Charging and discharging control circuit of battery and battery management system

Abstract

The invention discloses a charge and discharge control circuit of a battery and a battery management system, the charge and discharge control circuit comprises a first output end, a second output end, a charge and discharge switch module, a three-terminal fuse and a control module, 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 invention, 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 present invention 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. If lithium batteries lose effective control during the charging and discharging process, major safety accidents may occur. Traditional battery charging and discharging control circuits usually use MOS tubes or relays on the circuit to protect the battery. When abnormal charging and discharging is detected, the battery charging and discharging control circuit is opened by cutting off the switch device. However, this protection method has hidden dangers. Once the switch device itself fails (such as the MOS tube is broken down or the relay is adhered), the battery protection scheme by cutting off the switch device will fail. Therefore, in the related art, an additional set of MOS tubes or relays in series will be added to the existing set of MOS tubes or relays in the charging and discharging control circuit to achieve double protection. However, this design has high cost and occupies a large space, and has low cost performance. Therefore, how to improve the safety of the battery charging and discharging control circuit while reducing the circuit design cost has become an urgent problem to be solved. Summary of the invention

[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 of a battery, comprising a first output end, a second output end, a charge and discharge switch module, a three-terminal fuse, a heating module 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 heating module comprises 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; the control module is respectively connected to the control ends of the charging switch tube, the discharging switch tube, the three-terminal fuse and the heating control switch tube, and is used to control at least one of the charge and discharge switch module, the three-terminal fuse and the heating control switch tube to be disconnected in an abnormal situation, so as to disconnect the electrical connection between the negative electrode of the battery and the second output end or disconnect the power supply to the heating film.

[0005] The charge and discharge control circuit of the battery provided according to 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 blown to cut off the circuit. Compared with the double protection scheme 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, and uses a three-terminal fuse and a group of charge and discharge switch modules to achieve double protection of the charge and discharge circuit. At the same time, the heating film is connected to the connection point of the charge and discharge switch module and the three-terminal fuse through the heating control switch tube, so that in the process of charging or discharging the battery, the heating control switch tube and the three-terminal fuse or the charge and discharge switch module can be used to form a double protection of the heating circuit, which effectively reduces the risk of failure of a single component leading to failure of the entire protection mechanism, and can also effectively reduce the cost of the circuit.

[0006] In the charge and discharge control circuit of the battery provided in an embodiment of the present invention, the abnormal situation includes any one of the following: the output voltage of the first output terminal and the second output terminal is too high, the output current of the first output terminal and the second output terminal is too high, the temperature of the charge and discharge switch module is too high, the voltage of the battery is too high, and the temperature of the battery is too high.

[0007] In the charge and discharge control circuit of the battery provided in the embodiment of the present invention, when the abnormal situation is detected, the control module controls the charge and discharge switch module to be disconnected, and detects whether there is current in the second branch; When it is detected that current exists in the second branch, the control module controls the three-terminal fuse to blow.

[0008] In the battery charge and discharge control circuit provided in the embodiment of the present invention, when the battery supplies power to the heating film through the heating control switch tube and the charge and discharge switch module, and the abnormal situation is detected, the control module controls the charge and discharge switch module to be disconnected, and detects whether there is current flowing through the heating film; When it is detected that current flows through the heating film, the control module controls the heating control switch tube to be disconnected.

[0009] In the charge and discharge control circuit of the battery provided in the embodiment of the present invention, when the first output end and the second output end supply power to the heating film through the heating control switch tube and the three-terminal fuse, and the abnormal situation is detected, the control module controls the heating control switch tube to be disconnected, and detects whether there is current flowing through the heating film; When detecting that current flows through the heating film, the control module controls the three-terminal fuse to melt.

[0010] In the battery charge and discharge control circuit provided in the embodiment of the present invention, it also 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.

[0011] In the battery charge and discharge control circuit provided in the embodiment of the present invention, 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.

[0012] The battery charge and discharge control circuit provided in the 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.

[0013] 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.

[0014] The battery charge and discharge control circuit provided in the 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, and the output ends of the second voltage sampling module and the second temperature detection module are connected to the control module.

[0015] In the charge and discharge control circuit of the battery provided in the embodiment of the present invention, the charge and discharge control circuit further includes a branch fuse arranged in the first branch.

