A dual-battery mirror charging circuit

Abstract

The present invention discloses a dual-battery mirror charging circuit, comprising a first switch unit, a second switch unit, a third switch unit, a fourth switch unit and a controller; a first end of the first switch unit is electrically connected to a positive output end of a DC power supply and a first end of the second switch unit, and a second end of the first switch unit is electrically connected to a positive end of the first battery; a second end of the second switch unit is electrically connected to a first node with a first end of the third switch unit, a negative end of the first battery and a positive end of the second battery; a first end of the fourth switch unit is electrically connected to a negative output end of the DC power supply and a second end of the third switch unit, and a second end of the fourth switch unit is electrically connected to a negative end of the second battery; the controller controls the first switch unit and the third switch unit to be synchronously turned on, the second switch unit and the fourth switch unit to be synchronously turned on, and the first switch unit and the second switch unit to be asynchronously turned on, which can effectively reduce line loss and circuit cost.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuits, and in particular to a dual-battery mirror charging circuit. Background Art

[0002] Lithium batteries have significant advantages such as low energy consumption, high specific capacity and specific energy, high operating voltage, long cycle life, low self-discharge, environmental friendliness, good cycle performance, and long life. They are widely used in portable electronic devices such as laptops, mobile phones, cameras, and mining lamps. With the increasing demand for environmentally friendly, safe and stable power sources and the development of electric vehicles, green, environmentally friendly, and high-energy lithium batteries have been more widely used. Therefore, the number of lithium battery manufacturers has increased in recent years, and the formation systems are also diverse.

[0003] After lithium batteries are produced, they need to be formed, that is, the newly produced batteries need to be charged for the first time to activate the batteries. Currently, the charging circuits during the formation of lithium batteries and the charging circuits after the lithium batteries are put into use are complicated. Each battery needs to have a separately configured charging circuit, which requires more wires and results in greater line losses. Moreover, when multiple lithium batteries are formed and charged together, the size of the entire system or equipment becomes larger, resulting in higher costs. Summary of the invention

[0004] The present invention provides a dual-battery mirror charging circuit to simplify the wiring design of a battery pack charging circuit, reduce line loss and lower costs.

[0005] According to one aspect of the present invention, a dual-battery mirror charging circuit is provided, wherein the battery pack comprises a first battery and a second battery, and the dual-battery mirror charging circuit comprises: a first switch unit, a second switch unit, a third switch unit, a fourth switch unit and a controller;

[0006] The first end of the first switch unit is electrically connected to the positive output end of the DC power supply and the first end of the second switch unit, and the second end of the first switch unit is electrically connected to the positive terminal of the first battery;

[0007] The second end of the second switch unit is electrically connected to a first node with the first end of the third switch unit, the negative terminal of the first battery and the positive terminal of the second battery;

[0008] The first end of the fourth switch unit is electrically connected to the negative output end of the DC power supply and the second end of the third switch unit, and the second end of the fourth switch unit is electrically connected to the negative end of the second battery;

[0009] The controller is electrically connected to a control end of the first switch unit, a control end of the second switch unit, a control end of the third switch unit, and a control end of the fourth switch unit;

[0010] The controller controls the first switch unit and the third switch unit to be synchronously turned on, controls the second switch unit and the fourth switch unit to be synchronously turned on, and controls the first switch unit and the second switch unit to be asynchronously turned on.

[0011] Optionally, the dual-battery mirror charging circuit further includes: a first energy storage circuit;

[0012] The first end of the first energy storage circuit is electrically connected to the second end of the first switch unit, the second end of the first energy storage circuit is electrically connected to the positive terminal of the first battery, and the third end of the first energy storage circuit is electrically connected to the first node.

[0013] Optionally, the dual-battery mirror charging circuit further includes: a second energy storage circuit;

[0014] The first end of the second energy storage circuit is electrically connected to the second end of the fourth switch unit, the second end of the second energy storage circuit is electrically connected to the negative terminal of the second battery, and the third end of the second energy storage circuit is electrically connected to the first node.

