Charging and discharging loop control system of split-port battery management system

Abstract

The invention discloses a charging and discharging loop control system of a split-port battery management system. The charging and discharging loop control system comprises a battery management chip, a first discharging switch circuit, a first current detection resistor, a first charging switch circuit and a second discharging switch circuit, wherein the first discharging switch circuit is connected to a discharging loop in series; the first current detection resistor, the first charging switch circuit and the second discharging switch circuit are connected to a charging loop in series; the first operational amplifier control circuit is connected with the first current detection resistor and the second discharge switch circuit; the battery management chip is connected with the first discharging switch circuit and the first charging switch circuit; the first operational amplifier control circuit is configured to control the work of the second discharge switch circuit according to the magnitude of the charging current; therefore, discharge protection is achieved, one-way conduction of the charging current is achieved, and discharge safety of the split charging loop is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management systems, and in particular to a charging and discharging circuit control system of a split-port battery management system. Background Art

[0002] In the field of battery management design, due to the large deviation between charging current and discharging current, in order to better manage the battery, people usually adopt a split-port design, that is, setting different interfaces for charging and discharging respectively, so that they each go through different circuits. Compared with the same-port design, this design method is different from the same-port design. In the same-port design, the charging and discharging switches are connected in series in the same circuit, while in the split-port design, the charging switch and the discharging switch are located in different circuits. In this way, the charging circuit of the battery loses the charging protection originally provided by the discharge switch in the same-port design.

[0003] However, in the current common split-port design solutions, there is usually no additional protection design for this protection deficiency problem. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings and provide a charging and discharging circuit control system for a split-port battery management system, thereby achieving discharge protection, realizing unidirectional conduction of the charging current, and effectively ensuring the discharge safety of the split-port charging circuit.

[0005] To achieve the above object, the specific scheme of the present invention is as follows:

[0006] A charge and discharge circuit control system of a split-port battery management system includes a battery management chip, a first discharge switch circuit connected in series to the discharge circuit, a first current detection resistor connected in series to the charging circuit, a first charging switch circuit, and a second discharge switch circuit; it also includes a first operational amplifier control circuit connected to the first current detection resistor and the second discharge switch circuit; the battery management chip is connected to the first discharge switch circuit and the first charging switch circuit; the first operational amplifier control circuit is configured to control the operation of the second discharge switch circuit according to the size of the charging current.

[0007] Furthermore, the first discharge switch circuit is arranged at the negative end of the discharge circuit; the electrical detection resistor, the first charging switch circuit and the second discharge switch circuit are arranged at the negative end of the charging circuit; the negative end of the discharge circuit and the negative end of the charging circuit are connected in parallel to the negative electrode of the battery pack.

[0008] Furthermore, the second discharge switch circuit includes a first switch device, a control end of the first switch device is connected to a first operational amplifier control circuit; and a switch end of the first switch device is connected in series to a charging circuit.

[0009] Furthermore, the first switching device is a MOS tube, an IGBT tube, a triode or a relay.

[0010] Furthermore, the first operational amplifier control circuit includes a first operational amplifier processing chip, a second switching device, a third switching device and a fourth switching device; the positive and negative input terminals of the first operational amplifier processing chip are respectively connected to the two ends of the first current detection resistor; the output terminal of the first operational amplifier processing chip is connected to the control terminal of the second switching device; the control terminal of the second switching device is connected to one end of its switch terminal and then connected to the negative terminal of the charging circuit; the control terminal of the third switching device is connected to the other end of the switch terminal of the second switching device and then connected to the positive electrode of the battery pack; one end of the switch terminal of the third switching device is connected to the positive electrode of the battery pack, and the other end is connected to the control terminal of the fourth switching device and then grounded; one end of the switch terminal of the fourth switching device is connected to the other end of the switch terminal of the third switching device, and the other end of the switch terminal of the fourth switching device is connected to the second discharge switch circuit.

[0011] Furthermore, the first charging switch circuit includes a fifth switch device, a control end of the fifth switch device is connected to the battery management chip; and a switch end of the fifth switch device is connected in series to the charging circuit.

[0012] Furthermore, the first charging switch circuit also includes a sixth switch device and a seventh switch device; the control end of the sixth switch device is connected to one end of the switch end of the seventh switch device, one end of the switch end of the sixth switch device is connected to the control end of the fifth switch device, and the other end of the switch end of the sixth switch device is connected to the negative end of the charging circuit; the control end of the seventh switch device is connected to the negative end of the charging circuit, the control end of the seventh switch device is also connected to one end of the switch end of the sixth switch device and then connected to the battery management chip, and the other end of the switch end of the seventh switch device is connected to the negative end of the charging circuit.

