Sodium ion storage battery charging protection control system

Abstract

The invention discloses a sodium-ion storage battery charging protection control system, relates to the technical field of sodium-ion storage battery charging, and solves the problems that a traditional charging protection control system is high in cost and a battery is difficult to fully charge. The device comprises 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 the main charging switch control unit is used for controlling the charging unit to charge the sodium battery module and adjusting the charging current according to the voltage change of the sodium battery module. The sodium-ion storage battery protection control system is used for protecting the upper limit voltage when the sodium-ion storage battery is charged and preventing the battery from being damaged, overcharge protection can be performed on the battery without a protection chip, and when the battery is close to the upper limit voltage in the charging process, the charging current is continuously reduced until the battery is fully charged, so that the battery is protected. And the CCA discharge times of the battery and the available capacity of the battery are improved to the maximum extent.

Description

Technical Field

[0001] The 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 mainly rely on the movement of sodium ions between the positive and negative electrode materials to work, which is similar to the working principle of lithium-ion batteries. In the field of automotive batteries, sodium-ion batteries have upper and lower voltage limits during the charging and discharging process. When the voltage reaches the upper limit, the battery can no longer be charged, and further charging will damage the battery, but it can be discharged. When the voltage reaches the lower limit, it cannot meet the power requirements for starting the car and needs to be charged.

[0003] The sodium-ion battery in the car is charged by the on-board generator in the car. The charging current is very large so that the sodium-ion battery can be quickly charged to the upper voltage limit. Due to the characteristics of sodium batteries, the high-current charging current can reach tens of amperes, which can easily damage the battery and affect the battery life. At the same time, the electricity charged is virtual electricity. Once the high current is removed, the voltage of the sodium battery will drop significantly, and the sodium-ion battery cannot be fully charged. The charging speed of a small current is slow, but it will not damage the battery, which helps to increase the battery life and can charge the battery to a full state. It is necessary to solve the above problems by adjusting the current size during the charging process to achieve a fast charging time and fully charge 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 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, take 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 to 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] To achieve the above-mentioned purpose, the technical solution of the present invention is a sodium ion battery charging protection control system, comprising: Sodium battery module; A sampling unit, which is electrically connected to the sodium battery module and is used to collect the voltage of the sodium battery module; A comparison switch control unit is used to compare the voltage collected by the sampling unit with the reference voltage, and form a discharge loop. 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 loop 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 loop, and no longer reduces the voltage of the sodium battery module; A voltage stabilizing unit, which is electrically connected to the comparison switch control unit and is used to stabilize the voltage of the circuit; A secondary switch control unit, wherein the secondary switch control unit is electrically connected to the voltage stabilizing unit, and if the switch of the comparison switch control unit is turned on, the secondary switch control unit controls the switch to be turned on; if the switch of the comparison switch control unit is turned off, the secondary switch control unit controls the switch to be turned off; A main charging switch control unit, wherein the main charging switch control unit is electrically connected to the secondary switch control unit, and 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; 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 is.

[0007] 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 in series to the positive and negative electrodes of the sodium battery module to form a sampling loop.

[0008] Further, the comparison switch control unit includes a comparator U1, a PMOS tube Q3, and a PNP triode 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 electric module through the resistor R15. The third connection end of the comparator U1 is connected to the negative electrode of the sodium electric module. The source of the PMOS tube Q3 is connected to the positive electrode of the sodium electric module. The drain of the PMOS tube Q3 is connected to the sodium The cathode of the sodium electric 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 anode of the sodium electric module, 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 through the resistor R12, and the switching signals of the PMOS tube Q3 and the PNP transistor Q4 are synchronized.

[0009] Furthermore, the comparison switch control unit is also 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.

[0010] 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 electric module, the cathode of the rectifier diode D1 is connected to the collector of the NPN transistor Q5 through a 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 a 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, and the anode of the zener diode ZD2 is connected to the negative electrode of the sodium electric module.

[0011] Further, 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, 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.

[0012] 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 .

[0013] 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.

[0014] Furthermore, the total charging switch control unit further includes 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.

[0015] 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.