[0016] 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.

[0017] The battery management system provided according to 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 blown to cut off the circuit. Compared with the double protection scheme 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, and uses a three-terminal fuse and a group of charge and discharge switch modules to achieve double protection of the charge and discharge circuit. At the same time, the heating film is connected to the connection point of the charge and discharge switch module and the three-terminal fuse through the heating control switch tube, so that in the process of charging or discharging the battery, the heating control switch tube and the three-terminal fuse or the charge and discharge switch module can be used to form a double protection of the heating circuit, which effectively reduces the risk of failure of a single component causing failure of the entire protection mechanism, and can also effectively reduce the cost of the circuit.

[0018] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments; Figure 1 is a schematic diagram of the structure of a charge and discharge control circuit provided by an embodiment of the present invention; Figure 2 is a structural schematic diagram of a charge and discharge control circuit provided by another embodiment of the present invention; Figure 3 is a structural schematic diagram of a charge and discharge control circuit provided by another embodiment of the present invention; Figure 4 It is a structural schematic diagram of a charge and discharge control circuit provided by another embodiment of the present invention. DETAILED DESCRIPTION

[0021] 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 the overall technical solution of the present invention, but it cannot be understood as a limitation on the scope of protection of the present invention.

[0022] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, "above", "below", "within", etc. are understood to include the number itself, "any one" means one or more, "at least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. If there is a description of the first and the second, it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0023] It should be noted that the terms such as setting, installing, and connecting in the embodiments of the present invention should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the embodiments of the present invention in combination with the specific content of the technical solution. For example, the term "connection" can be a mechanical connection, an electrical connection, or mutual communication; it can be directly connected or indirectly connected through an intermediate medium.

[0024] 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.

[0025] Traditional battery charge and discharge control circuits usually use MOS tubes or relays on the circuit to protect the battery. When abnormal charge and discharge is detected, the battery charge and discharge control circuit is opened by cutting off the switch device. However, this protection method has hidden dangers. Once the switch device itself fails (such as the MOS tube is broken down or the relay is stuck), the battery protection scheme by cutting off the switch device will fail. Therefore, in the related art, an additional set of MOS tubes or relays in series is added on the basis of the existing set of MOS tubes or relays in the charge and discharge control circuit to achieve double protection. However, the cost of using two sets of MOS tubes or relays is high, and the space occupied is large, and the cost performance is low.

[0026] Based on this, an embodiment of the present invention proposes a battery charge and discharge control circuit and a battery management system. By connecting a charge and discharge switch module to the negative electrode 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 electrode of the battery and the second output terminal. On this basis, a three-terminal fuse connected in series with the charge and discharge switch module is added. The three-terminal fuse can be quickly blown 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 a three-terminal fuse to replace one group of MOS tubes or relays, and realizes the dual protection mechanism of the circuit by combining the three-terminal fuse in series with a group of charge and discharge switch modules. At the same time, the heating film is connected to the connection point of the charge and discharge switch module and the three-terminal fuse through the heating control switch tube, so that in the process of charging or discharging the battery, the heating control switch tube and the three-terminal fuse or the charge and discharge switch module can be used to form a heating circuit for dual protection, which effectively reduces the risk of failure of the entire protection mechanism due to failure of a single component, and can also effectively reduce the cost of the circuit.

[0027] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0028] Reference Figure 1 The first aspect of the present invention provides a charge and discharge control circuit 100 for a battery. The charge and discharge control battery can be connected to the positive and negative electrodes of the battery respectively. By switching the on and off states of the components in the charge and discharge control circuit 100, the charge and discharge operation of the battery can be realized. 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 heating module, a first output terminal 110, a second output terminal 120, a first branch 130 and a second branch 140, wherein one end of the first branch 130 is connected to the positive electrode of the battery, and the other end is connected to the first output terminal 110, and one end of the second branch 140 is connected to the negative electrode of the battery, and the other end is connected to the second output terminal 120.

