to the second power supply 30, and the ground end of the second power supply 30 is grounded to the second end of the energy storage capacitor 12. The second power source 30 is a battery or other power source that needs to be charged or discharged, which is not particularly limited in this embodiment. In one example, one charge-discharge loop 13 is shared by charging the second power source 30 and discharging the second power source 30. In another example, the charge-discharge circuit 13 includes a charge sub-circuit 131 and a discharge sub-circuit 132, charging the second power supply 30 through the charge sub-circuit 131, and discharging the second power supply 30 through the discharge sub-circuit 132.

In one embodiment, for each of the charge-discharge cells 10, the storage capacitor 12 is charged to a first set voltage, which is greater than the remaining voltage of the second power supply 30, before charging the second power supply 30; when the second power supply 30 is charged, the first power supply 20, the power conversion circuit 11, the energy storage capacitor 12, the charge-discharge circuit 13, and the second power supply 30 form a charge circuit.

Illustratively, the first set voltage is any voltage value greater than the remaining voltage of the second power supply 30; alternatively, the first set voltage is a voltage value that is greater than the remaining voltage of the second power supply 30 and is close to the remaining voltage of the second power supply 30, for example, a voltage difference between the first set voltage and the remaining voltage of the second power supply 30 is less than or equal to a first difference threshold, which is a smaller value.

Illustratively, the energy storage capacitor 12 may be charged by the first power source 20 before the second power source 30 is charged, or the energy storage capacitor 12 may be charged to the first set voltage by other power sources than the first power source 20 and the second power source 30.

In one embodiment, for each of the charge-discharge cells 10, the storage capacitor 12 is charged to a second set voltage, which is less than the remaining voltage of the second power supply 30, before discharging the second power supply 30; when discharging the second power supply 30, the charge-discharge circuit 13, the energy storage capacitor 12, the power conversion circuit 11, and the first power supply 20 form a discharge circuit.

Illustratively, the second set voltage is any voltage value less than the remaining voltage of the second power supply 30; alternatively, the second set voltage is a voltage value smaller than the remaining voltage of the second power supply 30 and close to the remaining voltage of the second power supply 30, for example, a voltage difference between the remaining voltage of the second power supply 30 and the second set voltage is smaller than or equal to a second difference threshold, which is a smaller value.

Illustratively, the energy storage capacitor 12 may be charged by the second power source 30 before the second power source 30 is discharged, or the energy storage capacitor 12 may be charged by the first power source 20 or other power sources other than the first and second power sources 20 and 30, so that the energy storage capacitor 12 is charged to the second set voltage.

In this embodiment, on the one hand, before charging the second power supply, the second power supply is charged to a first set voltage greater than the residual voltage of the second power supply, so that when the second power supply is connected to charge, a current path from the first power supply to the second power supply can be formed, and the residual voltage of the second power supply is prevented from flowing backward to the charge-discharge circuit to damage components in the charge-discharge circuit. On the other hand, before discharging the second power supply, the energy storage capacitor is charged to a second set voltage smaller than the residual voltage of the second power supply, so that a current path from the second power supply to the first power supply can be formed when the second power supply is connected for discharging, and the voltage of the energy storage capacitor is prevented from flowing backwards to the charge and discharge loop to damage components in the charge and discharge loop. By the mode, the safety of the charging and discharging device for charging and discharging the second power supply can be improved.

Referring to fig. 2, fig. 2 is a schematic structural diagram of another embodiment of a charging and discharging device according to the present application. As shown in fig. 2, the charge and discharge apparatus further includes a first switch 40 and a control unit (not shown in fig. 2). The charge-discharge unit 10 of the charge-discharge device further comprises a current limiting circuit 14.

Wherein the first switch 40 is connected between the charge-discharge circuit 13 and the second power supply 30. The first switch 40 is turned on when the second power supply 30 needs to be charged or discharged, and the first switch 40 is turned off when the second power supply 30 does not need to be charged or discharged. The first switch 40 may be disposed outside the second power source 30 or inside the second power source 30, which is not particularly limited in this embodiment.

The first end of the current limiting circuit 14 is connected with the first end of the charge-discharge loop 13, and the second end of the current limiting circuit 14 is connected with the second end of the charge-discharge loop 13. Specifically, the current limiting circuit 14 includes a current limiting resistor 141 and a second switch 142. Illustratively, the resistance of the current limiting resistor 141 may be selected according to the actual current limiting requirement.

In an embodiment, a first end of the current limiting resistor 141 is connected to a first end of the charge/discharge circuit 13, a second end of the current limiting resistor 141 is connected to a first end of the second switch 142, a second end of the second switch 142 is connected to a second end of the charge/discharge circuit 13, and a control end of the second switch 142 is connected to the control unit.

Illustratively, the second switch 142 is a mos transistor, a source of the second switch 142 is connected to the second terminal of the current limiting resistor 141, a drain of the second switch 142 is connected to the second terminal of the charge-discharge circuit 13, and a gate (control terminal) of the second switch 142 is connected to the control unit. A first body diode is included between the source and the drain of the second switch 142, and an anode of the first body diode is connected to the source of the second switch 142 and a cathode of the first body diode is connected to the drain of the second switch 142. The first body diode of the second switch 142 is used to isolate the surge current generated when the first switch 40 is turned on.

In another embodiment, a first end of the second switch 142 is connected to a first end of the charge/discharge circuit 13, a second end of the second switch 142 is connected to a first end of the current limiting resistor 141, a control end of the second switch 142 is connected to the control unit, and a second end of the current limiting resistor 141 is connected to a second end of the charge/discharge circuit 13.

The charge-discharge circuit 13 includes a charge sub-circuit 131 and a discharge sub-circuit 132. The first end of the charging sub-loop 131 and the first end of the discharging sub-loop 132 are connected to the first end of the energy storage capacitor 12, and the second end of the charging sub-loop 131 and the second end of the discharging sub-loop 132 are connected to the second power supply 30. When the second power supply 30 needs to be charged, the second power supply 30 is charged through the charging sub-loop 131; when the second power supply 30 needs to be charged, the second power supply 30 is discharged through the discharge sub-loop 132.

