Charging and discharging control circuit of battery and battery management system

Abstract

The utility model discloses a charge and discharge control circuit of a battery and a battery management system, which comprises a first output end, a second output end, a charge and discharge switch module, a three-end fuse and a control module, and is characterized in that the first output end is connected to the positive electrode of the battery through a first branch; the second output end is connected to the negative electrode of the battery through a second branch; the charging and discharging switch module is arranged on the second branch and comprises a charging switch tube and a discharging switch tube which are connected in series; the three-terminal fuse is arranged on the second branch circuit and is located between the charging and discharging switch module and the second output terminal; the control module is connected with the charging switch tube, the discharging switch tube and the control end of the three-end fuse, and is used for controlling the charging and discharging switch module and / or the three-end fuse to break the electric connection between the negative electrode of the battery and the second output end. According to the embodiment of the utility model, the reliability and safety of the charging and discharging control circuit of the battery can be effectively improved, and the circuit cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of battery charging and discharging, and in particular to a battery charging and discharging control circuit and a battery management system. Background Art

[0002] With the widespread use of lithium batteries, their safe use has become a key consideration. Loss of effective control during the charging and discharging process can lead to serious safety accidents. Traditional battery charge and discharge control circuits typically use MOSFETs or relays to protect the battery. When abnormal charging or discharging is detected, the battery charge and discharge control circuit is opened by disconnecting the switching device. However, this protection method has hidden dangers. If the switching device itself fails (such as a MOSFET breakdown or a relay adhesion), the battery protection scheme that disconnects the switching device will be ineffective. Therefore, in related art, an additional set of MOSFETs or relays connected in series is added to the existing set of MOSFETs or relays in the charge and discharge control circuit to achieve dual protection. However, this design is costly and space-consuming, and has a low cost-effectiveness ratio. Therefore, how to improve the safety of battery charge and discharge control circuits while reducing circuit design costs has become an urgent problem that needs to be solved. Utility Model Content

[0003] The purpose of the present invention is to solve at least one of the technical problems existing in the prior art and to provide a battery charge and discharge control circuit and a battery management system, which can effectively improve the reliability and safety of the battery charge and discharge control circuit while reducing the circuit cost.

[0004] In a first aspect, an embodiment of the present invention provides a charge and discharge control circuit for a battery, comprising a first output end, a second output end, a charge and discharge switch module, a three-terminal fuse, and a control module, wherein the first output end is connected to the positive electrode of the battery through a first branch; the second output end is connected to the negative electrode of the battery through a second branch; the charge and discharge switch module is arranged in the second branch, and comprises a charging switch tube and a discharging switch tube connected in series; the three-terminal fuse is arranged in the second branch and is located between the charge and discharge switch module and the second output end; the control module is respectively connected to the charging switch tube, the discharging switch tube, and the control end of the three-terminal fuse, and is used to control the charge and discharge switch module and / or the three-terminal fuse to disconnect the electrical connection between the negative electrode of the battery and the second output end.

[0005] The battery charge and discharge control circuit provided by the embodiment of the present invention has at least the following beneficial effects: the charge and discharge switch module is connected to the negative electrode of the battery, and the electrical connection between the negative electrode of the battery and the second output terminal can be cut off by switching the switch tube in the charge and discharge switch module to an open circuit state; and on this basis, a three-terminal fuse connected in series with the charge and discharge switch module is added, and the three-terminal fuse can be quickly melted to cut off the circuit. Compared with the dual protection solution of using two groups of MOS tubes or relays in the related art, the embodiment of the present invention uses a three-terminal fuse to replace one group of MOS tubes or relays. The three-terminal fuse and a group of charge and discharge switch modules can achieve dual protection of the circuit, which can reduce the risk of failure of a single component causing failure of the entire protection mechanism, and at the same time can effectively reduce the cost of the circuit. In addition, connecting the three-terminal fuse in series with the charge and discharge switch module and arranging them on the same branch can effectively reduce the space occupied by the circuit, simplify the wiring design of the circuit, and improve the cost performance of the circuit.

[0006] In the battery charge and discharge control circuit provided in an embodiment of the present invention, it also includes a heating control switch tube and a heating film for heating the battery, one end of the heating film is connected to the positive electrode of the battery, and the other end is connected to the connection point between the charge and discharge switch module and the three-terminal fuse through the heating control switch tube.

[0007] In the battery charge and discharge control circuit provided by the embodiment of the present utility model, the control module is further connected to the control end of the heating control switch tube.

