BMS high-voltage charging forbidding and low-voltage charging forbidding protection circuit and circuit protection board thereof

Abstract

The utility model provides a BMS (Battery Management System) high-voltage charging forbidding and low-voltage charging forbidding protection circuit and a circuit protection board thereof, and the BMS protection circuit is additionally provided with a secondary protection circuit on the basis of a primary protection chip. The secondary protection circuit comprises a high-voltage charging forbidding detection circuit, a low-voltage charging forbidding detection circuit and a cut-off circuit. The high-voltage charging forbidding detection circuit collects the voltage of the BMS battery pack and compares the voltage with a high-voltage threshold value, if the voltage of the BMS battery pack is higher than the high-voltage threshold value, the high-voltage charging forbidding detection circuit sends a signal to control the cut-off circuit to be cut off, and otherwise, the circuit operates normally. The low-voltage charging forbidding detection circuit collects the voltage of the BMS battery pack and compares the voltage with a low-voltage threshold value, if the voltage of the BMS battery pack is lower than the low-voltage threshold value, the low-voltage charging forbidding detection circuit sends a signal to control the cut-off circuit to be cut off, and otherwise, the circuit system operates normally. Through the circuit, protection of the BMS circuit can be completed depending on circuit logic, excessive dependence on an IC is not needed, and the circuit can freely customize a high-voltage threshold value and a low-voltage threshold value.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and a circuit protection board thereof. Background Art

[0002] In the field of battery technology, BMS (Battery Management System) is an electronic system that monitors and manages the battery's operating status, including charging and discharging processes, temperature control, voltage management, and safety protection functions. BMS is widely used in electric vehicles, portable devices, and energy storage systems.

[0003] Typically, a BMS has overcharge protection, but if the battery voltage continues to rise, the charger must be completely disconnected, triggering a permanent failure. Furthermore, when the battery voltage falls below the over-discharge voltage, copper deposition can occur, leading to internal short circuits. Further charging can cause the battery cells to overheat and cause thermal runaway. Typically, a BMS has over-discharge protection, but if the battery voltage continues to drop due to self-consumption or other factors, further charging should not be allowed, requiring the BMS to trigger a permanent failure.

[0004] There are two existing solutions. The first employs a secondary protection IC, which is reversible and prevents permanent failure. The second employs an IC with high-voltage and low-voltage charge prohibitions, which can provide permanent battery protection. However, both methods rely heavily on the integrated IC, making parameter customization difficult. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and circuit protection board thereof, and adds a secondary protection circuit on the basis of the primary protection chip.

[0006] In a first aspect, the present invention provides a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, which includes at least: a battery pack, a load positive electrode port, a load negative electrode port, a charge and discharge control MOS tube and a primary protection chip, wherein the primary protection chip is connected between the battery pack positive electrode and the charge and discharge control MOS tube, and further includes: a secondary protection circuit, wherein the secondary protection circuit is connected between the battery pack positive electrode and the load positive electrode port;

[0007] Among them, the secondary protection circuit includes: a high-voltage charging prohibition detection circuit, a low-voltage charging prohibition detection circuit and a cutoff circuit.

[0008] Through this circuit design, the secondary protection of the BMS can be achieved only through circuit logic without using an integrated IC, without over-reliance on the integrated IC, and the parameters can be customized.

[0009] Furthermore, the high-voltage charging prohibition detection circuit includes: a first comparator, a first voltage regulator, a first regulating resistor and a second regulating resistor.

[0010] Furthermore, the high-voltage charging prohibition detection circuit includes:

[0011] One end of the first regulating resistor is connected to the positive terminal of the load, and the other end is connected to the second regulating resistor and the positive input terminal of the first comparator.

[0012] One end of the second regulating resistor is connected to the first regulating resistor, and the other end is grounded.

[0013] The negative input terminal of the first comparator is connected to the positive terminal of the battery pack and the positive terminal of the load, the output terminal of the first comparator is connected to the cutoff circuit, and the positive input terminal of the first comparator is grounded.

[0014] One end of the first voltage stabilizer is connected to the positive terminal of the load, and the other end is grounded, and is connected in parallel with the first regulating resistor and the second regulating resistor.

[0015] Through this circuit design, the first comparator can collect the battery voltage and compare it with the high voltage threshold. Based on the comparison result, the output terminal of the first comparator outputs a high level or a low level to the cutoff circuit, thereby controlling whether the cutoff circuit is cut off.

[0016] Furthermore, the low-voltage charging prohibition detection circuit includes: a second comparator, a second voltage regulator, a third regulating resistor and a fourth regulating resistor.

[0017] Furthermore, the low-voltage charging prohibition detection circuit further includes:

[0018] One end of the third regulating resistor is connected to the positive electrode of the battery pack, and the other end is connected to the negative input terminal of the second comparator and the fourth regulating resistor.

