Protection circuit of storage battery and electric automobile

Abstract

The utility model discloses a protection circuit of a storage battery and an electric automobile. The protection circuit of the storage battery comprises an anti-reverse unit, a current protection unit, a current monitoring unit, a voltage protection unit and a voltage monitoring unit, the anti-reverse unit is respectively connected with the current monitoring unit and the voltage monitoring unit, the voltage monitoring unit is connected with the voltage protection unit, and the current monitoring unit is connected with the current protection unit. The protection circuit of the storage battery is connected with the storage battery, the protection circuit of the storage battery can provide anti-reverse, high-voltage limiting, voltage monitoring, current monitoring and over-current protection functions for the storage battery, the speed of protection and response can be improved, the technical problem of slow protection reaction caused by aging of a fuse can be avoided, and the service life of the storage battery is prolonged. And the problem that the protection cannot be realized due to the aging of the fuse can also be avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of protection circuits, in particular to a protection circuit for a storage battery and an electric vehicle. Background Technique

[0002] With the development of technology, the technology of new energy electric vehicles has been continuously mature, and new energy electric vehicles have gradually become popular. For different models of new energy vehicles, storage batteries with different powers are generally installed, and electric power is provided by the storage batteries to different loads and functional circuits to meet different driving and application needs of users.

[0003] Various loads and functional circuits are prone to various problems during use. In order to avoid damage to the circuit caused by any equipment failure, fuses or relays are generally set between the storage battery and various loads and functional circuits. When a circuit or the storage battery fails and suddenly generates abnormal current and voltage, or when the vehicle-mounted computer monitors that the load and the circuit have failed, the fuse can be disconnected or the relay can be closed to protect the storage battery and other equipment.

[0004] However, setting fuses or relays for circuit protection has the following technical problems: in actual use, the protection speed of fuses and relays is slow. If both are used under high current for a long time, they will age faster, further affecting the protection effect. Content of the Utility Model

[0005] The utility model provides a protection circuit for a storage battery and an electric vehicle, and the protection circuit for the storage battery can solve one or more of the above technical problems.

[0006] The first aspect of the embodiment of the utility model provides a protection circuit for a storage battery, and the protection circuit for the storage battery includes: an anti-reverse unit, a current protection unit, a monitored current unit, a voltage protection unit, and a monitored voltage unit;

[0007] The first end of the anti-reverse unit is connected to the monitored current unit, the monitored current unit is connected to the current protection unit, the second end of the anti-reverse unit is connected to the monitored voltage unit, and the monitored voltage unit is connected to the voltage protection unit;

[0008] The input end of the anti-reverse unit is connected to the output end of the storage battery, and when the voltage at the output end of the storage battery is negative, the anti-reverse function is realized. The monitored current unit is used to monitor the current at the output end of the anti-reverse unit. The current protection unit is used to realize overcurrent protection when the monitored current of the monitored current unit is greater than the current threshold. The monitored voltage unit is used to monitor the output voltage of the power distribution chip connected to the storage battery, and the voltage protection unit is used to realize overvoltage protection when the monitored voltage of the monitored voltage unit is greater than the voltage threshold.

[0009] In a possible implementation of the first aspect, the anti-reverse unit includes: a bidirectional diode, a first anti-reverse capacitor, a second anti-reverse capacitor, a third anti-reverse capacitor, an anti-reverse PMOS transistor, a first anti-reverse resistor, a second anti-reverse resistor, and an anti-reverse voltage stabilizing diode;

[0010] One end of the bidirectional diode is respectively connected to one end of the first anti-reverse capacitor and the source terminal of the anti-reverse PMOS transistor. The other end of the first anti-reverse capacitor is connected to one end of the second anti-reverse capacitor. The other end of the second anti-reverse capacitor and the other end of the bidirectional diode are respectively connected to the ground terminal;

[0011] The drain terminal of the anti-reverse PMOS transistor is respectively connected to one end of the first anti-reverse resistor, one end of the third anti-reverse capacitor, and the negative terminal of the anti-reverse voltage stabilizing diode. One end of the second anti-reverse resistor is respectively connected to the other end of the first anti-reverse resistor, the other end of the third anti-reverse capacitor, the gate terminal of the anti-reverse PMOS transistor, and the positive terminal of the anti-reverse voltage stabilizing diode. The other end of the second anti-reverse resistor is connected to the ground terminal.

[0012] In a possible implementation of the first aspect, the monitoring current unit includes: a monitoring chip, a first monitoring current resistor, a second monitoring current resistor, a third monitoring current resistor, a fourth monitoring current resistor, a fifth monitoring current resistor, a first monitoring current capacitor, a second monitoring current capacitor, a third monitoring current capacitor, and a monitoring current diode;

[0013] Both ends of the first monitoring current resistor are respectively connected to one end of the second monitoring current resistor and one end of the third monitoring current resistor. Both ends of the first monitoring current capacitor are respectively connected to the other end of the second monitoring current resistor and the other end of the third monitoring current resistor;

[0014] Both ends of the first monitoring current capacitor are respectively connected to the positive terminal and the negative terminal of the monitoring current diode. The positive terminal and the negative terminal of the monitoring current diode are respectively connected to two input pins of the monitoring chip. The power supply terminal is respectively connected to the power supply pin of the monitoring chip and one end of the second monitoring current capacitor. The other end of the second monitoring current capacitor is connected to the ground terminal. The output terminal of the monitoring chip is connected to one end of the fourth monitoring current resistor. The other end of the fourth monitoring current resistor is respectively connected to one end of the fifth monitoring current resistor and one end of the third monitoring current capacitor. The other end of the third monitoring current capacitor is connected to the ground terminal. The other end of the fifth monitoring current resistor outputs the monitoring current.

