BMS charging and discharging control circuit, method and electronic device

Abstract

The present invention relates to a BMS charge and discharge control circuit, method and electronic device, comprising: a controller, a battery pack connected to the controller, and a discharge output terminal and a charge input terminal connected to the battery pack; a current detection module connected to the controller and the battery pack for respectively collecting the charging current and the discharge current of the battery pack during charging and discharging; a first charging control module and a second charging control module connected to the controller, wherein after the first charging control module and the second charging control module are connected in series, one end is connected to the current detection module and the other end is connected to the charge input terminal; a discharge control module connecting the controller, the current detection module and the discharge output terminal. The implementation of the present invention can effectively prevent leakage of the charging port.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic equipment, and more specifically, to a BMS charge and discharge control circuit, method and electronic equipment. Background Art

[0002] For the existing BMS control charging and discharging circuit, it usually samples the same port design of the charging and discharging circuit. In the process of designing the same port for the charging and discharging ports, since the battery discharge current is generally much larger than the charging current, the disadvantage of the same port is that the MOS for charging control and discharging control on the protection board must be exactly the same. During discharge, the current will pass through the charging control MOS, which increases the cost, internal resistance and heat. In some other circuits, the split port design is also used: it can save some MOS material costs, but the charging port can actually discharge, and there may be backflow and leakage, which poses a safety hazard. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a BMS charge and discharge control circuit, method and electronic device in view of the above-mentioned technical defects of the prior art.

[0004] The technical solution adopted by the present invention to solve the technical problem is: constructing a BMS charge and discharge control circuit, including: a controller, a battery pack connected to the controller, and a discharge output terminal and a charge input terminal connected to the battery pack;

[0005] A current detection module connected to the controller and the battery pack, used to respectively collect the charging current and the discharging circuit current of the battery pack during charging and discharging;

[0006] A first charging control module and a second charging control module connected to the controller, wherein after the first charging control module and the second charging control module are connected in series, one end of the first charging control module is connected to the current detection module, and the other end is connected to the charging input terminal;

[0007] A discharge control module is connected to the controller, the current detection module and the discharge output end.

[0008] Preferably, the first charging control module includes a first MOS tube; the gate of the first MOS tube is connected to the controller, the source of the first MOS tube is connected to the current detection module, and the drain of the first MOS tube is connected to the second charging control module.

[0009] Preferably, the second charging control module includes a second MOS tube; the gate of the second MOS tube is connected to the controller, the source of the second MOS tube is connected to the charging input terminal, and the drain of the second MOS tube is connected to the first charging control module.

[0010] Preferably, the discharge control module includes at least one third MOS tube, the gate of the at least one third MOS tube is connected to the controller, the source of the at least one third MOS tube is connected to the current detection module, and the drain of the at least one third MOS tube is connected to the discharge output end.

[0011] Preferably, the at least one third MOS tube includes a plurality of third MOS tubes; the gates of the plurality of third MOS tubes are connected in parallel and then connected to the controller, the sources of the plurality of third MOS tubes are connected in parallel and then connected to the current detection module, and the drains of the plurality of third MOS tubes are connected in parallel and then connected to the discharge output end.

[0012] Preferably, the current detection module comprises a detection resistor, a first end of the detection resistor is respectively connected to the battery pack and the controller, and a second end of the detection resistor is respectively connected to the first charging control module, the discharging control module and the controller.

[0013] The present invention also constructs an electronic device, comprising the BMS charge and discharge control circuit as described in any one of the above.

[0014] The present invention also constructs a BMS charge and discharge control method, which is applied to the BMS charge and discharge control circuit as described in any one of the above, comprising:

[0015] S1, set the controller to the initial working state;

[0016] S2, determine whether there is a charging device connected to the charging input terminal, if so, enter the charging state, if not, enter the discharging state;

[0017] In the charging state, the following steps are performed:

[0018] S1A, setting the discharge control module and the first charge control module to the off state, and the second charge control module to the on state, and determining whether the current detection module has a charging current; if so, executing step S2A; if not, executing step S4A;

[0019] S2A, setting the first charging control module to a conducting state, charging the battery pack, and determining whether the battery pack enters a charging protection state during the charging process, and executing step S3A when the battery pack enters the charging protection state;

[0020] S3A, setting the first charging control module to an off state, and executing step S4A;

[0021] S4A, setting the second charging control module to an off state, and executing step S2;

[0022] In the discharge state, the following steps are performed:

[0023] S1B, setting the discharge control module to the on state, and determining whether there is the discharge current, if so, executing step S2B, if not, executing step S3B;

[0024] S2B, clear the discharge protection flag to discharge, and determine whether the battery pack enters a discharge protection state during the discharge process. When entering the discharge protection state, execute step S3B;

[0025] S3B, setting the discharge control module to the off state, and executing the step S2.