[0008] The battery charge and discharge control circuit provided in the embodiment of the present invention further includes a heating state detection module connected to the connection point between the heating film and the heating control switch tube, and the output end of the heating state detection module is connected to the control module.

[0009] The battery charge and discharge control circuit provided in an embodiment of the present invention further includes a sampling resistor arranged between the negative electrode of the battery and the charge and discharge switch module, and a current sampling module connected to the sampling resistor, wherein the output end of the current sampling module is connected to the control module.

[0010] The battery charge and discharge control circuit provided in an embodiment of the present invention further includes a first voltage sampling module connected to the first output end and the second output end, and the output end of the first voltage sampling module is connected to the control module.

[0011] The battery charge and discharge control circuit provided in the embodiment of the present invention further includes a first temperature detection module for measuring the temperature of the charge and discharge switch module, and the output end of the first temperature detection module is connected to the control module.

[0012] The battery charge and discharge control circuit provided in an embodiment of the present invention further includes a second voltage sampling module for detecting the battery voltage and a second temperature detection module for detecting the battery temperature. The output ends of the second voltage sampling module and the second temperature detection module are connected to the control module.

[0013] In the battery charge and discharge control circuit provided in an embodiment of the present utility model, the charge and discharge control circuit further includes a branch fuse provided in the first branch.

[0014] In a second aspect, an embodiment of the present invention provides a battery management system, comprising the battery charge and discharge control circuit as described in the embodiment of the first aspect above.

[0015] The battery management system provided by the embodiment of the present invention has at least the following beneficial effects: by connecting the charge-discharge switch module to the negative electrode of the battery, the switch tube in the charge-discharge switch module can be switched to an open circuit state, thereby effectively cutting off the electrical connection between the negative electrode of the battery and the second output terminal. On this basis, a three-terminal fuse connected in series with the charge-discharge switch module is added. Similarly, the three-terminal fuse can quickly melt to cut off the circuit. Compared with the dual protection scheme composed of two groups of MOS tubes or relays in the related art, the embodiment of the present invention cleverly uses a three-terminal fuse to replace one of the MOS tubes or relays. By combining the three-terminal fuse in series with a group of charge-discharge switch modules to achieve a dual protection mechanism for the circuit, this design can effectively control the cost of the circuit. In addition, arranging the three-terminal fuse and the charge-discharge switch module on the same branch can effectively save the space occupied by the circuit, simplify the wiring design of the circuit, make the entire circuit more compact and efficient, and facilitate the layout of the circuit in the battery management system. While ensuring safety, it also significantly improves the cost performance of the circuit.

[0016] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0019] Figure 1It is a structural diagram of a charge and discharge control circuit provided by an embodiment of the utility model;

[0020] Figure 2 This is a structural diagram of a charge and discharge control circuit provided by another embodiment of the present utility model;

[0021] Figure 3 This is a structural diagram of a charge and discharge control circuit provided by another embodiment of the present utility model;

[0022] Figure 4 It is a structural diagram of a charge and discharge control circuit provided by another embodiment of the present utility model. DETAILED DESCRIPTION

[0023] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0024] In the description of this utility model, "several" means one or more, "more" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, and "above," "below," and "within" are understood to include the number itself. "Any one" means one or more, and "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, or implicitly indicating the number of the indicated technical features, or implicitly indicating the order of the indicated technical features.

[0025] It should be noted that the terms "set," "install," and "connect" in the embodiments of the present invention should be interpreted broadly. Those skilled in the art can reasonably determine the specific meanings of these terms in the embodiments of the present invention based on the specific content of the technical solution. For example, the term "connect" can refer to mechanical connection, electrical connection, or communication; it can refer to direct connection or indirect connection through an intermediary.

[0026] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0027] Traditional battery charge and discharge control circuits typically use MOSFETs or relays to protect the battery. When abnormal charging and discharging is detected, the battery charge and discharge control circuit is opened by disconnecting the switching device. However, this protection method has potential risks. If the switching device itself fails (such as a MOSFET breakdown or a relay adhesion), the battery protection scheme that disconnects the switching device will be ineffective. Therefore, in related technologies, an additional set of MOSFETs or relays connected in series is added to the existing set of MOSFETs or relays in the charge and discharge control circuit to achieve dual protection. However, using two sets of MOSFETs or relays is costly, occupies a large space, and has a low cost-effectiveness ratio.