[0029] A charge and discharge switch module 200 and a three-terminal fuse 300 are arranged on the second branch 140. The charge and discharge switch module 200 can be located between the negative terminal of the battery and the three-terminal fuse 300, and is composed of a charging switch tube 210 and a discharging switch tube 220 connected in series. The two switch tubes are respectively connected to the control module 400, and can be controlled by the control module 400 to switch the on-off state, thereby effectively cutting off or connecting the electrical connection between the negative electrode of the battery and the second output terminal 120. Specifically, the charge and discharge control circuit 100 also includes a discharge driving module 221 for switching the on-off state of the discharge switch tube 220, and a charging driving module 211 for switching the on-off state of the charging switch tube 210. The control module 400 is connected to the discharge switch tube 220 through the discharge driving module 221, and is connected to the charging switch tube 210 through the charging driving module 211, so that the control module 400 can drive the discharge driving module 221 to switch the discharge switch tube 220 to the on state or the open state. The three-terminal fuse 300 and the charge and discharge switch module 200 are arranged on the same side of the battery. For example, the three-terminal fuse 300 and the charge and discharge switch module 200 are simultaneously arranged on the low side of the battery, that is, simultaneously arranged on the second branch 140. One connection end of the three-terminal fuse 300 is connected to the charge and discharge switch module 200, and the other connection end can be connected to the second output end 120. The control end 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 driving module 310. Under normal circumstances, the three-terminal fuse 300 remains in a conducting 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 end of the charging switch tube 210, the discharging switch tube 220 and the three-terminal fuse 300. It can judge the working state of the charging and discharging control circuit 100 by real-time monitoring the voltage, current and other parameters of the charging and discharging control circuit 100, and can timely 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.

[0030] Combination Figure 1The first output terminal 110 is used to connect to the positive terminal of an external power load or a charging device. The first output terminal 110 is connected to the positive terminal of the battery through the first branch 130, and an additional fuse can be arranged on the first branch 130; the second output terminal 120 is used to connect to the negative terminal of the external power load or the charging device, and is connected to the negative terminal of the battery through the second branch 140. Specifically, the second branch 140 is arranged with a charge and discharge switch module 200 and a three-terminal fuse 300, wherein the second output terminal 120 is connected to the negative terminal of the battery by sequentially connecting the three-terminal fuse 300, the charging switch tube 210 and the discharging switch tube 220. The control module 400 is connected to the three-terminal fuse 300, the charging switch tube 210 and the discharging switch tube 220 through the corresponding driving modules.

[0031] In one embodiment, when the charge and 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 and discharge control circuit 100 are respectively connected to the charging device, at this time, the current flows into the first branch 130 through the first input terminal, then flows through the battery through the first branch 130, and flows through the charge and discharge switch module 200 from the second branch 140, wherein the charge switch tube 210 and the discharge switch tube 220 are both in the on state, therefore, the current can flow to the three-terminal fuse 300 through the charge switch tube 210 and the discharge switch tube 220, and then return to the charging device from the second output terminal 120. In the case of abnormal conditions during the charging process, such as battery overvoltage, battery overheating or underheating, or overheating of the charge and discharge switch module 200, the control module 400 can be used to drive the charge switch tube 210 to switch to the open circuit state, thereby cutting off the second branch 140. If the charging switch tube 210 fails at this time, that is, it cannot be switched to an 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.

[0032] In one embodiment, when the charge and 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 and discharge control circuit 100 are respectively connected to the power load, at this time, the current flows from the first branch 130 to the first output terminal 110, flows through the power load, flows from the second output terminal 120 into the second branch 140, flows through the three-terminal fuse 300, and flows into the charge and discharge switch module 200, wherein the charging switch tube 210 and the discharging switch tube 220 are both in the on state, therefore, the current flows to the negative terminal of the battery through the discharging switch tube 220 and the charging switch tube 210. In the case of abnormal conditions during the discharge process, such as overheating of the battery, the charge and discharge switch module 200, and overcurrent of the circuit, the control module 400 can be used to drive the discharge switch tube 220 to switch to the open circuit state, thereby cutting off the second branch 140. If the discharge switch tube 220 fails at this time, that is, it cannot be switched to an 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.

[0033] Therefore, by using a three-terminal fuse 300 to replace one of the MOS tubes or relays, the three-terminal fuse 300 and a set of charge and discharge switch modules 200 can achieve double protection of the circuit, which can reduce the risk of failure of a single component leading to failure of the entire protection mechanism, and can also effectively reduce the cost of the circuit.