[0013] Furthermore, the first discharge switch circuit includes an eighth switch device, a control end of the eighth switch device is connected to the battery management chip; and a switch end of the eighth switch device is connected in series to the discharge loop.

[0014] Further, the first discharge switch circuit also includes a ninth switch device and a tenth switch device; the control end of the ninth switch device is connected to one end of the switch end of the tenth switch device, one end of the switch end of the ninth switch device is connected to the control end of the eighth switch device, and the other end of the switch end of the ninth switch device is connected to the negative end of the discharge circuit; the control end of the tenth switch device is connected to the negative end of the discharge circuit, the control end of the tenth switch device is also connected to one end of the switch end of the ninth switch device and then connected to the battery management chip, and the other end of the switch end of the tenth switch device is connected to the negative end of the discharge circuit.

[0015] Furthermore, it also includes a second charging switch circuit and a second operational amplifier control circuit connected in series to the discharge circuit; the charging circuit and the discharge circuit are connected in parallel with a second current detection resistor in series, and the second current detection resistor is connected to the negative pole of the battery pack; the second operational amplifier control circuit controls the operation of the second charging switch circuit according to the size of the discharge current.

[0016] The beneficial effects of the present invention are as follows: the present invention achieves discharge protection by arranging a first current detection resistor and a second discharge switch circuit on the charging circuit, and uses a first operational amplifier control circuit to control the on and off of the second discharge switch circuit according to the size of the charging current, thereby realizing unidirectional conduction of the charging current, effectively ensuring the discharge safety of the branch charging circuit, and at the same time using the first operational amplifier control circuit to control the second discharge switch circuit, which has the characteristics of fast response speed and stable and reliable, and the circuit is simple to build.

[0017] In addition, the present invention separately sets the first current detection resistor in the charging circuit, so that the first operational amplifier control circuit will work only when charging and will not work when discharging. Compared with the method of collecting the total current, it has the characteristics of stronger anti-interference ability and higher current collection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure provided by an embodiment of the present invention;

[0019] Figure 2 is a circuit schematic diagram provided by an embodiment of the present invention;

[0020] Figure 3 is a partial schematic diagram of a battery management chip provided by an embodiment of the present invention;

[0021] Figure 4 is a circuit schematic diagram of a voltage-reducing circuit provided by an embodiment of the present invention;

[0022] Figure 5 is a circuit schematic diagram of a second discharge switch circuit provided by an embodiment of the present invention;

[0023] Figure 6 is a circuit schematic diagram of a first operational amplifier control circuit provided by an embodiment of the present invention;

[0024] Figure 7 is a circuit schematic diagram of a first charging switch circuit provided by an embodiment of the present invention;

[0025] Figure 8 is a circuit schematic diagram of a first discharge switch circuit provided by an embodiment of the present invention;

[0026] Fig. 9 is a circuit schematic diagram of a second charging switch circuit provided by an embodiment of the present invention;

[0027] Fig.10 is a circuit schematic diagram of a second operational amplifier control circuit provided by an embodiment of the present invention;

[0028] Explanation of the accompanying drawings: 100, battery management chip; 200, first discharge switch circuit; 300, first current detection resistor; 400, first charging switch circuit; 500, second discharge switch circuit; 600, first operational amplifier control circuit; 700, step-down circuit; 800, second charging switch circuit; 900, second operational amplifier control circuit. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, but the implementation scope of the present invention is not limited thereto.

[0030] like Figures 1 to 10 As shown, a charge and discharge circuit control system of a split-port battery management system described in this embodiment includes a battery management chip 100, a first discharge switch circuit 200 connected in series to the discharge circuit, and a first current detection resistor 300, a first charging switch circuit 400 and a second discharge switch circuit 500 connected in series to the charging circuit; and also includes a first operational amplifier control circuit 600 connected to the first current detection resistor 300 and the second discharge switch circuit 500; the battery management chip 100 is connected to the first discharge switch circuit 200 and the first charging switch circuit 400; the first operational amplifier control circuit 600 is configured to control the operation of the second discharge switch circuit 500 according to the size of the charging current.

