Reverse connection prevention circuit, charging and discharging control circuit of battery pack and battery pack system

Abstract

The utility model discloses an anti-reverse connection circuit, a charging and discharging control circuit of a battery pack and a battery pack system, and relates to the field of circuits, when a charger is positively connected with an external output end, a controllable sub-switch is turned off, and the external output positive electrode and an internal charging input end can be kept connected under the action of a first preset driving signal. When the charger is reversely connected with the external output end, the controllable sub-switch is switched on, and the first preset driving signal is pulled down, so that the external output positive electrode and the internal charging input end are disconnected, and the internal battery pack is prevented from reversely charging the charger. The number of the controllable sub-switches is at least two, and the controllable sub-switches are backups for each other, so that the redundancy reliability of the whole system is improved. The anti-reverse-connection circuit is used for controlling the charging and discharging switch to be turned off under the condition that the charger is reversely connected, so that the potential safety hazard that the charger exceeds withstand voltage and is even damaged is avoided, and the safety and the reliability of the charging process of the battery pack are ensured.

Description

Technical Field

[0001] The utility model relates to the field of circuits, in particular to an anti-reverse connection circuit, a battery pack charge and discharge control circuit and a battery pack system. Background Art

[0002] Lithium batteries are now widely used in daily life. They can be recharged through an external charger, allowing for repeated use and high environmental performance. When an external charger charges a battery pack, the charger's positive terminal is normally connected to the battery pack's positive terminal, and the charger's negative terminal is connected to the battery pack's negative terminal. However, if the external charger is connected in reverse, with the charger's positive terminal connected to the battery pack's negative terminal and the charger's negative terminal connected to the battery pack's positive terminal, the battery pack will charge the charger, raising the charger's voltage, causing the charger's components to exceed their withstand voltage, and even causing damage. Preventing this safety hazard caused by reverse charger connection is a technical problem that urgently needs to be addressed. Utility Model Content

[0003] The purpose of the utility model is to provide an anti-reverse connection circuit, a battery pack charge and discharge control circuit and a battery pack system, which utilize the anti-reverse connection circuit to control the charge and discharge switch to be turned off when the charger is reversely connected, thereby avoiding the safety hazard of the charger exceeding the withstand voltage or even being damaged, and ensuring the safety and reliability of the battery pack charging process.

[0004] In order to solve the above technical problems, the utility model provides an anti-reverse connection circuit, comprising:

[0005] a first voltage-dividing resistor;

[0006] A second voltage-dividing resistor, a first end of which is connected to the external output negative electrode;

[0007] N controllable sub-switches, wherein first ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to an external output positive electrode, a first end of the first voltage-dividing resistor, and an internal charging input terminal; second ends of the N controllable sub-switches are connected to each other, and a common connection point is used to receive a first preset drive signal; control ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to a second end of the first voltage-dividing resistor and a second end of the second voltage-dividing resistor; N is a positive integer greater than 1;

[0008] The controllable sub-switch is used to cooperate with the first preset driving signal to control the disconnection between the external output positive electrode and the internal charging input terminal when the voltage of the external output negative electrode is greater than the voltage of the external output positive electrode.

[0009] Optionally, also include:

[0010] N first current limiting modules are connected to the N controllable sub-switches in a one-to-one correspondence, wherein the first ends of the first current limiting modules are connected to the control ends of the corresponding controllable sub-switches, the second ends of the N first current limiting modules are connected to each other, and a common connection point is respectively connected to the second end of the second voltage-dividing resistor and the second end of the first voltage-dividing resistor.

[0011] Optionally, also include:

[0012] The second current limiting module has a first end connected to the second ends of the N controllable sub-switches respectively, and a second end used to receive a first preset driving signal.

[0013] Optionally, also include:

[0014] The first unidirectional conducting module has a positive electrode for receiving the first preset driving signal and a negative electrode connected to the second end of the second current limiting module.

[0015] Optionally, also include:

[0016] The first voltage stabilizing module has a positive electrode connected to the first end of the first voltage-dividing resistor, the external output positive electrode, and the first ends of the N controllable sub-switches, and a negative electrode connected to the second end of the first voltage-dividing resistor, the second end of the second voltage-dividing resistor, and the control ends of the N controllable sub-switches.

[0017] Optionally, also include:

[0018] a capacitor, wherein a first end is respectively connected to the positive electrode of the first voltage stabilizing module, the first end of the first voltage-dividing resistor, the external output positive electrode, and the first ends of the N controllable sub-switches, and a second end is respectively connected to the negative electrode of the first voltage stabilizing module, the second end of the first voltage-dividing resistor, the second end of the second voltage-dividing resistor, and the control ends of the N controllable sub-switches.

[0019] Optionally, also include:

[0020] The second unidirectional conducting module has a positive electrode connected to the external output negative electrode, and a negative electrode connected to the first end of the second voltage-dividing resistor.

[0021] In order to solve the above technical problems, the present invention also provides a charge and discharge control circuit for a battery pack, comprising a charge and discharge switch and the aforementioned anti-reverse connection circuit;

[0022] The first end of the charge and discharge switch is connected to the positive electrode of the battery in the battery pack, and the second end serves as the internal charging input end, which is respectively connected to the first end of the anti-reverse connection circuit and the external output positive electrode; the control end is used to access the first preset drive signal and is connected to the second end of the anti-reverse connection circuit.