In an embodiment, the charging sub-loop 131 includes a third switch 131a and a first diode 131b. The first end of the third switch 131a is connected to the first end of the storage capacitor 12, the second end of the third switch 131a is connected to the anode of the first diode 131b, the control end of the third switch 131a is connected to the control unit, and the cathode of the first diode 131b is connected to the second power supply 30. Specifically, the cathode of the first diode 131b is connected to the second power supply 30 through the first switch 40.

The third switch 131a is used for controlling on and off of the charging sub-loop 131. The third switch 131a is a mos transistor, the drain electrode of the third switch 131a is connected to the first end of the storage capacitor 12, the source electrode of the third switch 131a is connected to the anode electrode of the first diode 131b, and the gate electrode (control end) of the third switch 131a is connected to the control unit. A second body diode is included between the source and the drain of the third switch 131a, and an anode of the second body diode is connected to the source of the third switch 131a and a cathode of the second body diode is connected to the drain of the third switch 131 a.

The first diode 131b is used to isolate the surge current generated when the first switch 40 is turned on. The first diode 131b is also used for isolating a large voltage spike generated at the moment of the short circuit of the third switch 131a, so as to protect the second power supply 30. When the third switch 131a has a short circuit fault, the first end and the second end of the third switch 131a generate a large voltage spike to pull down the voltage of the anode end of the first diode 131b, so that the voltage drop between the anode and the cathode of the first diode 131b cannot turn on the first diode 131b, and the large voltage spike can be isolated.

In one embodiment, the discharge sub-loop 132 includes a fourth switch 132a and a second diode 132b. The first end of the fourth switch 132a is connected to the first end of the storage capacitor 12, the second end of the fourth switch 132a is connected to the cathode of the second diode 132b, the control end of the fourth switch 132a is connected to the control unit, and the anode of the second diode 132b is connected to the second power supply 30. Specifically, the anode of the second diode 132b is connected to the second power supply 30 through the first switch 40.

The fourth switch 132a is used for controlling on and off of the discharging loop 132. Illustratively, the fourth switch 132a is a mos transistor. The source of the fourth switch 132a is connected to the first end of the storage capacitor 12, the drain of the fourth switch 132a is connected to the cathode of the second diode 132b, and the gate (control end) of the fourth switch 132a is connected to the control unit. A third body diode is included between the source and the drain of the fourth switch 132a, and an anode of the third body diode is connected to the source of the fourth switch 132a and a cathode of the third body diode is connected to the drain of the fourth switch 132 a. The third body diode of the fourth switch 132a is used to isolate the surge current generated when the first switch 40 is turned on.

When the fourth switch 132a has a short-circuit fault, the first and second ends of the fourth switch 132a generate a large voltage spike, and the second diode 132b is used for isolating the large voltage spike generated by the short-circuit moment of the fourth switch 132a to protect the second power supply 30.

In an embodiment, to ensure the stability and safety of the charging of the second power supply 30, when the second power supply 30 needs to be charged, the control unit is configured to control the first switch 40 to be turned off before the second power supply 30 is charged, control the current limiting circuit 14 to be turned on, and control the first power supply 20 to charge the voltage of the first end of the energy storage capacitor 12 to the first set voltage through the power conversion circuit 11, and control the first switch 40 to be turned on when the second power supply 30 is charged, and then control the first power supply 20, the power conversion circuit 11, the energy storage capacitor 12, the charge-discharge circuit 13 and the second power supply 30 to form a charging loop.

Specifically, the control unit is configured to control the first switch 40 to be turned off before charging the second power supply 30, control the second switch 142 of the current limiting circuit 14 to be turned on, and control the first power supply 20 to charge the voltage of the first end of the storage capacitor 12 to the first set voltage through the power conversion circuit 11, control the first switch 40 to be turned on when charging the second power supply 30, and then control the third switch 131a of the charging sub-circuit 131 to be turned on, so that the first power supply 20, the power conversion circuit 11, the storage capacitor 12, the charging sub-circuit 131 of the charging and discharging circuit 13, and the second power supply 30 form a charging circuit.

Controlling the current limiting circuit 14 to conduct before the second power supply 30 is charged prevents a larger rush current from occurring at the second end of the charging sub-loop 131 when the voltage at the first end of the storage capacitor 12 is charged to a larger voltage. In one specific application, the first set voltage is a voltage value that is greater than the residual voltage of the second power supply 30 and is close to the residual voltage of the second power supply 30. After the voltage at the first end of the energy storage capacitor 12 is charged to the first set voltage, the third switch 131a of the charging sub-circuit 131 is controlled to be turned on, and the third switch 131a of the charging sub-circuit 131 is controlled to be turned on, so that on one hand, a current path from the first power supply 20 to the second power supply 30 can be formed when the second power supply 30 is connected, and the residual voltage of the second power supply 30 is prevented from flowing backward to the charging and discharging circuit 13 to damage components of the charging and discharging circuit 13, and on the other hand, since the first set voltage is close to the residual voltage of the second power supply 30, the voltage fluctuation when the second power supply 30 is connected to charge can be reduced, and the stable charging of the second power supply 30 is realized.

In an embodiment, to ensure the stability and safety of the discharging of the second power supply 30, when the discharging of the second power supply 30 is required, the control unit is configured to control the first switch 40 to be turned on before the discharging of the second power supply 30, control the current limiting circuit 14 to be turned on, and control the second power supply 30 to charge the voltage of the first end of the energy storage capacitor 12 to the second set voltage through the current limiting circuit 14, and control the second power supply 30, the charge-discharge loop 13, the energy storage capacitor 12, the power conversion circuit 11 and the first power supply 20 to form a discharge loop when the discharging of the second power supply 30 is required.