[0031] Specifically, the first current detection resistor 300 is resistor RN1; when the battery pack needs to be charged, the charging circuit is used, the battery management chip 100 controls the first charging switch circuit 400 to open, and the first operational amplifier control circuit 600 collects the charging current of the resistor RN1 and amplifies it. When the charging current is greater than a preset value A, the first operational amplifier control circuit 600 outputs a high level to the second discharge switch circuit 500, and the second discharge switch circuit 500 is opened at this time; after the first operational amplifier control circuit 600 detects that the charging current is less than a preset value A, the first operational amplifier control circuit 600 outputs a low level to the second discharge switch circuit 500, so that the second discharge switch circuit 500 is disconnected, and no discharge to the outside is performed through the charging circuit at this time; when the battery pack needs to be discharged, the discharge circuit is used, and the battery management chip 100 controls the first discharge switch circuit 200 to open, thereby supplying power to the outside.

[0032] This embodiment provides a first current detection resistor 300 and a second discharge switch circuit 500 on the charging circuit, and uses a first operational amplifier control circuit 600 to control the on and off of the second discharge switch circuit 500 according to the size of the charging current, thereby achieving discharge protection and realizing unidirectional conduction of the charging current, effectively ensuring the discharge safety of the split-port charging circuit. At the same time, the first operational amplifier control circuit 600 is used to control the second discharge switch circuit 500, which has the characteristics of fast response speed and stable and reliable, and the circuit is simple to build.

[0033] In addition, this embodiment separately sets the first current detection resistor 300 in the charging circuit, so that the first operational amplifier control circuit 600 works only during charging and does not work during discharging. Compared with the method of collecting the total current, it has the characteristics of stronger anti-interference ability and higher current collection accuracy.

[0034] In this embodiment, Figure 1 , Figure 2 and Figure 4 As shown, it also includes a step-down circuit 700; the step-down circuit 700 is connected to the positive electrode of the battery pack and is configured to power the battery management chip 100; and the step-down circuit 700 also provides the required operating voltage for other circuit modules. Specifically, as Figures 1 to 3 As shown, the battery management chip 100 is chip IC2, the VDD pin of chip IC2 is connected to the buck circuit 700 after being connected in series with resistor R11; the DSG pin of chip IC2 is connected to the first discharge switch circuit 200, the CHG pin of chip IC2 is connected to the first charge switch circuit 400; the VSS pin of chip IC2 is grounded.

[0035] It should be noted that the specific model of the chip IC2 is not limited, as long as it can meet the charge and discharge control of the battery pack, such as the chip model HC32L072KATA.

[0036] The charge and discharge circuit control system of the split-port battery management system of this embodiment is preferably as follows: Figure 1 and Figure 2 As shown, the first discharge switch circuit 200 is arranged at the negative end of the discharge circuit; the electrical detection resistor, the first charging switch circuit 400 and the second discharge switch circuit 500 are arranged at the negative end of the charging circuit; the negative end of the discharge circuit and the negative end of the charging circuit are connected in parallel to the negative electrode of the battery pack; such an arrangement facilitates the control of the first discharge switch circuit 200, the first charging switch circuit 400 and the second discharge switch circuit 500. In this embodiment, the positive electrode of the discharge circuit and the positive electrode of the charging circuit can be arranged to share a charging and discharging positive electrode P+.

[0037] like Figure 2 and Figure 5 As shown, in the charging and discharging circuit control system of the split-port battery management system of this embodiment, in some implementations, the second discharge switch circuit 500 includes a first switch device, the control end of the first switch device is connected to the first operational amplifier control circuit 600; the switch end of the first switch device is connected in series to the charging circuit. In this embodiment, the first switch device is a MOS tube, an IGBT tube, a triode or a relay.

[0038] For example, Figure 2 and Figure 5 As shown, the first switch device is a MOS tube M1, the gate of the MOS tube M1 is connected to the first operational amplifier control circuit 600, the drain of the MOS tube M1 is connected to the first charging switch circuit 400, and the source of the MOS tube M1 is connected to the negative electrode of the battery pack; further, the second discharge switch circuit 500 also includes a parallel Zener diode ZD2 and a resistor R10, one end of the Zener diode ZD2 and the resistor R10 connected in parallel is connected to the gate of the MOS tube M1, and the other end of the Zener diode ZD2 and the resistor R10 connected in parallel is connected to the source of the MOS tube M1; in this way, when the first operational amplifier control circuit 600 outputs a high level, the MOS tube M1 is driven to turn on, so that the charging circuit is turned on; and when the first operational amplifier control circuit 600 outputs a low level, the driving voltage of the MOS tube M1 is turned off, so that it will not be discharged to the outside through the charging circuit, thereby achieving discharge protection and realizing unidirectional conduction of the charging current.

