A battery pack charging and discharging control module and control method

Abstract

A battery pack charge and discharge control module and control method of the present invention include a main controller unit and a charge and discharge control module, wherein the charge and discharge control module includes a discharge control switch tube, a charge control switch tube, a discharge tube drive control circuit, and a charge tube drive control circuit; the discharge control switch tube and the charge control switch tube are both power MOSFETs, and a reverse-parallel parasitic diode is integrated between the drain and source; the charge control switch tube and the discharge control switch tube are connected in series with a common drain, the source of the discharge control switch tube is connected to the negative output terminal of the battery pack, and the source of the charge control switch tube is connected to the negative busbar; the positive electrode of the battery pack is connected to the positive busbar. The present invention can not only fully control the charge and discharge process of the battery pack, but also effectively solve the problem of load interruption caused by the inability of the battery to discharge in the event of a control unit failure, thereby greatly improving the reliability of the power supply of the battery backup power supply system.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a battery pack charge and discharge control module and a control method. Background Art

[0002] At present, batteries have been widely used in various industries as the main source of power and backup power. Single cells are limited by battery voltage and capacity, and are difficult to use alone in many occasions. In order to obtain a power source with higher power and voltage, it is often necessary to connect multiple single cells in series and use multiple groups of batteries in parallel.

[0003] Multiple groups of batteries of different types, manufacturers, batches, periods and models cannot be used in parallel directly due to differences in charging and discharging performance such as battery capacity, floating charge voltage, equalizing charge voltage and charging rate. Otherwise, the battery performance will drop sharply, and the battery stability and service life will be greatly reduced.

[0004] In recent years, in order to solve the problem of parallel use of different battery groups, battery combination circuit devices have emerged, such as Figure 1 As shown, a charging control module is connected in series to the negative output end of each battery group. Each charging control module adopts a MOS switch tube. An anti-parallel diode is integrated inside the MOS tube. The main controller unit controls each MOS tube to conduct charging in time and meet the requirements of different average floating charge voltages of different battery groups. The unidirectional conductivity of the diode can ensure that there is no circulating current when each battery group is discharged, thereby realizing electrical isolation when different battery groups are connected in parallel.

[0005] With the expansion of communication base stations and the requirements of energy conservation and emission reduction, second-life lithium batteries are becoming the mainstream of backup power for communication base stations. Communication base stations are facing the actual demand of using different types of batteries in parallel. Since the cycle charge and discharge life of lithium batteries is much longer than that of lead-acid batteries, when lithium batteries and lead-acid batteries are used in parallel, setting lithium battery priority discharge can give full play to the respective advantages of lithium batteries and lead-acid batteries. Therefore, the demand for group discharge is put forward for battery management equipment, that is, after the city power outage, lithium battery packs are used for discharge first, until the lithium battery packs are discharged, and then lead-acid batteries are used for discharge. The above-mentioned battery combination circuit device ( Figure 1 As shown in the figure, only the charging stage of the battery pack can be controlled. Due to the existence of the anti-parallel body diode, only no circulating current can be ensured during the discharge stage, and discharge control cannot be achieved.

[0006] In order to control the charging and discharging stages of the battery pack, two MOS tubes need to be used in reverse series design to replace Figure 1 The single-tube design in Figure 2As shown, one of them is a charge control switch tube, and the other is a discharge control switch tube. The anti-parallel diode integrated inside the MOS tube can ensure that a MOS tube and a diode are turned on in both the charging stage and the discharging stage, so that both charging and discharging can be controlled. Given that the MOS tube drive circuit is added to the gate G and the source S, the current two MOS tube reverse series design schemes are both MOS tube common source (common S pole) schemes, and an isolated power supply chip is required to convert the 48V power supply into an isolated 15V power output to power the driving power amplifier unit. The driving power amplifier unit can output two common ground drive signals to control the charging switch tube and the discharging switch tube respectively. Figure 2 This solution uses an isolated power chip and a dedicated driver chip, and MOS tubes with a common S pole in series. When the main control unit fails, both the charging control tube and the discharging control tube will be turned off, resulting in the battery being unable to discharge, which will in turn cause the base station to be disconnected, which will seriously affect the safety and reliability of the entire base station power supply system and communication system. In addition, the isolated power chip and the dedicated driver chip are expensive, and the common S pole of the MOS tube will complicate the busbar and heat dissipation process of the entire charging and discharging control module.