[0023] Optionally, the charge and discharge switch includes:

[0024] a first charge-discharge electronic switch, wherein a first end is connected to the positive electrode of a battery in the battery pack, and a control end is used to receive a second preset drive signal;

[0025] a second charge-discharge electronic switch, wherein the first end is connected to the second end of the first charge-discharge electronic switch, the second end is respectively connected to the external output positive electrode and the first end of the anti-reverse connection circuit, and the control end is used to receive the first preset drive signal and is connected to the second end of the anti-reverse connection circuit;

[0026] The first charge-discharge electronic switch and the second charge-discharge electronic switch are both provided with parasitic diodes, and the cathode of the parasitic diode of the first charge-discharge electronic switch is connected to the anode of the parasitic diode of the second charge-discharge electronic switch; the switching states of the first charge-discharge electronic switch and the second charge-discharge electronic switch remain consistent.

[0027] In order to solve the above technical problems, the present invention also provides a battery pack system, including several batteries and the charge and discharge control circuit of the battery pack as described above, and the positive poles of the batteries are connected to the charge and discharge control circuit of the battery pack.

[0028] The utility model provides an anti-reverse connection circuit, comprising a first voltage-dividing resistor, a second voltage-dividing resistor, and at least two controllable sub-switches. The first voltage-dividing resistor and the second voltage-dividing resistor divide the output voltage of the charger connected to the external output terminal and output the divided sub-voltage to the control terminal of the controllable sub-switch. When the charger is connected to the battery pack in a positive direction, the first end of the controllable sub-switch is connected to the positive pole of the charger, and the voltage is maintained at the output voltage of the charger. The voltage of the control terminal is maintained at the sub-voltage. At this time, the controllable sub-switch is turned off, which will not affect the first preset drive signal. The external output positive pole and the internal charging input terminal can maintain a connection under the action of the first preset drive signal. When the charger is reversely connected to the battery pack, the first end of the controllable sub-switch is connected to the negative pole of the charger, and the voltage is substantially zero. The voltage of the control terminal is maintained at the sub-voltage. At this time, the controllable sub-switch is turned on, pulling down the first preset drive signal, disconnecting the external output positive pole and the internal charging input terminal, thereby preventing the internal battery pack from reversely charging the charger. The anti-reverse connection circuit is used to control the charge and discharge switches to be turned off when the charger is reversely connected, thereby avoiding the safety hazard of the charger exceeding the withstand voltage or even being damaged, ensuring the safety and reliability of the battery pack charging process.

[0029] The utility model also provides a battery pack charge and discharge control circuit and a battery pack system, which have the same beneficial effects as the above-mentioned anti-reverse connection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A schematic structural diagram of an anti-reverse connection circuit provided by the utility model;

[0032] Figure 2 This is a structural schematic diagram of a charge and discharge control circuit for a battery pack provided by the utility model. DETAILED DESCRIPTION

[0033] The core of this utility model is to provide an anti-reverse connection circuit, a battery pack charge and discharge control circuit and a battery pack system. The anti-reverse connection circuit is used to control the charge and discharge switch to be turned off when the charger is reversely connected, thereby avoiding the safety hazard of the charger exceeding the withstand voltage or even being damaged, and ensuring the safety and reliability of the battery pack charging process.

[0034] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, 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.

[0035] In some embodiments, please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of an anti-reverse connection circuit provided by the utility model; please refer to Figure 2 , Figure 2 This is a schematic diagram of the structure of a charge and discharge control circuit for a battery pack provided by the present invention. BAT+ represents the positive electrode of the battery in the battery pack, i.e., the internal charging input terminal when the charger is charging the battery pack; PACK+ represents the positive electrode of the battery pack, i.e., the external output positive electrode when the charger is charging the battery pack; PACK- represents the negative electrode of the battery pack, i.e., the external output negative electrode when the charger is charging the battery pack; MOS_G_CHG represents the second preset drive signal; and MOS_G_DSG represents the first preset drive signal. To solve the above technical problems, the present invention provides an anti-reverse connection circuit, wherein the charge and discharge switch includes:

[0036] A first voltage dividing resistor Rf1;

[0037] A second voltage-dividing resistor Rf2, a first end of which is connected to the external output negative electrode;

[0038] N controllable sub-switches, wherein first ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to an external output positive electrode, a first end of a first voltage-dividing resistor, and an internal charging input terminal; second ends of the N controllable sub-switches are connected to each other, and the common connection point is used to receive a first preset drive signal; control ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to a second end of the first voltage-dividing resistor and a second end of the second voltage-dividing resistor; N is a positive integer greater than 1;

[0039] The controllable sub-switch is used to cooperate with the first preset driving signal to control the disconnection between the external output positive electrode and the internal charging input terminal when the voltage of the external output negative electrode is greater than the voltage of the external output positive electrode.

[0040] It should be noted that in order to ensure the controllability and safety of the charging process, a charge and discharge switch is generally set between the external output terminal of the charger and the internal charging input terminal to control whether the charging process is started or not. The control end of the charge and discharge switch is connected to the first preset drive signal, and the charging process is controlled by adjusting the first preset drive signal. The external output positive pole and the external output negative pole are the two external output terminals for connecting the external charging device. The internal charging input terminal refers to the charging port of the module that actually needs to be charged in the device to be charged. For example, when the device to be charged is a battery pack, what actually needs to be charged is the battery in the battery pack. At this time, the internal charging input terminal is the positive pole of the battery in the battery pack.

[0041] It can be understood that the second end of the controllable sub-switch is directly connected to the first preset drive signal that drives the charge and discharge switch. When the controllable sub-switch is turned off, the first preset drive signal can be normally output to the control end of the charge and discharge switch to normally control the working process of the charge and discharge switch; and when the controllable sub-switch is turned on, the turned-on controllable sub-switch will affect the voltage value of the first preset drive signal output to the control end of the charge and discharge switch, thereby affecting the working process of the charge and discharge switch.