[0039] like Figure 2 and Figure 6As shown, the charge and discharge circuit control system of the split-port battery management system of this embodiment, in some embodiments, the first operational amplifier control circuit 600 includes a first operational amplifier processing chip, a second switch device, a third switch device and a fourth switch device; the positive and negative input terminals of the first operational amplifier processing chip are respectively connected to the two ends of the first current detection resistor 300; the output terminal of the first operational amplifier processing chip is connected to the control terminal of the second switch device; the control terminal of the second switch device is connected to one end of its switch end and then connected to the negative end of the charging circuit; the control terminal of the third switch device is connected to the other end of the switch end of the second switch device and then connected to the positive electrode of the battery pack; one end of the switch end of the third switch device is connected to the positive electrode of the battery pack, and the other end is connected to the control end of the fourth switch device and then grounded; one end of the switch end of the fourth switch device is connected to the other end of the switch end of the third switch device, and the other end of the switch end of the fourth switch device is connected to the second discharge switch circuit 500. In this embodiment, the second switching device is a MOS tube, an IGBT tube, a triode or a relay; the third switching device is a MOS tube, an IGBT tube, a triode or a relay; the fourth switching device is a MOS tube, an IGBT tube, a triode or a relay.

[0040] Specifically, when the charging current is greater than the preset value A, the first operational amplifier processing chip outputs a high level to the control end of the second switch device, so that the second switch device is turned on. At this time, the voltage at the positive electrode of the battery pack drives the first switch device to open after passing through the third switch device and the fourth switch device, that is, the MOS tube M1 is turned on. At this time, the excessive charging current will not burn the MOS tube M1 due to the crystal diode, and the structure is more reliable to use; when the charging current is less than the preset value A, the first operational amplifier processing chip outputs a low level to the control end of the second switch device, so that the second switch device is turned off, and then the driving voltage of the MOS tube M1 is turned off, thereby preventing external discharge through the charging circuit, and the structure is safer to use.

[0041] For example, Figure 2 and Figure 6As shown, the first operational amplifier processing chip is a chip IC1 of model GS8331, the second switch device is a transistor Q2, the third switch device is a transistor Q1, and the fourth switch device is a transistor Q3; the IN (-) pin and the IN (+) pin of the chip IC1 are connected in series with resistors R6 and R7 respectively and then connected to the two ends of the resistor RN1, the IN (-) pin of the chip IC1 is also connected in series with resistor R4 and then connected to the step-down circuit 700, the IN (-) pin and the IN (+) pin of the chip IC1 are connected in series with capacitors C3 and C4 respectively and then connected to the negative electrode C- of the charging circuit, the Vss pin of the chip IC1 is connected to the negative electrode C- of the charging circuit, the OUT pin of the chip IC1 is connected in series with resistor R5 and diode D2 in sequence and then connected to the base of the transistor Q2, and the chip IC1 The VDD pin of the transistor is connected in series with the capacitor C2 and then connected to the negative electrode of the charging circuit; the base of the transistor Q2 is connected to the negative electrode C- of the charging circuit through the capacitor C1 and the resistor R9 connected in parallel, the collector of the transistor Q2 is connected in series with the resistor R2 and then connected to the base of the transistor Q1, and the emitter of the transistor Q2 is connected to the negative electrode C- of the charging circuit; the base of the transistor Q1 is connected in series with the resistor R1 and then connected to the positive electrode B+ of the battery pack, the emitter of the transistor Q1 is connected to the positive electrode B+ of the battery pack, and the collector of the transistor Q1 is connected to the collector of the transistor Q3; the base of the transistor Q3 is connected in series with the resistor R3 and then connected to the collector of the transistor Q1, the base of the transistor Q3 is connected in series with the voltage regulator diode ZD1 and then grounded, and the emitter of the transistor Q1 is connected in series with the resistor R8 and then connected to the gate of the MOS tube M1.

[0042] This embodiment connects the chip IC1 to the negative electrode C- of the charging circuit to ensure the safety, stability and accuracy of the chip IC1 op amp. When the first charging switch circuit 400 is turned off, the negative electrode C- of the charging circuit is suspended, and the chip IC1 no longer works.

[0043] like Figure 2 and Figure 7 As shown, in the charging and discharging circuit control system of the split-port battery management system of this embodiment, in some embodiments, the first charging switch circuit 400 includes a fifth switch device, and the control end of the fifth switch device is connected to the battery management chip 100; the switch end of the fifth switch device is connected in series to the charging circuit. In this embodiment, the fifth switch device is a MOS tube, an IGBT tube, a triode or a relay. Specifically, the CHG pin of the chip IC2 can control the on-off of the charging circuit by controlling the conduction state of the fifth switch device.