[0015] In a possible implementation of the first aspect, the current protection unit includes: a first current protection resistor, a second current protection resistor, a third current protection resistor, a fourth current protection resistor, a fifth current protection resistor, a sixth current protection resistor, a first current protection capacitor, a second current protection capacitor, a first current protection diode, a second current protection diode, a current voltage stabilizing diode, a current PNP type triode, a first current NPN type triode, and a second current NPN type triode;

[0016] The negative terminal of the current voltage stabilizing diode is connected to the output terminal of the monitoring current unit. The positive terminal of the current voltage stabilizing diode is respectively connected to one end of the first current protection resistor and the collector terminal of the current PNP type triode. The power supply terminal is respectively connected to the emitter terminal of the current PNP type triode, one end of the second current protection resistor, and one end of the first current protection capacitor. One end of the third current protection resistor is respectively connected to the base of the current PNP type triode, the other end of the second current protection resistor, and the other end of the first current protection capacitor;

[0017] The other end of the third current protection resistor is connected to the positive terminal of the first current protection diode. The negative terminal of the first current protection diode is respectively connected to the collector terminal of the first current NPN type triode and the negative terminal of the second current protection diode. The positive terminal of the second current protection diode outputs a current protection signal;

[0018] The emitter of the first current NPN type triode is connected to the ground terminal. The base terminal of the first current NPN type triode is respectively connected to the other end of the first current protection resistor, one end of the fourth current protection resistor, one end of the second current protection capacitor, and the collector terminal of the second current NPN type triode;

[0019] The base terminal of the second current NPN type triode is respectively connected to one end of the fifth current protection resistor and one end of the sixth current protection resistor. The emitter terminal of the first current NPN type triode, the other end of the fourth current protection resistor, the other end of the second current protection capacitor, the emitter terminal of the second current NPN type triode, and the other end of the sixth current protection resistor are connected to the ground terminal. The other end of the fifth current protection resistor is a level input terminal.

[0020] In a possible implementation of the first aspect, the monitoring voltage unit includes: a first monitoring voltage resistor, a second monitoring voltage resistor, and a monitoring voltage capacitor;

[0021] One end of the first monitoring voltage resistor is respectively connected to one end of the second monitoring voltage resistor and one end of the monitoring voltage capacitor;

[0022] The other end of the second monitoring voltage resistor and the other end of the monitoring voltage capacitor are connected to the ground terminal;

[0023] A voltage signal is sampled at the connection end of the first monitoring voltage resistor and the second monitoring voltage resistor to monitor the voltage value of the power supply link.

[0024] In a possible implementation manner of the first aspect, the voltage protection unit includes: a first voltage protection resistor, a second voltage protection resistor, a third voltage protection resistor, a fourth voltage protection resistor, a fifth voltage protection resistor, a sixth voltage protection resistor, a seventh voltage protection resistor, a first voltage protection capacitor, a second voltage protection capacitor, a third voltage protection capacitor, a first voltage regulating diode, a second voltage regulating diode, a voltage NMOS transistor, a voltage NPN transistor, a voltage PMOS transistor, a protection inductor, a first polarized capacitor, and a second polarized capacitor;

[0025] The negative electrode end of the first voltage regulating diode, the negative electrode end of the second voltage regulating diode, one end of the first voltage protection capacitor, one end of the first voltage protection resistor, and the drain electrode end of the voltage PMOS transistor are connected; the positive electrode end of the second voltage regulating diode, the other end of the first voltage protection capacitor, the other end of the first voltage protection resistor, the gate electrode end of the voltage PMOS transistor, one end of the second voltage protection resistor, and one end of the second voltage protection capacitor are connected;

[0026] The other end of the second voltage protection capacitor is connected to one end of the third voltage protection resistor. The other end of the third voltage protection resistor is respectively connected to the source electrode end of the voltage PMOS transistor, the positive electrode end of the first polarized capacitor, and one end of the protection inductor. The other end of the protection inductor is connected to the positive electrode end of the second polarized capacitor. The negative electrode end of the first polarized capacitor and the negative electrode end of the second polarized capacitor are connected to the ground terminal;

[0027] The other end of the second voltage protection resistor is connected to the drain electrode end of the voltage NMOS transistor. The gate electrode end of the voltage NMOS transistor is respectively connected to one end of the fourth voltage protection resistor, one end of the fifth voltage protection resistor, and the collector electrode end of the voltage NPN transistor. The collector electrode end of the voltage NPN transistor receives a voltage signal. The other end of the fifth voltage protection resistor is connected to the power supply terminal;

[0028] The base electrode end of the voltage NPN transistor is respectively connected to one end of the third voltage protection capacitor, one end of the sixth voltage protection resistor, and one end of the seventh voltage protection resistor. The other end of the sixth voltage protection resistor is connected to the positive electrode end of the first voltage regulating diode;

[0029] The source terminal of the voltage NMOS transistor, the other end of the fourth voltage protection resistor, the emitter terminal of the voltage NPN transistor, the other end of the third voltage protection capacitor, and the other end of the seventh voltage protection resistor are connected to the ground terminal.