[0019] One end of the fourth regulating resistor is connected to the third regulating resistor, and the other end is grounded.

[0020] The negative input terminal of the second comparator is connected to the positive electrode of the battery pack, the output terminal of the second comparator is connected to the cutoff circuit, the positive input terminal of the second comparator is connected to the positive electrode of the load port and is grounded at the same time.

[0021] One end of the second voltage stabilizer is connected to the positive terminal of the load, and the other end is grounded and connected in parallel with the negative input terminal of the second comparator.

[0022] Through this circuit design, the second comparator can collect the battery voltage and compare it with the high voltage threshold. Based on the comparison result, the output terminal of the second comparator outputs a high level or a low level to the cutoff circuit, thereby controlling whether the cutoff circuit is cut off.

[0023] Furthermore, the cutoff circuit includes: a three-terminal fuse and a switch MOS tube.

[0024] Furthermore, the cutoff circuit further includes:

[0025] The first port of the three-terminal fuse is connected to the positive electrode of the battery pack, the second port of the three-terminal fuse is connected to the positive electrode of the load interface, and the third port of the three-terminal fuse is connected to the source of the switch MOS tube.

[0026] The gate of the switch MOS tube is connected to the high-voltage charging prohibition circuit and the low-voltage charging prohibition circuit, and the drain of the switch MOS tube is grounded.

[0027] Through this circuit design, the cutoff circuit can respond to the high / low level signal sent by the low-voltage charging prohibition detection circuit or the high-voltage charging prohibition detection circuit. When a high level is received, the switching MOS tube is turned on, the three-terminal fuse blows and cuts off the main circuit, triggering a low / high voltage permanent failure fault.

[0028] In the second aspect, the utility model proposes a circuit protection board, including: a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, and the protection circuit is integrated on a circuit substrate; the battery protection board includes: the BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, and a circuit substrate, and the BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit is integrated on the circuit substrate.

[0029] In summary, the present invention proposes a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and its circuit protection board. On the basis of the primary protection chip, a secondary protection circuit is added. The secondary protection circuit includes a high-voltage charging prohibition detection circuit, a low-voltage charging prohibition detection circuit and a cutoff circuit. The high-voltage charging prohibition detection circuit is used to detect whether the battery pack voltage is higher than the high-voltage threshold, and generate a corresponding level signal to send to the cutoff circuit; the low-voltage charging prohibition detection circuit is used to detect whether the battery pack voltage is lower than the low-voltage threshold, and generate a corresponding level signal to send to the cutoff circuit; the cutoff circuit is used to receive the level signal sent by the high / low voltage charging prohibition detection circuit. When a high level is received, the cutoff circuit is cut off, and when a low level is received, the circuit system operates normally. Among them, the high-voltage threshold and the low-voltage threshold can be adjusted.

[0030] Compared with the prior art, the present invention has at least the following beneficial effects:

[0031] The utility model proposes a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and circuit protection board, which can rely on circuit logic to complete the protection of the BMS circuit without over-reliance on integrated ICs. In addition, the protection circuit proposed by the utility model can freely customize the high-voltage threshold and the low-voltage threshold to maximize the utilization of battery pack performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1This is a schematic diagram of a BMS circuit diagram shown in an embodiment of the present utility model.

[0033] Figure 2 This is a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit shown in an embodiment of the present utility model. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1:

[0035] See also Figure 1 , is a schematic diagram of a BMS circuit diagram shown in an embodiment of the present utility model, which includes a BMS basic circuit and a BMS protection circuit, and the BMS protection circuit is connected between the battery pack positive electrode and the load positive electrode port of the BMS circuit.

[0036] U1 is a first-level protection IC that provides standard protection against overcharge, over-discharge, overcurrent, and short-circuit. These protections are all recoverable, and the parameter settings are within the normal operating range of the battery, preventing damage to the battery. Its operating principle is that U1 detects the battery voltage. When the voltage reaches the overcharge or over-discharge threshold, U1 controls the MOSFET Q1 to open and close, thereby interrupting and re-opening the charge and discharge circuit.

[0037] See also Figure 2 , is a schematic diagram of a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit shown in an embodiment of the present utility model, which at least includes: a battery pack, a load positive electrode port, a load negative electrode port, a charge and discharge control MOS tube and a primary protection chip, wherein the primary protection chip is connected between the battery pack positive electrode and the charge and discharge control MOS tube, and is characterized in that it also includes: a secondary protection circuit, wherein the secondary protection circuit is connected between the battery pack positive electrode and the load positive electrode port;

[0038] Among them, the secondary protection circuit includes: a high-voltage charging prohibition detection circuit, a low-voltage charging prohibition detection circuit and a cutoff circuit.