[0044] like Figure 2 and Figure 6As shown, the charging and discharging circuit control system of the split-port battery management system of this embodiment, in some embodiments, the first charging switch circuit 400 also includes a sixth switch device and a seventh switch device; the control end of the sixth switch device is connected to one end of the switch end of the seventh switch device, one end of the switch end of the sixth switch device is connected to the control end of the fifth switch device, and the other end of the switch end of the sixth switch device is connected to the negative end of the charging circuit; the control end of the seventh switch device is connected to the negative end of the charging circuit, and the control end of the seventh switch device is also connected to one end of the switch end of the sixth switch device and then connected to the battery management chip 100, and the other end of the switch end of the seventh switch device is connected to the negative end of the charging circuit. In this embodiment, the conduction state of the fifth switch device is controlled by the CHG pin of the chip IC2 to control the conduction state of the sixth switch device and the seventh switch device, so as to control the on and off of the charging circuit, so that the responsiveness of the fifth switch device is higher. In this embodiment, the sixth switch device is a MOS tube, an IGBT tube, a triode or a relay; the seventh switch device is a MOS tube, an IGBT tube, a triode or a relay.

[0045] For example, Figure 2 and Figure 6 As shown, the fifth switch device is a MOS transistor MC1, the sixth switch device is a transistor Q4, and the seventh switch device is a transistor Q5; the gate of the MOS transistor MC1 is connected in series with a resistor R13 and then connected to the emitter of the transistor Q4, the source and drain of the MOS transistor MC1 are connected in series to the negative end of the charging circuit, and the source of the MOS transistor MC1 is connected to the resistor RN1; a voltage stabilizing diode D4 and a resistor R14 arranged in parallel are connected between the emitter of the transistor Q4 and the source of the MOS transistor MC1, one end of the voltage stabilizing diode D4 and the resistor R14 connected in parallel is connected to the emitter of the transistor Q4, and the voltage stabilizing diode D 4 and the resistor R14 are connected in parallel to the source of the MOS tube MC1; the collector of the transistor Q4 is connected in series with the resistor R12 and then connected to the source of the MOS tube MC1, the base of the transistor Q4 is connected to the emitter of the transistor Q5, the collector of the transistor Q5 is connected to the source of the MOS tube MC1, the base of the transistor Q5 is connected in series with the resistor R15 and then connected to the source of the MOS tube MC1, a diode D3 is connected between the base of the transistor Q5 and the emitter of the transistor Q4, and the base of the transistor Q5 and the common end of the diode D3 are connected in series with the diode D1 and then connected to the CHG pin of the chip IC2.

[0046] like Figure 2 and Figure 8As shown, in the charge and discharge circuit control system of the split-port battery management system of this embodiment, in some embodiments, the first discharge switch circuit 200 includes an eighth switch device, and the control end of the eighth switch device is connected to the battery management chip 100; the switch end of the eighth switch device is connected in series to the discharge circuit. In this embodiment, the eighth switch device is a MOS tube, an IGBT tube, a triode or a relay. Specifically, the DSG pin of the chip IC2 can control the on-off of the discharge circuit by controlling the conduction state of the eighth switch device.

[0047] like Figure 2 and Figure 8 As shown, the charge and discharge circuit control system of the split-port battery management system of this embodiment, in some embodiments, the first discharge switch circuit 200 also includes a ninth switch device and a tenth switch device; the control end of the ninth switch device is connected to one end of the switch end of the tenth switch device, one end of the switch end of the ninth switch device is connected to the control end of the eighth switch device, and the other end of the switch end of the ninth switch device is connected to the negative end of the discharge circuit; the control end of the tenth switch device is connected to the negative end of the discharge circuit, and the control end of the tenth switch device is also connected to one end of the switch end of the ninth switch device and then connected to the battery management chip 100, and the other end of the switch end of the tenth switch device is connected to the negative end of the discharge circuit. In this embodiment, the ninth switch device is a MOS tube, an IGBT tube, a triode or a relay; the tenth switch device is a MOS tube, an IGBT tube, a triode or a relay.