[0007] Therefore, in order to ensure the stable and reliable operation of key equipment such as base station communication equipment, improve the utilization efficiency of batteries and extend the service life of batteries, there is an urgent need for a control module and control method with higher reliability and lower cost that can effectively manage the parallel charging and discharging operation of different battery groups such as lead-acid batteries and iron-lithium batteries. Summary of the invention

[0008] A battery pack charge and discharge control module proposed in the present invention can solve the technical defects in the background technology.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] A battery pack charge and discharge control module comprises a discharge control switch tube, a charge control switch tube, a discharge tube drive control circuit, a charge tube drive control circuit, a main controller unit and the like.

[0011] The charging control switch tube and the discharging control switch tube are both power MOSFETs, and a reverse-parallel parasitic diode is integrated between the drain and source. The charging control switch tube and the discharging control switch tube are connected in series with a common drain (common D pole), that is, the drains D of the two switch tubes are connected together, the source S of the discharging control switch is connected to the negative output terminal of the battery pack, and the source S of the charging control switch tube is connected to the negative busbar.

[0012] The discharge tube drive control circuit is composed of an optocoupler element, a resistor element, a capacitor element and a voltage regulator element, specifically: the input of the optocoupler element P1 is connected to the output of the main controller unit, the collector of the optocoupler element P1 is connected to the positive electrode of the battery pack through the resistor R11, and the collector of P1 is also connected to the cathode of the voltage regulator tube D11, and the emitter of the optocoupler element P1 is connected to the source S of the discharge control switch tube T1; the anode of the voltage regulator tube D11 is connected to the base of transistors Q11 and Q12; the transistors Q11 and Q12 form a totem pole structure, that is, the upper tube Q11 is an NPN transistor, the lower tube Q12 is a PNP transistor, the bases of Q11 and Q12 are connected together as input, and the emitters of Q11 and Q12 are connected together as output; the bases of Q11 and Q12 The anode of the voltage regulator tube D11 is connected to the anode of the voltage regulator tube D11, and is also connected to the source S of the discharge control switch tube T1 through the resistor R14; the emitters of Q11 and Q12 are connected to the gate G of the discharge control switch tube T1, and are also connected to the cathode of the voltage regulator tube D12; the emitter of the transistor Q12 and the anode of the voltage regulator tube D12 are both connected to the source S of the discharge control switch tube; the collector of the transistor Q11 is connected to the positive electrode of the battery pack through the resistors R13, R12 and the capacitor C11, wherein the resistor R12 and the capacitor C11 are connected in parallel and then connected in series with the resistor R13, one end of R13 is connected to the collector of the transistor Q11, and one end of the resistor R12 and the capacitor C11 are connected in parallel to the positive electrode of the battery pack; a capacitor C12 is also connected between the positive output line of the battery pack and the source S of the discharge control switch tube T1.

[0013] The charging tube drive control circuit is composed of an optocoupler element, a resistor element, a capacitor element and a voltage regulator element, specifically: the input of the optocoupler element P2 is connected to the output of the main controller unit, the collector of the optocoupler element P2 is connected to the positive electrode of the battery pack through a resistor R21, and the collector of P2 is also connected to the cathode of the voltage regulator tube D21, and the anode of D21 is connected to the source S of the charging control switch tube T2; the emitter of the optocoupler element P2 is connected to the source S of the charging control switch tube T2 through a resistor R24, and at the same time, the emitter of the optocoupler source P2 is also connected to the base of transistors Q21 and Q22; transistors Q21 and Q22 form a totem pole structure, that is, the upper tube Q21 is an NPN transistor, the lower tube Q22 is a PNP transistor, the bases of Q21 and Q22 are connected together as input, and Q2 The emitters of Q1 and Q22 are connected together as output; the bases of Q21 and Q22 are connected to the emitter output terminal of the optocoupler element P2; the emitters of Q21 and Q22 are connected to the gate G of the charge control switch tube T2, and are also connected to the cathode of the voltage regulator tube D22; the emitter of the transistor Q22 and the anode of the voltage regulator tube D22 are all connected to the source S of the charge control switch tube; the collector of the transistor Q21 is connected to the positive electrode of the battery pack through the resistors R23, R22 and the capacitor C21, wherein the resistor R22 and the capacitor C21 are connected in parallel and then in series with the resistor R23, one end of R23 is connected to the collector of the transistor Q21, and one end of the resistor R22 and the capacitor C21 are connected in parallel to the positive electrode of the battery pack; a capacitor C22 is also connected between the positive output line of the battery pack and the source S of the charge control switch tube T2.

