A sodium ion battery charging protection control system

Abstract

The present invention discloses a sodium-ion battery charging protection control system, which relates to the technical field of sodium-ion battery charging and solves the problems of high cost and difficulty in fully charging batteries in traditional charging protection control systems. It includes: a sodium battery module; a sampling unit; a comparison switch control unit; a voltage stabilizing unit; a secondary switch control unit; a total charging switch control unit; and a charging unit. The total charging switch control unit is used to control the charging unit to charge the sodium battery module and adjust the charging current according to the change in the sodium battery module voltage. The sodium-ion battery protection control system is used to protect the upper limit voltage of the sodium-ion battery during charging to prevent damage to the battery. The battery can be protected from overcharging without the need for a protection chip. When the battery approaches the upper limit voltage during charging, the charging current is continuously reduced until the battery is fully charged, thereby maximizing the CCA discharge times and the usable capacity of the battery.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium ion battery charging, in particular to a sodium ion battery charging protection control system. Background Art

[0002] Sodium-ion batteries operate primarily through the movement of sodium ions between the positive and negative electrode materials, similar to the working principle of lithium-ion batteries. In the automotive battery field, sodium-ion batteries have upper and lower voltage limits during the charge and discharge process. When the voltage reaches the upper limit, the battery cannot be charged, and further charging will damage the battery, but discharge is possible. When the voltage reaches the lower limit, it cannot meet the power requirements for starting the vehicle and needs to be charged.

[0003] Sodium-ion batteries in cars are charged via the car's onboard generator, using a high current to quickly charge the battery to its upper voltage limit. Due to the characteristics of sodium batteries, high-current charging can reach tens of amperes, which can damage the battery and reduce its lifespan. Furthermore, the charged electricity is a virtual charge. Once the high current is removed, the sodium battery's voltage drops significantly, preventing the battery from being fully charged. Low-current charging is slower but does not damage the battery, helping to extend its lifespan while still allowing it to be fully charged. These issues need to be addressed by adjusting the current during the charging process, ensuring fast charging times while still fully charging the sodium-ion battery.

[0004] The hardware protection circuit of traditional sodium-ion batteries only has an on-off function. When charging to the upper limit protection voltage, the circuit is disconnected. When it is lower than the recovery voltage, the charging circuit is restored. Because the charging current of the on-board generator is very large, taking the H6 battery vehicle as an example, the vehicle's charging current is 60A. Using traditional protection chip circuits as battery protection control systems will have the following defects: 1. The battery cannot be fully charged, and about 10-15% of the battery capacity is lost, affecting the battery's CCA discharge times and the actual usable capacity of the battery; 2. The protection chip is expensive, the circuit is complex, and the components have poor reliability and are easily damaged in extreme environments and long-term use. Summary of the Invention

[0005] The purpose of the present invention is to solve the above problems and design a sodium ion battery charging protection control system to solve the problems of high cost and difficulty in fully charging the battery in traditional charging protection control systems.

[0006] The technical solution of the present invention to achieve the above-mentioned purpose is to provide a sodium ion battery charging protection control system, comprising:

[0007] Sodium battery module;

[0008] A sampling unit, electrically connected to the sodium battery module, for collecting the voltage of the sodium battery module;

[0009] The comparison switch control unit is used to compare the voltage collected by the sampling unit with the reference voltage and form a discharge circuit. If the sampled voltage is greater than the reference voltage, the comparison switch control unit controls the switch to open and consumes the power of the sodium battery module through the discharge circuit to reduce the voltage of the sodium battery module; if the sampled voltage is less than the reference voltage, the comparison switch control unit controls the switch to close, disconnects the discharge circuit, and no longer reduces the voltage of the sodium battery module;

[0010] a voltage stabilizing unit, electrically connected to the comparison switch control unit and configured to stabilize the voltage of the circuit;

[0011] A secondary switch control unit, the secondary switch control unit being electrically connected to the voltage stabilizing unit, and controlling the switch to be turned on if the switch of the comparison switch control unit is turned on; and controlling the switch to be turned off if the switch of the comparison switch control unit is turned off;

[0012] A main charging switch control unit, the main charging switch control unit being electrically connected to the secondary switch control unit. If the secondary switch control unit controls the switch to be turned on, the main charging switch control unit controls the switch to be turned off; if the secondary switch control unit controls the switch to be turned off, the main charging switch control unit controls the switch to be turned on.