Specifically, the control unit is configured to control the first switch 40 to be turned on before discharging the second power supply 30, control the second switch 142 of the current limiting circuit 14 to be turned on, and control the second power supply 30 to charge the voltage at the first end of the storage capacitor 12 to the second set voltage through the current limiting circuit 14, and control the fourth switch 132a of the discharging sub-loop 132 of the charging and discharging circuit to be turned on when discharging the second power supply 30, so that the second power supply 30, the charging and discharging loop 13, the storage capacitor 12, the power conversion circuit 11 and the first power supply 20 form a discharging loop.

The current limiting circuit 14 is controlled to be turned on before the second power supply 30 is discharged, so that the second power supply 30 can slowly charge the energy storage capacitor 12 to the second set voltage through the current limiting circuit 14. In a specific application, the second set voltage is a voltage value smaller than the residual voltage of the second power supply 30 and close to the residual voltage of the second power supply 30. After the voltage at the first end of the energy storage capacitor 12 is charged to the second set voltage, the fourth switch 132a of the discharging sub-loop 132 is controlled to be turned on, on one hand, a current path from the second power supply 30 to the first power supply 20 can be formed after the discharging sub-loop 132 is turned on, so that the voltage at the first end of the energy storage capacitor 12 is prevented from flowing backward to the charging and discharging loop 13 to damage components of the charging and discharging loop 13, and on the other hand, the voltage fluctuation during discharging of the second power supply 30 can be reduced due to the fact that the second set voltage is close to the residual voltage of the second power supply 30, and stable discharging of the second power supply 30 is realized.

Note that, the first switch 40, the second switch 142, the third switch 131a, and the fourth switch 132a in this embodiment may be a relay, a power switch tube, a field effect tube (such as a silicon mos tube, a silicon carbide mos tube), or the like, and the specific types of the first switch 40, the second switch 142, the third switch 131a, and the fourth switch 132a are not specifically limited in this embodiment. Illustratively, the first, second, third, and fourth switches 40, 142, 131a, 132a are voltage-tolerant to greater than 1000V. The first diode 131b and the second diode 132b may be silicon diodes, silicon carbide diodes, for example schottky diodes. The on-voltage drop of the first diode 131b and the second diode 132b is low, for example, less than 0.3V, and the reverse withstand voltage of the first diode 131b and the second diode 132b is greater than 1000V.

Alternatively, in the present embodiment, when a short-circuit fault is detected in the third switch 131a of the charging sub-circuit 131 during the process of charging the second power supply 30 through the charging sub-circuit 131, or when a short-circuit fault is detected in the fourth switch 132a of the discharging sub-circuit 132 during the process of discharging the second power supply 30 through the discharging sub-circuit 132, the control unit is further configured to stop the charging of the second power supply 30 by the corresponding charging and discharging unit 10. For example, the control unit may stop the charging of the second power supply 30 by the respective charge and discharge unit 10 by turning off the switch of the power conversion circuit 11 in the respective charge and discharge unit 10, the switch in the charge and discharge loop 13.

Specifically, when the third switch 131a of the charge sub-circuit 131 has a short-circuit fault or the fourth switch 132a of the discharge sub-circuit 132 has a short-circuit fault, a large voltage difference exists between the first terminal of the charge/discharge circuit 13 and the second terminal of the charge/discharge circuit 13. Therefore, in the present embodiment, the control unit may obtain the voltage at the first end of the charge-discharge circuit 13 and the voltage at the second end of the charge-discharge circuit 13 through the voltage sampling circuit (not illustrated in fig. 2), and determine that the third switch 131a of the charge-discharge circuit 131 has a short-circuit fault or the fourth switch 132a of the discharge sub-circuit 132 has a short-circuit fault when the voltage difference between the voltage at the first end of the charge-discharge circuit 13 and the voltage at the second end of the charge-discharge circuit 13 is greater than the second threshold.

In this embodiment, when the second power supply 30 is charged or discharged through the plurality of charging and discharging units 10 at the same time, if a short circuit fault occurs in the third switch 131a or the fourth switch 132a in one of the charging and discharging units 10, the charging and discharging unit 10 can be quickly cut off, without affecting the normal operation of the other charging and discharging units 10, so as to ensure that the charging and discharging process of the second power supply 30 can be performed normally.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a charge-discharge device according to another embodiment of the present application. In the charge/discharge device shown in fig. 3, the charge/discharge unit 10 further includes at least one of an overcurrent protection circuit 15, a transient suppression diode 16, and a filter circuit 17.

One end of the over-current protection circuit 15 is connected to the first end of the charge/discharge circuit 13, and the other end of the over-current protection circuit 15 is connected to the second power supply 30. Illustratively, the overcurrent protection circuit 15 includes a fuse that fuses to automatically cut off the circuit connection between the charge-discharge circuit 13 and the second power supply 30 when the current flowing through the fuse is excessive and reaches the fusing current of the fuse, so as to protect the second power supply 30 from being burned by a large current.

A first terminal of the transient suppression diode 16 is connected to a first terminal of the storage capacitor 12 and a second terminal of the transient suppression diode 16 is connected to a second terminal of the storage capacitor 12. During discharge of the second power supply 30, when the first terminal of the transient suppression diode 16 has an abnormally high voltage and reaches its breakdown voltage, the transient suppression diode 16 changes from a high resistance state to a low resistance state, providing a low-resistance conduction path for the instantaneous current, and clamping the abnormally high voltage to a safe voltage, for example, to 950V, so as to protect the power conversion circuit 11 from the abnormally high voltage.

The filter circuit 17 is located between the storage capacitor 12 and the charge-discharge loop 13. The filter circuit 17 illustratively includes a filter inductance. The first end of the filter inductor is connected with the first end of the energy storage capacitor 12, the second end of the filter inductor is connected with the first end of the charge-discharge loop 13, the third end of the filter inductor is connected with the second end of the energy storage capacitor 12, and the fourth end of the filter inductor is connected with the grounding end of the second power supply 30.