[0048] For example, Figure 2 and Figure 8As shown, the eighth switch device is a MOS transistor MC2, the ninth switch device is a transistor Q6, and the tenth switch device is a transistor Q7; the gate of the MOS transistor MC2 is connected in series with a resistor R17 and then connected to the emitter of the transistor Q6, the source and drain of the MOS transistor MC2 are connected in series to the negative end of the discharge circuit, and the source of the MOS transistor MC2 is connected to the negative electrode B- of the battery pack, and the drain of the MOS transistor MC2 is connected to the negative electrode P- of the discharge circuit; a voltage stabilizing diode D7 and a resistor R19 arranged in parallel are connected between the emitter of the transistor Q6 and the source of the MOS transistor MC2, and one end of the voltage stabilizing diode D7 and the resistor R19 connected in parallel is connected to the transistor Q6 The emitter of the transistor Q7 is connected, and the other end of the voltage stabilizing diode D7 and the resistor R19 in parallel is connected to the source of the MOS transistor MC2; the collector of the transistor Q6 is connected in series with the resistor R12 and then connected to the source of the MOS transistor MC2, the base of the transistor Q6 is connected to the emitter of the transistor Q7, the collector of the transistor Q7 is connected to the source of the MOS transistor MC2, the base of the transistor Q7 is connected in series with the resistor R18 and then connected to the source of the MOS tube MC2, a diode D6 is connected between the base of the transistor Q7 and the emitter of the transistor Q6, and the base of the transistor Q7 and the common end of the diode D6 are connected in series with the diode D1 and then connected to the DSG pin of the chip IC2.

[0049] like Figure 2 and Figure 4 As shown, the charge and discharge loop control system of the split-port battery management system of this embodiment, further, the step-down circuit 700 includes a diode D9, a resistor R21, a resistor R22, a transistor Q8, a voltage-stabilizing diode ZD4, a diode D8, a capacitor C5 and a voltage-stabilizing diode ZD3; the positive electrode of the diode D9 is connected to the positive electrode B+ of the battery pack, one end of the resistor R21 is connected to the negative electrode of the diode D9, the collector of the transistor Q8 is connected to the other end of the resistor R21, one end of the resistor R22 is connected to the collector of the transistor Q8, and the voltage-stabilizing diode One end of the tube ZD4 is connected to the other end of the resistor R22 and the base of the transistor Q8, the positive electrode of the diode D8 is connected to the emitter of the transistor Q8, the end of the capacitor C5 and the voltage-stabilizing diode ZD3 connected in parallel is connected to the negative electrode of the diode D8, and the end of the capacitor C5 and the voltage-stabilizing diode ZD3 connected in parallel also leads to the VSYS power supply node; the other end of the capacitor C5 and the voltage-stabilizing diode ZD3 connected in parallel is connected to the other end of the voltage-stabilizing diode ZD4, and the other end of the capacitor C5 and the voltage-stabilizing diode ZD3 connected in parallel is also connected to the negative electrode C- of the charging circuit. The VDD pin of the chip IC2 is connected to the VSYS power supply node through the resistor R11; the IN (-) pin of the chip IC1 is connected to the VSYS power supply node through the series resistor R4. In this embodiment, the step-down circuit 700 is connected to the negative electrode C- of the charging circuit to ensure the safety of the voltage provided by the VSYS power supply node to the chip IC1.

[0050] like Figure 2 , Fig. 9 and Fig.10 As shown, the charge and discharge circuit control system of the split-port battery management system of this embodiment, in some embodiments, further includes a second charging switch circuit 800 and a second operational amplifier control circuit 900 connected in series to the discharge circuit; the charging circuit and the discharge circuit are connected in parallel with a second current detection resistor in series, and the second current detection resistor is connected to the negative electrode of the battery pack; the second operational amplifier control circuit 900 controls the operation of the second charging switch circuit 800 according to the magnitude of the discharge current. The working principle of the second operational amplifier control circuit 900 and the second charging switch circuit 800 is the same as the working principle of the second discharge switch circuit 500 and the first operational amplifier control circuit 600, which will not be repeated here; thus, by setting the second charging switch circuit 800 and the second operational amplifier control circuit 900 on the discharge circuit, and using the second operational amplifier control circuit 900 to control the on and off of the second charging switch circuit 800 according to the magnitude of the discharge current, charging protection is achieved, and unidirectional conduction of the discharge current is realized, effectively ensuring the charging safety of the split-port discharge circuit.

[0051] Specifically, Figure 1 and Figure 2 As shown, the second current detection resistor is resistor R20, one end of resistor R20 is connected to the negative electrode B- of the battery pack, and the other end is connected to the common negative electrode of the charging circuit and the discharging circuit. Resistor R20 is also connected to chip IC2 so that chip IC2 can collect the total charging current or the total discharging current, thereby controlling the charging and discharging operation.

[0052] like Figure 2 and Fig. 9 As shown, in the charge and discharge circuit control system of the split-port battery management system of this embodiment, in some implementations, the second charging switch circuit 800 includes a fifteenth switch device, the control end of the fifteenth switch device is connected to the second operational amplifier control circuit 900; the switch end of the fifteenth switch device is connected in series to the discharge circuit. In this embodiment, the fifteenth switch device is a MOS tube, an IGBT tube, a triode or a relay.