[0042] It is not difficult to understand that in the normal charging process of the battery pack, the charge-discharge switch will be kept on under the action of the first preset driving signal to transmit the power input by the charger to the positive electrode of the battery, so as to realize the charging process of the battery. After setting the anti-reverse connection circuit including the first voltage dividing resistor Rf1, the second voltage dividing resistor Rf2 and the controllable sub-switch, the first voltage dividing resistor Rf1 and the second voltage dividing resistor Rf2 will output the voltage between the positive electrode and the negative electrode of the battery pack to the control end of the controllable sub-switch after voltage division; when the charger is connected to the battery pack in positive, the positive electrode of the charger is connected to the positive electrode of the battery pack, the negative electrode of the charger is connected to the negative electrode of the battery pack, the charge-discharge switch can keep the normal conduction process and carry out normal charging, at this time the voltage at the control end of the controllable sub-switch is the sub-voltage obtained by voltage division of the output voltage of the charger, the voltage at the first end is the positive electrode output voltage of the charger, the controllable sub-switch keeps off and does not affect the normal conduction of the charge-discharge switch. When the charger is connected to the battery pack in reverse, the positive electrode of the charger is connected to the negative electrode of the battery pack, the negative electrode of the charger is connected to the positive electrode of the battery pack, at this time if the charge-discharge switch continues to keep the on state, the voltage of the positive electrode of the battery will be greater than the voltage of the positive electrode of the battery pack, and the reverse charging condition occurs, therefore the charge-discharge switch needs to be switched to the off state, at this time the voltage at the control end of the controllable sub-switch is the sub-voltage obtained by voltage division of the output voltage of the charger, the voltage at the first end is the negative electrode voltage of the charger, which is generally close to zero, the controllable sub-switch is switched to the on state, the first preset driving signal is pulled low, so as to control the charge-discharge switch to be switched from on to off, at this time the voltage of the positive electrode of the battery cannot be output to the charger in reverse through the charge-discharge switch.

[0043] It should be noted that this application does not specifically limit the specific type of charge and discharge switch and the specific implementation of the battery pack's charge and discharge control circuit. The charge and discharge switch can specifically be a switching device such as a triode, a MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor), or an IGBT (Insulated Gate Bipolar Transistor). The setting of the first preset drive signal also needs to be set according to the specific situation of the charge and discharge switch. This application does not specifically limit this. For example, when the charge and discharge switch is a MOS tube, the first preset drive signal should be a drive signal set according to the threshold voltage of the MOS tube. The specific implementation and resistance values ​​of the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2 can be selected and set according to the specific voltage conditions of the battery pack and the charger. For ease of application, variable resistors can also be used to implement the first voltage divider resistor Rf1 and the second voltage divider resistor Rf2. This application does not specifically limit this. This application does not make any special restrictions on the specific type and implementation method of the controllable sub-switch. It can be implemented using switching devices such as transistors, MOS tubes, IGBTs, etc., and can be directly consistent with the type of charging and discharging switches, or other switching devices can be replaced according to actual conditions.

[0044] It is not difficult to understand that the anti-reverse connection circuit designed in this application can use the cooperation of the first voltage-dividing resistor Rf1, the second voltage-dividing resistor Rf2 and the controllable sub-switch to identify whether the charger is reversely connected and take corresponding actions, effectively protecting the charger and battery pack, giving the battery pack an anti-reverse connection function, and further protecting the lithium battery and external devices. The anti-reverse connection circuit provided in this application is not only applicable to the charge and discharge control circuit of the lithium battery pack, but can also be used in other devices and devices that need to be charged, effectively protecting the safety and reliability of the device during the charging process.

[0045] It should be noted that in actual applications, battery packs are used in conjunction with a BMS (Battery Management System). The BMS system includes charge and discharge control circuits to control the battery's input and output, prevent overcharging and overdischarging, and protect the battery. Several stacked batteries and the BMS together constitute a battery pack. This application does not specifically limit the specific type and implementation of the BMS system. This application also does not specifically limit the specific type and stacking method of the multiple batteries in the battery pack.

[0046] It is not difficult to understand that in order to ensure the accuracy and reliability of the controllable sub-switch's control over the switching state of the charge and discharge switch, at least two controllable sub-switches are set in the circuit. Multiple controllable sub-switches can play a redundant role. After one of the controllable sub-switches fails, the other controllable sub-switches can also realize the function, ensuring that the charge and discharge switch can be effectively turned off when the charger is reversed; at the same time, multiple controllable sub-switches can also play a shunt role, so that the current flowing through each controllable sub-switch is relatively small, especially when the voltage specification of the charger is relatively large, the safety and reliability of the controllable sub-switches can be effectively determined. This application does not make any special restrictions on the specific setting number, type, and implementation method of each controllable sub-switches. Each controllable sub-switch can be implemented using switch devices of the same specifications and models, or can be implemented using switch devices of different specifications and models. It can be selected and adjusted according to actual conditions. Figure 2 As shown, two controllable sub-switches, a controllable sub-switch Q21 and a controllable sub-switch Q22, are provided to implement the controllable sub-switches.

[0047] Specifically, by adopting multiple controllable sub-switches to realize the structure of the entire controllable sub-switch, it is possible to ensure the effective implementation of the functions of the controllable sub-switches, ensure that the anti-reverse connection circuit can still ensure the process of shutting off the charge and discharge switches when some controllable sub-switches fail, and ensure the safety and reliability of the battery pack and charger.