[0028] Based on this, an embodiment of the present invention proposes a battery charge and discharge control circuit and a battery management system. By connecting the charge and discharge switch module to the negative pole of the battery, the switch tube in the charge and discharge switch module can be switched to an open circuit state when necessary to cut off the electrical connection between the negative pole of the battery and the second output end; and on this basis, a three-terminal fuse connected in series with the charge and discharge switch module is added. The three-terminal fuse can quickly melt to cut off the circuit under abnormal circumstances. Compared with the dual protection scheme of using two groups of MOS tubes or relays in the related art, the embodiment of the present invention cleverly uses the three-terminal fuse to replace one of the groups of MOS tubes or relays. By combining the three-terminal fuse in series with a group of charge and discharge switch modules to realize the dual protection mechanism of the circuit, the risk of failure of the entire protection mechanism due to failure of a single component can be reduced, and the cost of the circuit can also be effectively reduced. In addition, connecting the three-terminal fuse in series with the charge and discharge switch module and arranging them on the same branch can effectively reduce the space occupied by the circuit, simplify the wiring design of the circuit, make the entire circuit more compact and efficient, and improve the cost performance of the circuit.

[0029] The following is a further description of the embodiments of the present invention with reference to the accompanying drawings.

[0030] Reference Figure 1 The first embodiment of the present invention provides a charge and discharge control circuit 100 for a battery. The charge and discharge control circuit 100 can be connected to the positive and negative poles of the battery, respectively. By switching the on and off states of the components in the charge and discharge control circuit 100, the battery can be charged and discharged. Specifically, the charge and discharge control circuit 100 includes a charge and discharge switch module 200, a three-terminal fuse 300, a control module 400, a first output terminal 110, a second output terminal 120, a first branch 130, and a second branch 140. One end of the first branch 130 is connected to the positive pole of the battery, and the other end is connected to the first output terminal 110, while one end of the second branch 140 is connected to the negative pole of the battery, and the other end is connected to the second output terminal 120.

[0031] A charge-discharge switch module 200 and a three-terminal fuse 300 are arranged on the second branch 140. The charge-discharge switch module 200 can be located between the negative terminal of the battery and the three-terminal fuse 300. It consists of a charging switch tube 210 and a discharging switch tube 220 connected in series. These two switches are respectively connected to the control module 400 and can be switched between on and off states under the control of the control module 400, thereby effectively disconnecting or connecting the electrical connection between the negative terminal of the battery and the second output terminal 120. Specifically, the charge-discharge control circuit 100 also includes a discharge driving module 221 for switching the on and off states of the discharge switch tube 220, and a charging driving module 211 for switching the on and off states of the charging switch tube 210. The control module 400 is connected to the discharge switch tube 220 via the discharge driving module 221, and is connected to the charging switch tube 210 via the charging driving module 211. The control module 400 can drive the discharge driving module 221 to switch the discharge switch tube 220 between the on and off states. The three-terminal fuse 300 and the charge-discharge switch module 200 are arranged on the same side of the battery. For example, the three-terminal fuse 300 and the charge-discharge switch module 200 are both arranged on the low side of the battery, that is, both arranged on the second branch 140. One connection terminal of the three-terminal fuse 300 is connected to the charge-discharge switch module 200, and the other connection terminal can be connected to the second output terminal 120. The control terminal of the three-terminal fuse 300 can be directly connected to the control module 400 or connected to the control module 400 through the fuse driver module 310. Under normal circumstances, the three-terminal fuse 300 remains in a conductive state and does not affect the normal operation of the circuit. However, when an abnormal situation occurs in the circuit, the three-terminal fuse 300 can be controlled by the control module 400 to quickly melt to cut off the circuit, prevent the fault from further expanding, and protect the battery and circuit components from damage. The control module 400 is respectively connected to the control ends of the charging switch tube 210, the discharging switch tube 220 and the three-terminal fuse 300. It can judge the working status of the charging and discharging control circuit 100 by monitoring the voltage, current and other parameters of the charging and discharging control circuit 100 in real time, and can promptly cut off the charging switch tube 210 or the discharging switch tube 220 in an abnormal situation, or trigger the three-terminal fuse 300 to melt, so as to ensure the safety of the circuit.