[0026] Preferably, in the step S1, in the initial working state, the first charging control module is in an off state, and the second charging control module and the discharging control module are in an on state.

[0027] Preferably, the step S2A further includes clearing a discharge protection flag of the battery pack.

[0028] A BMS charge and discharge control circuit, method and electronic device implementing the present invention have the following beneficial effects: leakage of the charging port can be effectively prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0030] Figure 1 It is a structural schematic diagram of a BMS charge and discharge control circuit of the present invention;

[0031] Figure 2 This is a circuit schematic diagram of an embodiment of a BMS charge and discharge control circuit of the present invention;

[0032] Figure 3 It is a program flow chart of an embodiment of a BMS charge and discharge control method of the present invention. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0034] like Figure 1As shown, in a first embodiment of a BMS charge and discharge control circuit of the present invention, it includes: a controller 110, a battery pack 120 connected to the controller 110, and a discharge output terminal 150 and a charging input terminal 140 connected to the battery pack; a current detection module 130 connected to the controller 110 and the battery pack 120 for respectively collecting the charging current and the discharging current of the battery pack during charging and discharging; a first charging control module 161 and a second charging control module 162 connected to the controller 110, wherein after the first charging control module 161 and the second charging control module 162 are connected in series, one end is connected to the current detection module 130 and the other end is connected to the charging input terminal 140; a discharge control module 170 connecting the controller 110, the current detection module and the discharge output terminal 150. Specifically, the battery pack is connected to the controller, and the charging and discharging process of the battery pack is controlled by the controller. In the initial stage, the controller is set to the initial working state; and first determine whether there is a charging device connected to the charging input terminal. If there is a charging device connected, the charging state is entered, and if there is no charging device connected, the discharge state is entered. In the charging state, the discharge control module and the first charging control module are first set to the off state, and the second charging control module is set to the on state. Among them, when the first charging control module is in the off state, it is in a state of small current passing, and when the first charging control module is in the on state, it is in a state of large current passing. In the normal charging process, when the first charging control module is in the off state, due to the conduction of the second charging control module, there will still be a small current, that is, charging current, in its charging circuit. At this time, it is judged whether the current detection module has charging current; if there is charging current, it means that the charging device is connected normally, and the first charging control module is set to the on state, and the battery pack is charged by the charging device outputting a large current. During the charging process, the state of the charging battery pack is judged to confirm whether the battery pack enters the charging protection state. When the battery pack enters the charging protection state, the second charging control module and the first charging module are turned off to end the charging. If the current detection module does not collect the charging current when the second charging control module is in the on state, it means that the charging device is not connected normally, and normal charging cannot be performed at this time, then the second charging control module is turned off, and whether the charging device is connected is confirmed again, so as to proceed to the next step. In the discharge state without a charging device connected, the discharge control module is set to the on state, and the discharge current in the discharge state is obtained through the current detection module. When there is no discharge current, the discharge control module is turned off to reconfirm the state of the battery pack. If there is a discharge current, the discharge is normal. By turning off the first charging control module in the discharge state, it can effectively prevent the voltage of the battery pack from being reversed through the charging input terminal and causing leakage.

[0035] like Figure 2As shown, in one embodiment, the first charging control module 161 includes a first MOS tube; the gate of the first MOS tube is connected to the controller, the source of the first MOS tube is connected to the current detection module, and the drain of the first MOS tube is connected to the second charging control module. Specifically, the first charging control module can realize the on or off setting through the MOS tube, the source of the first MOS tube QA1 is connected to the current detection module, the gate is connected to the controller, and the drain is connected to the second charging control module, and the controller outputs high and low levels to control the on or off of the MOS tube QA1. The reverse cutoff of the MOS tube QA1 can effectively prevent the output current of the battery pack from charging the device through the charging input terminal, which is dangerous. In addition, when the MOS tube QA1 is turned off, there is a small forward current. When the MOS tube QA1 is turned on, the forward conduction voltage drop of the MOS tube QA1 is small, which can allow a large current to pass through without affecting the charging process.

[0036] In one embodiment, the second charging control module 162 includes a second MOS tube; the gate of the second MOS tube is connected to the controller, the source of the second MOS tube is connected to the charging input terminal, and the drain of the second MOS tube is connected to the first charging control module. Specifically, the second charging controller uses a MOS tube QA2, wherein the gate of the MOS tube QA2 is connected to the controller, the source is connected to the charging input terminal, and the drain is connected to the first charging control module. When there is no charging device connected, the MOS tube QA2 can be turned off by the controller output control level, and when there is a charging device connected, the MOS tube QA2 can be turned on by the controller output control level.

