Non-isolated boost circuit applied to sodium ion battery

Abstract

The invention relates to the technical field of sodium ion batteries, and discloses a non-isolated booster circuit applied to a sodium ion battery. The non-isolated booster circuit is characterized in that the positive electrode of a battery pack is connected with a second inductor, a first capacitor, a sixth MOS tube source electrode and a first MOS tube drain electrode, and the other end of the second inductor is connected with a second MOS tube drain electrode and a fourth MOS tube source electrode; the other end of the first capacitor, a drain electrode of the sixth MOS tube and a drain electrode of the fourth MOS tube are connected with a load or a positive electrode of a power supply; the negative electrode of the battery pack is connected with the first inductor, the second capacitor, the drain electrode of the fifth MOS tube and the source electrode of the second MOS tube; the other end of the first inductor is connected with the source electrode of the first MOS tube and the drain electrode of the third MOS tube; the other end of the second capacitor, a source electrode of the fifth MOS tube and a source electrode of the third MOS tube are connected with a load or a negative electrode of a power supply; the circuit can efficiently adjust the current flow direction in different working states, the circuit structure is simplified, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium ion batteries, and in particular to a non-isolated boost circuit applied to sodium ion batteries. Background Art

[0002] In recent years, as the global energy shortage problem has become increasingly severe, sodium-ion batteries have shown great application potential in the field of electric two-wheeled vehicles and low-speed electric vehicles due to their low cost and high safety. The core power source of these electric vehicles is the power battery, which usually meets the specific output voltage and output capacity requirements through a series-parallel combination of single cells. In practical applications, there is a significant difference between the charge and discharge voltage range of the sodium-ion battery pack and the voltage range required for the actual operation of electric vehicles. This difference requires a converter that can adapt to a wide range of input and output during the full charge and discharge process of the battery. At present, the commonly used technical solution is to combine the battery with a DC-DC boost circuit to achieve the boost function, thereby matching the external discharge circuit.

[0003] However, this solution is just a simple superposition at the circuit level, and does not achieve the effect of simplifying the circuit structure and reducing costs. More importantly, due to the significant differences in the inherent output characteristics of sodium-ion batteries and traditional 48V lead-acid and lithium battery systems, they are not universal, so they need to be equipped with dedicated chargers and controllers to match them. This highly specialized and high-cost feature undoubtedly limits the application of sodium-ion batteries in a wider range of fields.

[0004] Therefore, there is an urgent need for a non-isolated boost circuit for sodium ion batteries, which simplifies the circuit structure, reduces cost and complexity, and expands the application range of sodium ion batteries. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a non-isolated boost circuit applied to a sodium ion battery, which can match the sodium ion battery with a charger and a load, thereby improving the use efficiency and life of the sodium ion battery.

[0006] The present invention provides a non-isolated boost circuit for a sodium ion battery, comprising: A battery pack, a first inductor, a second inductor, a first capacitor, a second capacitor, a first MOS tube, a second MOS tube, a third MOS tube, a fourth MOS tube, a fifth MOS tube, and a sixth MOS tube; One end of the second inductor, one end of the first capacitor, the source of the sixth MOS tube and the drain of the first MOS tube are connected to the positive electrode of the battery pack; the other end of the second inductor is connected to the drain of the second MOS tube and the source of the fourth MOS tube; the other end of the first capacitor, the drain of the sixth MOS tube and the drain of the fourth MOS tube are connected to the positive electrode of the load or the power supply; One end of the first inductor, one end of the second capacitor, the drain of the fifth MOS tube and the source of the second MOS tube are connected to the negative electrode of the battery pack; the other end of the first inductor is connected to the source of the first MOS tube and the drain of the third MOS tube; the other end of the second capacitor, the source of the fifth MOS tube and the source of the third MOS tube are connected to the negative electrode of the load or the power supply; The battery pack is a sodium ion battery.

[0007] In some embodiments, when the battery pack is in a discharging state and when the voltage of the battery pack is greater than or equal to the voltage of the load, the fifth MOS tube and the sixth MOS tube are turned on, the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are turned off, and the battery pack discharges the load through the fifth MOS tube and the sixth MOS tube; In some embodiments, when the battery pack is in a discharging state and when the voltage of the battery pack is less than the voltage of the load, the first MOS tube and the second MOS tube and the third MOS tube and the fourth MOS tube are alternately turned on and off according to a predetermined time period, and the battery pack discharges the load alternately through the second MOS tube, the fourth MOS tube and the second inductor or the first MOS tube, the third MOS tube and the first inductor.

[0008] In some embodiments, when the battery pack is in a charging state, the fifth MOS tube and the sixth MOS tube are turned off, and the first MOS tube and the second MOS tube and the third MOS tube and the fourth MOS tube are alternately turned on and off according to a predetermined time period, and the battery pack is alternately charged through the second MOS tube, the fourth MOS tube and the second inductor or the first MOS tube, the third MOS tube and the first inductor.