[0048] As a specific embodiment, Figure 2 As shown, the charge and discharge control circuit where the charge and discharge switch in the BMS system is located includes a first charge and discharge electronic switch Q11, a second charge and discharge electronic switch Q12, a third current limiting module RX3, a fourth current limiting module RX4, a first resistor R1, a second resistor R2, a second voltage stabilizing module composed of a Zener diode DZ21 and a Zener diode DZ22, and a third voltage stabilizing module composed of a Zener diode DZ31 and a Zener diode DZ32. MOS_G_CHG is the second preset drive signal corresponding to the first charge and discharge electronic switch Q11, and MOS_D_DSG is the first preset drive signal corresponding to the second charge and discharge electronic switch Q12, which controls the on and off of the first charge and discharge electronic switch Q11 and the second charge and discharge electronic switch Q12. The anti-reverse connection circuit includes a controllable sub-switch Q21, a controllable sub-switch Q22, a first current limiting module RX11, a first current limiting module RX12, a first voltage dividing resistor Rf1, a second voltage dividing resistor Rf2, a second current limiting module RX2, a first unidirectional conduction module D1, a second unidirectional conduction module D2, a first voltage stabilizing module DZ1 and a capacitor C0.

[0049] Taking the charger's output voltage of 12V during normal charging as an example, under normal discharge and normal charging conditions, the second preset drive signal MOS_G_CHG and the first preset drive signal MOS_G_DSG are set high, driving the first charge-discharge electronic switch Q11 and the second charge-discharge electronic switch Q12 to conduct. Current flows from BAT+ through the first charge-discharge electronic switch Q11 and the second charge-discharge electronic switch Q12 to PACK+, discharging the battery pack. Alternatively, current flows from PACK+ through the first charge-discharge electronic switch Q11 and the second charge-discharge electronic switch Q12 to BAT+, charging the battery pack normally. In both cases, the reverse polarity protection circuit is inoperative. During normal use of the charger, that is, during normal charging, the PACK+ voltage is higher than PACK-. Once the charger is reversely connected, the PACK- voltage is higher than PACK+, and current flows from PACK- through the second unidirectional conduction module D2, the second voltage divider resistor Rf2, and the first voltage divider resistor Rf1 to PACK+, generating a voltage drop across the first voltage divider resistor Rf1. The specific voltage is (V PACK- -V PACK+ -V D2 )*R f2 / (R f2 +R f1 ), V PACK- Wherein: PACK-terminal voltage, V PACK+ is the voltage of PACK+ terminal, V D2 is the voltage drop across the second unidirectional conduction module D2, R f1 is the resistance of the first voltage divider resistor Rf1, R f2 is the resistance of the second voltage-dividing resistor Rf2; this voltage is also the driving voltage of the controllable sub-switch. As can be seen from the above formula, adjusting the resistance ratio of the first voltage-dividing resistor Rf1 to the second voltage-dividing resistor Rf2 can change the voltage across the first voltage-dividing resistor Rf1. When the voltage across the first voltage-dividing resistor Rf1 is greater than the turn-on threshold Vth of the controllable sub-switch, current will flow from MOS_G_DSG through the first unidirectional conduction module D1, the second current-limiting module RX2, the controllable sub-switch to PACK+, so the voltage level of MOS_G_DSG will change from V PACK+ +12V becomes V PACK+ This causes the voltage across GS of the second charge and discharge electronic switch Q12 to be less than the turn-on threshold Vth, the second charge and discharge electronic switch Q12 is turned off, and the connection between BAT+ and PACK+ is disconnected, which protects the charger and battery pack.

[0050] The utility model provides an anti-reverse connection circuit, comprising a first voltage-dividing resistor Rf1, a second voltage-dividing resistor Rf2, and at least two controllable sub-switches. The first voltage-dividing resistor Rf1 and the second voltage-dividing resistor Rf2 divide the output voltage of a charger connected to an external output terminal and output the divided sub-voltage to a control terminal of the controllable sub-switch. When the charger is connected to a battery pack in a forward direction, the first terminal of the controllable sub-switch is connected to the positive terminal of the charger, and the voltage is maintained at the output voltage of the charger. The voltage at the control terminal is maintained at the sub-voltage. At this time, the controllable sub-switch is turned off and does not affect a first preset drive signal. The charge-discharge switch can remain on under the action of the first preset drive signal, and the connection between the external output positive terminal and the internal charging input terminal is maintained. When the charger is connected to the battery pack in a reverse direction, the first terminal of the controllable sub-switch is connected to the negative terminal of the charger, and the voltage is substantially zero. The voltage at the control terminal is maintained at the sub-voltage. At this time, the controllable sub-switch is turned on, pulling down the first preset drive signal, causing the charge-discharge switch to turn off, disconnecting the external output positive terminal and the internal charging input terminal, thereby preventing the internal battery pack from reversely charging the charger. The anti-reverse connection circuit is used to control the charge and discharge switches to be turned off when the charger is reversely connected, thereby avoiding the safety hazard of the charger exceeding the withstand voltage or even being damaged, ensuring the safety and reliability of the battery pack charging process.

[0051] Based on the above embodiment:

[0052] As an optional embodiment, the method further includes:

[0053] N first current limiting modules are connected to the N controllable sub-switches in a one-to-one correspondence, the first end of the first current limiting module is connected to the control end of the corresponding controllable sub-switch, the second ends of the N first current limiting modules are connected to each other, and the common connection point is respectively connected to the second end of the second voltage dividing resistor Rf2 and the second end of the first voltage dividing resistor Rf1.