[0030] In the first aspect of the embodiment of the present invention, an electric vehicle is provided, and the electric vehicle includes: a vehicle body and the protection circuit of the storage battery as described above;

[0031] The vehicle body is provided with a storage battery and a power distribution system. The protection circuit of the storage battery is respectively connected to the storage battery and the power distribution system. The power distribution system is configured to detect the voltage and current of the storage battery through the protection circuit of the storage battery, and when the voltage or current does not meet the threshold requirements, control the protection circuit of the storage battery to provide overvoltage or overcurrent protection for the storage battery.

[0032] Compared with the prior art, a protection circuit of a storage battery and an electric vehicle provided by the embodiment of the present invention have the beneficial effects that: the protection circuit of the storage battery of the present invention is connected to the storage battery, and the protection circuit of the storage battery can provide functions of reverse connection prevention, high voltage limitation, voltage monitoring, current monitoring, and overcurrent protection for the storage battery, which can improve the speed of protection and response, can avoid the technical problem of slow protection reaction caused by fuse aging, and can also avoid the problem that protection cannot be achieved due to fuse aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic structural diagram of a protection circuit of a storage battery provided by an embodiment of the present invention;

[0034] Figure 2 is a circuit schematic diagram of a protection circuit of a storage battery provided by an embodiment of the present invention;

[0035] Figure 3 is a circuit schematic diagram of an anti-reverse unit provided by an embodiment of the present invention;

[0036] Figure 4 is a circuit schematic diagram of a monitoring current unit provided by an embodiment of the present invention;

[0037] Figure 5 is a circuit schematic diagram of a current protection unit provided by an embodiment of the present invention;

[0038] Figure 6 is a circuit schematic diagram of a monitoring voltage unit provided by an embodiment of the present invention;

[0039] Figure 7 is a circuit schematic diagram of a voltage protection unit provided by an embodiment of the present invention;

[0040] Figure 8 It is a schematic structural diagram of an electric vehicle provided by an embodiment of the present utility model. Specific embodiments

[0041] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0042] To solve the above problems, a protection circuit for a storage battery and an electric vehicle provided by the embodiments of the present application will be introduced and described in detail through the following specific embodiments.

[0043] Referring to Figure 1-2 , a schematic structural diagram of a protection circuit for a storage battery provided by an embodiment of the present utility model and a circuit schematic diagram of a protection circuit for a storage battery provided by an embodiment of the present utility model are respectively shown.

[0044] Among them, by way of example, the protection circuit for the storage battery may include: an anti-reverse unit, a current protection unit, a monitored current unit, a voltage protection unit, and a monitored voltage unit;

[0045] Among them, a first end of the anti-reverse unit is connected to the monitored current unit, the monitored current unit is connected to the current protection unit, a second end of the anti-reverse unit is connected to the monitored voltage unit, and the monitored voltage unit is connected to the voltage protection unit;

[0046] An input end of the anti-reverse unit is connected to an output end of the storage battery. When the voltage at the output end of the storage battery is negative, the anti-reverse unit is used to implement the anti-reverse function; the monitored current unit is used to monitor the current at an output end of the anti-reverse unit; the current protection unit is used to implement overcurrent protection when the monitored current of the monitored current unit is greater than a current threshold; the monitored voltage unit is used to monitor the output voltage of a power distribution chip connected to the storage battery; the voltage protection unit is used to implement overvoltage protection when the monitored voltage of the monitored voltage unit is greater than a voltage threshold.

[0047] By providing a protection circuit for the storage battery at the output end of the storage battery, the present utility model can provide functions of anti-reverse, high-voltage limitation, voltage monitoring, current monitoring, and overcurrent protection for the storage battery, thereby improving the speed of protection and response, avoiding the technical problem of slow protection reaction caused by fuse aging, and also avoiding the problem of inability to achieve protection due to fuse aging.

[0048] To implement the anti-reverse function, refer to Figure 3 , which shows the circuit schematic diagram of an anti-reverse unit provided by an embodiment of the present invention.

[0049] In one embodiment, the anti-reverse unit includes: a bidirectional diode (D4), a first anti-reverse capacitor (C3), a second anti-reverse capacitor (C5), a third anti-reverse capacitor (C4), an anti-reverse PMOS transistor (Q2), a first anti-reverse resistor (R7), a second anti-reverse resistor (R10), and an anti-reverse zener diode (D3).

[0050] Among them, one end of the bidirectional diode (D4) is respectively connected to one end of the first anti-reverse capacitor (C3) and the source terminal of the anti-reverse PMOS transistor (Q2), the other end of the first anti-reverse capacitor (C3) is connected to one end of the first anti-reverse capacitor (C5), and the other end of the first anti-reverse capacitor (C5) and the other end of the bidirectional diode (D4) are respectively connected to the ground terminal;

[0051] The drain terminal of the anti-reverse PMOS transistor (Q2) is respectively connected to one end of the first anti-reverse resistor (R7), one end of the third anti-reverse capacitor (C4), and the negative terminal of the anti-reverse zener diode (D3), one end of the first anti-reverse resistor (R10) is respectively connected to the other end of the first anti-reverse resistor (R7), the other end of the third anti-reverse capacitor (C4), the gate terminal of the anti-reverse PMOS transistor (Q2), and the positive terminal of the anti-reverse zener diode (D3), and the other end of the first anti-reverse resistor (R10) is connected to the ground terminal.