[0016] Compared with the prior art, the beneficial effects are: The sodium ion battery protection control system of the present invention is used to protect the upper limit voltage of the sodium ion battery during charging to prevent damage to the battery, and the battery can be charged and protected without the need for a protection chip. During the charging process, the voltage of the sodium battery module is collected by the 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 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 total charging switch control unit controls the switch to close, and controls the charging unit to stop charging the battery, thereby playing a role in overcharge protection.

[0017] If the sampled voltage is less than the reference voltage, the comparison switch control unit will control the switch to close and disconnect the discharge circuit to stop reducing the voltage of the battery. At the same time, the secondary switch control unit will also control the switch to close, and the total 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 total 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.

[0018] 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

[0019] Figure 1 It is a structural schematic diagram of the sodium ion battery charging protection control system of the present invention; Figure 2 It is a circuit schematic diagram of the sodium ion battery charging protection control system in the present invention; Figure 3 It is a circuit state diagram when the battery cell module cannot be charged at high voltage (upper voltage limit) and is stepped down to a specified low voltage through the circuit; Figure 4 This is a circuit state diagram when the battery module is at low voltage and the circuit can be charged and the step-down circuit is turned off; Figure 5 It is the operation logic diagram of each switch in the circuit; Figure 6 It is a graph showing the relationship between battery voltage and charging current.

[0020] 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

[0021] 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 creative work are within the scope of protection of the present invention.

[0022] 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 in the figure is not shown) and other modules.

[0023] The sodium battery module 1, i.e., a sodium ion battery, may be composed of several battery cells. The sampling unit 2 will be connected to the positive and negative electrodes of the corresponding battery cell to collect the voltage of the battery cell. The comparison switch control unit 3 will be connected to the sampling unit 2 to compare the voltage collected by the sampling unit 2 with the reference voltage, and control the corresponding switch to open or close according to the comparison result, switching to different circuit states. The closer the battery is to the upper limit voltage of charging, the more frequent the switching is, so as to gradually reduce the charging current, so as to charge the battery as much as possible within the upper limit voltage range of the battery to increase the usable capacity of the battery.

[0024] 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.

[0025] 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 is closed; if the switch of the comparison switch control unit 3 is open, the secondary switch control unit 5 controls the switch to open.

[0026] 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 according to the switch state of the comparison switch control unit 3. If the secondary switch control unit 5 controls the switch to close, the main charging switch control unit 6 controls the switch to open; if the secondary switch control unit 5 controls the switch to open, the main charging switch control unit 6 controls the switch to close, and the switch states of the two are opposite.

[0027] The charging unit 7, i.e., the charging circuit, will be connected to the total charging switch control unit 6, and then the total charging switch control unit 6 will be connected to the battery, and the total 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.

[0028] Specifically, please refer to Figure 2-Figure 4 In the circuit shown, B1 is a sodium battery module 1, i.e., a 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 a filter capacitor C3 to form a filter loop to eliminate noise when the battery supplies power to the circuit.

[0029] Node 2 is connected to the positive electrode of the battery, and then connected to the negative electrode of the battery through resistors R3 and R4 to form a sampling loop. Resistors R3 and R4 form sampling unit 2. Because the voltage of the battery itself is very high, if the comparison switch control unit 3 is directly connected to it, the components may be damaged due to excessive voltage. Resistors R3 and R4 are voltage divider resistors that can indirectly collect the battery voltage.

[0030] The comparator U1, the resistor R15, the resistor R14, the PMOS tube Q3, the PNP transistor Q4, the resistor R2, and the resistor R1 together form a comparison switch control unit 3. The node 4 in the circuit is connected to the positive electrode of the battery, the second connection end of the comparator U1 is connected to the node 4 through the resistor R15, and the third connection end is connected to the negative electrode of the battery to form a loop. The node 3 is located between the resistor R3 and the resistor R4, and the first connection end of the comparator U1 is connected to the node 3.

[0031] Node 6 is connected to the positive electrode of the battery, the source of the PMOS tube Q3 is connected to node 6, and the drain of the PMOS tube Q3 is connected to the negative electrode of the battery through resistors R2 and R1. Node 5 is located between the comparator U1 and the resistor R15, and the gate of the PMOS tube Q3 is connected to node 5 through a resistor R14.

[0032] During specific operation, when the voltage of the battery module is higher than 3.5V, the voltage of node 3 in the sampling loop 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 loop will be lower than 2.5V, and the comparator U1 will be closed and disconnected.