[0013] A charging unit is electrically connected to the sodium battery module through a circuit. The total charging switch control unit is used to control the charging unit to charge the sodium battery module, and adjust the charging current by adjusting the switching frequency of the total charging switch according to the voltage change of the sodium battery module. The closer the voltage of the sodium battery module is to the upper limit voltage, the smaller the charging current.

[0014] Furthermore, the sampling unit includes two voltage-dividing resistors R3 and R4 connected in series. The voltage-dividing resistors R3 and R4 are electrically connected to the positive and negative electrodes of the sodium battery module after being connected in series to form a sampling loop.

[0015] Furthermore, the comparison switch control unit includes a comparator U1, a PMOS tube Q3, and a PNP transistor Q4. The first connection end of the comparator U1 is connected between the voltage-dividing resistors R3 and R4. The second connection end of the comparator U1 is connected to the positive electrode of the sodium battery module through the resistor R15. The third connection end of the comparator U1 is connected to the negative electrode of the sodium battery module. The source of the PMOS tube Q3 is connected to the positive electrode of the sodium battery module. The drain of the PMOS tube Q3 is connected to the sodium battery module through the resistors R2 and R1. The negative electrode of the sodium battery module is connected, the gate of the PMOS tube Q3 is connected between the comparator U1 and the resistor R15 through the resistor R14, the emitter of the PNP transistor Q4 is connected to the positive electrode of the sodium battery module, the base of the PNP transistor Q4 is connected between the comparator U1 and the resistor R15 through the resistor R13, and the collector of the PNP transistor Q4 is connected to the secondary switch control unit through the resistor R12, and the switching signals of the PMOS tube Q3 and the PNP transistor Q4 are synchronized.

[0016] Furthermore, the comparison switch control unit is further connected to a light emitting diode LED1 , and the light emitting diode LED1 is connected in parallel with the resistors R2 and R1 via a resistor RG1 .

[0017] Furthermore, the voltage stabilizing unit includes a rectifier diode D1, a zener diode ZD2, an NPN transistor Q5, a capacitor C1 and a capacitor C2. The anode of the rectifier diode D1 is connected to the positive electrode of the sodium battery module, the cathode of the rectifier diode D1 is connected to the collector of the NPN transistor Q5 through the resistor R5, the cathode of the zener diode ZD2 is connected to the base of the NPN transistor Q5, and is connected to the collector of the NPN transistor Q5 through the resistor R6. One end of the capacitor C1 is connected to the anode of the zener diode ZD2, and the other end is connected to the resistor R6. One end of the capacitor C2 is connected to the anode of the zener diode ZD2, and the other end is connected to the emitter of the NPN transistor Q5. The anode of the zener diode ZD2 is connected to the negative electrode of the sodium battery module.

[0018] Furthermore, the secondary switch control unit includes a rectifier diode D2, an NPN transistor Q6, a resistor R7 and a resistor R8. The anode of the rectifier diode D2 is connected to the emitter of the NPN transistor Q5 through the resistor R9, and the cathode of the rectifier diode D2 is respectively connected to the collector of the NPN transistor Q6 and the total charging switch control unit. The resistor R7 is connected between the base of the NPN transistor Q5 and the resistor R12. One end of the resistor R8 is connected to the emitter of the NPN transistor Q5 and the total charging switch control unit, and the other end is connected between the resistor R12 and the resistor R7.

[0019] Furthermore, a voltage zener diode ZD1 is connected between the rectifier diode D2 and the resistor R8 , a cathode of the voltage zener diode ZD1 is connected to a cathode of the rectifier diode D2 , and an anode of the voltage zener diode ZD1 is connected to the resistor R8 .