[0015] Optionally, the first energy storage circuit comprises: a first inductor, a first capacitor and a second capacitor;

[0016] The first end of the first inductor is electrically connected to the second end of the first switch unit and the first end of the first capacitor, and the second end of the first inductor is electrically connected to the positive terminal of the first battery and the first end of the second capacitor;

[0017] The second end of the first capacitor and the second end of the second capacitor are both electrically connected to the first node.

[0018] Optionally, the second energy storage circuit includes a second inductor, a third capacitor and a fourth capacitor;

[0019] The first end of the second inductor is electrically connected to the second end of the fourth switch unit and the first end of the third capacitor, and the second end of the second inductor is electrically connected to the negative terminal of the second battery and the first end of the fourth capacitor;

[0020] The second end of the third capacitor and the second end of the fourth capacitor are both electrically connected to the first node.

[0021] Optionally, the first switch unit includes a first transistor, the second switch unit includes a second transistor, the third switch unit includes a third transistor, and the fourth switch unit includes a fourth transistor.

[0022] Optionally, the dual-battery mirror charging circuit further includes: a third inductor and a fourth inductor;

[0023] The first end of the third inductor is electrically connected to the positive output end of the DC power supply, and the second end of the third inductor is electrically connected to the first end of the first switch unit and the first end of the second switch unit;

[0024] The first end of the fourth inductor is electrically connected to the negative output end of the DC power supply, and the second end of the fourth inductor is electrically connected to the second end of the third switch unit and the first end of the fourth switch unit.

[0025] Optionally, the dual-battery mirror charging circuit further includes: a current detection unit;

[0026] The first end of the current detection unit is electrically connected to the second end of the second switch unit and the first end of the third switch unit, and the second end of the current detection unit is electrically connected to the negative terminal of the first battery and the positive terminal of the second battery.

[0027] Optionally, when the power levels of the first battery and the second battery have not reached a preset power level, the controller controls the first switch unit and the second switch unit to be alternately turned on at a preset frequency.

[0028] Optionally, when the power of the first battery and the power of the second battery do not reach a preset power, the first switch unit and the third switch unit are controlled to be turned on, and when the power of the first battery exceeds a preset power, the second switch unit and the fourth switch unit are controlled to be turned on;

[0029] Alternatively, when the power of the first battery and the power of the second battery have not reached the preset power, the second switch unit and the fourth switch unit are controlled to be turned on, until the power of the second battery exceeds the preset power, the first switch unit and the third switch unit are controlled to be turned on.

[0030] The dual-battery mirror charging circuit provided by the embodiment of the present invention forms a first branch by setting a first switch unit electrically connected between the positive output terminal of the DC power supply and the positive terminal of the first battery, forms a second branch by setting a second switch unit electrically connected between the positive output terminal of the DC power supply and the first node, forms a third switch unit electrically connected between the negative output terminal of the DC power supply and the first node, and forms a second branch by setting the first node to be electrically connected to the negative terminal of the first battery and the positive terminal of the second battery, forms a third branch by setting a fourth switch electrically connected between the negative output terminal of the DC power supply and the negative terminal of the second battery, The controller controls the first switch unit and the third switch unit to be turned on synchronously to charge the first battery, and the controller controls the second switch unit and the fourth switch unit to be turned on synchronously to charge the second battery. The two batteries can be charged by setting only three branches, which can effectively reduce the wiring of the battery pack charging circuit, thereby effectively reducing the line loss caused by the wires during the charging process, and can improve the charging efficiency, and reduce the cost caused by too many wires. For a charging system or device that charges multiple battery packs, the size of the system or device can be effectively reduced, and the cost can be further reduced.

[0031] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a structural schematic diagram of a dual-battery mirror charging circuit provided by an embodiment of the present invention;

[0034] Figure 2 is a structural schematic diagram of another dual-battery mirror charging circuit provided by an embodiment of the present invention;

[0035] Figure 3 is a structural schematic diagram of another dual-battery mirror charging circuit provided by an embodiment of the present invention;