[0014] When the differential battery groups are operated in parallel, each battery group needs to use a set of charge and discharge control modules. Multiple sets of charge and discharge control modules can be integrated together to form a differential battery group shared manager to manage the charge and discharge operation of the differential battery groups.

[0015] The main controller unit may include a microprocessor, voltage and current data sampling, operation display, software program and related auxiliary peripheral circuits, etc., and controls the on and off of the charging control switch tube and the discharging control switch tube in each group of charging and discharging control modules by setting the operating parameters of each group of batteries, collecting the battery group voltage and the DC power supply output bus voltage. Multiple charging and discharging control modules share one main controller unit.

[0016] In order to achieve stable, reliable and efficient operation of the above-mentioned battery pack charge and discharge control module, the present invention also provides a battery pack charge and discharge control method, which is specifically:

[0017] In the discharge tube drive control circuit, when the main controller outputs a high level, the optocoupler element P1 in the discharge tube drive control module is turned on, the collector of P1 outputs a low level, the emitters of transistors Q11 and Q12 output a low level, the gate-source voltage of the discharge control switch tube T1 is a low level (0V), and the discharge control switch tube T1 is turned off; correspondingly, when the main controller outputs a low level, the gate-source voltage of the discharge control switch tube T1 is a high level, and the discharge control switch tube T1 is turned on.

[0018] In the charging tube drive control circuit, when the main controller outputs a high level, the optocoupler element P2 in the charging tube drive control module is turned on, the emitter of P2 outputs a high level, the transistor Q21 is turned on, the transistor Q22 is turned off, the emitters of the transistors Q21 and Q22 output a high level, the gate-source voltage of the charging control switch tube T2 is a high level, and the charging control switch tube T2 is turned on; correspondingly, when the main controller outputs a low level, the gate-source voltage of the charging control switch tube T2 is a low level (0V), and the charging control switch tube T2 is turned off.

[0019] Correspondingly, when the main controller unit fails, the main controller will output a low level, and the optocoupler elements in all charge and discharge control modules will be turned off. At this time, the discharge control switch tube is turned on, and the charge control switch tube is turned off. The discharge control switch tube and the parasitic diode inside the charge control switch tube together form a discharge channel, ensuring that the discharge channel is unobstructed, ensuring that the load is not powered off due to a control system failure, and improving the safety and reliability of the backup power system.

[0020] Accordingly, during the charging stage of the battery pack, the discharge control switch tube is kept turned on all the time, and the charging current or voltage of the battery pack is adjusted by controlling the on and off of the charging control switch tube. During the charging stage, the discharge control switch tube is kept turned on all the time, rather than continuing the current through the parasitic diode of the discharge control switch tube, which can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the charging stage.

[0021] Accordingly, during the discharge stage of the battery pack, the charging control switch tube is kept turned on all the time, and the discharge current or voltage of the battery pack is adjusted by controlling the on and off of the discharge control switch tube. During the discharge stage, the charging control switch tube is kept turned on all the time, rather than continuing the current through the parasitic diode of the charging control switch tube, which can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the discharge stage.

[0022] It can be seen from the above technical solution that the battery pack charge and discharge control module of the present invention has the following beneficial effects:

[0023] 1) The battery pack charge and discharge control module and method described in the present invention can effectively control the charge and discharge process of the battery pack, and is particularly suitable for the shared management of differential battery packs, and can control the synchronous charging or group charging, synchronous discharging or group discharging of each battery pack.

[0024] 2) The battery pack charge and discharge control module and method described in the present invention can keep the battery discharge circuit unobstructed even if the main control unit fails, and can also ensure electrical isolation between the battery packs, which can significantly improve the safety and reliability of the battery backup system.

[0025] 3) The battery pack charge and discharge control module described in the present invention does not need to use a relatively expensive isolation power chip and a dedicated switch tube driver chip, which can reduce equipment costs.