[0052] Under normal circumstances, KL30_IN is the output terminal of the battery, KL30_IN is positive, and GND is negative. When KL30_IN is negative and GND is positive, it means the input voltage is reversed. At this time, the anti-reverse PMOS transistor (Q2) cannot be turned on, and the anti-reverse unit cannot conduct, thus realizing the anti-reverse function.

[0053] In specific implementation, the anti-reverse function can be realized by turning on and off the anti-reverse PMOS transistor (Q2). The first anti-reverse resistor (R7) and the second anti-reverse resistor (R10) divide the voltage to output an enabling signal. The third anti-reverse capacitor (C4) can play a filtering role, and the anti-reverse zener diode (D3) protects the GS of the anti-reverse PMOS transistor (Q2).

[0054] To implement the function of monitoring current, refer to Figure 4 , which shows the circuit schematic diagram of a monitoring current unit provided by an embodiment of the present invention.

[0055] In one embodiment, the monitored current unit includes: a monitoring chip (U1), a first monitored current resistor (R4), a second monitored current resistor (R12), a third monitored current resistor (R13), a fourth monitored current resistor (R16), a fifth monitored current resistor (R15), a first monitored current capacitor (C8), a second monitored current capacitor (C9), a third monitored current capacitor (C11), and a monitored current diode (D5).

[0056] Referring to Figure 4 , both ends of the first monitored current resistor (R4) are respectively connected to one end of the second monitored current resistor (R12) and one end of the third monitored current resistor (R13), and both ends of the first monitored current capacitor (C8) are respectively connected to the other end of the second monitored current resistor (R12) and the other end of the third monitored current resistor (R13);

[0057] Both ends of the first monitored current capacitor (C8) are respectively connected to the positive and negative terminals of the monitored current diode (D5), the positive and negative terminals of the monitored current diode (D5) are respectively connected to two input pins of the monitoring chip (U1), the power supply terminal is respectively connected to the power supply pin of the monitoring chip (U1) and one end of the second monitored current capacitor (C9), and the other end of the second monitored current capacitor (C9) is connected to the ground terminal.

[0058] The output terminal of the monitoring chip (U1) is connected to one end of the fourth monitored current resistor (R16), the other end of the fourth monitored current resistor (R16) is respectively connected to one end of the fifth monitored current resistor (R15) and one end of the third monitored current capacitor (C11), the other end of the third monitored current capacitor (C11) is connected to the ground terminal, and the other end of the fifth monitored current resistor (R15) outputs the monitored current.

[0059] When monitoring the current, the monitoring chip (U1) can sample the current on the first monitored current resistor (R4), can output a voltage signal of a fixed multiple on the Out Pin of the monitoring chip (U1), and after the output voltage signal passes through the fourth monitored current resistor (R16) and the fifth monitored current resistor (R15), the sampled voltage can be output from the other end of the fifth monitored current resistor (R15), and the current can be obtained through conversion to obtain the monitored current, so as to realize the current monitoring function.

[0060] It should be noted that the other end of the fifth monitoring current resistor (R15) is MCU_K30_CURR_ADC, which can be the PIN of the MCU with ADC function in the power distribution system of the battery. MCU_K30_CURR_ADC monitors the current. The current can be large or small. For example, there is a MAX value in the code. If the current exceeds the MAX value, it is determined that the current is abnormal.

[0061] To implement the overcurrent protection function, refer to Figure 5 which shows the circuit schematic diagram of a current protection unit provided by an embodiment of the present invention.

[0062] In one embodiment, the current protection unit includes: a first current protection resistor (R17), a second current protection resistor (R11), a third current protection resistor (R14), a fourth current protection resistor (R18), a fifth current protection resistor (R19), a sixth current protection resistor (R20), a first current protection capacitor (C7), a second current protection capacitor (C10), a first current protection diode (D6), a second current protection diode (D7), a current zener diode (D8), a current PNP type triode (Q5), a first current NPN type triode (Q6), and a second current NPN type triode (Q7).

[0063] The negative end of the current zener diode (D8) is connected to the output end of the monitoring current unit. The positive end of the current zener diode (D8) is respectively connected to one end of the first current protection resistor (R17) and the collector end of the current PNP type triode (Q5). The power supply end is respectively connected to the emitter end of the current PNP type triode (Q5), one end of the second current protection resistor (R11), and one end of the first current protection capacitor (C7). One end of the third current protection resistor (R14) is respectively connected to the base of the current PNP type triode (Q5), the other end of the second current protection resistor (R11), and the other end of the first current protection capacitor (C7);

[0064] The other end of the third current protection resistor (R14) is connected to the positive end of the first current protection diode (D6). The negative end of the first current protection diode (D6) is respectively connected to the collector end of the first current NPN type triode (Q6) and the negative end of the second current protection diode (D7). The positive end of the second current protection diode (D7) outputs a current protection signal;

[0065] The emitter of the first current NPN transistor (Q6) is connected to the ground terminal. The base terminal of the first current NPN transistor (Q6) is respectively connected to the other end of the first current protection resistor (R17), one end of the fourth current protection resistor (R18), one end of the second current protection capacitor (C10), and the collector terminal of the second current NPN transistor (Q7).