[0036] Figure 4 It is a structural schematic diagram of another dual-battery mirror charging circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0039] Figure 1 A schematic diagram of a dual-battery mirror charging circuit provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the dual battery includes a first battery 01 and a second battery 02, and the mirror charging circuit of the dual battery includes: a first switch unit 10, a second switch unit 20, a third switch unit 30, a fourth switch unit 40 and a controller 50; the first end of the first switch unit 10 is electrically connected to the positive output terminal "+" of the DC power supply E0 and the first end of the second switch unit 20, and the second end of the first switch unit 10 is electrically connected to the positive terminal V1+ of the first battery 01; the second end of the second switch unit 20 is electrically connected to the first end of the third switch unit 30, the negative terminal V1- of the first battery 01 and the positive terminal V2+ of the second battery 02 at a first node a. ; The first end of the fourth switch unit 40 is electrically connected to the negative output terminal "-" of the DC power supply E0 and the second end of the third switch unit 30, and the second end of the fourth switch unit 40 is electrically connected to the negative terminal V2- of the second battery 02; the controller 50 is electrically connected to the control end of the first switch unit 10, the control end of the second switch unit 20, the control end of the third switch unit 30 and the control end of the fourth switch unit 40; the controller 50 controls the first switch unit 10 and the third switch unit 30 to be synchronously turned on, controls the second switch unit 20 and the fourth switch unit 40 to be synchronously turned on, and controls the first switch unit 10 and the second switch unit 20 to be asynchronously turned on.

[0040] Specifically, the first switch unit 10 is electrically connected between the positive output terminal "+" of the DC power supply E0 and the positive terminal V1+ of the first battery 01, forming a first branch for transmitting electric energy. The second switch unit 20 is electrically connected between the positive output terminal "+" of the DC power supply E0 and the first node a, the third switch unit 30 is electrically connected between the negative output terminal "-" of the DC power supply E0 and the first node a, and the first node a is electrically connected to the negative terminal V1- of the first battery 01 and the positive terminal V2+ of the second battery 02, then the first node a and the negative terminal V1- of the first battery 01 and the positive terminal V2+ of the second battery 02 form a second branch for transmitting electric energy. The fourth switch unit 40 is electrically connected between the negative output terminal "-" of the DC power supply E0 and the negative terminal V2- of the second battery 02, forming a third branch for transmitting electric energy. The first switch unit 10 and the third switch unit 30 are synchronously turned on under the control of the controller 50, the second switch unit 20 and the fourth switch unit 40 are synchronously turned on under the control of the controller 50, and the first switch unit 10 and the second switch unit 20 are asynchronously turned on under the control of the controller 50. In this way, when the first switch unit 10 and the third switch unit 30 are turned on, the current provided by the positive output terminal "+" of the DC power supply E0 flows through the first switch unit 10, the positive terminal V1+ of the first battery 01, the negative terminal V1- of the first battery 01 and the third switch unit 30 to the negative output terminal "-" of the DC power supply E0, forming a power-on circuit for charging the first battery 01, thereby realizing charging of the first battery 01. During the conduction of the second switch unit 20 and the fourth switch unit 40, the current provided by the positive output terminal "+" of the DC power supply E0 flows through the second switch unit 20, the positive terminal V2+ of the second battery 02, the negative terminal V2- of the second battery 02 and the fourth switch unit 40 to the negative output terminal "-" of the DC power supply E0, forming a power-on circuit for charging the second battery 02, and the second battery 02 can be charged. That is, the charging of two batteries can be achieved by only setting three branches (i.e., three wires), which can effectively reduce the wiring of the battery pack charging circuit, thereby effectively reducing the line loss caused by the wires during the charging process, and can improve the charging efficiency, and reduce the cost caused by too many wires. For a charging system or device that charges multiple battery packs, the volume of the system or device can be effectively reduced, and the cost can be further reduced. Among them, the first battery 01 and the second battery 02 can both be lithium batteries.

[0041] Exemplarily, the controller 50 may include an output terminal corresponding to each switch unit to achieve independent control of each switch unit; or the first switch unit 10 and the third switch unit 30 may be connected to the same output terminal of the controller 50, and the second switch unit 20 and the fourth switch unit 40 may be connected together to another output terminal of the controller 50, so that the controller 50 can synchronously control the first switch unit 10 and the third switch unit 30, and the controller 50 can synchronously control the second switch unit 20 and the fourth switch unit 40. The connection mode between the controller 50 and each switch unit can be set according to design requirements, and the embodiment of the present invention does not specifically limit this.