[0032] Combine Figure 1The first output terminal 110 is connected to the positive terminal of an external electrical load or charging device. The first output terminal 110 is connected to the positive terminal of the battery through a first branch 130. An additional fuse may also be provided on the first branch 130. The second output terminal 120 is connected to the negative terminal of the external electrical load or charging device and is connected to the negative terminal of the battery through a second branch 140. Specifically, the second branch 140 is provided with a charge-discharge switch module 200 and a three-terminal fuse 300. The second output terminal 120 is connected to the negative terminal of the battery by sequentially connecting the three-terminal fuse 300, the charge switch tube 210, and the discharge switch tube 220. The control module 400 is connected to the three-terminal fuse 300, the charge switch tube 210, and the discharge switch tube 220 through corresponding driver modules.

[0033] In one embodiment, when the charge-discharge control circuit 100 is in the battery charging state, that is, the first output terminal 110 and the second output terminal 120 of the charge-discharge control circuit 100 are respectively connected to the charging device, current flows through the first input terminal into the first branch 130, then flows through the battery through the first branch 130, and flows through the charge-discharge switch module 200 from the second branch 140. The charging switch 210 and the discharging switch 220 are both in the on state. Therefore, current can flow through the charging switch 210 and the discharging switch 220 to the three-terminal fuse 300, and then return to the charging device from the second output terminal 120. If an abnormal condition occurs during the charging process, such as battery overvoltage, battery overheating or underheating, or overheating of the charge-discharge switch module 200, the control module 400 can drive the charging switch 210 to switch to the open circuit state, thereby disconnecting the second branch 140. If the charging switch tube 210 fails at this time, that is, it cannot be switched to the open circuit state, the three-terminal fuse 300 can be driven to melt, cutting off the second branch 140, thereby achieving double protection of the circuit.

[0034] In one embodiment, when the charge-discharge control circuit 100 is in the battery discharge state, that is, the first output terminal 110 and the second output terminal 120 of the charge-discharge control circuit 100 are respectively connected to the electrical load, the current flows from the first branch 130 to the first output terminal 110, flows through the electrical load, and then flows from the second output terminal 120 into the second branch 140. After flowing through the three-terminal fuse 300, it flows into the charge-discharge switch module 200. In this case, the charge switch tube 210 and the discharge switch tube 220 are both in the on state. Therefore, the current flows to the negative terminal of the battery through the discharge switch tube 220 and the charge switch tube 210. In the event of an abnormality during the discharge process, such as overheating of the battery or the charge-discharge switch module 200, or overcurrent in the circuit, the control module 400 can be used to drive the discharge switch tube 220 to switch to the open circuit state, thereby disconnecting the second branch 140. If the discharge switch tube 220 fails at this time, that is, it cannot be switched to the open circuit state, the three-terminal fuse 300 can be driven to melt, cutting off the second branch 140, thereby achieving double protection of the circuit.

[0035] Therefore, by using a three-terminal fuse 300 to replace one of the MOS tubes or relays, and using a three-terminal fuse 300 and a set of charge and discharge switch modules 200, double protection of the circuit can be achieved, which can reduce the risk of failure of a single component leading to failure of the entire protection mechanism, and at the same time effectively reduce the cost of the circuit.

[0036] Placing the charge-discharge switch module 200 and the three-terminal fuse 300 on the same side simplifies the circuit board's wiring design, reducing cross-wiring and component connection complexity. Furthermore, the relevant protection components used to control circuit on / off are all located in the same area, facilitating installation and inspection. Furthermore, centralizing the protection components on the same side makes it easier to design thermal management strategies, such as using heat sinks, fans, or heat pipes, to improve heat dissipation efficiency, reduce circuit design costs, and mitigate localized overheating caused by uneven component distribution.

[0037] Reference Figure 2 , Figure 2 Figure 5 is a schematic diagram of the structure of a charge and discharge control circuit 100 provided in another embodiment of the present invention. In low-temperature environments, battery performance can be affected, such as reduced discharge capacity and undercharging. This is because the fluidity of the electrolyte inside the battery deteriorates at low temperatures, reducing the internal operating efficiency of the battery. Therefore, a heating film 500 can be provided to heat the battery, allowing the battery to reach a suitable operating temperature during the charge and discharge process, thereby improving the fluidity and operating efficiency of the electrolyte inside the battery, and further improving the battery's performance in low-temperature environments.