Referring to fig. 4, fig. 4 is a schematic structural diagram of a charge-discharge device according to another embodiment of the present application. As shown in fig. 4, the charge and discharge device includes a plurality of charge and discharge cells 10, and the input terminals of the power conversion circuits 11 of the plurality of charge and discharge cells 10 may be connected to the same first power supply 20, or the input terminals of the power conversion circuits 11 of the plurality of charge and discharge cells 10 may be connected to different first power supplies 20, respectively. The second ends of the charge-discharge circuits 13 of the plurality of charge-discharge cells 10 are all connected to the same second power supply 30 through the first switch 40. When the second power supply 30 needs to be charged, the second power supply 30 can be charged through the plurality of charging and discharging units 10; when the second power supply 30 needs to be discharged, the second power supply 30 may charge the first power supply 20 through the plurality of charge and discharge units 10, or may charge different first power supplies 20 through the plurality of charge and discharge units 10, respectively.

Referring to fig. 5, fig. 5 is a schematic structural diagram of a charge-discharge system according to an embodiment of the application. As shown in fig. 5, the charge and discharge system includes a first power source 20, a charge and discharge device, a first switch 40, a second power source 30, a control unit, the first switch 40, and a battery management system 60 (BMS, battery Management System). The first power supply 20, the charge and discharge device, and the control unit are located in a charge stake, and the second power supply 30 and the battery management system 60 are located on the vehicle.

Wherein the first power source 20 is specifically a power grid, and the second power source 30 is specifically a vehicle battery.

The charge and discharge device includes at least one charge and discharge unit 10 (only one charge and discharge unit 10 is taken as an example in fig. 5), and each charge and discharge unit 10 includes a power conversion circuit 11, an energy storage capacitor 12, a charge and discharge circuit 13, and a current limiting circuit 14. The power conversion circuit 11 includes a bidirectional AC/DC conversion sub-circuit 111 and a bidirectional DC/DC conversion sub-circuit 112.

The control unit includes an upper computer 51, a first controller 52, and a second controller 53. Illustratively, the first controller 52 and the second controller 53 may be a DSP (Digital Signal Processing ), an MCU (Microcontroller Unit, micro control unit), or the like, which is not particularly limited in this embodiment. Alternatively, the upper computer 51, the first controller 52, and the second controller 53 may also be implemented by one controller. The upper computer 51 is connected to the first controller 52, the upper computer 51 is connected to the second controller 53, the first controller 52 is connected to the second controller 53, the second controller 53 is connected to the battery management system 60, and the upper computer 51 is connected to the battery management system 60.

Specifically, when the battery management system 60 receives the charge and discharge instruction, the charge and discharge instruction is fed back to the host computer 51, and the detected information about the second power supply 30 is fed back to the host computer 51 in real time. The related information of the second power supply 30 includes information of a remaining voltage, a current, a remaining power, a charge/discharge state, a charged power, and the like of the second power supply 30. The charge-discharge instruction includes one of a charge instruction for instructing to charge the second power supply 30 and a discharge instruction for instructing to discharge the second power supply 30. Illustratively, the charge and discharge instruction is triggered by the user clicking a control button on a terminal device, which may be a vehicle-mounted intelligent terminal, a mobile phone, a notebook computer, a tablet, or the like.

The upper computer 51 monitors the operating states of the first controller 52 and the second controller 53 in real time, and after receiving the charge and discharge command, determines the control parameters of the switch in the bidirectional AC/DC conversion sub-circuit 111 and the control parameters of the switch in the bidirectional DC/DC conversion sub-circuit 112 according to the related information of the second power supply 30, and sends the control parameters of the switch in the bidirectional AC/DC conversion sub-circuit 111 and the control parameters of the switch in the bidirectional DC/DC conversion sub-circuit 112 to the first controller 52 and the second controller 53, respectively. Illustratively, the control parameters include the voltage, current, switching frequency, etc., required to control the switch.

The first controller 52 controls the switching operation in the bidirectional AC/DC conversion sub-circuit 111 according to the acquired control parameters of the switches in the bidirectional AC/DC conversion sub-circuit 111. The second controller 53 is configured to control the switching operation in the bidirectional DC/DC conversion sub-circuit 111 according to the acquired control parameter of the switching in the bidirectional DC/DC conversion sub-circuit 111. The second controller 53 further obtains the voltage at the first end of the storage capacitor 12, the voltages at the first end and the second end of the charge-discharge loop 13, and controls the operating states of the switches in the charge-discharge loop 13, the current limiting circuit 14, and the first switch 40 through the voltage sampling circuit.

Referring to fig. 6, fig. 6 is a flow chart of an embodiment of a charge/discharge method according to the present application. The method is applicable to the charge-discharge device shown in any one of fig. 1 to 3 and is used in the case of charging the second power supply. As shown in fig. 6, the method includes the steps of:

s61: before the second power supply is charged, the energy storage capacitor is charged, so that the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply.

S62: when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge and discharge loop and the second power supply are controlled to form a charge loop.

In this embodiment, before the second power supply is charged, the second power supply is charged to a first set voltage greater than the residual voltage of the second power supply, so that a current path from the first power supply to the second power supply can be formed when the second power supply is connected for charging, and the residual voltage of the second power supply is prevented from flowing backward to the charge-discharge circuit to damage components in the charge-discharge circuit. In this way, the safety of the charging/discharging device for charging the second power supply can be improved.

Referring to fig. 7, fig. 7 is a flow chart of another embodiment of the charge/discharge method according to the present application. The method is applied to the charge and discharge device shown in fig. 2 or 3, and is used in the case of charging the second power supply. As shown in fig. 7, the method includes the steps of:

S71: before the second power supply is charged, the first switch is controlled to be turned off, and the second switch of the current limiting circuit is controlled to be turned on.

S72: the first power supply is controlled to charge the voltage of the first end of the energy storage capacitor to a first set voltage through the power conversion circuit.

S73: the first switch is controlled to be turned on.

S74: and controlling the second switch to be switched off and controlling the third switch of the charging sub-loop to be switched on so as to enable the first power supply, the power conversion circuit, the energy storage capacitor, the charging and discharging loop and the second power supply to form a charging loop.