[0020] Furthermore, the total charging switch control unit includes a resistor R11 and an NMOS tube Q2. The drain of the NMOS tube Q2 is connected to the charging circuit through CP-, the gate of the NMOS tube Q2 is connected to the cathode of the rectifier diode D2 through the resistor R11, and the source of the NMOS tube Q2 is connected to the resistor R8 and the negative electrode of the sodium battery module.

[0021] Furthermore, the main charging switch control unit further includes an NMOS tube module Q1, and the NMOS tube module Q1 is composed of a plurality of NMOS tubes Q2 connected in parallel. The NMOS tube module Q1 is connected in parallel with the NMOS tubes Q2.

[0022] Furthermore, it also includes a filter circuit, which includes a filter capacitor C3, and the filter capacitor C3 is connected to the positive and negative electrodes of the sodium battery module.

[0023] Compared with the prior art, the beneficial effects are:

[0024] The sodium-ion battery protection control system of the present invention is used to protect the upper voltage limit of the sodium-ion battery during charging, preventing damage to the battery, and can protect the battery from charging without the need for a protection chip. During the charging process, the voltage of the sodium-ion battery module is collected by a sampling unit, and the comparison switch control unit compares the sampled voltage with the reference voltage. If the sampled voltage is greater than the reference voltage, the comparison switch control unit controls the switch to open and consumes the sodium-ion battery module power through the discharge circuit to reduce the battery voltage. At the same time, the secondary switch control unit also controls the switch to open, and the main charging switch control unit controls the switch to close, and controls the charging unit to stop charging the battery, thereby providing overcharge protection.

[0025] If the sampled voltage is lower than the reference voltage, the comparison switch control unit will control the switch to close, disconnecting the discharge circuit and no longer reducing the voltage of the battery. At the same time, the secondary switch control unit will also control the switch to close, and the main charging switch control unit will control the switch to open, and control the charging unit to charge the battery. The charging current is adjusted by adjusting the switching frequency of the main charging switch according to the change of the sodium battery module voltage. That is, the closer the sodium battery module voltage is to the upper limit voltage, the smaller the charging current is, until the battery is fully charged.

[0026] When the battery approaches the upper limit voltage during the charging process, the charging current is continuously reduced until the battery is fully charged, thereby maximizing the battery's CCA discharge times and the battery's usable capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural diagram of the sodium ion battery charging protection control system of the present invention;

[0028] Figure 2 This is a circuit diagram of the sodium ion battery charging protection control system of the present invention;

[0029] Figure 3 This is a circuit state diagram when the battery cell module cannot be charged at high voltage (upper voltage limit) and the voltage is reduced to a specified low voltage through the circuit;

[0030] Figure 4 This is a circuit state diagram when the battery module is charging at low voltage and the step-down circuit is turned off;

[0031] Figure 5 It is the operating logic diagram of each switch in the circuit;

[0032] Figure 6 This is a graph showing the relationship between battery voltage and charging current.

[0033] In the figure, 1. Sodium battery module; 2. Sampling unit; 3. Comparison switch control unit; 4. Voltage stabilization unit; 5. Secondary switch control unit; 6. Total charging switch control unit; 7. Charging unit. DETAILED DESCRIPTION

[0034] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] like Figure 1 As shown, a preferred embodiment of the present invention proposes a sodium ion battery charging protection control system, which mainly includes a sodium battery module 1, a sampling unit 2, a comparison switch control unit 3, a voltage stabilizing unit 4, a secondary switch control unit 5, a total charging switch control unit 6, and a charging unit 7 ( Figure 2-4 The circuit is not shown) and other modules.

[0036] The sodium battery module 1, i.e., a sodium-ion battery, may be composed of several battery cells. The sampling unit 2 is connected to the positive and negative terminals of the corresponding battery cells to collect the voltage of the battery cells. The comparison switch control unit 3 is connected to the sampling unit 2 to compare the voltage collected by the sampling unit 2 with the reference voltage. Based on the comparison result, the corresponding switch is controlled to open or close, switching to different circuit states. The closer the battery is to the upper charge voltage limit, the more frequent the switching is, gradually reducing the charging current to maximize the battery's charge capacity within the upper charge voltage range.