[0042] The dual-battery mirror charging circuit provided by the embodiment of the present invention forms a first branch by setting a first switch unit electrically connected between the positive output terminal of the DC power supply and the positive terminal of the first battery, forms a second branch by setting a second switch unit electrically connected between the positive output terminal of the DC power supply and the first node, forms a third switch unit electrically connected between the negative output terminal of the DC power supply and the first node, and forms a second branch by setting the first node to be electrically connected to the negative terminal of the first battery and the positive terminal of the second battery, forms a third branch by setting a fourth switch electrically connected between the negative output terminal of the DC power supply and the negative terminal of the second battery, The controller controls the first switch unit and the third switch unit to be turned on synchronously to charge the first battery, and the controller controls the second switch unit and the fourth switch unit to be turned on synchronously to charge the second battery. The two batteries can be charged by setting only three branches, which can effectively reduce the wiring of the battery pack charging circuit, thereby effectively reducing the line loss caused by the wires during the charging process, and can improve the charging efficiency, and reduce the cost caused by too many wires. For a charging system or device that charges multiple battery packs, the size of the system or device can be effectively reduced, and the cost can be further reduced.

[0043] Optional, reference Figure 1 When the power of the first battery 01 and the power of the second battery 02 do not reach the preset power, the controller 50 controls the first switch unit 10 and the second switch unit 20 to be alternately turned on at a preset frequency.

[0044] Specifically, during the process of charging the first battery 01 and the second battery 02, the controller 50 can obtain the power of the first battery 01 and the power of the second battery 02 in real time. The controller 50 can be set to include a first voltage acquisition terminal (not shown in the figure) for collecting the power of the first battery 01. The number of the first voltage acquisition terminals can be two, and the two first voltage acquisition terminals can be electrically connected to the positive terminal V1+ and the negative terminal V1- of the first battery 01, respectively, so as to realize the collection of the power of the first battery 01. Similarly, the controller 50 can also include a second voltage acquisition terminal (not shown in the figure) for collecting the power of the second battery 02. The number of the second voltage acquisition terminals can be two, and the two second voltage acquisition terminals can be electrically connected to the positive terminal V2+ and the negative terminal V2- of the second battery 02, respectively, so as to realize the collection of the power of the second battery 02. When the power of the first battery 01 and the power of the second battery 02 do not reach the preset power, the first switch unit 10 and the second switch unit 20 can be controlled to alternately conduct at a preset frequency at a preset frequency, and at this time, the third switch unit 30 and the fourth switch unit 40 are also alternately conducted at a preset frequency. Then, when the first switch unit 10 and the third switch unit 30 are turned on, the positive output terminal "+" of the DC power supply E0 forms a path with the positive terminal V1+ of the first battery 01 through the first switch unit 10, and the negative output terminal "-" of the DC power supply E0 forms a path with the negative terminal V1- of the first battery 01 through the third switch unit 30, so as to realize charging of the first battery 01. When the second switch unit 20 and the fourth switch unit 40 are turned on, the positive output terminal "+" of the DC power supply E0 forms a path with the positive terminal V2+ of the second battery 02 through the second switch unit 20, and the negative output terminal "-" of the DC power supply E0 forms a path with the negative terminal V2- of the second battery 02 through the fourth switch unit 40, so as to realize charging of the second battery 02.