[0034] When the charge-discharge switch module 200 and the three-terminal fuse 300 are placed on the same side, the wiring design of the circuit board can be simplified, and the complexity of cross wiring and connection between components can be reduced. At the same time, the related protection components used to control the on-off of the circuit are all in the same area, which is convenient for installation and inspection. In addition, placing the protection components on the same side can make 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 reduce local overheating problems caused by uneven component distribution.

[0035] In a low temperature environment, the performance of the battery will be affected, such as reduced discharge capacity, unsaturated charging, etc. This is because the fluidity of the electrolyte inside the battery deteriorates at low temperatures and the working efficiency inside the battery is reduced. Therefore, a heating module is provided in the charge and discharge control circuit, that is, a heating film 500 is provided for the battery to heat the battery so that the battery can reach a temperature suitable for use during the charge and discharge process, thereby improving the fluidity and working efficiency of the electrolyte inside the battery, and further improving the performance of the battery in a low temperature environment.

[0036] like Figure 1As 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 electrode of the battery, 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 make the heating control switch tube 510 turned on. 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 to form 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.

[0037] Specifically, when the charge and discharge control circuit 100 is in the battery charging state and the heating film 500 is heating the battery, if an abnormal situation occurs, such as the battery temperature is too high and the charging heating circuit needs to be cut off, the heating control switch tube 510 can be controlled to switch to an open circuit state first, so that the charging heating circuit is disconnected and the power supply to the heating film 500 is stopped. However, if current still flows through the heating film 500 at this time, it can be considered that the heating control switch tube 510 has failed and cannot be switched to an open circuit state. At this time, the three-terminal fuse 300 can be driven to melt, quickly cutting off the second branch 140 while cutting off the charging heating circuit of the heating film 500, so that the heating film 500 stops heating the battery. When the charge and discharge control circuit 100 is in the battery discharge state and the heating film 500 heats the battery, if an abnormal situation occurs and the discharge heating circuit needs to be cut off, the heating control switch tube 510 can be controlled to switch to an open circuit state first, so that the discharge heating circuit is disconnected and the power supply to the heating film 500 is stopped. However, if the heating control switch tube 510 fails and cannot be switched to the open circuit state, at this time, the three-terminal fuse 300 can be driven to switch to an open circuit state, cutting off the second branch 140 while cutting off the working circuit of the heating film 500, and stopping the heating film 500 from heating the battery.

[0038] Specifically, when the charge and discharge control circuit 100 is in the battery discharge state and the heating film 500 heats the battery, if an abnormal situation occurs, the charge and discharge switch module 200 can be controlled to disconnect first, in the hope of disconnecting the discharge heating circuit of the heating film 500 and stopping the power supply to the heating film 500. Then, the discharge heating circuit can be tested for current to determine whether current is still flowing through the heating film 500 or whether it is in a working state. If current is still flowing through the heating film, it means that the discharge heating circuit is not disconnected, that is, the charge and discharge switch module 200 fails, and the heating control switch tube 510 needs to be controlled to disconnect to complete the disconnection of the discharge heating circuit, thereby realizing double protection of the heating film 500 in the circuit discharge state.

[0039] Reference Figure 2 , Figure 2 1 is a schematic diagram of the structure of the charge and discharge control circuit provided by another embodiment of the present invention. 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, so as to determine whether the heating film 500 has current flowing through it or is in a working state, that is, whether the working circuit of the heating film 500 is charged. Furthermore, it can be determined 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, so 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, 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 the circuit to achieve circuit protection.

[0040] It is understandable that an electrical parameter sampling device for sampling circuit current and voltage, as well as a temperature detection device for detecting component temperature and 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.

[0041] Specifically, a sampling resistor 610 is further provided on the second branch 140 between the negative electrode of the battery and the charge and 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 and discharge switch module 200. The current sampling module 600 can be connected to both ends of the sampling resistor 610 at the same time. 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, so as to realize the function of current monitoring, which is helpful to timely discover the abnormal situation of the circuit.

[0042] In one embodiment, in a scenario where the battery charge and discharge control circuit 100 is in a working 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 a short-circuit current 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 has been driven to disconnect the switch tube, but the real-time current of the sampling resistor 610 can still be collected through the current sampling module 600, it can 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.