[0037] The voltage stabilizing unit 4 is connected in the circuit composed of the above units, generally connected between the comparison switch control unit 3 and the secondary switch control unit 5, and plays a role in stabilizing the voltage.

[0038] The secondary switch control unit 5 will automatically control the switch to open or close according to the switch state of the comparison switch control unit 3. If the switch of the comparison switch control unit 3 is closed, the secondary switch control unit 5 will be closed; if the switch of the comparison switch control unit 3 is open, the secondary switch control unit 5 will control the switch to open.

[0039] The main charging switch control unit 6 is electrically connected to the secondary switch control unit 5 and automatically controls the switch to open or close based on the switch state of the comparison switch control unit 3. If the secondary switch control unit 5 controls the switch to be closed, the main charging switch control unit 6 controls the switch to be opened; if the secondary switch control unit 5 controls the switch to be opened, the main charging switch control unit 6 controls the switch to be closed. The switch states of the two are opposite.

[0040] The charging unit 7, or the charging circuit, is connected to the main charging switch control unit 6, which is then connected to the battery. The main charging switch control unit 6 controls the charging circuit to charge the battery and can adjust the charging current according to the voltage of the sodium battery module 1. The closer the voltage of the sodium battery module 1 is to the upper limit voltage, the smaller the charging current will be until the battery is fully charged.

[0041] Specifically, you can refer to Figure 2-Figure 4 In the circuit shown, B1 is the sodium battery module 1, that is, the battery module. Node 1 in the circuit is connected to the positive electrode of the battery and is connected to the negative electrode of the battery through the filter capacitor C3 to form a filter circuit to eliminate noise when the battery supplies power to the circuit.

[0042] Node 2 is connected to the positive terminal of the battery, and then to the negative terminal of the battery through resistors R3 and R4, forming a sampling circuit. Resistors R3 and R4 form sampling unit 2. Because the battery voltage is very high, connecting the comparison switch control unit 3 directly to it may damage the components due to the excessive voltage. Resistors R3 and R4 act as voltage dividers, allowing for indirect sampling of the battery voltage.

[0043] Comparator U1, resistors R15 and R14, PMOS transistor Q3, PNP transistor Q4, resistor R2, and resistor R1 collectively form comparator switch control unit 3. Node 4 in the circuit is connected to the positive terminal of the battery. The second terminal of comparator U1 is connected to node 4 via resistor R15, and the third terminal is connected to the negative terminal of the battery, forming a loop. Node 3 is located between resistors R3 and R4, and the first terminal of comparator U1 is connected to node 3.

[0044] Node 6 is connected to the positive electrode of the battery. The source of PMOS transistor Q3 is connected to node 6. The drain of PMOS transistor Q3 is connected to the negative electrode of the battery through resistors R2 and R1. Node 5 is located between comparator U1 and resistor R15. The gate of PMOS transistor Q3 is connected to node 5 through resistor R14.

[0045] During specific operation, when the voltage of the battery module is higher than 3.5V, the voltage of node 3 in the sampling circuit will be higher than 2.5V, and the comparator U1 will open the variable path; when the voltage of the battery module is lower than 3.5V, the voltage of node 3 in the sampling circuit will be lower than 2.5V, and the comparator U1 will be closed and disconnected.

[0046] Node 7 is connected to the positive terminal of the battery. The emitter of PNP transistor Q4 is connected to node 7. The base of PNP transistor Q4 is connected to node 5 via resistor R13. The collector of PNP transistor Q4 is connected to secondary switch control unit 5 via resistor R12, specifically to node 8 in the circuit. The switching signals of PMOS transistor Q3 and PNP transistor Q4 are synchronized.

[0047] Light-emitting diode LED1 is connected in parallel with resistors R2 and R1 via resistor RG1. Specifically, the anode of LED1 is connected to resistor RG1, and the cathode is connected to the negative terminal of the battery. The other end of resistor RG1 is connected to the drain of PMOS transistor Q3. When the circuit self-discharges, LED1's indicator light illuminates; otherwise, it remains off.