[0054] It is understandable that in order to avoid direct connection between the control end of the controllable sub-switch and the divided sub-voltage, a first current limiting module connected one-to-one can be added to the control end of each controllable sub-switch. The first current limiting module can limit the driving current, prevent the driving current output to the control end of the controllable sub-switch from being too large, avoid damage to the driving chip due to insufficient driving capability, etc., and further protect the controllable sub-switch. The present application does not make any special restrictions on the specific type and implementation method of the first current limiting module. Generally, the first current limiting module can be implemented by a resistor. When the first current limiting module is implemented by a resistor, the resistor can also be used as a driving resistor of the controllable sub-switch to achieve impedance matching of the control end of the controllable sub-switch and reduce possible oscillations on the control end; at the same time, series resistance isolation can be achieved when the control ends of multiple controllable sub-switches are connected in parallel. Figure 2As shown, a first current limiting module RX11 corresponding to the controllable sub-switch 1 and a first current limiting module RX12 corresponding to the controllable sub-switch 2 are provided.

[0055] Specifically, by adding a first current limiting module connected to each controllable sub-switches in a one-to-one correspondence, the controllable sub-switches can be effectively protected. At the same time, the oscillation of the driving signal during the control process can be reduced, series resistance can be avoided, and the accuracy and reliability of the operation process of each controllable sub-switches can be ensured.

[0056] As an optional embodiment, the method further includes:

[0057] The second current limiting module RX2 has a first end connected to the second ends of the N controllable sub-switches respectively, and a second end used to receive a first preset driving signal.

[0058] It is readily understood that, given that the second end of the controllable sub-switch needs to be directly connected to the first preset drive signal, excessive drive current may occur at the second end. Therefore, a second current-limiting module RX2 may be provided between the controllable sub-switch and the first preset drive signal to limit the drive current output to the second end of the controllable sub-switch, further protecting the controllable sub-switch. The specific type and implementation of the second current-limiting module RX2 are not specifically limited herein, and may be implemented using a resistor or other means.

[0059] Specifically, by adding a second current limiting module RX2 connected to the second end of the controllable sub-switch, the controllable sub-switch can be further protected to ensure the normal operation of the controllable sub-switch; the structure is simple and easy to implement, which is conducive to the simple implementation of the entire anti-reverse connection circuit.

[0060] As an optional embodiment, the method further includes:

[0061] The first unidirectional conducting module D1 has a positive electrode for receiving a first preset driving signal and a negative electrode connected to the second end of the second current limiting module RX2.

[0062] It can be understood that, considering that the first end of the controllable sub-switch connected with the positive pole of the battery pack can have current leakage to the control end of the first preset driving signal and the charge-discharge switch through the controllable sub-switch, especially when the controllable sub-switch is implemented by using a MOS tube with a parasitic diode, the current can leak to the control end of the first preset driving signal and the charge-discharge switch through the parasitic diode, in order to prevent loop leakage, a first unidirectional conduction module D1 connected in series with the second current limiting module RX2 can be further added to regulate the current direction of this loop as flowing from the control end of the first preset driving signal and the charge-discharge switch to the second end of the controllable sub-switch, avoiding the current reverse and loop leakage. The specific type and implementation of the first unidirectional conduction module D1 are not particularly limited herein, and a unidirectional conduction device such as a diode or a thyristor can be used for implementation.

[0063] Specifically, by adding the first unidirectional conduction module D1, the leakage and current reverse in the loop can be effectively avoided, and the accurate operation of the circuit is ensured; the structure is simple and easy to implement, and is conducive to the simple implementation of the entire anti-reverse connection circuit.

[0064] As an optional embodiment, the application further comprises:

[0065] The first voltage stabilizing module DZ1 is connected with the first end of the first voltage dividing resistor Rf1, the positive pole of the external output, and the first end of the N controllable sub-switches in series, and is connected with the second end of the first voltage dividing resistor Rf1, the second end of the second voltage dividing resistor Rf2, and the control end of the N controllable sub-switches in parallel.

[0066] It can be understood that, considering that the voltage between the first end and the control end of the controllable sub-switch has a certain limit and cannot be too large, once the voltage between the two ends is too large, the device can be damaged, and therefore the first voltage stabilizing module DZ1 can be added in parallel between the two ends of the first voltage dividing resistor Rf1, the first voltage stabilizing module DZ1 can stabilize the voltage between the two ends of the first voltage dividing resistor Rf1 at a preset value, which can improve the stability and reliability of the voltage output to the control end of the controllable sub-switch after being divided by the first voltage dividing resistor Rf1 and the second voltage dividing resistor Rf2, and can also avoid the damage caused by the voltage between the first end and the control end of the controllable sub-switch exceeding the withstand voltage. The specific type and implementation of the first voltage stabilizing module DZ1 are not particularly limited herein, and a voltage stabilizing device such as a voltage stabilizing diode can be used for implementation.

[0067] Specifically, by adding the first voltage stabilizing module DZ1 in parallel between the first end and the control end of the controllable sub-switch, the stability and reliability of the driving voltage output to the control end of the controllable sub-switch can be effectively improved, and the voltage between the two ends of the controllable sub-switch can also be prevented from exceeding the withstand voltage, ensuring the safety and reliability of the entire anti-reverse connection circuit.

[0068] As an optional embodiment, the method further includes:

[0069] Capacitor C0 has a first end connected to the positive electrode of the first voltage stabilizing module DZ1, the first end of the first voltage-dividing resistor Rf1, the external output positive electrode, and the first ends of the N controllable sub-switches, and a second end connected to the negative electrode of the first voltage stabilizing module DZ1, the second end of the first voltage-dividing resistor Rf1, the second end of the second voltage-dividing resistor Rf2, and the control ends of the N controllable sub-switches.

[0070] It is not difficult to understand that in order to avoid damage to the circuit due to static electricity during the charging and discharging process of the battery, especially when the controllable sub-switch is implemented using a MOS tube, there will be a certain amount of static electricity between its gate and source. A capacitor C0 can also be added in parallel at both ends of the first voltage stabilizing module DZ1. Capacitor C0 can effectively prevent electrostatic damage to the controllable sub-switch and can also filter the external voltage input to the battery pack to reduce interference signals. The specific type and implementation method of capacitor C0 are not specifically limited in this application.