[0039] In an embodiment of the present invention, optionally, the high-voltage charging prohibition detection circuit includes: a first comparator U3A, a first voltage regulator U4, a first regulating resistor R7 and a second regulating resistor R8.

[0040] In an embodiment of the present utility model, optionally, the high-voltage charging prohibition detection circuit includes:

[0041] One end of the first regulating resistor R11 is connected to the positive terminal of the load, and the other end is connected to the second regulating resistor R22 and the positive input terminal of the first comparator U3BA.

[0042] One end of the second regulating resistor R22 is connected to the first regulating resistor R11 , and the other end is grounded.

[0043] The negative input terminal of the first comparator U3BA is connected to the positive terminal of the battery pack and the positive terminal of the load, the output terminal of the first comparator U3BA is connected to the cutoff circuit, and the positive input terminal of the first comparator U3A is grounded.

[0044] One end of the first voltage stabilizer U2 is connected to the positive terminal of the load, and the other end is grounded, and is connected in parallel with the first regulating resistor R7 and the second regulating resistor R8.

[0045] The negative input of the first comparator U3BA is connected to the positive terminal of the battery pack through the first and second adjustment resistors R7 and R8 to collect the battery pack voltage. The positive input of the first comparator U3BA is the high-voltage threshold Vef1 = 2.5V. When we want to set the high-voltage threshold to 4.5V, the battery voltage Vbat = 2.5*(R7+R8) / R8. The resistance values ​​of the first and second adjustment resistors R7 and R8 can be calculated as R7 = 40K and R8 = 50K. If the high-voltage charge prohibition voltage needs to be adjusted to another value, it can be adjusted by adjusting the first and second adjustment resistors R7 and R8.

[0046] In an embodiment of the present invention, optionally, the low-voltage charging prohibition detection circuit includes: a second comparator U3A, a second voltage regulator U2, a third regulating resistor R11 and a fourth regulating resistor R12.

[0047] In an embodiment of the present utility model, optionally, the low-voltage charging prohibition detection circuit further includes:

[0048] One end of the third regulating resistor R11 is connected to the positive electrode of the battery pack, and the other end is connected to the negative input terminal of the second comparator U3A and the fourth regulating resistor R12;

[0049] One end of the fourth regulating resistor R12 is connected to the third regulating resistor R11, and the other end is grounded;

[0050] The negative input terminal of the second comparator U3A is connected to the positive terminal of the battery pack, the output terminal of the second comparator U3A is connected to the cutoff circuit, the positive input terminal of the second comparator U3A is connected to the positive terminal of the load port, and is grounded at the same time;

[0051] One end of the second voltage regulator U2 is connected to the positive terminal of the load, and the other end is grounded and connected in parallel with the negative input terminal of the second comparator U3A.

[0052] The negative input of the second comparator U3A is connected to the positive terminal of the battery pack through resistor R3 to collect the battery voltage. The positive input of the second comparator U3A is the low-voltage threshold Vef2. The second voltage regulator U2 is a 2.5V regulator, and Vef = 2.5 * R12 / (R11 + R12). Therefore, the low-voltage threshold can be adjusted using the third and fourth adjustment resistors R11 and R12. If we want to adjust the low-voltage threshold to 1.5V, we can calculate R12 = 30K and R11 = 20K.

[0053] In an embodiment of the present invention, optionally, the cutoff circuit includes: a three-terminal fuse F1 and a switch MOS tube Q2.

[0054] In an embodiment of the present utility model, optionally, the cutoff circuit further includes:

[0055] The first port of the three-terminal fuse F1 is connected to the positive electrode of the battery pack, the second port of the three-terminal fuse F1 is connected to the positive electrode of the load interface, and the third port of the three-terminal fuse F1 is connected to the source of the switch MOS tube Q2.

[0056] The gate of the switch MOS tube Q2 is connected to the high-voltage charging prohibition circuit and the low-voltage charging prohibition circuit, and the drain of the switch MOS tube Q2 is grounded.

[0057] In an embodiment of the present invention, optionally, when the battery pack voltage is higher than 4.5V, the output terminal of the first comparator U3BA outputs a high level, the switch MOS tube Q2 is turned on, the three-terminal fuse F1 melts and cuts off the main circuit, triggering a high-voltage permanent failure fault.

[0058] In an embodiment of the present invention, optionally, when the battery pack voltage is lower than 1.5V, the output terminal of the second comparator U3A outputs a high level, the switch MOS tube Q2 is turned on, the three-terminal fuse F1 melts and cuts off the main circuit, triggering a low-voltage permanent failure fault. Example 2:

[0059] The utility model proposes a circuit protection board, comprising: a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, wherein the protection circuit is integrated on a circuit substrate; a battery protection board comprises: the BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, and a circuit substrate, wherein the BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit is integrated on the circuit substrate.