The details of step S71 to step S74 can refer to the embodiment shown in fig. 2, and are not described herein.

Alternatively, it is considered that when the resistance value of the current limiting resistor of the current limiting circuit is large, the current flowing through the current limiting circuit is small, and charging of the second power supply is mainly performed through the charging sub-loop. Therefore, the second switch of the current limiting circuit may be kept in an on state in step S74, i.e. the second switch is not controlled to be turned off.

Optionally, in this embodiment, after the first switch is controlled to be turned on and before the third switch of the charging sub-circuit is controlled to be turned on, the current limiting circuit is further subjected to overcurrent detection. Specifically, a first voltage of a first end of a charge-discharge loop and a second voltage of a second end of the charge-discharge loop are obtained; when the voltage difference between the first voltage and the second voltage is smaller than a first threshold value, determining that no overcurrent faults exist at two ends of the current limiting circuit, and controlling the third switch to be turned on; when the voltage difference between the first voltage and the second voltage is larger than or equal to a second threshold value, it is determined that overcurrent faults exist at two ends of the current limiting circuit, and at the moment, the third switch is not controlled to be conducted, namely the second power supply is not charged through the charging sub-loop, so that the safety of charging the second power supply is further improved. The first threshold may be set according to actual conditions, for example.

Optionally, in this embodiment, after the third switch of the charging sub-loop is controlled to be turned on, the short circuit detection is further performed on the third switch of the charging sub-loop. Specifically, a first voltage of a first end of a charge-discharge loop and a second voltage of a second end of the charge-discharge loop are obtained; when the voltage difference between the first voltage and the second voltage is larger than or equal to a second threshold value, it is determined that a short circuit fault exists in the third switch of the charging sub-circuit, and charging of the second power supply by the corresponding charging and discharging unit is stopped at the moment, so that the safety of charging of the second power supply is further improved. Specifically, the charging of the second power supply by the charging and discharging unit can be stopped by turning off the switch of the power conversion circuit in the charging and discharging unit and the switch in the charging and discharging loop. The second threshold value may be set according to actual conditions, for example.

Referring to fig. 8, fig. 8 is a flow chart of a charge and discharge method according to another embodiment of the present application. The method is applied to the charge and discharge device shown in fig. 4, and is used in the case of charging the second power supply. As shown in fig. 8, the method includes the steps of:

s81: at least one target charge-discharge cell is determined from the at least one charge-discharge cell.

In this embodiment, it may be determined, according to an actual charging requirement of the second power supply, that the second power supply is charged by at least one target charging and discharging unit from at least one charging and discharging unit.

S82: the method comprises the steps of executing charging of the energy storage capacitor before charging of the second power supply on each target charging and discharging unit one by one, enabling the energy storage capacitor to be charged to a first set voltage, and controlling the first power supply, the power conversion circuit, the energy storage capacitor, the charging and discharging loop and the second power supply to form a charging loop when the second power supply is charged.

When each target charging and discharging unit is simultaneously connected to charge the second power supply, larger impact current can be generated to damage the second power supply, the voltage fluctuation of the second power supply in the charging process is larger, and the charging is unstable. Therefore, in step S82, after the current target charge/discharge unit connected thereto can normally charge the second power supply through its own charge/discharge circuit, for example, after the third switch of the charge sub-circuit in the target charge/discharge unit is turned on, the next target charge/discharge unit is connected thereto.

S83: and after the second power supply is determined to be charged, controlling each target charge and discharge unit to stop working one by one.

When the charging of the second power supply by each target charge-discharge cell is stopped at the same time, a large rush current may be generated to damage the second power supply. Therefore, in step S83, after the current connected target charge/discharge unit is controlled to stop working, the next target charge/discharge unit is controlled to stop working.

Specifically, for each target charge-discharge unit, controlling the target charge-discharge unit to stop operating includes the steps of: acquiring a first voltage of a first end of a charge-discharge loop and a second voltage of a second end of the charge-discharge loop; gradually reducing the duty cycle of a switch in the power conversion circuit to gradually reduce the first voltage; and controlling the third switch of the charging sub-loop to be turned off in response to the first voltage being greater than the second voltage and the voltage difference between the first voltage and the second voltage being less than a third threshold. The third threshold is a smaller value, and the third threshold can be set according to practical situations. The switching-off of the third switch is realized by gradually reducing the duty ratio of the switch in the power conversion circuit, so that the voltage difference between the first voltage and the second voltage is smaller than the third threshold value, on one hand, the switching-off current of the third switch is smaller, the stop process of the target charging and discharging unit is performed stably and safely, the components in the second power supply and the target charging and discharging unit cannot be damaged, on the other hand, the switching-off loss of the third switch can be reduced, and the voltage peak generated at the switching-off moment of the third switch can be cut off by the first diode.

Alternatively, step S83 may be replaced with: and after the second power supply is determined to be charged, gradually controlling each target charge and discharge unit to stop working. Specifically, the steps of gradually decreasing the duty ratio of the switch in the power conversion circuit and controlling the third switch of the charge electronic circuit to be turned off when the first voltage is greater than the second voltage and the voltage difference between the first voltage and the second voltage is less than the third threshold value are simultaneously performed for each target charge-discharge unit.

In this embodiment, when at least one target charging and discharging unit is determined, each target charging and discharging unit is accessed one by one to charge the second power supply, and after the second power supply is charged, each target charging and discharging unit is stopped one by one to charge the second power supply, so that the whole charging process can be performed stably and safely.

Referring to fig. 9, fig. 9 is a flow chart of an embodiment of a charge/discharge method according to the present application. The method is applied to the charge-discharge device shown in any one of fig. 1 to 3, and is used in the case of discharging the second power supply. As shown in fig. 9, the method includes the steps of:

s91: before discharging the second power supply, the energy storage capacitor is charged, so that the energy storage capacitor is charged to a second set voltage, and the second set voltage is smaller than the residual voltage of the second power supply.

S92: when the second power supply is discharged, the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply are controlled to form a discharge loop.