[0071] Specifically, electrostatic damage in the circuit can be avoided by adding a capacitor C0 connected to the positive pole of the battery pack, while improving the anti-interference ability of the entire anti-reverse connection circuit and the battery pack's charge and discharge control circuit, ensuring the accurate implementation of the anti-reverse connection circuit and the battery pack's charge and discharge control circuit.

[0072] As an optional embodiment, the method further includes:

[0073] The second unidirectional conducting module D2 has a positive electrode connected to the external output negative electrode, and a negative electrode connected to the first end of the second voltage-dividing resistor Rf2.

[0074] It is understandable that, considering that the positive electrode of the battery pack is directly connected to the negative electrode of the battery pack through the first voltage-divider resistor Rf1 and the second voltage-divider resistor Rf2, when the charger is reversely connected, there is a possibility that reverse leakage current will be output from the positive electrode of the battery pack to the negative electrode of the battery pack, causing damage to the charger. To prevent leakage in this circuit, a second unidirectional conduction module D2 can be further added between the second voltage-divider resistor Rf2 and the negative electrode of the battery pack to set the current direction of this circuit to flow from the negative electrode of the battery pack to the second voltage-divider resistor Rf2, thereby avoiding current reverse flow and circuit leakage. The specific type and implementation method of the second unidirectional conduction module D2 are not specifically limited in this application, and it can be implemented using unidirectional conduction devices such as diodes and thyristors.

[0075] Specifically, by adding a second unidirectional conduction module D2, leakage and current reverse in the loop can be effectively avoided, ensuring the accurate operation of the circuit; the structure is simple and easy to implement, which is conducive to the simple implementation of the entire anti-reverse connection circuit.

[0076] In order to solve the above technical problems, the present invention also provides a charge and discharge control circuit for a battery pack, comprising a charge and discharge switch and the aforementioned anti-reverse connection circuit;

[0077] The first end of the charge and discharge switch is connected to the positive electrode of the battery in the battery pack, and the second end serves as the internal charging input end, which is respectively connected to the first end of the anti-reverse connection circuit and the external output positive electrode. The control end is used to access the first preset drive signal and is connected to the second end of the anti-reverse connection circuit.

[0078] It is not difficult to understand that the anti-reverse connection circuit provided in this application needs to be used in conjunction with the charge and discharge switch in the charge and discharge control circuit in the battery pack to protect the battery pack and charger by adjusting the on and off states of the charge and discharge switch.

[0079] For an introduction to a charge and discharge control circuit of a battery pack provided by the present invention, please refer to the above-mentioned embodiment of the anti-reverse connection circuit, and the present invention will not be described in detail here.

[0080] As an optional embodiment, the charge and discharge switch includes:

[0081] A first charge-discharge electronic switch Q11, having a first end connected to the positive electrode of a battery in the battery pack and a control end for receiving a second preset drive signal;

[0082] A second charge-discharge electronic switch Q12, having a first end connected to the second end of the first charge-discharge electronic switch Q11, a second end connected to the external output positive electrode and the first end of the anti-reverse connection circuit respectively, and a control end for receiving a first preset drive signal and connected to the second end of the anti-reverse connection circuit;

[0083] The first charge-discharge electronic switch Q11 and the second charge-discharge electronic switch Q12 are both provided with parasitic diodes, and the cathode of the parasitic diode of the first charge-discharge electronic switch Q11 is connected to the anode of the parasitic diode of the second charge-discharge electronic switch Q12; the switching states of the first charge-discharge electronic switch Q11 and the second charge-discharge electronic switch Q12 are consistent.

[0084] It is understandable that in order to improve the accuracy and reliability of the working process of the charge and discharge switch, it can be achieved by setting up multiple charge and discharge electronic switches. In particular, when the charge and discharge switch is implemented by a MOS tube, when the charge and discharge switch is turned off, the voltage output from the positive end of the battery may be discharged through the parasitic diode of the charge and discharge switch. In this embodiment, the charge and discharge switch is implemented by setting two charge and discharge electronic switches, and the parasitic diodes of the two charge and discharge electronic switches are reversed. At this time, by synchronously controlling the two charge and discharge electronic switches, the charge and discharge circuit of the battery pack can be fully controlled, and there will be no situation where leakage cannot be controlled. The specific type and implementation method of the first charge and discharge electronic switch Q11 and the second charge and discharge electronic switch Q12 are not particularly limited in this application. In actual application, the charge and discharge switch is not limited to the two charge and discharge electronic switches used in this embodiment. It can also be implemented in other ways. Figure 2 As shown, a first charge-discharge electronic switch Q11 and a second charge-discharge electronic switch Q12 are used to implement the entire charge-discharge switch.

[0085] Specifically, the entire charge and discharge switch is implemented in a pair of tubes, which can achieve complete control of the charge and discharge circuit from the positive end of the battery to the positive end of the battery pack while synchronously controlling the two charge and discharge electronic switches. The parasitic diodes of the two charge and discharge electronic switches are reversed, and there is no leakage through the parasitic diodes, ensuring the accurate implementation of the entire charge and discharge control circuit.

[0086] As an optional embodiment, the method further includes:

[0087] a third current limiting module RX3 connected to the first charge and discharge electronic switch Q11, wherein a first end is connected to the control end of the first charge and discharge electronic switch Q11, and a second end is used to receive a second preset driving signal;

[0088] and / or,

[0089] The fourth current limiting module RX4 correspondingly connected to the second charge and discharge electronic switch Q12 has a first end connected to the control end of the second charge and discharge electronic switch Q12, and a second end used to receive the first preset driving signal and connected to the second end of the anti-reverse connection circuit.