[0026] 4) The battery pack charge and discharge control module described in the present invention adopts a MOS tube common drain (D pole) series connection scheme instead of a common source (S pole) scheme, which can optimize module heat dissipation and busbar technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a battery pack parallel circuit device in the prior art;

[0028] Figure 2 It is a schematic diagram of a common management device for different battery groups in the prior art;

[0029] Figure 3 A battery pack charge and discharge control module and method according to the present invention realizes the principle diagram of shared management of different battery packs;

[0030] Figure 4 It is a discharge tube driving control principle diagram in a battery pack charge and discharge control module and method described in the present invention;

[0031] Figure 5 It is a schematic diagram of the driving control principle of a charging tube in a battery pack charging and discharging control module and method described in the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0033] See also Figure 3The battery pack charge and discharge control module comprises a main controller unit 3 and a charge and discharge control module, wherein the main controller unit 3 and the charge and discharge control module are connected via two control signals; the charge and discharge control module comprises a discharge control switch tube 6, a charge control switch tube 7, a discharge tube drive control circuit 8, and a charge tube drive control circuit 9; the main controller unit 3 is respectively connected to the discharge tube drive control circuit 8 and the charge tube drive control circuit 9 via control signals;

[0034] The discharge control switch tube 6 and the charge control switch tube 7 are both power MOSFETs, and a reverse-parallel parasitic diode is integrated between the drain and source;

[0035] The charging control switch tube 7 and the discharging control switch tube 6 are connected in series with a common drain, that is, the drains of the two MOSFETs are connected together, the source of the discharging control switch tube 6 is connected to the negative output terminal of the battery pack, and the source of the charging control switch tube 7 is connected to the negative busbar; the positive pole of the battery pack is connected to the positive busbar.

[0036] in,

[0037] After receiving the control signal from the main controller unit 3, the discharge tube drive control circuit 8 outputs a control signal to the gate and source of the discharge control switch tube 6 after isolation, conditioning and amplification;

[0038] After receiving the control signal from the main controller unit 3 , the charging tube drive control circuit 9 outputs a control signal to the gate and source of the charging control switch tube 7 after isolation, conditioning and amplification.

[0039] The following are specific instructions:

[0040] The charging control switch tube 6 and the discharging control switch tube 7 are both power MOSFETs, and a reverse-parallel parasitic diode is integrated between the drain and source. The charging control switch tube 6 and the discharging control switch tube 7 are connected in series with a common drain (common D pole), that is, the drains D of the two switch tubes are connected together, the source S of the discharging control switch tube 6 is connected to the negative output terminal of the battery pack 4, and the source S of the charging control switch tube is connected to the negative busbar.

[0041] When multiple groups of differential battery packs are shared, each group of batteries needs to be connected to a charge and discharge control module. As shown in the figure, when two groups of differential battery packs are shared in parallel, the negative electrode of the first battery pack 4 is connected to the negative busbar via the first charge and discharge control module 5, and the second battery pack 10 is connected to the negative busbar via the second charge and discharge control module 11. The input 1 of the positive busbar and the input 2 of the negative busbar can be connected to the DC output of the rectifier power supply, and the load 12 is connected in parallel on both sides of the DC busbar. The first battery pack 4 and the second battery pack 10 can be battery packs of different types, models, periods, and brands. The first charge and discharge control module and the second charge and discharge control module have the same internal structure and can control the charge and discharge of the first battery pack 4 and the second battery pack 10 respectively. When multiple groups of differential battery packs are shared in parallel, the multiple charge and discharge control modules can be integrated together to form a differential battery pack sharing manager to manage the charge and discharge operation of the differential battery packs.

[0042] The main controller unit 3 may include a microprocessor, voltage and current data sampling, operation display, software program and related auxiliary peripheral circuits, etc., and controls the on and off of the charging control switch tube 6 and the discharging control switch tube 7 in each group of charging and discharging control modules by setting the operating parameters of each group of batteries (including but not limited to battery type, equalization charging voltage, floating charging voltage, charging current limit value, discharging current limit value, etc.), collecting the battery group voltage and the DC power supply output busbar voltage. Multiple charging and discharging control modules share one main controller unit 3.