[0043] 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 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 charge and discharge control circuit 100 of the battery is in a working 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 any one of the charging switch tube 210 or the discharging switch tube 220 reaches a preset first over-temperature 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 has been driven to disconnect the switch tube, but the operating temperature of the switch tube collected by the first temperature detection module 230 still maintains an upward trend, it can 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 and cut off the second branch 140 to achieve 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, and 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 when the battery is charging and discharging. Therefore, the circuit voltage can be monitored during the battery charging and discharging process, and abnormal conditions of the circuit can be discovered in time.

[0047] In one embodiment, the charge and discharge control circuit 100 of the battery is in a working state (including a charging state and a discharging state), and 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, that is, an abnormal situation occurs, 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 occurrence of safety accidents; if the charge and discharge switch module 200 has been driven to disconnect the switch tube, but it is detected that there is still current in the second branch, it can 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 and cut off the second branch 140 to achieve double protection of the circuit.

[0048] Specifically, the circuit voltage detected by the first voltage sampling module 700 can be used to determine whether the second branch 140 is cut off. For example, after the charge and discharge switch module 200 has been driven to disconnect the switch tube, if the output voltage that can still be collected by the first voltage sampling module 700 is greater than the preset voltage value, it can be said that the charge and discharge control circuit is still in a charged state, that is, the second branch 140 is not cut off, that is, the charge and discharge switch module 200 fails; and if the circuit voltage detected by the first voltage sampling module 700 at this time is less than or equal to the preset voltage value, it can be considered that the second branch 140 has been cut off and the charge and discharge switch module 200 has not failed.

[0049] Specifically, the current sampling module 600 can also detect the real-time current of the sampling resistor 610 to determine whether the second branch 140 is cut off. For example, after the switch tube in the charge-discharge switch module 200 has been driven to be disconnected, the current sampling module 600 can still sample the real-time current of the sampling resistor 610 to be greater than zero, which means that there is still current in the second branch 140 and the second branch 140 is not cut off, that is, the charge-discharge switch module 200 is invalid. If the real-time current sampled from the sampling resistor 610 is equal to zero at this time, it can be considered that the second branch 140 has been cut off and the charge-discharge switch module 200 has not failed.

[0050] Specifically, the temperature of the charge-discharge switch module 200 detected by the first temperature detection module 230 can also be used to determine whether the second branch 140 is cut off. For example, after the switch tube in the charge-discharge switch module 200 has been driven to disconnect, if the temperature of the charge-discharge switch module 200 detected by the first temperature detection module 230 is still in a rising trend, it can be explained that there is still current flowing through the second branch 140, and the second branch 140 is not cut off, that is, the charge-discharge switch module 200 fails. If the temperature of the charge-discharge switch module 200 detected at this time is in a cooling trend, it can be considered that the second branch 140 has been cut off and the charge-discharge switch module 200 has not failed.

[0051] Reference Figure 3 , Figure 3It is a structural diagram of a charge and discharge control circuit 100 provided by another embodiment of the present invention. In the process of charging and discharging a battery, the voltage and temperature of the battery are crucial. Therefore, a second voltage sampling module 800 and a second temperature detection module 900 may 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 of the battery; 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, and help to timely discover and prevent the battery from overheating.

[0052] In one embodiment, the battery is in a charging state, and 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, that is, an abnormal situation occurs, 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 to prevent the battery from being overcharged; if the charge and discharge switch module 200 has been driven to disconnect the switch tube, but the battery voltage that can still be collected by the second voltage sampling module 800 maintains an upward trend, it can be considered that the charge and discharge switch module 200 has failed, or, 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 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.

[0053] In one embodiment, during the process of charging and discharging the battery, 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 over-temperature value, that is, an abnormal situation occurs, 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 is stopped, and a safety accident caused by overheating of the battery is prevented; if the charge and discharge switch module 200 has been driven to disconnect the switch tube, but the second temperature detection module 900 can still detect that the battery temperature maintains an upward trend, it can be considered that the charge and discharge switch module 200 has failed, or, 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 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 to achieve double protection of the circuit.

[0054] Reference Figure 4 , Figure 4 FIG. 1 is a schematic diagram of a charge and discharge control circuit according to another embodiment of the present invention. Figure 4 As 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 in 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 state and charge and discharge process of the battery, 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 voltage and temperature of the battery can be sampled through the analog front end module 1000.