[0037] In one embodiment, the discharge control module 170 includes at least one third MOS tube, the gate of at least one third MOS tube is connected to the controller, the source of at least one third MOS tube is connected to the current detection module, and the drain of at least one third MOS tube is connected to the discharge output terminal. Specifically, a MOS tube, i.e., a third MOS tube, is provided on the discharge circuit, and the discharge of the battery pack is controlled by controlling the conduction or shutdown of the third MOS tube. At the same time, by shutting down the first charging control module, the current in the discharge circuit is prevented from being fed back to the charging input terminal.

[0038] Optionally, at least one third MOS tube includes a plurality of third MOS tubes; the gates of the plurality of third MOS tubes are connected in parallel and then connected to the controller, the sources of the plurality of third MOS tubes are connected in parallel and then connected to the current detection module, and the drains of the plurality of third MOS tubes are connected in parallel and then connected to the discharge output terminal. Specifically, the discharge circuit connected to the battery pack can be provided with a plurality of MOS tubes according to the needs of the discharge current. By providing the plurality of MOS tubes, the discharge current of the battery pack can be increased to meet the needs of the working current in the working process.

[0039] Optionally, the current detection module includes a detection resistor, the first end of the detection resistor is respectively connected to the battery pack and the controller, and the second end of the detection resistor is respectively connected to the first charging control module, the discharge control module and the controller. Specifically, the current detection module used to detect the charging current or the discharging current of the charging or discharging process can be a detection resistor Rs, and the controller obtains the voltage signal at both ends of the detection resistor Rs to obtain the current passing through the detection resistor Rs.

[0040] An electronic device of the present invention comprises a BMS charge and discharge control circuit as described above. Specifically, the BMS charge and discharge control circuit is provided in the electronic device to prevent damage to the charger during the charge and discharge process of the battery pack.

[0041] In addition, Figure 3 As shown, a BMS charge and discharge control method of the present invention is applied to a BMS charge and discharge control circuit as any one of the above items, comprising:

[0042] S1, set the controller to the initial working state;

[0043] S2. Determine whether there is a charging device connected to the charging input terminal. If so, enter the charging state. If not, enter the discharging state.

[0044] In the charging state, perform the following steps:

[0045] S1A, setting the discharge control module and the first charging control module to the off state, and the second charging control module to the on state, and determining whether the current detection module has a charging current; if so, executing step S2A; if not, executing step S4A;

[0046] S2A, setting the first charging control module to a conducting state, charging the battery pack, and determining whether the battery pack enters a charging protection state during the charging process, and executing step S3A when the battery pack enters the charging protection state;

[0047] S3A, setting the first charging control module to an off state, and executing step S4A;

[0048] S4A, setting the second charging control module to the off state, and executing step S2;

[0049] In the discharge state, perform the following steps:

[0050] S1B, setting the discharge control module to the on state, and determining whether there is a discharge current, if so, executing step S2B, if not, executing step S3B;

[0051] S2B, clear the discharge protection flag to discharge, and determine whether the battery pack enters the discharge protection state during the discharge process. When entering the discharge protection state, execute step S3B;

[0052] S3B, set the discharge control module to the off state, and execute step S2.

[0053] Specifically, in the above-mentioned BMS charge and discharge control circuit, it is possible to set the default working mode of the charge and discharge circuit through the controller, that is, to set a default initial working state. In the initial working state, it is determined whether there is a charging device connected to the charging input terminal according to the preset rules. If there is a charging device connected, the entire control circuit can be controlled by the controller to enter the charging state, and if there is no charging device, it can be controlled to enter the discharge state. This process can be understood, and whether there is a charging device connected to the charging input terminal can be determined by the charging device connection, which can be implemented by a hardware circuit. That is, the initial working state can be set to the discharge state. When a charging device is connected, it can be switched to the charging state, otherwise it can remain in the discharge state.

[0054] When entering the charging state, the discharge control module and the first charging control module can be set to the off state, and the second charging control module can be set to the on state. Under normal circumstances, even if the first charging module is off, since the second charging module is on, a small current will still flow through the first charging control module. At this time, the current can be obtained by the current detection module, that is, it is judged that there is a charging current. The charging device is judged to be in a normal access state by the charging current. At this time, the high-current charging state can be entered by turning on the first charging control module. If no charging current is detected when the charging device is connected and the second charging module is turned on, it means that the charging circuit is abnormal at this time, for example, the charging device may not be normally connected or the charging device is working abnormally, etc. At this time, the second charging control module is turned off to turn off the entire charging circuit, and the working circuit is further judged. During the normal charging process when the first charging control module is turned on, it can be judged whether the battery pack enters the charging protection state. Before entering the charging protection, it can be charged normally. After entering the charging protection, the first charging control module and the second charging control module are turned off to end the charging process. When entering the discharge state, the discharge control module is set to the on state, and the current detection device is used to determine whether there is a discharge current. If there is a discharge current, it means that the discharge circuit is normal, the discharge protection flag is cleared for normal discharge, and during the discharge process, it is determined whether the battery pack has entered the discharge protection state. If the battery pack enters the discharge protection state, it means that the battery pack can no longer discharge, and the discharge control module is turned off to turn off the discharge process of the discharge circuit. During the charge and discharge process, the first charge control module, the second charge control module and the discharge control module are controlled in sequence to prevent the normal charge and discharge process of the battery pack from being realized, and to prevent the discharge current of the battery pack from entering the charging reflux charging input terminal output during the discharge process to cause leakage.