[0043] See also Figure 4The discharge tube drive control circuit 8 is composed of an optical coupling element, a resistor element, a capacitor element and a voltage regulator element, specifically: the input of the optical coupling element P1 is connected to the output of the main controller unit, the collector of the optical coupling element P1 is connected to the positive electrode of the battery pack through the resistor R11, and the collector of P1 is also connected to the cathode of the voltage regulator tube D11, and the emitter of the optical coupling element P1 is connected to the source S of the discharge control switch tube T1; the anode of the voltage regulator tube D11 is connected to the base of the transistors Q11 and Q12; the transistors Q11 and Q12 form a totem pole structure, that is, the upper tube Q11 is an NPN transistor, the lower tube Q12 is a PNP transistor, the bases of Q11 and Q12 are connected together as input, and the emitters of Q11 and Q12 are connected together as output; the bases of Q11 and Q12 The anode of the voltage regulator tube D11 is connected to the anode of the voltage regulator tube D11, and is also connected to the source S of the discharge control switch tube T1 through the resistor R14; the emitters of Q11 and Q12 are connected to the gate G of the discharge control switch tube T1, and are also connected to the cathode of the voltage regulator tube D12; the emitter of the transistor Q12 and the anode of the voltage regulator tube D12 are both connected to the source S of the discharge control switch tube; the collector of the transistor Q11 is connected to the positive electrode of the battery pack through the resistors R13, R12 and the capacitor C11, wherein the resistor R12 and the capacitor C11 are connected in parallel and then connected in series with the resistor R13, one end of R13 is connected to the collector of the transistor Q11, and one end of the resistor R12 and the capacitor C11 are connected in parallel to the positive electrode of the battery pack; a capacitor C12 is also connected between the positive output line of the battery pack and the source S of the discharge control switch tube T1.

[0044] See also Figure 5, the charging tube driving control circuit 9 is composed of an optical coupling element, a resistor element, a capacitor element and a voltage regulator element, specifically: the input of the optical coupling element P2 is connected to the output of the main controller unit, the collector of the optical coupling element P2 is connected to the positive electrode of the battery pack through the resistor R21, and the collector of P2 is also connected to the cathode of the voltage regulator tube D21, and the anode of D21 is connected to the source S of the charging control switch tube T2; the emitter of the optical coupling element P2 is connected to the source S of the charging control switch tube T2 through the resistor R24, and the emitter of the optical coupling element P2 is also connected to the base of the transistors Q21 and Q22; the transistors Q21 and Q22 form a totem pole structure, that is, the upper tube Q21 is an NPN transistor, the lower tube Q22 is a PNP transistor, the bases of Q21 and Q22 are connected together as input, Q The emitters of Q21 and Q22 are connected together as output; the bases of Q21 and Q22 are connected to the emitter output terminal of the optocoupler element P2; the emitters of Q21 and Q22 are connected to the gate G of the charge control switch tube T2, and are also connected to the cathode of the voltage regulator tube D22; the emitter of the transistor Q22 and the anode of the voltage regulator tube D22 are all connected to the source S of the charge control switch tube; the collector of the transistor Q21 is connected to the positive electrode of the battery pack through the resistors R23, R22 and the capacitor C21, wherein the resistor R22 and the capacitor C21 are connected in parallel and then in series with the resistor R23, one end of R23 is connected to the collector of the transistor Q21, and one end of the resistor R22 and the capacitor C21 are connected in parallel to the positive electrode of the battery pack; a capacitor C22 is also connected between the positive output line of the battery pack and the source S of the charge control switch tube T2.

[0045] See also Figure 3 , Figure 4 , Figure 5 In order to realize the stable, reliable and efficient operation of the battery pack charge and discharge control module, the present invention provides a battery pack charge and discharge control method, which is specifically:

[0046] In the discharge tube drive control circuit 8, when the main controller unit 3 outputs a high level, the optocoupler element P1 in the discharge tube drive control module is turned on, the collector of P1 outputs a low level, the bases of transistors Q11 and Q12 are at a low level, the emitter output is also at a low level, the gate-source voltage of the discharge control switch tube T1 is at a low level (0V), and the discharge control switch tube T1 is turned off; correspondingly, when the main controller unit 3 outputs a low level, the optocoupler element P1 is turned off, the bases of transistors Q11 and Q12 are at a high level, the transistor Q11 is turned on, the gate-source voltage of the discharge control switch tube T1 is at a high level, and the discharge control switch tube T1 is turned on.

[0047] In the charging tube drive control circuit 9, when the main controller unit 3 outputs a high level, the optocoupler element P2 in the charging tube drive control module is turned on, the emitter of P2 outputs a high level, the transistor Q21 is turned on, the transistor Q22 is turned off, the emitters of transistors Q21 and Q22 output a high level, the gate-source voltage of the charging control switch tube T2 is a high level, and the charging control switch tube T2 is turned on; correspondingly, when the main controller outputs a low level, the optocoupler element P2 is turned off, the emitter of P2 is a low level, that is, the bases of transistors Q21 and Q22 are low level, Q21 is turned off, Q22 is turned on, the emitters of transistors Q21 and Q22 output a low level, the gate-source voltage of the charging control switch tube T2 is a low level (0V), and the charging control switch tube T2 is turned off.