[0038] like Figure 2As shown, in the charge and discharge control circuit 100, a heating film 500 and a heating control switch tube 510 are also provided. One end of the heating film 500 is connected to the positive pole of the battery, and the other end of the heating film 500 is connected to one end of the heating control switch tube 510, and the other end of the heating control switch tube 510 is connected to the connection point between the charge and discharge switch module 200 and the three-terminal fuse 300. At the same time, the control end of the heating control switch tube 510 is connected to the control module 400 through the heating drive module 530. Therefore, the heating drive module 530 can be driven by the control module 400 to turn on the heating control switch tube 510. At this time, the current can flow through the positive end of the battery through the heating film 500, and the heating control switch tube 510 in the on state, and flow to the three-terminal fuse 300 or the charge and discharge switch module 200, forming a charging heating circuit or a discharge heating circuit. In the charging heating circuit, the heating control switch tube 510 and the three-terminal fuse 300 form a double protection for the charging heating circuit, and in the discharge heating circuit, the heating control switch tube 510 and the charge and discharge switch module 200 form a double protection for the discharge heating circuit.

[0039] When the charge-discharge control circuit 100 is in the battery charging state and the heating film 500 is heating the battery, if the heating control switch tube 510 fails and cannot be switched to the open circuit state, the three-terminal fuse 300 can be driven to melt, quickly disconnecting the second branch 140 and simultaneously disconnecting the charging and heating circuit of the heating film 500, so that the heating film 500 stops heating the battery. When the charge-discharge control circuit 100 is in the battery discharging state and the heating film 500 is heating the battery, if the heating control switch tube 510 fails and cannot be switched to the open circuit state, the discharge switch tube 220 can be driven to switch to the open circuit state, disconnecting the second branch 140 and simultaneously disconnecting the working circuit of the heating film 500, so that the heating film 500 stops heating the battery.

[0040] like Figure 2As shown, the charge and discharge control circuit 100 also includes a heating state detection module 520. The input end of the heating state detection module 520 is connected to the connection point between the heating film 500 and the heating control switch tube 510, and the output end of the heating state detection module 520 is connected to the control module 400. Therefore, the control module 400 can use the heating state detection module 520 to detect whether the input end of the heating state detection module 520 is charged, thereby determining whether the heating film 500 is in a working state, that is, whether the working circuit of the heating film 500 is charged, and then It is possible to determine whether the heating control switch tube 510 has failed. For example, if the heating film 500 is in a working state, the working circuit of the heating film 500 is in a charged state, and therefore, the input end of the heating state detection module 520 is also in a charged state accordingly; if the heating control switch tube 510 is driven by the control module 400 and should be in an open circuit state, but the input end of the heating state detection module 520 is in a charged state, then it can be considered that the heating control switch tube 510 has failed, and the three-terminal fuse 300 can be blown or the discharge switch tube 220 can be driven to open circuit to achieve circuit protection.

[0041] It is understandable that an electrical parameter sampling device for sampling the circuit current and voltage, as well as a temperature detection device for detecting the component temperature and the battery temperature can be added to the battery charge and discharge control circuit 100, so as to monitor the working condition of the charge and discharge control circuit 100, detect abnormal conditions of the circuit in time, and then cut off the second branch 140 in time to protect the circuit.

[0042] Specifically, a sampling resistor 610 is further provided on the second branch 140 between the negative electrode of the battery and the charge-discharge switch module 200. One end of the sampling resistor 610 is connected to the negative electrode of the battery, and the other end is connected to the charge-discharge switch module 200. A current sampling module 600 may also be connected to both ends of the sampling resistor 610. The output end of the current sampling module 600 is connected to the control module 400. Therefore, the control module 400 can detect the current flowing through the sampling resistor 610 through the current sampling module 600, thereby realizing a current monitoring function and helping to promptly detect circuit abnormalities.

[0043] In one embodiment, when the battery charge and discharge control circuit 100 is in an operating state (including a charging state and a discharging state), the control module 400 can obtain the real-time current of the sampling resistor 610 through the current sampling module 600. If the real-time current exceeds a preset overcurrent value (or short-circuit current value), it is necessary to drive the switch tube in the charge and discharge switch module 200 to be disconnected, thereby opening the circuit between the negative electrode of the battery and the second output terminal 120, that is, disconnecting the second branch 140 to prevent the occurrence of a safety accident. If the charge and discharge switch module 200 is driven to disconnect the switch tube, but the real-time current of the sampling resistor 610 can still be collected by the current sampling module 600, it can be considered that the charge and discharge switch module 200 has failed. In this case, the three-terminal fuse 300 can be driven to melt, disconnecting the second branch 140, thereby achieving double protection for the circuit. In addition, a branch fuse 131 may be provided on the first branch 130. The branch fuse 131 may be a one-time fast-blow fuse. When the circuit is overloaded or short-circuited, the current suddenly increases, causing the branch fuse 131 to heat up and melt. The branch fuse 131 then automatically cuts off the circuit to ensure the safety of the circuit and equipment. Alternatively, the branch fuse 131 may also be provided with a control end, and the control end of the branch fuse 131 is also connected to the control module 400. When it is considered that the charge and discharge switch module 200 has failed, the control module 400 may also choose to drive the branch fuse 131 to melt and cut off the first branch 130.