[0066] The base terminal of the second current NPN transistor (Q7) is respectively connected to one end of the fifth current protection resistor (R19) and one end of the sixth current protection resistor (R20). The emitter terminal of the first current NPN transistor (Q6), the other end of the fourth current protection resistor (R18), the other end of the second current protection capacitor (C10), the emitter terminal of the second current NPN transistor (Q7), and the other end of the sixth current protection resistor (R20) are connected to the ground terminal. The other end of the fifth current protection resistor (R19) is the level input terminal.

[0067] During use, when the current on the first monitoring current resistor (R4) gradually rises, the voltage on the Out Pin of the monitoring chip (U1) also rises synchronously. If it reaches the critical value, the first current NPN transistor (Q6) conducts, and the EFUSE_ON signal output from the positive terminal of the second current protection diode (D7) is pulled low. The EFUSE_ON signal can be transmitted to the voltage protection unit, causing the voltage protection unit to turn off, and then disconnecting the current path to achieve the overcurrent protection function.

[0068] Specifically, one end of the fifth current protection resistor (R19) is the level input terminal MCU_EFUSE_RELEASE. Under normal circumstances, MCU_EFUSE_RELEASE is at a low level. When the current on the first monitoring current resistor (R4) gradually rises, the voltage at the collector of the current PNP transistor (Q5) rises, and the first current NPN transistor (Q6) conducts. The voltage at the collector of the first current NPN transistor (Q6) is pulled low, that is, the base of the current PNP transistor (Q5) is pulled low, so that the current PNP transistor (Q5) conducts. The collector of the current PNP transistor (Q5) is pulled up to the power supply voltage (MCU_5V). At this time, the high level at the collector of the current PNP transistor (Q5) will maintain the high level. Without the high level input of the external MCU_EFUSE_RELEASE to the fifth current protection resistor (R19), this state will be maintained all the time, which is self-locking.

[0069] At this time, even if the current of the first monitoring current resistor (R4) drops, the EFUSE_ON signal output at the positive terminal of the second current protection diode (D7) remains low. The MCU_K30_CURR_ADC continuously samples the working current. When the sampled current value is less than the limit for a time that meets the requirements of the battery power distribution system, the MCU of the power distribution system outputs a high-level pulse signal of MCU_EFUSE_RELEASE. When the high level of MCU_EFUSE_RELEASE is input, the second current NPN transistor (Q7) conducts, and the collector of the current PNP transistor (Q5) is pulled low, that is, the base of the first current NPN transistor (Q6) is pulled low, and the first current NPN transistor (Q6) turns off, and it will not continuously pull EFUSE_ON, releasing EFUSE_ON, thus entering a new round of current monitoring and protection process.

[0070] To implement the function of monitoring voltage, refer to Figure 6 , which shows the circuit schematic diagram of a monitoring voltage unit provided by an embodiment of the present invention.

[0071] In one embodiment, the monitoring voltage unit includes: a first monitoring voltage resistor (R22), a second monitoring voltage resistor (R21), and a monitoring voltage capacitor (C12);

[0072] One end of the first monitoring voltage resistor (R22) is respectively connected to one end of the first monitoring voltage resistor (R21) and one end of the monitoring voltage capacitor (C12);

[0073] The other end of the first monitoring voltage resistor (R21) and the other end of the monitoring voltage capacitor (C12) are connected to the ground terminal;

[0074] The connection end of the first monitoring voltage resistor (R22) and the first monitoring voltage resistor (R21) samples the voltage signal to monitor the voltage value of the power supply link.

[0075] The first monitoring voltage resistor (R22) and the second monitoring voltage resistor (R21) divide the voltage. The MCU_K30_VOL_ADC at the connection end of the first monitoring voltage resistor (R22) and the second monitoring voltage resistor (R21) samples the divided voltage level, and the voltage value of the power supply link can be obtained through calculation to achieve the voltage monitoring function.

[0076] To implement the function of overvoltage protection, refer to Figure 7 , which shows the circuit schematic diagram of a voltage protection unit provided by an embodiment of the present invention.

[0077] In one embodiment, the voltage protection unit includes: a first voltage protection resistor (R2), a second voltage protection resistor (R3), a third voltage protection resistor (R1), a fourth voltage protection resistor (R8), a fifth voltage protection resistor (R5), a sixth voltage protection resistor (R6), a seventh voltage protection resistor (R9), a first voltage protection capacitor (C1), a second voltage protection capacitor (C2), a third voltage protection capacitor (C6), a first voltage regulating diode (D2), a second voltage regulating diode (D1), a voltage NMOS transistor (Q3), a voltage NPN transistor (Q4), a voltage PMOS transistor (Q1), a protection inductor (LC1), a first polarized capacitor (CC1), and a second polarized capacitor (CC2);

[0078] The negative terminal of the first voltage regulating diode (D2), the negative terminal of the second voltage regulating diode (D1), one end of the first voltage protection capacitor (C1), one end of the first voltage protection resistor (R2), and the drain terminal of the voltage PMOS transistor (Q1) are connected; the positive terminal of the second voltage regulating diode (D1), the other end of the first voltage protection capacitor (C1), the other end of the first voltage protection resistor (R2), the gate terminal of the voltage PMOS transistor (Q1), one end of the second voltage protection resistor (R3), and one end of the second voltage protection capacitor (C2) are connected;