[0053] For example, Fig. 9As shown, the fifteenth switch device is a MOS transistor MC3, the gate of the MOS transistor MC3 is connected to the second operational amplifier control circuit 900, the source of the MOS transistor MC3 is connected to the first discharge switch circuit 200, and the drain of the MOS transistor MC3 is connected to the RSN terminal of the resistor R20; further, the second charging switch circuit 800 also includes a parallel Zener diode PZD2 and a resistor PR10, one end of the Zener diode PZD2 and the resistor PR10 connected in parallel is connected to the gate of the MOS transistor MC3, and the other end of the Zener diode PZD2 and the resistor PR10 connected in parallel is connected to the source of the MOS transistor MC3; thus, when the second operational amplifier control circuit 900 outputs a high level, the MOS transistor MC3 is driven to open, thereby making the discharge circuit conductive; and when the second operational amplifier control circuit 900 outputs a low level, the driving voltage of the MOS transistor MC3 is turned off, so that no current is formed to the outside through the discharge circuit, thereby achieving charging protection and realizing unidirectional conduction of the discharge current; thus, the battery pack is safer to use when charging and discharging.

[0054] like Figure 2 and Fig.10 As shown, the charge and discharge loop control system of the split-port battery management system of this embodiment, in some embodiments, the second operational amplifier control circuit 900 includes an eleventh operational amplifier processing chip, a twelfth switch device, a thirteenth switch device and a fourteenth switch device; the negative input terminal of the second operational amplifier processing chip is grounded, and the positive input terminal is connected to one end of the second current detection resistor; the output terminal of the second operational amplifier processing chip is connected to the control terminal of the twelfth switch device; the control terminal of the twelfth switch device is connected to one end of its switch terminal and then grounded; the control terminal of the thirteenth switch device is connected to the other end of the switch terminal of the twelfth switch device and then connected to the positive electrode of the battery pack; one end of the switch terminal of the thirteenth switch device is connected to the positive electrode of the battery pack, and the other end is connected to the control terminal of the fourteenth switch device and then grounded; one end of the switch terminal of the fourteenth switch device is connected to the other end of the switch terminal of the thirteenth switch device, and the other end of the switch terminal of the fourteenth switch device is connected to the second charging switch circuit 800. In this embodiment, the twelfth switching device is a MOS tube, an IGBT tube, a triode or a relay; the thirteenth switching device is a MOS tube, an IGBT tube, a triode or a relay; the fourteenth switching device is a MOS tube, an IGBT tube, a triode or a relay.

[0055] For example, Fig.10As shown, the second operational amplifier processing chip is a chip IC3 of model GS8331, the twelfth switch device is a transistor PQ2, the thirteenth switch device is a transistor PQ1, and the fourteenth switch device is a transistor PQ3; the IN (-) pin of the chip IC3 is connected in series with a resistor PR6 and then grounded, the IN (+) pin is connected in series with a resistor PR7 and then connected to the RSN end of the resistor R20, the IN (-) pin of the chip IC3 is also connected in series with a resistor PR4 and then connected to the VSYS power supply node, the IN (-) pin and the IN (+) pin of the chip IC3 are connected in series with capacitors PC3 and PC4 respectively and then grounded, the Vss pin of the chip IC3 is suspended, the OUT pin of the chip IC3 is connected in series with resistors PR5 and diode PD2 in sequence and then connected to the base of the transistor PQ2, and the chip The VDD pin of IC3 is connected in series with capacitor PC2 and then grounded; the base of transistor PQ2 is connected in series with capacitor PC1 and resistor PR9 and then grounded; the collector of transistor PQ2 is connected in series with resistor PR2 and then connected to the base of transistor PQ1, and the emitter of transistor PQ2 is grounded; the base of transistor PQ1 is connected in series with resistor PR1 and then connected to the positive electrode B+ of the battery pack, the emitter of transistor PQ1 is connected to the positive electrode B+ of the battery pack, and the collector of transistor PQ1 is connected to the collector of transistor PQ3; the base of transistor PQ3 is connected in series with resistor PR3 and then connected to the collector of transistor PQ1, the base of transistor PQ3 is connected in series with voltage regulator diode PZD1 and then grounded, and the emitter of transistor PQ1 is connected in series with resistor PR8 and then connected to the gate of MOS tube MC3.

[0056] The above description is only a preferred embodiment of the present invention. Therefore, any equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the protection scope of the patent application of the present invention.