[0044] The charge and discharge control circuit 100 may further include a first temperature detection module 230, which may be disposed on the surface of the charge and discharge switch module 200. The temperatures of both the charge switch tube 210 and the discharge switch tube 220 in the charge and discharge switch module 200 may be measured by the first temperature detection module 230, and the output end of the first temperature detection module 230 is connected to the control module 400, thereby enabling temperature monitoring of the charge and discharge switch module 200 to prevent the charge and discharge switch module 200 from being damaged due to excessive temperature.

[0045] In one embodiment, the battery charge and discharge control circuit 100 is in an operating state, and the control module 400 can detect the operating temperature of each switch tube in the charge and discharge switch module 200 in real time through the first temperature detection module 230. If it is detected that the operating temperature of either the charging switch tube 210 or the discharging switch tube 220 reaches a preset first overtemperature value, it is necessary to drive the switch tube in the charge and discharge switch module 200 to disconnect, so that the circuit between the negative electrode of the battery and the second output terminal 120 is open, that is, the second branch 140 is disconnected to prevent the switch tube from failing due to overtemperature and causing a safety accident. If the charge and discharge switch module 200 is driven to disconnect the switch tube, but the operating temperature of the switch tube collected by the first temperature detection module 230 continues to rise, it can be considered that the charge and discharge switch module 200 has failed. In this case, the three-terminal fuse 300 can be driven to melt, cutting off the second branch 140, thereby achieving double protection of the circuit.

[0046] The charge and discharge control circuit 100 may further include a first voltage sampling module 700. One end of the first voltage sampling module 700 is connected to the first output end 110, and the other end is connected to the second output end 120. The control end of the first voltage sampling module 700 is connected to the control module 400. The first voltage sampling module 700 is used to measure the total voltage of the circuit during charging and discharging of the battery. Therefore, the circuit voltage can be monitored during the charging and discharging process of the battery, and abnormal conditions of the circuit can be discovered in a timely manner.

[0047] In one embodiment, the battery charge and discharge control circuit 100 is in an operating state (including a charging state and a discharging state). The control module 400 can obtain the output voltage between the first output terminal 110 and the second output terminal 120 through the first voltage sampling module 700. If the output voltage exceeds a preset first overvoltage value, it is necessary to drive the switch tube in the charge and discharge switch module 200 to be disconnected, so that the circuit between the negative electrode of the battery and the second output terminal 120 is open, that is, the second branch 140 is disconnected to prevent the occurrence of a safety accident. If the charge and discharge switch module 200 is driven to disconnect the switch tube, but the output voltage collected by the first voltage sampling module 700 is still greater than the preset voltage value, it can be considered that the charge and discharge switch module 200 has failed. In this case, the three-terminal fuse 300 can be driven to melt, disconnecting the second branch 140, thereby achieving double protection for the circuit.

[0048] In addition, the circuit voltage detected by the first voltage sampling module 700 can also be used to determine whether the second branch 140 has been disconnected. For example, when the real-time current of the sampling resistor 610 can still be collected after the switch tube in the charge-discharge switch module 200 is disconnected due to overcurrent, or when the operating temperature of the switch tube collected after the charge-discharge switch module 200 is disconnected due to overheating, if the circuit voltage collected by the first voltage sampling module 700 is greater than a preset voltage value, it can be considered that the charge-discharge switch module 200 has failed. At this time, the three-terminal fuse 300 can be driven to melt, disconnecting the second branch 140, thereby achieving double protection of the circuit; if the circuit voltage sampled by the first voltage sampling module 700 is less than or equal to the preset voltage value, it can be considered that the charge-discharge control circuit 100 has been opened, and the charge-discharge switch module 200 has not failed.