[0045] Exemplarily, in the process of controlling the first switch unit 10 and the second switch unit 20 to be alternately turned on at a preset frequency, if the power of the first battery 01 reaches the preset power but the power of the second battery 02 does not reach the preset power, the first switch unit 10 and the third switch unit 30 can be controlled to stop being turned on and remain in the disconnected state, and the second switch unit 20 and the fourth switch unit 40 can be controlled to remain in the on state until the power of the second battery 02 also reaches the preset power, and the second switch unit 20 and the fourth switch unit 40 are controlled to be disconnected, so that the first switch unit 10, the second switch unit 20, the third switch unit 30 and the fourth switch unit 40 are all disconnected, thereby completing the charging process of the first battery 01 and the second battery 02. Similarly, in the process of controlling the first switch unit 10 and the second switch unit 20 to be alternately turned on at a preset frequency, if the power of the second battery 02 reaches the preset power but the power of the first battery 01 does not reach the preset power, the second switch unit 20 and the fourth switch unit 40 can be controlled to stop being turned on and remain in a disconnected state, and the first switch unit 10 and the third switch unit 30 can be controlled to remain in a turned-on state until the power of the first battery 01 also reaches the preset power, and then the first switch unit 10 and the third switch unit 30 are controlled to be disconnected, so that the first switch unit 10, the second switch unit 20, the third switch unit 30 and the fourth switch unit 40 are all disconnected, thereby completing the charging process of the first battery 01 and the second battery 02. Alternatively, in the process of controlling the first switch unit 10 and the second switch unit 20 to be alternately turned on at a preset frequency, if the power of the first battery 01 and the power of the second battery 02 reach the preset power at the same time, the first switch unit 10, the second switch unit 20, the third switch unit 30 and the fourth switch unit 40 can be controlled to be disconnected at the same time, thereby completing the charging process of the first battery 01 and the second battery 02.

[0046] Optionally, when the controller 50 determines that the power of the first battery 01 and the power of the second battery 02 have not reached the preset power, it can first charge only one of the batteries, and then charge the other battery after the charging of the first battery is completed. Figure 1 , when the power of the first battery 01 and the power of the second battery 02 have not reached the preset power, the first switch unit 10 and the third switch unit 30 are controlled to be turned on, until the power of the first battery 01 exceeds the preset power, the second switch unit 20 and the fourth switch unit 40 are controlled to be turned on; or, when the power of the first battery 01 and the power of the second battery 02 have not reached the preset power, the second switch unit 20 and the fourth switch unit 40 are controlled to be turned on, until the power of the second battery 02 exceeds the preset power, the first switch unit 10 and the third switch unit 30 are controlled to be turned on.

[0047] Optional, Figure 2FIG. 1 is a schematic diagram of the structure of another dual-battery mirror charging circuit provided by an embodiment of the present invention. Figure 2 As shown, the first switch unit 10 includes a first transistor Q1, the second switch unit 20 includes a second transistor Q2, the third switch unit 30 includes a third transistor Q3, and the fourth switch unit 40 includes a fourth transistor Q4.

[0048] Specifically, each transistor may be an insulated gate field effect transistor, may be an IGBT, or each transistor may be a triode, and the channel type of each transistor may be N-type or P-type. In other feasible embodiments of the present invention, the types of each transistor may be different, and the embodiment of the present invention does not specifically limit this. Taking the case that each transistor is an N-type IGBT, the drain of the first transistor Q1 may be electrically connected to the positive output terminal "+" of the DC power supply E0 and the drain of the second transistor Q2, the source of the first transistor Q1 may be electrically connected to the positive terminal V1+ of the first battery 01, the source of the second transistor Q2 may be electrically connected to the drain of the third transistor Q3, the negative terminal V1- of the first battery 01 and the positive terminal V2+ of the second battery 02 at the first node a, the drain of the fourth transistor Q4 may be electrically connected to the negative output terminal "-" of the DC power supply E0 and the source of the third transistor Q3, the source of the fourth transistor Q4 may be electrically connected to the negative terminal V2- of the second battery 02, and the gates of each transistor may be electrically connected to the controller 50. In this way, the controller 50 can charge the first battery 01 when controlling the first transistor Q1 and the third transistor Q3 to be turned on, and can charge the second battery 02 when controlling the second transistor Q2 and the fourth transistor Q4 to be turned on.

[0049] The embodiment of the present invention only exemplifies that each switching unit only includes one transistor. In other feasible embodiments of the present invention, each switching unit may include multiple transistors, and each transistor may be electrically connected in a source-drain connection manner, and can also achieve the function of a switch. The embodiment of the present invention does not make any specific limitation on this.

[0050] In another feasible embodiment of the present invention, the switches in the first switch unit 10, the second switch unit 20, the third switch unit 30 and the fourth switch unit 40 can also be relay switches, and the controller 50 controls the power on or off of each relay coil to control each switch to be turned on or off accordingly.