[0048] The voltage stabilization unit 4, or the voltage stabilization circuit, provides a stable output voltage. It primarily includes components such as a rectifier diode D1, a Zener diode ZD2, an NPN transistor Q5, a capacitor C1, a capacitor C2, a resistor R5, and a resistor R6. The collector of the NPN transistor Q5 is connected to the cathode of the rectifier diode D1 via resistor R5, and the anode of the rectifier diode D1 is connected to node 7. The anode of the Zener diode ZD2 is connected to the negative electrode of the battery, while the cathode of the Zener diode ZD2 is connected to the base of the NPN transistor Q5 and to the collector of the NPN transistor Q5 via resistor R6. One end of the capacitor C1 is connected to resistor R6, and the other end is connected to the anode of the Zener diode ZD2. One end of the capacitor C2 is connected to the anode of the Zener diode ZD2, and the other end is connected to the emitter of the NPN transistor Q5, thereby forming a voltage stabilization loop. Capacitors C1 and C2 primarily serve functions such as filtering and energy storage.

[0049] The secondary switch control unit 5 primarily includes components such as a rectifier diode D2, an NPN transistor Q6, resistors R7, R8, and R9. Node 10 in the circuit is connected to the collector of the NPN transistor Q6. The cathode of the rectifier diode D2 is connected to node 10, and its anode is connected to the emitter of the NPN transistor Q5 via resistor R9. The collector of the NPN transistor Q6 is connected to the cathode of the rectifier diode D2, and its anode is connected to the emitter of the NPN transistor Q5 via resistor R9. Resistor R12 is connected to node 8, which is connected to the base of the NPN transistor Q6 via resistor R7. Node 9 is connected to the negative terminal of the battery, the emitter of the NPN transistor Q6 is connected to node 9, and resistor R8 is connected between nodes 8 and 9. The cathode of the Zener diode ZD1 is connected to node 10, and its anode is connected to node 9.

[0050] The main charging switch control unit 6 primarily includes components such as resistor R11, resistor R10, NMOS transistor Q2, and NMOS transistor module Q1. During charging, the current flowing through a single NMOS transistor Q2 is insufficient. The NMOS transistor module Q1 is equivalent to multiple NMOS transistors Q2 connected in parallel to increase the current. Node 12 in the circuit is connected to the charging circuit via CP-. The drain of NMOS transistor Q2 is connected to node 12, the source of NMOS transistor Q2 is connected to the negative terminal of the battery, and the gate of NMOS transistor Q2 is connected to node 11. Node 11 is connected to node 10 via resistor R11. The NMOS transistor module Q1 is connected to node 12, the negative terminal of the battery, and node 11 via resistor R10.

[0051] Node 12 is connected to the charging circuit CP- and connected to the negative electrode of the battery through the NMOS transistor Q2. If the NMOS transistor Q2 is disconnected, the charging circuit at node 12 is disconnected and the battery cannot be charged.

[0052] The working principle of the circuit is explained below. Figure 3 、 Figure 5 . Figure 3 In circuit state 1, the battery module cannot be charged at high voltage and is stepped down to a specified low voltage through the circuit. The specific logic flow is as follows:

[0053] When the voltage of the battery module is higher than 3.5V, the voltage of node 3 in the sampling circuit will be higher than 2.5V, and the comparator U1 will open the variable path. Node 4 is connected to the positive electrode of the battery, and then to the negative electrode of the battery through the resistor R15 and the comparator U1, forming a loop.

[0054] Node 6 is connected to the positive electrode of the battery, and node 5 is divided by resistor R15 and comparator U1. The voltage at node 5 is lower than that at node 6, so PMOS tube Q3 opens the variable path; node 6 is connected to the positive electrode of the battery, and connected to the negative electrode of the battery through PMOS tube Q3, resistor R2, and resistor R1, forming a self-discharge circuit, which limits the discharge current and consumes the battery power through this circuit to reduce the battery voltage; at the same time, node 6 is connected to the positive electrode of the battery, and connected to the negative electrode of the battery through PMOS tube Q3 and light-emitting diode LED1, forming a self-discharge indicator light circuit. During self-discharge, the indicator light of light-emitting diode LED1 in this circuit lights up, indicating that the battery is self-discharging.