[0079] The other end of the second voltage protection capacitor (C2) is connected to one end of the third voltage protection resistor (R1). The other end of the third voltage protection resistor (R1) is respectively connected to the source terminal of the voltage PMOS transistor (Q1), the positive terminal of the first polarized capacitor (CC1), and one end of the protection inductor (LC1). The other end of the protection inductor (LC1) is connected to the positive terminal of the second polarized capacitor (CC2). The negative terminals of the first polarized capacitor (CC1) and the second polarized capacitor (CC2) are connected to the ground terminal;

[0080] The other end of the second voltage protection resistor (R3) is connected to the drain terminal of the voltage NMOS transistor (Q3). The gate terminal of the voltage NMOS transistor (Q3) is respectively connected to one end of the fourth voltage protection resistor (R8), one end of the fifth voltage protection resistor (R5), and the collector terminal of the voltage NPN transistor (Q4). The collector terminal of the voltage NPN transistor (Q4) receives a voltage signal. The other end of the fifth voltage protection resistor (R5) is connected to the power supply terminal;

[0081] The base terminal of the voltage NPN transistor (Q4) is respectively connected to one end of the third voltage protection capacitor (C6), one end of the sixth voltage protection resistor (R6), and one end of the seventh voltage protection resistor (R9). The other end of the sixth voltage protection resistor (R6) is connected to the positive terminal of the first voltage stabilizing diode (D2).

[0082] The source terminal of the voltage NMOS transistor (Q3), the other end of the fourth voltage protection resistor (R8), the emitter terminal of the voltage NPN transistor (Q4), the other end of the third voltage protection capacitor (C6), and the other end of the seventh voltage protection resistor (R9) are connected to the ground terminal.

[0083] When the power supply link voltage is low, the voltage NPN transistor (Q4) is in the off state. If the voltage rises to the threshold of 20V at this time, the first voltage stabilizing diode (D2) is in series with the sixth voltage protection resistor (R6) and the seventh voltage protection resistor (R9) for voltage division, which can control the voltage NPN transistor (Q4) to turn on, the voltage NMOS transistor (Q3) to turn off, the voltage difference between the GS of the voltage PMOS transistor (Q1) to be 0, the voltage PMOS transistor (Q1) to turn off, and the power supply link to be disconnected, achieving high-voltage limit protection.

[0084] For example, with a normal voltage of 9 - 16V, when the voltage is greater than 16V but less than the overvoltage value, the power distribution system of the battery can actively turn off some non-essential functions and retain important detection and measurement functions. When the voltage is less than 9V but greater than the minimum voltage for the operation of the battery's power distribution system (in general design, it is ensured that the system can still operate normally at 5 - 9V, and there will be slight differences for each product), the power distribution system of the battery will also actively turn off some non-essential functions and retain important detection and reporting modules.

[0085] For the self-locking function, during specific operation, when the current on the first monitoring current resistor (R4) gradually increases, the voltage on the Out Pin signal of the monitoring chip (U1) also increases synchronously. If the critical value is reached, the first current NPN transistor (Q6) conducts, the EFUSE_ON signal is pulled low, the voltage NMOS transistor (Q3) turns off, which in turn causes the voltage PMOS transistor (Q1) to turn off, and the current path is disconnected to achieve the overcurrent protection function. The current PNP transistor (Q5) and the first current NPN transistor (Q6) are paired to achieve output self-locking.

[0086] In actual application, during the process of the Out Pin signal of the monitoring chip (U1) changing from low to high, when the Out Pin signal of the monitoring chip (U1) reaches 4.268V (corresponding to a current of 17A), the EFUSE_ON signal output at the positive terminal of the second current protection diode (D7) is pulled low, turning off the voltage PMOS transistor (Q1). Thereafter, regardless of whether the Out Pin signal of the monitoring chip (U1) increases or decreases, the EFUSE_ON signal output at the positive terminal of the second current protection diode (D7) remains low. Only after the MCU_EFUSE_RELEASE outputs a high-level pulse signal for 100 ms, the EFUSE_ON signal output at the positive terminal of the second current protection diode (D7) resumes to a high level, entering a new round of overcurrent protection process. When the current exceeds 17A again, the EFUSE_ON signal output at the positive terminal of the second current protection diode (D7) will output a low-level protection signal again.

[0087] In addition, each power MOS transistor of the present utility model can be selected according to the specific load, and the current and voltage limit values can be adjusted by resistors according to actual needs, with relatively high flexibility.

[0088] In this embodiment, the embodiment of the present utility model provides a protection circuit for a storage battery, and its beneficial effects are as follows: The protection circuit of the storage battery of the present utility model is connected to the storage battery. The protection circuit of the storage battery can provide functions of reverse connection prevention, high voltage limitation, voltage monitoring, current monitoring, and overcurrent protection for the storage battery, can improve the speed of protection and response, can avoid the technical problem of slow protection response caused by fuse aging, and can also avoid the problem of inability to achieve protection due to fuse aging.