[0051] Optional, Figure 3 FIG. 1 is a schematic diagram of a dual-battery mirror charging circuit according to another embodiment of the present invention. Figure 3As shown, the dual-battery mirror charging circuit also includes: a first energy storage circuit 60; the first end of the first energy storage circuit 60 is electrically connected to the second end of the first switch unit 10, the second end of the first energy storage circuit 60 is electrically connected to the positive terminal V1+ of the first battery 01, and the third end of the first energy storage circuit 60 is electrically connected to the first node a.

[0052] Specifically, the first energy storage circuit 60 can store electric energy when the first switch unit 10 and the third switch unit 30 are turned on. And in the process of the first switch unit 10 and the third switch unit 30 being turned on, the electric energy stored in the first energy storage circuit 60 becomes larger and larger, so that the voltage and current output to the first battery 01 become larger and larger, and the voltage boosting effect can be achieved. In the process of the second switch unit 20 and the fourth switch unit 40 being turned on, the first energy storage circuit 60 gradually discharges, so that the voltage and current output to the first battery 01 become smaller and smaller, and the voltage reduction effect can be achieved. .

[0053] Optional, Figure 4 FIG. 1 is a schematic diagram of a dual-battery mirror charging circuit according to another embodiment of the present invention. Figure 4 As shown, the first energy storage circuit 60 includes a first inductor L1, a first capacitor C1 and a second capacitor C2; the first end of the first inductor L1 is electrically connected to the second end of the first switch unit 10 and the first end of the first capacitor C1, the second end of the first inductor L1 is electrically connected to the positive terminal V1+ of the first battery 01 and the first end of the second capacitor C2; the second end of the first capacitor C1 and the second end of the second capacitor C2 are both electrically connected to the first node a.

[0054] Specifically, when the first switch unit 10 and the third switch unit 30 are turned on, the electric energy provided by the DC power supply E0 is transmitted to the first battery 01. During this process, the first inductor L1 and the second capacitor C2 store energy, so that the voltage and current provided to the first battery 01 gradually increase, that is, the first switch unit 10, the first inductor L1 and the second capacitor C2 constitute a boost circuit to realize charging of the first battery 01. After the first switch unit 10 and the third switch unit 30 are disconnected, the second switch unit 20 and the fourth switch unit 40 are turned on, and the electric energy stored in the second capacitor C2 and the first inductor L1 is discharged through the first capacitor C1. At this time, the voltage and current output to the first battery 01 gradually decrease, that is, the first capacitor C1 and the second switch unit 20 constitute a step-down circuit until the electric energy stored in the second capacitor C2 and the first inductor L1 is zero, and the charging of the first battery 01 is stopped.

[0055] Optional, reference Figure 3The mirror charging circuit of the dual battery also includes: a second energy storage circuit 70; a first end of the second energy storage circuit 70 is electrically connected to the second end of the fourth switch unit 40, a second end of the second energy storage circuit 70 is electrically connected to the negative end of the second battery 02, and a third end of the second energy storage circuit 70 is electrically connected to the first node a.

[0056] Specifically, the second energy storage circuit 70 stores electric energy when the second switch unit 20 and the fourth switch unit 40 are turned on. And in the process of the second switch unit 20 and the fourth switch unit 40 being turned on, the electric energy stored in the second energy storage circuit 70 becomes larger and larger, so that the voltage and current output to the second battery 02 become larger and larger, and a voltage boosting effect can be achieved. In the process of the first switch unit 10 and the third switch unit 30 being turned on, the second energy storage circuit 70 gradually discharges, so that the voltage and current output to the second battery 02 become smaller and smaller, and a voltage reduction effect can be achieved.

[0057] Optional, reference Figure 4 , the second energy storage circuit 70: includes a second inductor L2, a third capacitor C3 and a fourth capacitor C4; the first end of the second inductor L2 is electrically connected to the second end of the fourth switch unit 40 and the first end of the third capacitor C3, the second end of the second inductor L2 is electrically connected to the negative terminal V2- of the second battery 02 and the first end of the fourth capacitor C4; the second end of the third capacitor C3 and the second end of the fourth capacitor C4 are both electrically connected to the first node a.