[0048] Correspondingly, when the main controller unit 3 fails, the main controller will output a low level, and the optocoupler elements in all the charge and discharge control modules will be turned off. At this time, the discharge control switch tube is turned on, and the charge control switch tube is turned off. The discharge control switch tube and the parasitic diode inside the charge control switch tube together form a discharge channel, ensuring that the discharge channel is unobstructed, and ensuring that the load is not powered off due to a control system failure, thereby improving the safety and reliability of the backup power system.

[0049] During the charging stage of the battery pack, the discharge control switch tube is kept turned on all the time. The charging current or voltage of the battery pack is adjusted by controlling the on and off of the charging control switch tube. During the charging stage, the discharge control switch tube is kept turned on all the time, rather than using the parasitic diode of the discharge control switch tube for freewheeling. This can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the charging stage.

[0050] During the discharge stage of the battery pack, the charging control switch tube is kept turned on all the time. The discharge current or voltage of the battery pack is adjusted by controlling the on and off of the discharge control switch tube. During the discharge stage, the charging control switch tube is kept turned on all the time, rather than using the parasitic diode of the charging control switch tube for freewheeling. This can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the discharge stage.

[0051] The following further describes the charging and discharging process of the battery pack controlled by the charging and discharging control module through specific implementation examples in combination with the working principle and control method of the charging and discharging control module.

[0052] See also Figure 3 , Figure 4 , Figure 5When the mains power is normal, the main controller unit 3 outputs a low level to the optocoupler element P1 of the discharge tube drive control circuit 8, and outputs a high level to the optocoupler element module P2 of the charging tube drive control circuit 9. At this time, the charging control switch tube and the discharge control switch tube are both turned on, and the output current of the rectifier module is used to charge the battery pack 4 through the turned-on charging control switch tube and the discharge control switch tube. When the main controller unit 3 detects that the battery voltage reaches the set equalization charging voltage or floating charging voltage, or detects that the charging current of the battery pack exceeds the set charging rate, the main controller unit will output a low level to the optocoupler element P2 of the charging tube drive control circuit 9, and the charging control switch tube will be turned off, and the battery pack stops charging. At this time, the parasitic diodes of the discharge control switch tube and the charging control switch tube can ensure that the discharge circuit remains unobstructed when the mains power is cut off. When the battery pack voltage or charging current drops, the charging control switch tube is turned on again to continue charging the battery pack.

[0053] When multiple groups of different battery packs are operated in parallel, when the AC power is normal, the battery pack is in the charging stage, and the main controller unit can output a low-level signal to the discharge tube drive control circuit to keep the discharge control switch tube turned on; output a PWM signal to the charging tube drive control circuit to make the charging control switch tube turn on periodically according to a certain rule, thereby adjusting the balanced distribution of the charging current of each battery group.

[0054] When the city power is cut off, the main controller unit 3 outputs a high level to the optocoupler element P1 of the discharge tube drive control circuit 8, and outputs a high level to the optocoupler element module P2 of the charging tube drive control circuit 9. At this time, the charging control switch tube and the discharge control switch tube are both turned on, and the discharge current of the battery charges the battery pack 4 through the turned-on charging control switch tube and the discharge control switch tube. When the main controller unit 3 detects that the battery voltage reaches the set discharge termination voltage, or detects that the discharge current of the battery pack exceeds the set discharge rate, the main controller unit will output a high level to the optocoupler element P1 of the discharge tube drive control circuit 8, and the discharge control switch tube will be turned off, and the battery pack stops discharging. At this time, the parasitic diodes of the charging control switch tube and the discharge control switch tube can ensure that the charging circuit remains unobstructed when the city power is on. When the discharge current of the battery pack decreases, the discharge control switch tube is turned on again to continue discharging the battery pack.

[0055] When the mains power is cut off and the battery pack is in the standby power discharge stage, when it is detected that the battery pack has a charging circulation current, the main controller unit will output a low level to the optocoupler element module P2 of the charging tube drive control circuit 9, and the charging control switch tube will be turned off.