[0055] Node 7 is connected to the positive terminal of the battery, and node 5 is divided by resistor R15 and comparator U1. The voltage at node 5 is lower than that at node 7, so PNP transistor Q4 opens the variable path. Node 7 is connected to the positive terminal of the battery, and connected to the negative terminal of the battery through PNP transistor Q4, resistor R12, and resistor R8 to form a loop. In this loop, node 9 is connected to the negative terminal of the battery. The voltage at node 8 is higher than that at node 9, so NPN transistor Q6 opens the variable path.

[0056] Node 10 is connected to the negative terminal of the battery through the path opened by NPN transistor Q6, so the voltage at node 10 is 0V; node 11 is connected to node 10 through resistor R11, so the voltage at node 11 is also 0V, so NMOS transistor Q2 is turned off;

[0057] The node 12 is connected to the charging circuit CP- and is connected to the negative electrode of the battery through the NMOS transistor Q2. When the NMOS transistor Q2 is disconnected, the charging circuit at the node 12 is disconnected and the battery cannot be charged.

[0058] At this time, the circuit uses the circuit at node 6 to self-discharge the battery module to reduce the voltage. At the same time, the charging circuit at node 12 is disconnected, and the battery cannot be charged, which plays a role in overcharge protection.

[0059] refer to Figure 4 、 Figure 5 , Figure 4 In circuit state 2, when the battery module is at low voltage, the circuit can charge and turn off the step-down circuit. The specific logic flow is as follows:

[0060] When the voltage of the battery module is lower than 3.5V, the voltage at node 3 in the sampling circuit will be lower than 2.5V, and the comparator U1 will be turned off. No current will flow through node 5, which is connected to node 4, node 6, and the positive electrode of the battery through resistor R15. Therefore, the voltage at node 5 is the same as that at node 6, so the PMOS tube Q3 is turned off.

[0061] At node 6, the discharge circuit connected to the negative electrode of the battery through the PMOS tube Q3, the resistor R2, and the resistor R1 is disconnected, and the battery cannot self-discharge; at the same time, at node 6, the self-discharge indicator light circuit connected to the negative electrode of the battery through the PMOS tube Q3 and the light-emitting diode LED1 is disconnected, and the battery self-discharge indicator light does not light up.

[0062] There is no current flowing through node 5. It is connected to node 4, node 7, and the positive terminal of the battery through resistor R15. Therefore, the voltage at node 5 is the same as that at node 7, so the PNP transistor Q4 is turned off.

[0063] There is no current flowing through node 8. It is connected to node 9 and the negative terminal of the battery through resistor R8. The voltage at node 8 and node 9 is the same, both are 0V, so the NPN transistor Q6 is turned off.

[0064] Node 10 is connected to the positive electrode of the battery through diode D1, resistor R5, NPN transistor Q5, resistor R9, and diode D2, and is connected to the negative electrode of the battery through Zener diode ZD1, forming a voltage stabilization loop. Node 10 maintains a high level.

[0065] The node 11 is connected to the node 10 through the resistor R11 , and the node 11 also maintains a high level, so the NMOS transistor Q2 opens the variable path, and the working state of the NMOS transistor module Q1 is the same as that of the NMOS transistor Q2 .

[0066] The voltage divided by resistors R4 and R3 is compared with the reference voltage of comparator U1, and the source voltage of the main switch NMOS tube Q2 and the NMOS tube module Q1 is automatically adjusted to open and close the NMOS tube Q2 and the NMOS tube module Q1. The input charging voltage and current are regulated by the switching frequency.

[0067] The charging current passes through PC-, passes through node 12, NMOS tube Q2, and is connected to the negative electrode of the battery. The battery charging circuit is turned on and charges the battery.