In this embodiment, before discharging the second power supply, the energy storage capacitor is charged to a second set voltage smaller than the residual voltage of the second power supply, so that when the second power supply is connected to discharge, a current path from the second power supply to the first power supply can be formed, and the voltage of the energy storage capacitor is prevented from flowing backward to the charge-discharge circuit to damage components in the charge-discharge circuit. In this way, the safety of the charging and discharging device to the second power supply can be improved.

Referring to fig. 10, fig. 10 is a flow chart of another embodiment of the charge/discharge method according to the present application. The method is applied to the charge-discharge device shown in fig. 2 or 3, and is used in the case of discharging the second power source. As shown in fig. 10, the method includes the steps of:

s101: the first switch is controlled to be conducted, and the second switch of the current limiting circuit is controlled to be conducted.

S102: and controlling the second power supply to charge the voltage of the first end of the energy storage capacitor to a second set voltage through the current limiting circuit.

S103: and controlling the second switch to be disconnected and controlling the fourth switch of the discharging electronic circuit to be conducted so as to enable the second power supply, the charging and discharging circuit, the energy storage capacitor, the power conversion circuit and the first power supply to form a discharging circuit.

The specific contents of step S101 to step S103 may refer to the embodiment shown in fig. 2, and will not be described herein.

Alternatively, considering that the current flowing through the current limiting circuit is small when the resistance value of the current limiting resistor of the current limiting circuit is large, discharging the second power supply is mainly performed through the discharging sub-loop. Therefore, in step S103, the second switch of the current limiting circuit may be kept in an on state, i.e. the second switch is not controlled to be turned off.

Optionally, in this embodiment, after the fourth switch of the control discharging electronic circuit is turned on, the short circuit detection is further performed on the fourth switch of the discharging electronic circuit. Specifically, a first voltage of a first end of a charge-discharge loop and a second voltage of a second end of the charge-discharge loop are obtained; when the voltage difference between the second voltage and the first voltage is larger than or equal to a second threshold value, determining that a short circuit fault exists in the fourth switch of the discharging loop, and stopping discharging the second power supply by the corresponding charging and discharging unit at the moment so as to further improve the safety of discharging the second power supply. Specifically, the discharging of the second power supply by the charging and discharging unit can be stopped by turning off the switch of the power conversion circuit in the charging and discharging unit and the switch in the charging and discharging loop.

Referring to fig. 11, fig. 11 is a flow chart of a charge and discharge method according to another embodiment of the present application. The method is applied to the charge and discharge device shown in fig. 4, and is used in the case of discharging the second power supply. As shown in fig. 11, the method includes the steps of:

s111: at least one target charge-discharge cell is determined from the at least one charge-discharge cell.

In this embodiment, it may be determined, according to an actual discharge requirement of the second power supply, that the second power supply is discharged by at least one target charge-discharge unit from the at least one charge-discharge unit.

S112: and each target charge-discharge unit is controlled to charge the energy storage capacitor before discharging the second power supply one by one, so that the energy storage capacitor is charged to a second set voltage, and the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply are controlled to form a discharge loop when discharging the second power supply.

When each target charging and discharging unit is simultaneously connected to charge the second power supply, larger impact current can be generated to damage the second power supply, the voltage fluctuation of the second power supply in the discharging process is larger, and the discharging is unstable. Therefore, in step S112, after the current target charge/discharge unit connected thereto can normally discharge the second power supply through its own charge/discharge circuit, for example, after the fourth switch of the discharge sub-circuit in the target charge/discharge unit is turned on, the next target charge/discharge unit is connected thereto.

S113: after the second power supply is determined to be discharged, each target charge and discharge unit is controlled to stop working one by one.

When the discharge of the second power supply by each target charge-discharge cell is stopped at the same time, a large rush current may be generated to damage the second power supply. Therefore, in step S113, after the current target charge/discharge unit is controlled to stop working, the next target charge/discharge unit is controlled to stop working.

Specifically, for each target charge-discharge unit, the step of controlling the target charge-discharge unit to stop operation includes: and after the duty ratio of the switch in the power conversion circuit is gradually reduced to 0, the fourth switch of the control discharging electronic loop is turned off. The switching-off circuit of the fourth switch is almost 0 after the duty ratio of the switch in the switching circuit is gradually reduced to 0, so that on one hand, the process of stopping the target charging and discharging unit can be stably and safely carried out, on the other hand, the switching-off loss of the fourth switch is the lowest, and the voltage peak generated at the switching-off moment of the fourth switch can be blocked by the second diode.

Alternatively, step S113 may be replaced with: and after the second power supply is determined to be charged, gradually controlling each target charge and discharge unit to stop working. Specifically, the step of controlling the fourth switch of the discharge sub-circuit to be turned off after gradually decreasing the duty ratio of the switch in the power conversion circuit to 0 is simultaneously performed for each target charge-discharge cell.

In this embodiment, when at least one target charging and discharging unit is determined, each target charging and discharging unit is accessed one by one to discharge the second power supply, and after the second power supply is discharged, each target charging and discharging unit is stopped one by one to discharge the second power supply, so that the whole discharging process can be performed stably and safely.

Referring to fig. 12, fig. 12 is a schematic frame diagram of an embodiment of an electronic device according to the present application. In this embodiment, the electronic device 120 includes a memory 121 and a processor 122.

The processor 122 may also be referred to as a CPU (Central Processing Unit ). The processor 122 may be an integrated circuit chip having signal processing capabilities. Processor 122 may also be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components. A general purpose processor may be a microprocessor or the processor 122 may be any conventional processor 122 or the like.

Memory 121 in electronic device 120 is used to store program instructions needed for execution by processor 122.

The processor 122 is configured to execute program instructions to implement the charge and discharge method of the present application.