[0056] When the mains power is cut off and the battery group is in group discharge mode, when the discharge of the battery group reaches the discharge termination voltage, the main controller unit will output a high level to the optocoupler element P1 of the discharge tube drive control circuit 8, and the discharge control switch tube will be turned off. At the same time, it will output a low level to the optocoupler element P2 of the charging tube drive control circuit 9, and the charging control switch tube will also be turned off. The charging control switch tube and the discharge control switch tube will be turned on again after the mains power is restored.

[0057] When multiple groups of different battery packs are operated in parallel, when the city power is cut off and the battery pack is in the discharge stage, the main controller unit can output a low-level signal to the charging tube drive control circuit to keep the charging control switch tube turned on; output a PWM signal to the discharge tube drive control circuit to make the discharge control switch tube turn on periodically according to a certain rule, thereby adjusting the discharge current of each battery group to be evenly distributed.

[0058] In summary, the present invention can not only fully control the charging and discharging process of the battery pack, but also effectively solve the problem of load interruption caused by the inability of the battery to discharge when the control unit fails, thereby greatly improving the reliability of the power supply of the battery backup power supply system.

[0059] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A battery pack charge and discharge control module, comprising a main controller unit (3) and a charge and discharge control module, wherein the main controller unit (3) and the charge and discharge control module are connected via two control signals; characterized in that: The charge and discharge control module comprises a discharge control switch tube (6), a charge control switch tube (7), a discharge tube drive control circuit (8), and a charge tube drive control circuit (9); the main controller unit (3) is respectively connected to the discharge tube drive control circuit (8) and the charge tube drive control circuit (9) via control signals; The discharge control switch tube (6) and the charge control switch tube (7) are both power MOSFETs, and a reverse-parallel parasitic diode is integrated between the drain and source; The charging control switch tube (7) and the discharging control switch tube (6) are connected in series with a common drain, that is, the drains of the two MOSFETs are connected together, the source of the discharging control switch tube (6) is connected to the negative output end of the battery pack, and the source of the charging control switch tube (7) is connected to the negative busbar; the positive electrode of the battery pack is connected to the positive busbar; in, After receiving the control signal from the main controller unit (3), the discharge tube drive control circuit (8) outputs a control signal to the gate and source of the discharge control switch tube (6) after isolation, conditioning and amplification; After receiving the control signal from the main controller unit (3), the charging tube drive control circuit (9) outputs a control signal to the gate and source of the charging control switch tube (7) after isolation, conditioning and amplification; The discharge tube drive control circuit (8) comprises an optical coupling element P1 whose input is connected to the output of the main controller unit (3); the collector of the optical coupling element P1 is connected to the positive electrode of the battery pack via a resistor R11; the collector of P1 is also connected to the cathode of a voltage regulator tube D11; the emitter of the optical coupling element P1 is connected to the source S of the discharge control switch tube T1; the anode of the voltage regulator tube D11 is connected to the bases of transistors Q11 and Q12; the transistors Q11 and Q12 form a totem pole structure, that is, the upper tube Q11 is an NPN transistor, the lower tube Q12 is a PNP transistor, the bases of Q11 and Q12 are connected together as input, and the emitters of Q11 and Q12 are connected together as output; the bases of Q11 and Q12 are connected to the anode of the voltage regulator tube D11 , and is also connected to the source S of the discharge control switch tube T1 through the resistor R14; the emitters of Q11 and Q12 are connected to the gate G of the discharge control switch tube T1, and are also connected to the cathode of the voltage regulator tube D12; the emitter of the transistor Q12 and the anode of the voltage regulator tube D12 are all connected to the source S of the discharge control switch tube; the collector of the transistor Q11 is connected to the positive electrode of the battery pack through the resistors R13, R12 and the capacitor C11, wherein the resistor R12 and the capacitor C11 are connected in parallel and then connected in series with the resistor R13, one end of R13 is connected to the collector of the transistor Q11, and one end of the resistor R12 and the capacitor C11 connected in parallel is connected to the positive electrode of the battery pack; the capacitor C12 is also connected between the positive output line of the battery pack and the source S of the discharge control switch tube T1; The charging tube driving control circuit (9) comprises an optical coupling element P2 whose input is connected to the output of the main controller unit (3); the collector of the optical coupling element P2 is connected to the positive electrode of the battery pack via a resistor R21; the collector of P2 is also connected to the cathode of a voltage regulator tube D21; the anode of D21 is connected to the source S of the charging control switch tube T2; the emitter of the optical coupling element P2 is connected to the source S of the charging control switch tube T2 via a resistor R24; the emitter of the optical coupling source P2 is also connected to the base of transistors Q21 and Q22; the transistors Q21 and Q22 form a totem pole structure, that is, the upper tube Q21 is an NPN transistor, the lower tube Q22 is a PNP transistor, the bases of Q21 and Q22 are connected together as input, and the emitters of Q21 and Q22 are connected together as output; the bases of Q21 and Q22 are connected to the emitter output end of the optocoupler element P2; the emitters of Q21 and Q22 are connected to the gate G of the charge control switch tube T2, and are also connected to the cathode of the voltage regulator tube D22; the emitter of the transistor Q22 and the anode of the voltage regulator tube D22 are all connected to the source S of the charge control switch tube; the collector of the transistor Q21 is connected to the positive electrode of the battery pack through the resistors R23, R22 and the capacitor C21, wherein the resistor R22 and the capacitor C21 are connected in parallel and then in series with the resistor R23, one end of R23 is connected to the collector of the transistor Q21, and one end of the resistor R22 and the capacitor C21 are connected in parallel to the positive electrode of the battery pack; a capacitor C22 is also connected between the positive output line of the battery pack and the source S of the charge control switch tube T2.