[0068] At this time, the circuit is turned on through the charging circuit at node 12, and the battery can be charged. The self-discharge circuit at node 6 is disconnected, and the battery no longer self-discharges to reduce the voltage of the battery module.

[0069] The battery module's upper voltage limit is not limited to 3.5V. The reference voltage of comparator U1 changes according to the battery's upper voltage limit. When the battery is charged with a high current to the upper voltage limit, the circuit switches between circuit state 1 and circuit state 2. The closer the battery is to the upper voltage limit, the more frequent the switching, gradually reducing the charging current.

[0070] The changes in voltage and current during charging of sodium ion batteries can be referred to Figure 6. At the beginning, it is charged with a constant high current. The charger will provide a constant charging current in the initial charging stage of the battery. As the battery gets closer to the upper limit of the charging voltage, it will be changed to constant voltage charging. The charging current will gradually decrease until the charging is terminated, so as to charge the battery as much as possible within the upper limit voltage range of the battery to increase the battery's usable capacity. The sodium ion battery charging protection control system of the present invention provides charging protection for the battery during the entire charging stage.

[0071] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Any changes that may be made to certain parts thereof by those skilled in the art all reflect the principles of the present invention and fall within the scope of protection of the present invention.

Claims

1. A sodium ion battery charging protection control system, characterized in that: include: Sodium battery module (1); A sampling unit (2) electrically connected to the sodium battery module (1) and used to collect the voltage of the sodium battery module (1); A comparison switch control unit (3) is used to compare the voltage collected by the sampling unit (2) with a reference voltage, and to form a discharge circuit. If the sampling voltage is greater than the reference voltage, the comparison switch control unit (3) controls the switch to open, and consumes the power of the sodium battery module (1) through the discharge circuit to reduce the voltage of the sodium battery module (1); if the sampling voltage is less than the reference voltage, the comparison switch control unit (3) controls the switch to close, disconnects the discharge circuit, and no longer reduces the voltage of the sodium battery module; a voltage stabilizing unit (4), electrically connected to the comparison switch control unit (3), and configured to stabilize the voltage of the circuit; A secondary switch control unit (5), the secondary switch control unit (5) being electrically connected to the voltage stabilizing unit (4), and if the switch of the comparison switch control unit (3) is turned on, the secondary switch control unit (5) controls the switch to be turned on; If the switch of the comparison switch control unit (3) is closed, the secondary switch control unit (5) controls the switch to be closed; A main charging switch control unit (6), the main charging switch control unit (6) and the secondary switch control unit (5) are electrically connected, and if the secondary switch control unit (5) controls the switch to be turned on, the main charging switch control unit (6) controls the switch to be turned off; if the secondary switch control unit (5) controls the switch to be turned off, the main charging switch control unit (6) controls the switch to be turned on; A charging unit (7) is electrically connected to the sodium battery module (1) through a circuit. The total charging switch control unit (6) is used to control the charging unit (7) to charge the sodium battery module (1), and to adjust the charging current by adjusting the switching frequency of the total charging switch control unit (6) according to the voltage change of the sodium battery module (1). The closer the voltage of the sodium battery module (1) is to the upper limit voltage, the smaller the charging current.

2. The sodium ion battery charging protection control system according to claim 1, characterized in that: The sampling unit (2) comprises two voltage-dividing resistors R3 and R4 connected in series, and the voltage-dividing resistors R3 and R4 are electrically connected to the positive and negative electrodes of the sodium battery module (1) after being connected in series, forming a sampling loop.