[0033] Node 7 is connected to the positive electrode of the battery, the emitter of the PNP transistor Q4 is connected to the node 7, the base of the PNP transistor Q4 is connected to the node 5 through the resistor R13, and the collector of the PNP transistor Q4 is connected to the secondary switch control unit 5 through the resistor R12, specifically, connected to the node 8 in the circuit. The switching signals of the PMOS tube Q3 and the PNP transistor Q4 are synchronized.

[0034] The light emitting diode LED1 is connected in parallel with the resistor R2 and the resistor R1 through the resistor RG1. Specifically, the anode of the light emitting diode LED1 is connected to the resistor RG1, and the cathode is connected to the negative electrode of the battery. The other end of the resistor RG1 is connected to the drain of the PMOS tube Q3. When the circuit is self-discharging, the indicator light of the light emitting diode LED1 will light up, otherwise the indicator light will not light up.

[0035] The voltage stabilizing unit 4, i.e., the voltage stabilizing circuit, plays the role of providing a stable output voltage. It mainly includes components such as a rectifier diode D1, a voltage stabilizing 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 through a resistor R5, and the anode of the rectifier diode D1 is connected to a node 7. The anode of the voltage stabilizing diode ZD2 is connected to the negative electrode of the battery, 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 through a resistor R6. One end of the capacitor C1 is connected to the resistor R6, and the other end is connected to the anode of the voltage stabilizing diode ZD2. 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, thereby forming a voltage stabilizing loop. The capacitor C1 and the capacitor C2 mainly play the roles of filtering and energy storage.

[0036] The secondary switch control unit 5 mainly includes components such as a rectifier diode D2, an NPN transistor Q6, a resistor R7, a resistor R8, and a resistor R9. The 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 the node 10, and the anode is connected to the emitter of the NPN transistor Q5 through the resistor R9. The collector of the NPN transistor Q6 is connected to the cathode of the rectifier diode D2, and the anode of the rectifier diode D2 is connected to the emitter of the NPN transistor Q5 through the resistor R9. The resistor R12 is connected to the node 8, and the node 8 is connected to the base of the NPN transistor Q6 through the resistor R7. The node 9 is connected to the negative electrode of the battery, the emitter of the NPN transistor Q6 is connected to the node 9, and the resistor R8 is connected between the node 8 and the node 9. The cathode of the voltage stabilizing diode ZD1 is connected to the node 10, and the anode is connected to the node 9.

[0037] The total charging switch control unit 6 mainly includes components such as resistor R11, resistor R10, NMOS tube Q2, and NMOS tube module Q1. When charging, the current that can pass through a single NMOS tube Q2 is not large enough. The NMOS tube module Q1 is equivalent to multiple NMOS tubes Q2 connected in parallel to increase the current. The node 12 in the circuit is connected to the charging circuit through CP-, the drain of the NMOS tube Q2 is connected to the node 12, the source of the NMOS tube Q2 is connected to the negative electrode of the battery, and the gate of the NMOS tube Q2 is connected to the node 11. The node 11 is connected to the node 10 through the resistor R11. The NMOS tube module Q1 is respectively connected to the node 12, the negative electrode of the battery, and the node 11 through the resistor R10.

[0038] Node 12 is connected to the charging circuit CP- and connected to the negative electrode of the battery through the NMOS tube Q2. When the NMOS tube Q2 is disconnected, the charging circuit at node 12 is disconnected, and the battery cannot be charged. When the NMOS tube Q2 is disconnected, the charging circuit at node 12 is disconnected, and the battery cannot be charged.

[0039] 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 described as follows: 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, and node 4 will be connected to the positive electrode of the battery, and then connected to the negative electrode of the battery through the resistor R15 and the comparator U1 to form a loop; 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 to form a self-discharge circuit, and current limiting discharge. The battery power is consumed 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 to form a self-discharge indicator light circuit. During self-discharge, the indicator light of the light-emitting diode LED1 in this circuit lights up, indicating that the battery is in self-discharge.