[0090] It is not difficult to understand that in order to avoid the direct connection between the control end of the charge and discharge electronic switch and the preset drive signal, a third current limiting module RX3 and / or a fourth current limiting module RX4 correspondingly connected to the control end of the two charge and discharge electronic switches can be added. The third current limiting module RX3 and the fourth current limiting module RX4 can play a role in limiting the drive current, preventing the drive current output to the control end of the controllable sub-switch from being too large, avoiding damage to the driver chip due to insufficient driving capability, and further protecting the charge and discharge electronic switch. The specific type and implementation method of the third current limiting module RX3 and the fourth current limiting module RX4 are not specifically limited in this application, and can generally be implemented by a resistor. The third current limiting module RX3 and the fourth current limiting module RX4 can be set one by one, or can be set at the same time. Specifically, they can be selected and set according to the specific circumstances of the first charge and discharge electronic switch Q11 and the second charge and discharge electronic switch Q12.

[0091] Specifically, by adding a third current limiting module RX3 and a fourth current limiting module RX4 correspondingly connected to the charge and discharge electronic switches, the charge and discharge electronic switches can be effectively protected, the accuracy and reliability of the action process of the charge and discharge electronic switches can be ensured, and the accurate implementation of the entire charge and discharge control circuit can be guaranteed.

[0092] As an optional embodiment, the method further includes:

[0093] A first resistor R1, having a first end connected to the positive electrode of a battery in the battery pack and a first end of the first charge and discharge electronic switch Q11, respectively, and a second end for receiving a second preset drive signal and connected to a second end of the third current limiting module RX3;

[0094] and / or,

[0095] The second resistor R2 has a first end connected to the first end of the anti-reverse connection circuit and the second end of the second charge and discharge electronic switch Q12, respectively, and a second end used to access the first preset drive signal, and is respectively connected to the second end of the fourth current limiting module RX4 and the second end of the anti-reverse connection circuit.

[0096] It is not difficult to understand that for the charge and discharge electronic switch, especially when the charge and discharge electronic switch is implemented using a MOS tube, static electricity will also exist between its gate and source. At this time, the electrostatic discharge process can be achieved by adding a first resistor R1 connected to the first charge and discharge electronic switch Q11 and / or a second resistor R2 connected to the second charge and discharge electronic switch Q12, thereby further protecting the charge and discharge electronic switch. The specific types and implementation methods of the first resistor R1 and the second resistor R2 are not particularly limited in this application. Other methods can also be used to achieve the electrostatic discharge process, not limited to the implementation method of the resistors in this embodiment.

[0097] Specifically, by increasing the first resistance R1 and the second resistance R2, the charging and discharging switch can be further protected, and the normal working process of the charging and discharging switch can be ensured; the structure is simple, easy to implement, and conducive to the simple implementation of the entire charging and discharging control circuit.

[0098] As an optional embodiment, further comprising:

[0099] The second voltage stabilizing module has a first end connected with the positive pole of the battery in the battery pack and the first end of the first charging and discharging switch Q11 respectively, and a second end for connecting with a second preset driving signal and connected with the second end of the third current limiting module RX3.

[0100] And / or,

[0101] The third voltage stabilizing module has a first end connected with the first end of the anti-reverse connection circuit and the second end of the second charging and discharging switch Q12 respectively, and a second end for connecting with a first preset driving signal and connected with the second end of the fourth current limiting module RX4 and the second end of the anti-reverse connection circuit respectively.

[0102] It can be understood that for the charging and discharging switch, especially when the charging and discharging switch is implemented by a MOS tube, the voltage between the gate and the source is also limited, and when the voltage of the two ends is too large, the charging and discharging switch will be damaged beyond the withstand voltage. Therefore, a second voltage stabilizing module corresponding to the first charging and discharging switch Q11 and a third voltage stabilizing module corresponding to the second charging and discharging switch Q12 can be added to stabilize the voltage between the gate and the source of the first charging and discharging switch Q11 or the second charging and discharging switch Q12 at a preset value. The specific type and implementation of the second voltage stabilizing module and the third voltage stabilizing module are not particularly limited in this application, and can be implemented by a voltage stabilizing device such as a voltage stabilizing diode; one of the second voltage stabilizing module and the third voltage stabilizing module can be selected, or both can be selected, and the selection and setting can be made according to the specific conditions of the first charging and discharging switch Q11 and the second charging and discharging switch Q12.

[0103] Specifically, by increasing the second voltage stabilizing module connected in parallel between the first end and the control end of the first charging and discharging switch Q11 and / or the third voltage stabilizing module connected in parallel between the second end and the control end of the second charging and discharging switch Q12, the stability and reliability of the first preset driving signal and the second preset driving signal can be effectively improved, and the damage of the charging and discharging switch caused by exceeding the withstand voltage can be avoided, ensuring the safety and reliability of the entire charging and discharging control circuit.

[0104] As an optional embodiment, the second voltage stabilizing module comprises:

[0105] A first voltage stabilizing diode, the anode of which is respectively connected to the anode of the battery in the battery pack and the first end of the first charge and discharge electronic switch Q11;

[0106] The second voltage-stabilizing diode has a cathode connected to the cathode of the first voltage-stabilizing diode, and an anode used for receiving the second preset driving signal and connected to the second end of the third current-limiting module RX3.