[0055] Furthermore, in step S1, in the initial working state, the first charging control module is in the off state, and the second charging control module and the discharge control module are in the on state. Specifically, in the working process setting of the BMS charge and discharge control circuit, its initial working state can be set to the discharge state, that is, the discharge control module is set to the on state, and in order to quickly determine the charging state when the charging device is connected, the second charging control module can be set to the on state.

[0056] Furthermore, in step S2A, the discharge protection flag of the battery pack is cleared. Specifically, when a battery pack needs to be charged, it will enter a discharge protection state. During the charging process of the battery pack, the discharge protection flag of the battery pack can be cleared to allow the battery to enter a normal charge and discharge state.

[0057] It can be understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. A BMS charge and discharge control method, characterized in that: Applied to a BMS charge and discharge control circuit, wherein the BMS charge and discharge control circuit comprises: a controller, a battery pack connected to the controller, and a discharge output terminal and a charge input terminal connected to the battery pack; A current detection module connected to the controller and the battery pack, used to respectively collect the charging current and the discharging current of the battery pack when charging and discharging; A first charging control module and a second charging control module connected to the controller, wherein after the first charging control module and the second charging control module are connected in series, one end of the first charging control module is connected to the current detection module, and the other end is connected to the charging input terminal; A discharge control module connecting the controller, the current detection module and the discharge output end; The method comprises the following steps: S1, set the controller to the initial working state; S2. Determine whether there is a charging device connected to the charging input terminal. If so, enter the charging state. If not, enter the discharging state. In the charging state, the following steps are performed: S1A, setting the discharge control module and the first charge control module to the off state, and the second charge control module to the on state, and determining whether the current detection module has a charging current; if so, executing step S2A; if not, executing step S4A; S2A, setting the first charging control module to a conducting state, charging the battery pack, and determining whether the battery pack enters a charging protection state during the charging process, and executing step S3A when the battery pack enters the charging protection state; S3A, setting the first charging control module to an off state, and executing step S4A; S4A, setting the second charging control module to an off state, and executing step S2; In the discharge state, the following steps are performed: S1B, setting the discharge control module to the on state, and determining whether there is a discharge current, if so, executing step S2B, if not, executing step S3B; S2B, clear the discharge protection flag to discharge, and determine whether the battery pack enters a discharge protection state during the discharge process. When entering the discharge protection state, execute step S3B; S3B, setting the discharge control module to the off state, and executing the step S2.

2. The BMS charge and discharge control method according to claim 1, characterized in that: The first charging control module includes a first MOS tube; the gate of the first MOS tube is connected to the controller, the source of the first MOS tube is connected to the current detection module, and the drain of the first MOS tube is connected to the second charging control module.

3. The BMS charge and discharge control method according to claim 1, characterized in that: The second charging control module includes a second MOS tube; the gate of the second MOS tube is connected to the controller, the source of the second MOS tube is connected to the charging input terminal, and the drain of the second MOS tube is connected to the first charging control module.

4. The BMS charge and discharge control method according to claim 1, characterized in that: The discharge control module includes at least one third MOS tube, the gate of the at least one third MOS tube is connected to the controller, the source of the at least one third MOS tube is connected to the current detection module, and the drain of the at least one third MOS tube is connected to the discharge output end.

5. The BMS charge and discharge control method according to claim 4, characterized in that: The at least one third MOS tube includes a plurality of third MOS tubes; the gates of the plurality of third MOS tubes are connected in parallel and then connected to the controller, the sources of the plurality of third MOS tubes are connected in parallel and then connected to the current detection module, and the drains of the plurality of third MOS tubes are connected in parallel and then connected to the discharge output end.

6. The BMS charge and discharge control method according to claim 1, characterized in that: The current detection module includes a detection resistor, a first end of the detection resistor is respectively connected to the battery pack and the controller, and a second end of the detection resistor is respectively connected to the first charging control module, the discharging control module and the controller.

7. The BMS charge and discharge control method according to claim 1, characterized in that: In the step S1, in the initial working state, the first charging control module is in an off state, and the second charging control module and the discharging control module are in an on state.

8. The BMS charge and discharge control method according to claim 1, characterized in that: The step S2A further includes clearing a discharge protection flag of the battery pack.

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