[0089] The embodiment of the present utility model also provides an electric vehicle. Refer to Figure 8 which shows a schematic structural diagram of an electric vehicle provided by an embodiment of the present utility model.

[0090] Among them, by way of example, the electric vehicle may include: a vehicle body and the protection circuit of the storage battery as described above;

[0091] The vehicle body is provided with a storage battery and a power distribution system. The protection circuit of the storage battery is respectively connected to the storage battery and the power distribution system. The power distribution system is used to detect the voltage and current of the storage battery through the protection circuit of the storage battery, and when the voltage or current does not meet the threshold requirements, control the protection circuit of the storage battery to provide overvoltage or overcurrent protection for the storage battery.

[0092] In the description of the embodiments of the present utility model, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. When an element such as a layer, region or substrate is referred to as "on" or "above" another element, it can be directly on the other element, or there can also be an intermediate element. On the contrary, when an element is referred to as "directly on" or "above" another element, there is no intermediate element. It should also be understood that when an element is referred to as "under" or "below" another element, it can be directly under or below the other element, or there can also be an intermediate element. On the contrary, when an element is referred to as "directly under" or "below" another element, there is no intermediate element. Unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0093] Those skilled in the art should understand that the embodiments of the present application can also provide a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memories, CD-ROMs, optical memories, etc.) that contain computer-usable program codes.

[0094] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), apparatuses and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the processes and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one Figure 1 one process or multiple processes and / or blocks Figure 1 one block or multiple blocks.

[0095] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce a manufacture including an instruction means that implements the functions specified in one or more of the procedures and / or blocks Figure 1 one or more of the procedures and / or blocks Figure 1 specified in the block or blocks.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the procedures and / or blocks Figure 1 one or more of the procedures and / or blocks Figure 1 specified in the block or blocks.

[0097] The foregoing is only a preferred embodiment of the present invention, and it should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A battery protection circuit, characterized in that: The battery protection circuit comprises: an anti-reverse unit, a current protection unit, a monitoring current unit, a voltage protection unit and a monitoring voltage unit; The first end of the anti-reverse unit is connected to the monitoring current unit, the monitoring current unit is connected to the current protection unit, the second end of the anti-reverse unit is connected to the monitoring voltage unit, and the monitoring voltage unit is connected to the voltage protection unit; The input end of the anti-reverse unit is connected to the output end of the battery, and the anti-reverse function is realized when the voltage of the output end of the battery is a negative value. The monitoring current unit is used to monitor the current of the output end of the anti-reverse unit. The current protection unit is used to realize overcurrent protection when the monitoring current of the monitoring current unit is greater than the current threshold. The monitoring voltage unit is used to monitor the output voltage of the power distribution chip connected to the battery. The voltage protection unit is used to realize overvoltage protection when the monitoring voltage of the monitoring voltage unit is greater than the voltage threshold.

2. The battery protection circuit according to claim 1, characterized in that: The anti-reverse unit includes: a bidirectional diode, a first anti-reverse capacitor, a second anti-reverse capacitor, a third anti-reverse capacitor, an anti-reverse PMOS tube, a first anti-reverse resistor, a second anti-reverse resistor and an anti-reverse voltage stabilizing diode; One end of the bidirectional diode is connected to one end of the first anti-reverse capacitor and the source end of the anti-reverse PMOS tube respectively, the other end of the first anti-reverse capacitor is connected to one end of the second anti-reverse capacitor, and the other end of the second anti-reverse capacitor and the other end of the bidirectional diode are connected to the ground end respectively; The drain terminal of the anti-reverse PMOS tube is respectively connected to one end of the first anti-reverse resistor, one end of the third anti-reverse capacitor and the negative terminal of the anti-reverse voltage stabilizing diode, one end of the second anti-reverse resistor is respectively connected to the other end of the first anti-reverse resistor, the other end of the third anti-reverse capacitor, the gate end of the anti-reverse PMOS tube and the positive terminal of the anti-reverse voltage stabilizing diode, and the other end of the second anti-reverse resistor is connected to the ground terminal.

3. The battery protection circuit according to claim 1, characterized in that: The monitoring current unit includes: a monitoring chip, a first monitoring current resistor, a second monitoring current resistor, a third monitoring current resistor, a fourth monitoring current resistor, a fifth monitoring current resistor, a first monitoring current capacitor, a second monitoring current capacitor, a third monitoring current capacitor, and a monitoring current diode; Two ends of the first monitoring current resistor are respectively connected to one end of the second monitoring current resistor and one end of the third monitoring current resistor, and two ends of the first monitoring current capacitor are respectively connected to the other end of the second monitoring current resistor and the other end of the third monitoring current resistor; The two ends of the first monitoring current capacitor are respectively connected to the positive terminal and the negative terminal of the monitoring current diode, the positive terminal and the negative terminal of the monitoring current diode are respectively connected to the two input pins of the monitoring chip, the power supply end is respectively connected to the power supply pin of the monitoring chip and one end of the second monitoring current capacitor, the other end of the second monitoring current capacitor is connected to the ground end, the output end of the monitoring chip is connected to one end of the fourth monitoring current resistor, the other end of the fourth monitoring current resistor is respectively connected to one end of the fifth monitoring current resistor and one end of the third monitoring current capacitor, the other end of the third monitoring current capacitor is connected to the ground end, and the other end of the fifth monitoring current resistor outputs the monitoring current.