[0040] Node 7 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 7, so PNP transistor Q4 opens the variable path. Node 7 is connected to the positive electrode of the battery, and connected to the negative electrode 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 electrode of the battery. The voltage at node 8 is higher than that at node 9, so NPN transistor Q6 opens the variable path. Node 10 is connected to the negative electrode 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 tube Q2 is turned off; The node 12 is connected to the charging circuit CP- and connected to the negative electrode of the battery through the NMOS tube Q2. When the NMOS tube Q2 is disconnected, the charging circuit at the node 12 is disconnected and the battery cannot be charged.

[0041] At this time, the circuit self-discharges the battery module to reduce the voltage through the circuit of node 6. 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.

[0042] refer to Figure 4 , Figure 5 , Figure 4 This is circuit state 2. When the battery module is at low voltage, the circuit can be charged and the buck circuit is turned off. The specific logic flow is described as follows: When the voltage of the battery module is lower than 3.5V, the voltage at node 3 in the sampling loop will be lower than 2.5V, and the comparator U1 will be turned off and disconnected; 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, so the voltage at node 5 is the same as that at node 6, so the PMOS tube Q3 is turned off and disconnected.

[0043] 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 is not on.

[0044] There is no current flowing through node 5, which is connected to node 4, node 7, and the positive electrode 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. There is no current at node 8, which is connected to node 9 and the negative electrode of the battery through resistor R8. The voltage at node 8 is the same as that at node 9, both are 0V, so the NPN transistor Q6 is turned off. At node 10, it 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 voltage stabilizing diode ZD1 to form a voltage stabilizing loop, and node 10 maintains a high level; 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 tube Q2 opens the variable path, and the working state of the NMOS tube module Q1 is the same as that of the NMOS tube Q2.

[0045] According to the voltage divided by the resistors R4 and R3 and the reference voltage of the comparator U1, the source voltage value 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, and the input charging voltage and current are regulated by the switching frequency.

[0046] The charging current passes through PC-, node 12, NMOS tube Q2, and is connected to the negative electrode of the battery. The battery charging circuit is turned on and the battery is charged.

[0047] 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.

[0048] The upper limit voltage of the battery module is not limited to 3.5V. The reference voltage of the comparator U1 changes according to the upper limit voltage of the battery. When the battery is charged to the upper limit voltage of the battery through a large current, it switches between circuit state 1 and circuit state 2. The closer the battery is to the upper limit voltage of the charge, the more frequent the switching is, so as to gradually reduce the charging current.

[0049] The changes in voltage and current when sodium ion batteries are charged 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. When the battery is closer to the upper limit voltage of charging, 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 usable capacity of the battery. The sodium ion battery charging protection control system of the present invention provides charging protection for the battery in the entire charging stage.

[0050] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope 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) which is electrically connected to the sodium battery module (1) and is 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 sampled 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 sampled 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), which is electrically connected to the comparison switch control unit (3) and is used 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 total charging switch control unit (6), the total charging switch control unit (6) being electrically connected to the secondary switch control unit (5), and if the secondary switch control unit (5) controls the switch to be turned on, the total 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 total charging switch control unit (6) controls the switch to be turned on; A charging unit (7), the charging unit (7) being electrically connected to the sodium battery module (1) via a circuit, the total charging switch control unit (6) being 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 is.

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 connected in series and electrically connected to the positive and negative electrodes of the sodium battery module (1) to form 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 tube Q3, and a PNP triode Q4; the first connection end of the comparator U1 is connected between 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 (1) through a resistor R15; the third connection end of the comparator U1 is connected to the negative electrode of the sodium battery module (1); the source electrode of the PMOS tube Q3 is connected to the positive electrode of the sodium battery module (1); the drain electrode of the PMOS tube Q3 is connected to the negative electrode of the sodium battery module (1) through resistors R2 and R1; The cathode of the module (1) is connected to the cathode of the module (1), the gate of the PMOS tube Q3 is connected between the comparator U1 and the resistor R15 through a 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 a resistor R13, the collector of the PNP transistor Q4 is connected to the secondary switch control unit (5) through a resistor R12, and the switch 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 also 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 electric 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 electric 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 a 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 regulator diode ZD1 is connected between the rectifier diode D2 and the resistor R8 , a cathode of the voltage regulator diode ZD1 is connected to a cathode of the rectifier diode D2 , and an anode of the voltage regulator 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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