Referring to fig. 13, fig. 13 is a schematic diagram of a frame of an embodiment of a computer readable storage medium according to the present application. The computer readable storage medium 130 of the embodiment of the present application stores a program instruction 1301, and the program instruction 1301 when executed implements the charge and discharge method provided by the present application. Wherein the program instructions 1301 may form a program file stored in the above-mentioned computer readable storage medium 130 in the form of a software product, so that a computer device (which may be a personal computer, a server, or a network device, etc.) performs all or part of the steps of the methods of the embodiments of the present application. And the aforementioned computer-readable storage medium 130 includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, an optical disk, or other various media capable of storing program codes, or a terminal device such as a computer, a server, a mobile phone, a tablet, or the like.

In some embodiments, functions or modules included in an apparatus provided by the embodiments of the present disclosure may be used to perform a method described in the foregoing method embodiments, and specific implementations thereof may refer to descriptions of the foregoing method embodiments, which are not repeated herein for brevity.

The foregoing description of various embodiments is intended to highlight differences between the various embodiments, which may be the same or similar to each other by reference, and is not repeated herein for the sake of brevity.

In the several embodiments provided in the present application, it should be understood that the disclosed method, apparatus and system may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of modules or units is merely a logical functional division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical, or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed over a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor (processor) to execute all or part of the steps of the methods of the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

The foregoing description is only of embodiments of the present application, and is not intended to limit the scope of the application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application or directly or indirectly applied to other related technical fields are included in the scope of the present application.

Claims

1. A charge-discharge apparatus, characterized in that the charge-discharge apparatus comprises at least one charge-discharge unit comprising:

the input end of the power conversion circuit is used for being connected with a first power supply;

the first end of the energy storage capacitor is connected with the first output end of the power conversion circuit, and the second end of the energy storage capacitor is connected with the second output end of the power conversion circuit;

the first end of the charge-discharge loop is connected with the first end of the energy storage capacitor, and the second end of the charge-discharge loop is used for being connected with a second power supply;

wherein, before charging the second power supply, the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply; when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge-discharge loop and the second power supply form a charge loop; and/or the number of the groups of groups,

Before discharging the second power supply, the energy storage capacitor is charged to a second set voltage, and the second set voltage is smaller than the residual voltage of the second power supply; when the second power supply is discharged, the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply form a discharge loop.

2. The charge and discharge device of claim 1, wherein the charge and discharge unit further comprises a current limiting circuit, a first end of the current limiting circuit being connected to the first end of the charge and discharge circuit, a second end of the current limiting circuit being connected to the second end of the charge and discharge circuit; the charging and discharging device further comprises a control unit and a first switch connected between the charging and discharging loop and the second power supply;

the control unit is used for controlling the first switch to be turned off before the second power supply is charged, controlling the current limiting circuit to be turned on, controlling the first power supply to charge the voltage of the first end of the energy storage capacitor to the first set voltage through the power conversion circuit, controlling the first switch to be turned on when the second power supply is charged, and then controlling the first power supply, the power conversion circuit, the energy storage capacitor, the charge-discharge loop and the second power supply to form the charge loop;

And before discharging the second power supply, controlling the first switch to be conducted, controlling the current limiting circuit to be conducted, controlling the second power supply to charge the voltage of the first end of the energy storage capacitor to the second set voltage through the current limiting circuit, and controlling the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply to form the discharge loop.

3. The charge and discharge device of claim 2, wherein the current limiting circuit comprises a current limiting resistor and a second switch;

the first end of the current limiting resistor is connected with the first end of the charge-discharge loop, the second end of the current limiting resistor is connected with the first end of the second switch, the second end of the second switch is connected with the second end of the charge-discharge loop, and the control end of the second switch is connected with the control unit.

4. The charge-discharge device of claim 1, wherein the charge-discharge circuit comprises a charge sub-circuit and a discharge sub-circuit;

the first end of the charging sub-loop, the first end of the discharging sub-loop and the first end of the energy storage capacitor are connected, and the second end of the charging sub-loop and the second end of the discharging sub-loop are connected with the second power supply.

5. The charge and discharge device according to claim 4, wherein the charge sub-circuit includes a third switch and a first diode, a first end of the third switch is connected to a first end of the energy storage capacitor, a second end of the third switch is connected to an anode of the first diode, a control end of the third switch is connected to the control unit, and a cathode of the first diode is used to be connected to the second power supply; and/or the number of the groups of groups,

the discharging sub-loop comprises a fourth switch and a second diode, wherein the first end of the fourth switch is connected with the first end of the energy storage capacitor, the second end of the fourth switch is connected with the cathode of the second diode, the control end of the fourth switch is connected with the control unit, and the anode of the second diode is used for being connected with the second power supply.

6. The charge-discharge device according to claim 1, wherein the charge-discharge unit further comprises at least one of an overcurrent protection circuit, a transient suppression diode, and a filter circuit; one end of the overcurrent protection circuit is connected with the first end of the charge-discharge loop, and the other end of the overcurrent protection circuit is connected with the second power supply; the first end of the transient suppression diode is connected with the first end of the energy storage capacitor, and the second end of the transient suppression diode is connected with the second end of the energy storage capacitor; the filter circuit is positioned between the energy storage capacitor and the charge-discharge loop.

7. A charge-discharge method, characterized in that it is applied to a charge-discharge device, said charge-discharge device comprising at least one charge-discharge unit comprising: the power conversion circuit, the energy storage capacitor and the charge-discharge loop are connected with the first power supply; the first end of the energy storage capacitor is connected with the first output end of the power conversion circuit, and the second end of the energy storage capacitor is connected with the second output end of the power conversion circuit; the first end of the charge-discharge loop is connected with the first end of the energy storage capacitor, and the second end of the charge-discharge loop is used for being connected with a second power supply;

the method comprises the following steps:

before the second power supply is charged, the energy storage capacitor is charged, so that the energy storage capacitor is charged to a first set voltage, and the first set voltage is larger than the residual voltage of the second power supply;

when the second power supply is charged, the first power supply, the power conversion circuit, the energy storage capacitor, the charge-discharge loop and the second power supply are controlled to form a charge loop; and/or the number of the groups of groups,

before discharging the second power supply, charging the energy storage capacitor to enable the energy storage capacitor to be charged to a second set voltage, wherein the second set voltage is smaller than the residual voltage of the second power supply;

And when the second power supply is discharged, controlling the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply to form a discharge loop.