2. The battery pack charge and discharge control module according to claim 1, characterized in that: The number of the charge and discharge control modules is n, where n is a natural number greater than or equal to 1; When n=2, The battery pack comprises a first battery pack (4) and a second battery pack (10); the discharge control module comprises a first charge and discharge control module (5) and a second charge and discharge control module (11); The negative electrode of the first storage battery group (4) is connected to the negative electrode busbar via a first charge and discharge control module (5), and the second storage battery group (10) is connected to the negative electrode busbar via a second charge and discharge control module (11); The input of the positive busbar and the input of the negative busbar are connected to the DC output of the rectifier power supply, and the load (12) is connected in parallel to both sides of the DC busbar.

3. A battery pack charge and discharge control method, based on the battery pack charge and discharge control module according to any one of claims 1 to 2, characterized in that: The following steps are involved: When the main controller unit (3) outputs a high level, the optocoupler element P1 in the discharge tube drive control circuit (8) is turned on, the collector of P1 outputs a low level, the emitters of transistors Q11 and Q12 output a low level, the gate-source voltage of the discharge control switch tube T1 is a low level, and the discharge control switch tube T1 is turned off; correspondingly, when the main controller outputs a low level, the gate-source voltage of the discharge control switch tube T1 is a high level, and the discharge control switch tube T1 is turned on; The charging tube drive control circuit is such that when the main controller outputs a high level, the optical coupling element P2 in the charging tube drive control circuit (9) is turned on, the emitter of P2 outputs a high level, the transistor Q21 is turned on, the transistor Q22 is turned off, the emitters of the transistors Q21 and Q22 output a high level, the gate-source voltage of the charging control switch tube T2 is a high level, and the charging control switch tube T2 is turned on; correspondingly, when the main controller outputs a low level, the gate-source voltage of the charging control switch tube T2 is a low level 0V, and the charging control switch tube T2 is turned off.

4. A battery pack charge and discharge control method according to claim 3, characterized in that: It also includes that when the main controller unit fails, the main controller will output a low level, and the optocoupler elements in all charge and discharge control modules will be turned off. At this time, the discharge control switch tube is turned on, and the charging control switch tube is turned off. The discharge control switch tube and the parasitic diode inside the charging control switch tube together form a discharge channel, ensuring that the discharge channel is unobstructed, and ensuring that the load is not powered off due to a control system failure, thereby improving the safety and reliability of the backup power system.

5. A battery pack charge and discharge control method according to claim 4, characterized in that: It also includes keeping the discharge control switch tube turned on all the time during the charging stage of the battery pack, and adjusting the charging current or voltage of the battery pack by controlling the on and off of the charging control switch tube. Keeping the discharge control switch tube turned on all the time during the charging stage, rather than continuing the current through the parasitic diode of the discharge control switch tube, can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the charging stage.

6. A battery pack charge and discharge control method according to claim 5, characterized in that: It also includes keeping the charging control switch tube turned on all the time during the discharge stage of the battery pack, and adjusting the discharge current or voltage of the battery pack by controlling the on and off of the discharge control switch tube. Keeping the charging control switch tube turned on all the time during the discharge stage, rather than continuing the current through the parasitic diode of the charging control switch tube, can reduce the voltage drop on the charge and discharge control module, and further reduce the loss and heat during the discharge stage.

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