[0055] 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 the overall voltage of the battery pack or the single cell voltage of a single cell in the battery pack is overvoltage, the battery pack is overheated, the charge and discharge switch module 200 is overheated, the charge and discharge control circuit 100 is overcurrent, and other abnormal conditions occur, 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 through 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 fails 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 situation 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 the preset first overvoltage value; or, when the current sampling module 600 performs current sampling on the sampling resistor 610, the sampled real-time current exceeds the 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 the preset first overtemperature value; or, when the second temperature detection module 900 performs temperature detection on the battery, the detected battery temperature exceeds the preset battery overtemperature value; or, when the second voltage sampling module 800 performs voltage sampling on the battery, the sampled battery voltage exceeds the preset second overvoltage value.

[0056] 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.

[0057] According to the battery management system provided by the embodiment of the present invention, at least the following beneficial effects are achieved: by connecting the charge and discharge switch module to the negative electrode of the battery, the switch tube in the charge and 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 and discharge switch module is added. Similarly, the three-terminal fuse can be quickly blown to cut off the circuit. Compared with the double 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 group of MOS tubes or relays, and realizes the dual protection mechanism of the circuit by connecting the three-terminal fuse in series with a group of charge and discharge switch modules. This design can effectively control the cost of the circuit. At the same time, the heating film is connected to the connection point of the charge and discharge switch module and the three-terminal fuse through the heating control switch tube, so that in the process of charging or discharging the battery, the heating control switch tube and the three-terminal fuse or the charge and discharge switch module can be used to form a double protection of the heating circuit, effectively reducing the risk of failure of the entire protection mechanism due to failure of a single component, and can also effectively reduce the cost of the circuit.

[0058] 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 knowledge scope of 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, arranged in the second branch, comprising a charge switch tube and a discharge switch tube connected in series; A three-terminal fuse, arranged in the second branch and located between the charge-discharge switch module and the second output terminal; A heating module, comprising a heating control switch tube and a heating film for heating the battery, one end of the heating film being connected to the positive electrode of the battery, and the other end being connected to the connection point between the charge and discharge switch module and the three-terminal fuse through the heating control switch tube; A control module is respectively connected to the control ends of the charging switch tube, the discharging switch tube, the three-terminal fuse and the heating control switch tube, and is used to control at least one of the charging and discharging switch modules, the three-terminal fuse and the heating control switch tube to be disconnected under abnormal circumstances, so as to disconnect the electrical connection between the negative electrode of the battery and the second output end or disconnect the power supply to the heating film.

2. The charge and discharge control circuit according to claim 1, characterized in that: The abnormal situation includes any one of the following: the output voltage of the first output terminal and the second output terminal is too high, the output current of the first output terminal and the second output terminal is too high, the temperature of the charge and discharge switch module is too high, the voltage of the battery is too high, and the temperature of the battery is too high.

3. The charge and discharge control circuit according to claim 2, characterized in that: When the abnormal situation is detected, the control module controls the charge and discharge switch module to be disconnected, and detects whether there is current in the second branch; When it is detected that current exists in the second branch, the control module controls the three-terminal fuse to blow.

4. The charge and discharge control circuit according to claim 2, characterized in that: When the battery supplies power to the heating film through the heating control switch tube and the charge-discharge switch module and the abnormal situation is detected, the control module controls the charge-discharge switch module to disconnect and detects whether there is current flowing through the heating film; When it is detected that current flows through the heating film, the control module controls the heating control switch tube to be disconnected.

5. The charge and discharge control circuit according to claim 2, characterized in that: When the first output end and the second output end supply power to the heating film through the heating control switch tube and the three-terminal fuse, and the abnormal situation is detected, the control module controls the heating control switch tube to be disconnected, and detects whether there is current flowing through the heating film; When detecting that current flows through the heating film, the control module controls the three-terminal fuse to melt.

6. The charge and discharge control circuit according to claim 1, 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.

7. The charge and discharge control circuit according to claim 1, characterized in that: 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.

8. The charge and discharge control circuit according to claim 1, characterized in that: 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.

9. The charge and discharge control circuit according to claim 1, characterized in that: 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.

10. The charge and discharge control circuit according to claim 1, characterized in that: It also 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.

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

12. A battery management system, characterized in that: The invention comprises the charge and discharge control circuit according to any one of claims 1 to 11.

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