[0107] It is not difficult to understand that in order to further ensure the safety and reliability of the charge and discharge electronic switch, the second voltage stabilizing module can be implemented by two voltage stabilizing diodes connected in reverse series, which can effectively realize the overvoltage protection process at both ends of the gate and source of the charge and discharge electronic switch. The specific type and implementation method of the two voltage stabilizing diodes are not specifically limited in this application. The third voltage stabilizing module can also be implemented by two voltage stabilizing diodes connected in reverse series, which will not be described in detail in this application. Figure 2 As shown, this embodiment uses a Zener diode DZ21 and a Zener diode DZ22 connected in series to implement the second voltage stabilization module, and uses a Zener diode DZ31 and a Zener diode DZ32 connected in series to implement the third voltage stabilization module.

[0108] Specifically, two reverse-connected voltage-stabilizing diodes can effectively achieve voltage stabilization and overvoltage protection functions, ensuring the safety and reliability of the charge and discharge electronic switch. This structure is simple and easy to implement, which is conducive to the simple implementation of the entire charge and discharge control circuit.

[0109] In order to solve the above technical problems, the present invention also provides a battery pack system, including a plurality of batteries and a charge and discharge control circuit of the battery pack as described above, wherein the positive poles of the batteries are connected to the charge and discharge control circuit of the battery pack.

[0110] For an introduction to a battery pack system provided by the present invention, please refer to the above-mentioned embodiment of the anti-reverse connection circuit, and the present invention will not be described in detail here.

[0111] It should also be noted that, in this specification, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0112] The above description of the disclosed embodiments will enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A reverse connection protection circuit, characterized in that: include: a first voltage-dividing resistor; A second voltage-dividing resistor, a first end of which is connected to the external output negative electrode; N controllable sub-switches, wherein first ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to an external output positive electrode, a first end of the first voltage-dividing resistor, and an internal charging input terminal; second ends of the N controllable sub-switches are connected to each other, and a common connection point is used to receive a first preset drive signal; control ends of the N controllable sub-switches are connected to each other, and a common connection point is respectively connected to a second end of the first voltage-dividing resistor and a second end of the second voltage-dividing resistor; N is a positive integer greater than 1; The controllable sub-switch is used to cooperate with the first preset driving signal to control the disconnection between the external output positive electrode and the internal charging input terminal when the voltage of the external output negative electrode is greater than the voltage of the external output positive electrode.

2. The anti-reverse connection circuit according to claim 1, wherein: Also includes: N first current limiting modules are connected to the N controllable sub-switches in a one-to-one correspondence, wherein the first ends of the first current limiting modules are connected to the control ends of the corresponding controllable sub-switches, the second ends of the N first current limiting modules are connected to each other, and a common connection point is respectively connected to the second end of the second voltage-dividing resistor and the second end of the first voltage-dividing resistor.

3. The anti-reverse connection circuit according to claim 1, wherein: Also includes: The second current limiting module has a first end connected to the second ends of the N controllable sub-switches respectively, and a second end used to receive a first preset driving signal.

4. The anti-reverse connection circuit according to claim 3, wherein: Also includes: The first unidirectional conducting module has a positive electrode for receiving the first preset driving signal and a negative electrode connected to the second end of the second current limiting module.

5. The anti-reverse connection circuit according to any one of claims 1 to 4, characterized in that: Also includes: The first voltage stabilizing module has a positive electrode connected to the first end of the first voltage-dividing resistor, the external output positive electrode, and the first ends of the N controllable sub-switches, and a negative electrode connected to the second end of the first voltage-dividing resistor, the second end of the second voltage-dividing resistor, and the control ends of the N controllable sub-switches.

6. The anti-reverse connection circuit according to claim 5, wherein: Also includes: a capacitor, wherein a first end is respectively connected to the positive electrode of the first voltage stabilizing module, the first end of the first voltage-dividing resistor, the external output positive electrode, and the first ends of the N controllable sub-switches, and a second end is respectively connected to the negative electrode of the first voltage stabilizing module, the second end of the first voltage-dividing resistor, the second end of the second voltage-dividing resistor, and the control ends of the N controllable sub-switches.

7. The anti-reverse connection circuit according to claim 6, wherein: Also includes: The second unidirectional conducting module has a positive electrode connected to the external output negative electrode, and a negative electrode connected to the first end of the second voltage-dividing resistor.

8. A charge and discharge control circuit for a battery pack, characterized in that: comprising a charge and discharge switch and an anti-reverse connection circuit according to any one of claims 1 to 7; The first end of the charge and discharge switch is connected to the positive electrode of the battery in the battery pack, and the second end serves as the internal charging input end, which is respectively connected to the first end of the anti-reverse connection circuit and the external output positive electrode; the control end is used to access the first preset drive signal and is connected to the second end of the anti-reverse connection circuit.

9. The charge and discharge control circuit of the battery pack according to claim 8, wherein: The charge and discharge switch includes: a first charge-discharge electronic switch, wherein a first end is connected to the positive electrode of a battery in the battery pack, and a control end is used to receive a second preset drive signal; a second charge-discharge electronic switch, wherein the first end is connected to the second end of the first charge-discharge electronic switch, the second end is respectively connected to the external output positive electrode and the first end of the anti-reverse connection circuit, and the control end is used to receive the first preset drive signal and is connected to the second end of the anti-reverse connection circuit; The first charge-discharge electronic switch and the second charge-discharge electronic switch are both provided with parasitic diodes, and the cathode of the parasitic diode of the first charge-discharge electronic switch is connected to the anode of the parasitic diode of the second charge-discharge electronic switch; the switching states of the first charge-discharge electronic switch and the second charge-discharge electronic switch remain consistent.

10. A battery pack system, characterized in that: The invention comprises a plurality of batteries and a charge and discharge control circuit of the battery pack as claimed in claim 8, wherein the positive electrodes of the batteries are connected to the charge and discharge control circuit of the battery pack.

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