Claims

1. A charge and discharge circuit control system for a split-port battery management system, characterized in that: It includes a battery management chip, a first discharge switch circuit connected in series to a discharge circuit, a first current detection resistor connected in series to a charge circuit, a first charge switch circuit, and a second discharge switch circuit; it also includes a first operational amplifier control circuit connected to the first current detection resistor and the second discharge switch circuit; the battery management chip is connected to the first discharge switch circuit and the first charge switch circuit; the first operational amplifier control circuit is configured to control the operation of the second discharge switch circuit according to the size of the charging current.

2. The charge and discharge circuit control system of a split-port battery management system according to claim 1, characterized in that: The first discharge switch circuit is arranged at the negative end of the discharge circuit; the electrical detection resistor, the first charging switch circuit and the second discharge switch circuit are arranged at the negative end of the charging circuit; the negative end of the discharge circuit and the negative end of the charging circuit are connected in parallel to the negative pole of the battery pack.

3. A charge and discharge circuit control system for a split-port battery management system according to claim 1 or 2, characterized in that: The second discharge switch circuit includes a first switch device, a control end of the first switch device is connected to a first operational amplifier control circuit; and a switch end of the first switch device is connected in series to a charging loop.

4. The charge and discharge circuit control system of a split-port battery management system according to claim 3, characterized in that: The first switch device is a MOS tube, an IGBT tube, a triode or a relay.

5. A charge and discharge circuit control system for a split-port battery management system according to claim 1 or 2, characterized in that: The first operational amplifier control circuit includes a first operational amplifier processing chip, a second switching device, a third switching device and a fourth switching device; the positive and negative input terminals of the first operational amplifier processing chip are respectively connected to the two ends of the first current detection resistor; the output terminal of the first operational amplifier processing chip is connected to the control terminal of the second switching device; the control terminal of the second switching device is connected to one end of its switch terminal and then connected to the negative terminal of the charging circuit; the control terminal of the third switching device is connected to the other end of the switch terminal of the second switching device and then connected to the positive electrode of the battery pack; one end of the switch terminal of the third switching device is connected to the positive electrode of the battery pack, and the other end is connected to the control terminal of the fourth switching device and then grounded; one end of the switch terminal of the fourth switching device is connected to the other end of the switch terminal of the third switching device, and the other end of the switch terminal of the fourth switching device is connected to the second discharge switch circuit.

6. A charge and discharge circuit control system for a split-port battery management system according to claim 1 or 2, characterized in that: The first charging switch circuit includes a fifth switch device, a control end of the fifth switch device is connected to a battery management chip; and a switch end of the fifth switch device is connected in series to the charging circuit.

7. The charge and discharge circuit control system of the split-port battery management system according to claim 6, characterized in that: The first charging switch circuit also includes a sixth switch device and a seventh switch device; the control end of the sixth switch device is connected to one end of the switch end of the seventh switch device, one end of the switch end of the sixth switch device is connected to the control end of the fifth switch device, and the other end of the switch end of the sixth switch device is connected to the negative end of the charging circuit; the control end of the seventh switch device is connected to the negative end of the charging circuit, the control end of the seventh switch device is also connected to one end of the switch end of the sixth switch device and then connected to the battery management chip, and the other end of the switch end of the seventh switch device is connected to the negative end of the charging circuit.

8. A charge and discharge circuit control system for a split-port battery management system according to claim 1 or 2, characterized in that: The first discharge switch circuit includes an eighth switch device, a control end of the eighth switch device is connected to a battery management chip; and a switch end of the eighth switch device is connected in series to a discharge loop.

9. A charge and discharge circuit control system for a split-port battery management system according to claim 8, characterized in that: The first discharge switch circuit also includes a ninth switch device and a tenth switch device; the control end of the ninth switch device is connected to one end of the switch end of the tenth switch device, one end of the switch end of the ninth switch device is connected to the control end of the eighth switch device, and the other end of the switch end of the ninth switch device is connected to the negative end of the discharge circuit; the control end of the tenth switch device is connected to the negative end of the discharge circuit, the control end of the tenth switch device is also connected to one end of the switch end of the ninth switch device and then connected to the battery management chip, and the other end of the switch end of the tenth switch device is connected to the negative end of the discharge circuit.

10. The charge and discharge circuit control system of a split-port battery management system according to claim 1, characterized in that: It also includes a second charging switch circuit and a second operational amplifier control circuit connected in series to the discharge circuit; the charging circuit and the discharge circuit are connected in parallel with a second current detection resistor in series, and the second current detection resistor is connected to the negative pole of the battery pack; the second operational amplifier control circuit controls the operation of the second charging switch circuit according to the size of the discharge current.

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