8. The method of claim 7, wherein the charge-discharge device further comprises a control unit and a first switch connected between the charge-discharge loop and the second power source; the charging and discharging unit further comprises a current limiting circuit, the current limiting circuit comprises a current limiting resistor and a second switch, the first end of the current limiting resistor is connected with the first end of the charging and discharging loop, the second end of the current limiting resistor is connected with the first end of the second switch, the second end of the second switch is connected with the second end of the charging and discharging loop, and the control end of the second switch is connected with the control unit; the charging and discharging loop comprises a charging sub-loop, a first end of the charging sub-loop is connected with a first end of the energy storage capacitor, a second end of the charging sub-loop is used for being connected with the second power supply, and the charging sub-loop comprises a third switch;

in the case of charging the second power supply, prior to said charging the storage capacitor, the method further comprises:

Controlling the first switch to be turned off and controlling the second switch to be turned on;

the charging of the energy storage capacitor comprises:

controlling the first power supply to charge the voltage of the first end of the energy storage capacitor to the first set voltage through the power conversion circuit;

after said charging said energy storage capacitor, and before said controlling said first power supply, said power conversion circuit, said energy storage capacitor, said charge-discharge loop, and said second power supply to form a charging loop, said method further comprises:

controlling the first switch to be conducted;

the controlling the first power supply, the power conversion circuit, the energy storage capacitor, the charge-discharge loop and the second power supply to form a charge loop includes:

and controlling the second switch to be opened and controlling the third switch to be closed so as to form the charging loop.

9. The method of claim 8, wherein the step of determining the position of the first electrode is performed,

after said controlling said first switch to conduct and before said controlling said third switch to conduct, said method further comprises:

acquiring a first voltage of a first end of the charge-discharge loop and a second voltage of a second end of the charge-discharge loop;

Said controlling the third switch to conduct comprises:

controlling the third switch to be turned on in response to a voltage difference between the first voltage and the second voltage being less than a first threshold;

and/or, after said controlling said third switch to be conductive, said method further comprises:

and stopping the charging of the second power supply by the corresponding charging and discharging unit in response to the voltage difference between the first voltage and the second voltage being greater than or equal to a second threshold.

10. The method of claim 7, wherein in the event of charging the second power source, the method further comprises:

determining at least one target charge-discharge unit from the at least one charge-discharge unit;

and performing the step of charging the energy storage capacitor before the step of charging the second power supply, so that the energy storage capacitor is charged to a first set voltage, and the subsequent steps.

11. The method according to claim 10, wherein the method further comprises:

and after the second power supply is determined to be charged, controlling each target charge and discharge unit to stop working one by one.

12. The method of claim 11, wherein the charge-discharge loop of the target charge-discharge cell comprises a charge sub-loop, a first end of the charge sub-loop being connected to a first end of the storage capacitor, a second end of the charge sub-loop being for connection to the second power source, the charge sub-loop comprising a third switch;

for each target charge-discharge unit, the step of controlling the target charge-discharge unit to stop working includes:

gradually decreasing a duty cycle of a switch in the power conversion circuit to gradually decrease the first voltage;

and controlling the third switch to be turned off in response to the first voltage being greater than the second voltage and a voltage difference between the first voltage and the second voltage being less than a third threshold.

13. The method of claim 7, wherein the charge-discharge device further comprises a control unit and a first switch connected between the charge-discharge loop and the second power source; the charging and discharging unit further comprises a current limiting circuit, the current limiting circuit comprises a current limiting resistor and a second switch, the first end of the current limiting resistor is connected with the first end of the charging and discharging loop, the second end of the current limiting resistor is connected with the first end of the second switch, the second end of the second switch is connected with the second end of the charging and discharging loop, and the control end of the second switch is connected with the control unit; the charging and discharging circuit comprises a discharging sub-circuit, a first end of the discharging sub-circuit is connected with a first end of the energy storage capacitor, a second end of the discharging sub-circuit is used for being connected with the second power supply, and the discharging sub-circuit comprises a fourth switch;

In the case of discharging the second power supply, the charging the energy storage capacitor includes:

controlling the first switch to be conducted and controlling the second switch to be conducted;

controlling the second power supply to charge the voltage of the first end of the energy storage capacitor to the second set voltage through the current limiting circuit;

the controlling the second power supply, the charge-discharge loop, the energy storage capacitor, the power conversion circuit and the first power supply to form a discharge loop includes:

and controlling the second switch to be opened and controlling the fourth switch to be closed so as to form the discharge loop.

14. The method of claim 13, wherein after said controlling said fourth switch to turn on, said method further comprises:

and stopping the discharge of the second power supply by the corresponding charge-discharge unit in response to the voltage difference between the second voltage and the first voltage being greater than or equal to a second threshold.

15. The method of claim 7, wherein in the event of discharging the second power source, the method further comprises:

and performing the step of charging the energy storage capacitor before discharging the second power supply, so that the energy storage capacitor is charged to a second set voltage, and the subsequent steps.

16. The method of claim 15, wherein the method further comprises:

and after the second power supply is determined to be discharged, controlling each target charge-discharge unit to stop working one by one.

17. The method of claim 16, wherein the charge-discharge loop of the target charge-discharge cell comprises a discharge sub-loop, a first end of the discharge sub-loop being connected to a first end of the storage capacitor, a second end of the discharge sub-loop being for connection to the second power source, the discharge sub-loop comprising a fourth switch;

and after gradually reducing the duty ratio of the switch in the power conversion circuit to 0, controlling the fourth switch to be turned off.

18. An electronic device comprising a memory and a processor coupled to each other,

The memory stores program instructions;

the processor is configured to execute program instructions stored in the memory to implement the method of any one of claims 7-17.

19. A computer readable storage medium for storing program instructions executable by a processor to implement the method of any one of claims 7-17.