[0060] In the embodiment of the present invention, optionally, the material used for the circuit substrate is glass fiber reinforced epoxy resin, but is not limited thereto.

[0061] In summary, the present invention proposes a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and its circuit protection board. On the basis of the primary protection chip, a secondary protection circuit is added. The secondary protection circuit includes a high-voltage charging prohibition detection circuit, a low-voltage charging prohibition detection circuit and a cutoff circuit. The high-voltage charging prohibition detection circuit is used to detect whether the battery pack voltage is higher than the high-voltage threshold, and generate a corresponding level signal to send to the cutoff circuit; the low-voltage charging prohibition detection circuit is used to detect whether the battery pack voltage is lower than the low-voltage threshold, and generate a corresponding level signal to send to the cutoff circuit; the cutoff circuit is used to receive the level signal sent by the high / low voltage charging prohibition detection circuit. When a high level is received, the cutoff circuit is cut off, and when a low level is received, the circuit system operates normally. Among them, the high-voltage threshold and the low-voltage threshold can be adjusted.

[0062] The utility model proposes a BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit and circuit protection board, which can rely on circuit logic to complete the protection of the BMS circuit without over-reliance on integrated ICs. In addition, the protection circuit proposed by the utility model can freely customize the high-voltage threshold and the low-voltage threshold to maximize the utilization of battery pack performance.

[0063] The specific embodiments described above further illustrate the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A BMS high-voltage charging prohibition and low-voltage charging prohibition protection circuit, including at least: A battery pack, a load positive electrode port, a load negative electrode port, a charge and discharge control MOS tube and a primary protection chip, wherein the primary protection chip is connected between the battery pack positive electrode and the charge and discharge control MOS tube, and is characterized in that it also includes: a secondary protection circuit, wherein the secondary protection circuit is connected between the battery pack positive electrode and the load positive electrode port; Among them, the secondary protection circuit includes: a high-voltage charging prohibition detection circuit, a low-voltage charging prohibition detection circuit and a cutoff circuit.

2. The protection circuit according to claim 1, wherein: The high-voltage charging prohibition detection circuit includes: a first comparator, a first voltage stabilizer, a first regulating resistor and a second regulating resistor.

3. The protection circuit according to claim 2, wherein: The high-voltage charging prohibition detection circuit includes: One end of the first regulating resistor is connected to the positive terminal of the load, and the other end is connected to the second regulating resistor and the positive input terminal of the first comparator; One end of the second regulating resistor is connected to the first regulating resistor, and the other end is grounded; The negative input terminal of the first comparator is connected to the positive terminal of the battery pack and the positive terminal of the load, the output terminal of the first comparator is connected to the cutoff circuit, and the positive input terminal of the first comparator is grounded; One end of the first voltage stabilizer is connected to the positive terminal of the load, and the other end is grounded, and is connected in parallel with the first regulating resistor and the second regulating resistor.

4. The protection circuit according to claim 1, wherein: The low-voltage charging prohibition detection circuit includes: a second comparator, a second voltage stabilizer, a third regulating resistor and a fourth regulating resistor.

5. The protection circuit according to claim 4, characterized in that: The low-voltage charging prohibition detection circuit further includes: One end of the third regulating resistor is connected to the positive electrode of the battery pack, and the other end is connected to the negative input terminal of the second comparator and the fourth regulating resistor; One end of the fourth regulating resistor is connected to the third regulating resistor, and the other end is grounded; The negative input terminal of the second comparator is connected to the positive electrode of the battery pack, the output terminal of the second comparator is connected to the cutoff circuit, the positive input terminal of the second comparator is connected to the positive electrode of the load port, and is grounded at the same time; One end of the second voltage stabilizer is connected to the positive terminal of the load, and the other end is grounded and connected in parallel with the negative input terminal of the second comparator.

6. The protection circuit according to claim 1, wherein: The cutoff circuit includes: a three-terminal fuse and a switch MOS tube.

7. The protection circuit according to claim 6, characterized in that: The cutoff circuit further includes: The first port of the three-terminal fuse is connected to the positive electrode of the battery pack, the second port of the three-terminal fuse is connected to the positive electrode of the load interface, and the third port of the three-terminal fuse is connected to the source of the switch MOS tube; The gate of the switch MOS tube is connected to the high-voltage charging prohibition circuit and the low-voltage charging prohibition circuit, and the drain of the switch MOS tube is grounded.

8. A circuit protection board, characterized in that: include: The protection circuit according to any one of claims 1 to 7, wherein the circuit is integrated on a circuit substrate; The battery protection board includes: the protection circuit and a circuit substrate, and the protection circuit is integrated on the circuit substrate.

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