[0049] Reference Figure 3 , Figure 3 : This is a structural diagram of the charge and discharge control circuit 100 provided by another embodiment of the present invention. In the process of charging and discharging the battery, the voltage and temperature of the battery are crucial. Therefore, a second voltage sampling module 800 and a second temperature detection module 900 can also be provided in the charge and discharge control circuit 100. Specifically, the second voltage sampling module 800 can detect the battery voltage, and the output end of the second voltage sampling module 800 is connected to the control module 400, so that the battery voltage can be monitored in real time to ensure that the battery is always kept within a safe working range during the charge and discharge process, and to prevent the battery from being damaged due to overvoltage or overdischarge; and the second temperature detection module 900 can detect the battery temperature. Since the battery generates heat during operation, if the temperature is too high, it may cause the chemical reaction inside the battery to accelerate, thereby causing battery damage. Therefore, the output end of the second temperature detection module 900 is connected to the control module 400, which can realize real-time monitoring of the battery temperature, which helps to timely detect and prevent battery overheating.

[0050] In one embodiment, when the battery is in a charging state, the control module 400 can collect the battery voltage of each single battery in the battery pack through the second voltage sampling module 800. If the sampled battery voltage reaches a preset second overvoltage value, the switch tube in the charge-discharge switch module 200 can be driven to disconnect, thereby opening the circuit between the negative electrode of the battery and the second output terminal 120, that is, disconnecting the second branch 140 to prevent the battery from overcharging. If the charge-discharge switch module 200 is driven to disconnect the switch tube, but the battery voltage collected by the second voltage sampling module 800 still maintains an upward trend, it can be considered that the charge-discharge switch module 200 has failed. Alternatively, if the output voltage between the first output terminal 110 and the second output terminal 120 collected by the first voltage sampling module 700 is greater than the preset voltage value, it can also be considered that the charge-discharge switch module 200 has failed. In this case, the three-terminal fuse 300 can be driven to melt, disconnecting the second branch 140, thereby achieving double protection for the circuit.

[0051] In one embodiment, during the battery charging and discharging process, the control module 400 can detect the battery temperature through the second temperature detection module 900. If the detected battery temperature reaches a preset battery overtemperature value, the switch tube in the charge and discharge switch module 200 can be driven to disconnect, so that the circuit between the negative electrode of the battery and the second output terminal 120 is open, that is, the second branch 140 is disconnected, the battery operation is stopped, and a safety accident caused by battery overheating is prevented. If the charge and discharge switch module 200 is driven to disconnect the switch tube, but the second temperature detection module 900 can still detect that the battery temperature continues to rise, it can be considered that the charge and discharge switch module 200 has failed. Alternatively, if the output voltage between the first output terminal 110 and the second output terminal 120 collected by the first voltage sampling module 700 is greater than a preset voltage value, it can also be considered that the charge and discharge switch module 200 has failed. At this time, the three-terminal fuse 300 can be driven to melt, cutting off the second branch 140, thereby achieving double protection of the circuit.

[0052] Reference Figure 4 , Figure 4 This is a schematic diagram of the structure of the charge and discharge control circuit provided by another embodiment of the present invention. Figure 4As shown, the charge and discharge control circuit 100 can be applied to a battery management system (BMS). In the battery management system, the second voltage sampling module 800 and the second temperature detection module 900 can be integrated into an analog front end module 1000 (Analog Front End, AFE). The analog front end module 1000 in the battery management system can monitor and manage the battery status and charge and discharge process, including the voltage and temperature of each single cell in the battery pack. Therefore, the control module 400 in the charge and discharge control circuit 100 can be connected to the analog front end module 1000, and the battery voltage and temperature can be sampled through the analog front end module 1000.

[0053] It can be understood that the charge and discharge control circuit 100 can be applied to a battery pack or to a single cell in a battery pack. Therefore, when an abnormal situation occurs, such as an overvoltage in the overall voltage of the battery pack or a single cell voltage in the battery pack, an overtemperature in the battery pack, an overtemperature in the charge and discharge switch module 200, or an overcurrent in the charge and discharge control circuit 100, the switch tube in the charge and discharge switch module 200 can be driven to disconnect, so that the circuit between the negative electrode of the battery and the second output terminal 120 is open, that is, the second branch 140 is disconnected and the circuit stops working; then, after driving the charge and discharge switch module 200 to disconnect the switch tube, the voltage between the first output terminal 110 and the second output terminal 120 can be sampled by the first voltage sampling module 700. If the sampled voltage exceeds the preset voltage value, it means that the charge and discharge switch module 200 has failed to drive, and the three-terminal fuse 300 can be driven to melt, cutting off the second branch 140, thereby achieving double protection of the circuit. The abnormal conditions of the charge and discharge control circuit 100 may specifically include: when the voltage between the first output terminal 110 and the second output terminal 120 is sampled by the first voltage sampling module 700, the sampled output voltage exceeds a preset first overvoltage value; or when the current sampling module 600 samples the current of the sampling resistor 610, the sampled real-time current exceeds a preset overcurrent value; or when the first temperature detection module 230 performs temperature detection on the charge and discharge switch module 200, the detected operating temperature exceeds a preset first overtemperature value; or when the second temperature detection module 900 performs temperature detection on the battery, the detected battery temperature exceeds a preset battery overtemperature value; or when the second voltage sampling module 800 performs voltage sampling on the battery, the sampled battery voltage exceeds a preset second overvoltage value.