[0058] Specifically, when the second switch unit 20 and the fourth switch unit 40 are turned on, the electric energy provided by the DC power supply E0 is transmitted to the second battery 02. During this process, the second inductor L2 and the fourth capacitor C4 store energy, so that the voltage and current provided to the second battery 02 gradually increase, that is, the fourth switch unit 40, the second inductor L2 and the fourth capacitor C4 constitute a boost circuit to realize charging of the second battery 02. After the second switch unit 20 and the fourth switch unit 40 are disconnected, the first switch unit 10 and the third switch unit 30 are turned on, and the electric energy stored in the fourth capacitor C4 and the second inductor L2 is discharged through the third capacitor C3. At this time, the voltage and current output to the second battery 02 gradually decrease, that is, the third capacitor C3 and the third switch unit 30 constitute a step-down circuit until the electric energy stored in the second inductor L2 and the fourth capacitor C4 is zero, and then the charging of the second battery 02 is stopped.

[0059] Optional, continue to refer to Figure 4 The dual-battery mirror charging circuit also includes: a current detection unit 80; a first end of the current detection unit 80 is electrically connected to the second end of the second switch unit 20 and the first end of the third switch unit 30, and a second end of the current detection unit 80 is electrically connected to the negative terminal V1- of the first battery 01 and the positive terminal V2+ of the second battery 02.

[0060] Specifically, the current detection unit 80 can be set to be electrically connected between the first node a and the negative terminal V1- of the first battery 01, that is, electrically connected between the first node a and the positive terminal V2+ of the second battery 02, so that the current detection unit 80 is set on the second branch. In this way, when the first switch unit 10 and the third switch unit 30 are turned on, the current transmitted to the first battery 01 can be detected by the current detection unit 80, and when the second switch unit 20 and the fourth switch unit 40 are turned on, the current transmitted to the second battery 02 can be detected by the current detection unit 80.

[0061] The controller 50 may include two current detection terminals, which may be electrically connected to two ends of the current detection unit 80 (not shown in the figure) to collect the current signal.

[0062] Exemplarily, the current detection unit 80 may include a detection resistor R0, so that the current flowing through the detection resistor R0 can be determined by the voltage across the detection resistor R0 and the resistance value of the detection resistor R0. The controller 50 can control all switch units to disconnect when the current is too large, or in a mode in which the first switch unit 10 and the second switch unit 20 are alternately turned on, the frequency of the alternating conduction of the first switch unit 10 and the second switch unit 20 can be controlled to be reduced when the current is too large, so as to avoid excessive charging current to the first battery 01 and the second battery 02, causing overcurrent damage.

[0063] Optional, continue to refer to Figure 4 The mirror charging circuit of the dual battery also includes: a third inductor L3 and a fourth inductor L4; the first end of the third inductor L3 is electrically connected to the positive output terminal "+" of the DC power supply E0, and the second end of the third inductor L3 is electrically connected to the first end of the first switch unit 10 and the first end of the second switch unit 20; the first end of the fourth inductor L4 is electrically connected to the negative output terminal "-" of the DC power supply E0, and the second end of the fourth inductor L4 is electrically connected to the second end of the third switch unit 30 and the first end of the fourth switch unit 40. The third inductor L3 and the fourth inductor L4 are used for filtering and can also play a role in energy storage.

[0064] Based on the same inventive concept, an embodiment of the present invention further provides a battery pack charging system, comprising multiple battery packs and multiple dual-battery mirror charging circuits provided by any embodiment of the present invention. The battery packs and the dual-battery mirror charging circuits can be arranged one-to-one, so that the battery pack charging system provided by the embodiment of the present invention includes the technical features of the dual-battery mirror charging circuit provided by any embodiment of the present invention, and can achieve the beneficial effects of the dual-battery mirror charging circuit provided by any embodiment of the present invention. The similarities can be referred to the above description of the dual-battery mirror charging circuit provided by the embodiment of the present invention, and will not be repeated here.

[0065] Exemplarily, when the charging system of a battery pack includes a plurality of dual-battery mirror charging circuits provided by any embodiment of the present invention, the mirror charging circuits of the dual batteries may share a controller, or some of the mirror charging circuits of the dual batteries may share a controller to reduce costs. This embodiment of the present invention does not specifically limit this.