3. The sodium ion battery charging protection control system according to claim 2, characterized in that: The comparison switch control unit (3) comprises a comparator U1, a PMOS transistor Q3, and a PNP transistor Q4; a first connection end of the comparator U1 is connected between voltage-dividing resistors R3 and R4; a second connection end of the comparator U1 is connected to the positive electrode of the sodium battery module (1) via a resistor R15; a third connection end of the comparator U1 is connected to the negative electrode of the sodium battery module (1); a source electrode of the PMOS transistor Q3 is connected to the positive electrode of the sodium battery module (1); and a drain electrode of the PMOS transistor Q3 is connected to the negative electrode of the sodium battery module (1) via resistors R2 and R1. The cathode of the module (1) is connected, the gate of the PMOS tube Q3 is connected between the comparator U1 and the resistor R15 through the resistor R14, the emitter of the PNP transistor Q4 is connected to the anode of the sodium battery module (1), the base of the PNP transistor Q4 is connected between the comparator U1 and the resistor R15 through the resistor R13, the collector of the PNP transistor Q4 is connected to the secondary switch control unit (5) through the resistor R12, and the switching signals of the PMOS tube Q3 and the PNP transistor Q4 are synchronized.

4. The sodium ion battery charging protection control system according to claim 3, characterized in that: The comparison switch control unit (3) is further connected to a light emitting diode LED1, and the light emitting diode LED1 is connected in parallel with the resistors R2 and R1 via a resistor RG1.

5. The sodium ion battery charging protection control system according to claim 4, characterized in that: The voltage stabilizing unit (4) comprises a rectifier diode D1, a voltage stabilizing diode ZD2, an NPN transistor Q5, a capacitor C1 and a capacitor C2. The anode of the rectifier diode D1 is connected to the positive electrode of the sodium battery module (1). The cathode of the rectifier diode D1 is connected to the collector of the NPN transistor Q5 via a resistor R5. The cathode of the voltage stabilizing diode ZD2 is connected to the base of the NPN transistor Q5 and is connected to the collector of the NPN transistor Q5 via a resistor R6. One end of the capacitor C1 is connected to the anode of the voltage stabilizing diode ZD2 and the other end is connected to the resistor R6. One end of the capacitor C2 is connected to the anode of the voltage stabilizing diode ZD2 and the other end is connected to the emitter of the NPN transistor Q5. The anode of the voltage stabilizing diode ZD2 is connected to the negative electrode of the sodium battery module (1).

6. The sodium ion battery charging protection control system according to claim 5, characterized in that: The secondary switch control unit (5) comprises a rectifier diode D2, an NPN transistor Q6, a resistor R7 and a resistor R8. The anode of the rectifier diode D2 is connected to the emitter of the NPN transistor Q5 via the resistor R9. The cathode of the rectifier diode D2 is connected to the collector of the NPN transistor Q6 and the total charging switch control unit (6) respectively. The resistor R7 is connected between the base of the NPN transistor Q5 and the resistor R12. One end of the resistor R8 is connected to the emitter of the NPN transistor Q5 and the total charging switch control unit (6), and the other end is connected between the resistor R12 and the resistor R7.

7. The sodium ion battery charging protection control system according to claim 6, characterized in that: A voltage stabilizing diode ZD1 is connected between the rectifier diode D2 and the resistor R8 . The cathode of the voltage stabilizing diode ZD1 is connected to the cathode of the rectifier diode D2 , and the anode of the voltage stabilizing diode ZD1 is connected to the resistor R8 .

8. The sodium ion battery charging protection control system according to claim 6, characterized in that: The total charging switch control unit (6) comprises a resistor R11 and an NMOS tube Q2, wherein the drain of the NMOS tube Q2 is connected to the charging circuit via CP-, the gate of the NMOS tube Q2 is connected to the cathode of the rectifier diode D2 via the resistor R11, and the source of the NMOS tube Q2 is connected to the resistor R8 and the negative electrode of the sodium battery module (1).

9. The sodium ion battery charging protection control system according to claim 8, characterized in that: The total charging switch control unit (6) further comprises an NMOS tube module Q1, wherein the NMOS tube module Q1 is composed of a plurality of NMOS tubes Q2 connected in parallel, and the NMOS tube module Q1 is connected in parallel with the NMOS tubes Q2.

10. The sodium ion battery charging protection control system according to claim 1, characterized in that: It also includes a filter circuit, which includes a filter capacitor C3, and the filter capacitor C3 is connected to the positive and negative electrodes of the sodium battery module (1).

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