4. The battery protection circuit according to claim 1, characterized in that: The current protection unit includes: a first current protection resistor, a second current protection resistor, a third current protection resistor, a fourth current protection resistor, a fifth current protection resistor, a sixth current protection resistor, a first current protection capacitor, a second current protection capacitor, a first current protection diode, a second current protection diode, a current voltage regulator diode, a current PNP transistor, a first current NPN transistor, and a second current NPN transistor; The negative terminal of the current zener diode is connected to the output terminal of the monitoring current unit, the positive terminal of the current zener diode is respectively connected to one end of the first current protection resistor and the collector terminal of the current PNP type transistor, the power supply terminal is respectively connected to the emitter terminal of the current PNP type transistor, one end of the second current protection resistor and one end of the first current protection capacitor, and one end of the third current protection resistor is respectively connected to the base of the current PNP type transistor, the other end of the second current protection resistor and the other end of the first current protection capacitor; The other end of the third current protection resistor is connected to the positive terminal of the first current protection diode, the negative terminal of the first current protection diode is respectively connected to the collector terminal of the first current NPN transistor and the negative terminal of the second current protection diode, and the positive terminal of the second current protection diode outputs a current protection signal; The emitter of the first current NPN transistor is connected to the ground terminal, and the base terminal of the first current NPN transistor is respectively connected to the other end of the first current protection resistor, one end of the fourth current protection resistor, one end of the second current protection capacitor and the collector terminal of the second current NPN transistor; The base terminal of the second current NPN type transistor is respectively connected to one end of the fifth current protection resistor and one end of the sixth current protection resistor, the emitter terminal of the first current NPN type transistor, the other end of the fourth current protection resistor, the other end of the second current protection capacitor, the emitter terminal of the second current NPN type transistor and the other end of the sixth current protection resistor are connected to the ground terminal, and the other end of the fifth current protection resistor is a level input terminal.

5. The battery protection circuit according to claim 1, characterized in that: The monitoring voltage unit includes: a first monitoring voltage resistor, a second monitoring voltage resistor and a monitoring voltage capacitor; One end of the first monitoring voltage resistor is connected to one end of the second monitoring voltage resistor and one end of the monitoring voltage capacitor respectively; The other end of the second monitoring voltage resistor and the other end of the monitoring voltage capacitor are connected to the ground terminal; The connection end of the first monitoring voltage resistor and the second monitoring voltage resistor samples a voltage signal to monitor the voltage value of the power link.

6. The battery protection circuit according to claim 1, characterized in that: The voltage protection unit includes: a first voltage protection resistor, a second voltage protection resistor, a third voltage protection resistor, a fourth voltage protection resistor, a fifth voltage protection resistor, a sixth voltage protection resistor, a seventh voltage protection resistor, a first voltage protection capacitor, a second voltage protection capacitor, a third voltage protection capacitor, a first voltage zener diode, a second voltage zener diode, a voltage NMOS tube, a voltage NPN transistor, a voltage PMOS tube, a protection inductor, a first polarity capacitor, and a second polarity capacitor; The negative terminal of the first voltage zener diode, the negative terminal of the second voltage zener diode, one end of the first voltage protection capacitor, one end of the first voltage protection resistor and the drain terminal of the voltage PMOS tube are connected; the positive terminal of the second voltage zener diode, the other end of the first voltage protection capacitor, the other end of the first voltage protection resistor, the gate terminal of the voltage PMOS tube, one end of the second voltage protection resistor and one end of the second voltage protection capacitor are connected; The other end of the second voltage protection capacitor is connected to one end of the third voltage protection resistor, the other end of the third voltage protection resistor is respectively connected to the source end of the voltage PMOS tube, the positive end of the first polarity capacitor and one end of the protection inductor, the other end of the protection inductor is connected to the positive end of the second polarity capacitor, and the negative end of the first polarity capacitor and the negative end of the second polarity capacitor are connected to the ground end; The other end of the second voltage protection resistor is connected to the drain end of the voltage NMOS tube, the gate end of the voltage NMOS tube is respectively connected to one end of the fourth voltage protection resistor, one end of the fifth voltage protection resistor and the collector end of the voltage NPN transistor, the collector end of the voltage NPN transistor receives a voltage signal, and the other end of the fifth voltage protection resistor is connected to the power supply end; The base terminal of the voltage NPN transistor is respectively connected to one end of the third voltage protection capacitor, one end of the sixth voltage protection resistor and one end of the seventh voltage protection resistor, and the other end of the sixth voltage protection resistor is connected to the positive terminal of the first voltage stabilizing diode; The source end of the voltage NMOS tube, the other end of the fourth voltage protection resistor, the emitter end of the voltage NPN transistor, the other end of the third voltage protection capacitor and the other end of the seventh voltage protection resistor are connected to the ground end.

7. An electric vehicle, characterized in that: The electric vehicle comprises: a vehicle body and a battery protection circuit as claimed in any one of claims 1 to 6; The automobile body is provided with a battery and a power distribution system. The protection circuit of the battery is connected to the battery and the power distribution system respectively. The power distribution system is used to detect the voltage and current of the battery through the protection circuit of the battery, and when the voltage or current does not meet the threshold requirement, control the protection circuit of the battery to provide overvoltage or overcurrent protection to the battery.

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