[0066] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-battery mirror charging circuit, the dual battery comprising a first battery and a second battery, characterized in that: The dual-battery mirror charging circuit comprises: a first switch unit, a second switch unit, a third switch unit, a fourth switch unit, a first energy storage circuit, a second energy storage circuit and a controller; The first end of the first switch unit is electrically connected to the positive output end of the DC power supply and the first end of the second switch unit, and the second end of the first switch unit is electrically connected to the positive terminal of the first battery; The second end of the second switch unit is electrically connected to a first node with the first end of the third switch unit, the negative terminal of the first battery and the positive terminal of the second battery; The first end of the fourth switch unit is electrically connected to the negative output end of the DC power supply and the second end of the third switch unit, and the second end of the fourth switch unit is electrically connected to the negative end of the second battery; The controller is electrically connected to a control end of the first switch unit, a control end of the second switch unit, a control end of the third switch unit, and a control end of the fourth switch unit; The controller controls the first switch unit and the third switch unit to be synchronously turned on, controls the second switch unit and the fourth switch unit to be synchronously turned on, and controls the first switch unit and the second switch unit to be asynchronously turned on; The first end of the first energy storage circuit is electrically connected to the second end of the first switch unit, the second end of the first energy storage circuit is electrically connected to the positive terminal of the first battery, and the third end of the first energy storage circuit is electrically connected to the first node; The first end of the second energy storage circuit is electrically connected to the second end of the fourth switch unit, the second end of the second energy storage circuit is electrically connected to the negative terminal of the second battery, and the third end of the second energy storage circuit is electrically connected to the first node; The first energy storage circuit comprises: a first inductor, a first capacitor and a second capacitor; The first end of the first inductor is electrically connected to the second end of the first switch unit and the first end of the first capacitor, the second end of the first inductor is electrically connected to the positive terminal of the first battery and the first end of the second capacitor; the second end of the first capacitor and the second end of the second capacitor are both electrically connected to the first node; The second energy storage circuit comprises a second inductor, a third capacitor and a fourth capacitor; The first end of the second inductor is electrically connected to the second end of the fourth switch unit and the first end of the third capacitor, the second end of the second inductor is electrically connected to the negative terminal of the second battery and the first end of the fourth capacitor; the second end of the third capacitor and the second end of the fourth capacitor are both electrically connected to the first node.

2. The dual-battery mirror charging circuit according to claim 1, characterized in that: The first switch unit includes a first transistor, the second switch unit includes a second transistor, the third switch unit includes a third transistor, and the fourth switch unit includes a fourth transistor.

3. The dual-battery mirror charging circuit according to claim 1, characterized in that: Also includes: a third inductor and a fourth inductor; The first end of the third inductor is electrically connected to the positive output end of the DC power supply, and the second end of the third inductor is electrically connected to the first end of the first switch unit and the first end of the second switch unit; A first end of the fourth inductor is electrically connected to the negative output end of the DC power supply, and a second end of the fourth inductor is electrically connected to the second end of the third switch unit and the first end of the fourth switch unit.

4. The dual-battery mirror charging circuit according to claim 1, characterized in that: Also includes: Current detection unit; The first end of the current detection unit is electrically connected to the second end of the second switch unit and the first end of the third switch unit, and the second end of the current detection unit is electrically connected to the negative terminal of the first battery and the positive terminal of the second battery.

5. The dual-battery mirror charging circuit according to claim 1, characterized in that: When the power of the first battery and the power of the second battery do not reach the preset power, the controller controls the first switch unit and the second switch unit to be alternately turned on at a preset frequency.

6. The dual-battery mirror charging circuit according to claim 1, characterized in that: When the power of the first battery and the power of the second battery do not reach the preset power, control the first switch unit and the third switch unit to be turned on, until the power of the first battery exceeds the preset power, control the second switch unit and the fourth switch unit to be turned on; Alternatively, when the power of the first battery and the power of the second battery have not reached the preset power, the second switch unit and the fourth switch unit are controlled to be turned on, until the power of the second battery exceeds the preset power, the first switch unit and the third switch unit are controlled to be turned on.

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