[0054] In a second aspect, an embodiment of the present invention provides a battery management system, comprising the battery charge and discharge control circuit as described in the embodiment of the first aspect above.

[0055] The battery management system provided by the embodiment of the present invention has at least the following beneficial effects: by connecting the charge-discharge switch module to the negative electrode of the battery, the switch tube in the charge-discharge switch module can be switched to an open circuit state, thereby effectively cutting off the electrical connection between the negative electrode of the battery and the second output terminal. On this basis, a three-terminal fuse connected in series with the charge-discharge switch module is added. Similarly, the three-terminal fuse can quickly melt to cut off the circuit. Compared with the dual protection scheme composed of two groups of MOS tubes or relays in the related art, the embodiment of the present invention cleverly uses a three-terminal fuse to replace one of the MOS tubes or relays. By combining the three-terminal fuse in series with a group of charge-discharge switch modules to achieve a dual protection mechanism for the circuit, this design can effectively control the cost of the circuit. In addition, arranging the three-terminal fuse and the charge-discharge switch module on the same branch can effectively save the space occupied by the circuit, simplify the wiring design of the circuit, make the entire circuit more compact and efficient, and facilitate the layout of the circuit in the battery management system. While ensuring safety, it also significantly improves the cost performance of the circuit.

[0056] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A battery charge and discharge control circuit, characterized in that: include: a first output terminal connected to the positive electrode of the battery through a first branch; a second output terminal connected to the negative electrode of the battery through a second branch; A charge and discharge switch module is provided in the second branch and includes a charge switch tube and a discharge switch tube connected in series; a three-terminal fuse, provided in the second branch and located between the charge-discharge switch module and the second output terminal; a control module, connected to the charging switch tube, the discharging switch tube and the control end of the three-terminal fuse, respectively, for controlling the charging and discharging switch modules and / or the three-terminal fuse to disconnect the electrical connection between the negative electrode of the battery and the second output end.

2. The charge and discharge control circuit according to claim 1, wherein: It also includes a heating control switch tube and a heating film for heating the battery, one end of the heating film is connected to the positive electrode of the battery, and the other end is connected to the connection point between the charge and discharge switch module and the three-terminal fuse through the heating control switch tube.

3. The charge and discharge control circuit according to claim 2, wherein: The control module is also connected to the control end of the heating control switch tube.

4. The charge and discharge control circuit according to claim 2, characterized in that: It also includes a heating state detection module connected to a connection point between the heating film and the heating control switch tube, and an output end of the heating state detection module is connected to the control module.

5. The charge and discharge control circuit according to claim 1, wherein: It also includes a sampling resistor arranged between the negative electrode of the battery and the charge and discharge switch module and a current sampling module connected to the sampling resistor, and the output end of the current sampling module is connected to the control module.

6. The charge and discharge control circuit according to claim 1, wherein: It also includes a first voltage sampling module connected to the first output end and the second output end, and the output end of the first voltage sampling module is connected to the control module.

7. The charge and discharge control circuit according to claim 1, wherein: It also includes a first temperature detection module for measuring the temperature of the charge and discharge switch module, and the output end of the first temperature detection module is connected to the control module.

8. The charge and discharge control circuit according to claim 1, wherein: It also includes a second voltage sampling module for detecting battery voltage and a second temperature detection module for detecting battery temperature. The output ends of the second voltage sampling module and the second temperature detection module are connected to the control module.

9. The charge and discharge control circuit according to claim 1, wherein: The charge and discharge control circuit further includes a branch fuse arranged in the first branch.

10. A battery management system, characterized in that: The charging and discharging control circuit comprises the charging and discharging control circuit according to any one of claims 1 to 9.

Images