[0009] In some embodiments, when the battery pack is in a stationary state, the first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube and the sixth MOS tube are all turned off.

[0010] In some embodiments, the first MOS transistor, the second MOS transistor, the third MOS transistor, the fourth MOS transistor, the fifth MOS transistor and the sixth MOS transistor are all N-channel enhancement type MOS transistors.

[0011] The embodiments of the present invention have the following technical effects: The circuit provided in this application takes into account the differences in charge and discharge characteristics between sodium-ion batteries and traditional batteries, and the circuit is specifically designed to better meet the needs of sodium-ion batteries. It can provide a boost function when the battery pack voltage is lower than the load demand, thereby expanding the application range of sodium-ion batteries. The circuit provided in this application adopts a non-isolated design. Compared with the isolated boost circuit, the non-isolated design simplifies the circuit structure, reduces the cost and complexity, and integrates non-isolated boost with charge and discharge management: the circuit not only realizes the boost function, but also integrates the charge and discharge management function, simplifies the system structure, and improves the integration. The circuit provided in this application can automatically adjust the working mode according to the discharge and charge status of the battery pack, thereby improving the efficiency and reliability of the system; when the battery pack is stationary, all MOS tubes are turned off, reducing the power consumption of the circuit. Through a carefully designed MOS tube control strategy, efficient and reliable energy conversion and management can be achieved under different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 is a structural diagram of a non-isolated boost circuit applied to a sodium ion battery provided by an embodiment of the present invention; Figure 2 is a discharge voltage curve diagram of a sodium ion battery provided by an embodiment of the present invention; Figure 3 is a discharge control signal timing diagram of a sodium ion battery provided by an embodiment of the present invention; Figure 4 is a charging voltage curve diagram of a sodium ion battery provided by an embodiment of the present invention; Figure 5 This is a timing diagram of a charging control signal of a sodium ion battery provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0015] Figure 1is a structural diagram of a non-isolated boost circuit for sodium ion batteries provided by an embodiment of the present invention. Figure 1 , a non-isolated boost circuit for sodium ion batteries, specifically comprising: A first inductor L1, a second inductor L2, a first capacitor C3, a second capacitor C4, a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, a fourth MOS transistor Q4, a fifth MOS transistor Q5 and a sixth MOS transistor Q6; One end of the second inductor L2, one end of the first capacitor C3, the source of the sixth MOS transistor Q6 and the drain of the first MOS transistor Q1 are connected to the positive electrode of the battery pack U1; the other end of the second inductor L2 is connected to the drain of the second MOS transistor Q2 and the source of the fourth MOS transistor Q4; the other end of the first capacitor C3, the drain of the sixth MOS transistor Q6 and the drain of the fourth MOS transistor Q4 are connected to the positive electrode of the load or the power supply; One end of the first inductor L1, one end of the second capacitor C4, the drain of the fifth MOS tube Q5, and the source of the second MOS tube Q2 are connected to the negative electrode of the battery pack U1; the other end of the first inductor L1 is connected to the source of the first MOS tube Q1 and the drain of the third MOS tube Q3; the other end of the second capacitor C4, the source of the fifth MOS tube Q5, and the source of the third MOS tube Q3 are connected to the load or the negative electrode of the power supply.

[0016] like Figure 1 As shown, when the port is connected to a load, it means that the battery pack is discharging; when the port is connected to a power source, it means that the battery pack is charging.

[0017] In some embodiments, when the battery pack U1 is in a discharging state and when the voltage of the battery pack U1 is greater than or equal to the load voltage, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned on, the first MOS tube Q1, the second MOS tube Q2, the third MOS tube Q3 and the fourth MOS tube Q4 are turned off, and the battery pack U1 discharges the load through the fifth MOS tube Q5 and the sixth MOS tube Q6; In some embodiments, when the battery pack U1 is in a discharging state and when the voltage of the battery pack U1 is less than the load voltage, the first MOS tube Q1 and the second MOS tube Q2 and the third MOS tube Q3 and the fourth MOS tube Q4 are alternately turned on and off according to a predetermined time period, and the battery pack U1 discharges to the load through the second MOS tube Q2, the fourth MOS tube Q4, the second inductor L2, the first MOS tube Q1, the third MOS tube Q3 and the first inductor L1.

[0018] For example, Figure 2is a discharge voltage curve diagram of a sodium ion battery provided by an embodiment of the present invention, see Figure 2 In the T0-T1 time period, the battery pack voltage is greater than or equal to the voltage required by the load, so the battery pack discharges normally to meet the load needs; in the T1-T2 time period, the battery pack voltage is less than the voltage required by the load, so a boost circuit is required to achieve boost to meet the load needs.

[0019] Figure 3 is a discharge control signal timing diagram of a sodium ion battery provided by an embodiment of the present invention, see Figure 3 , the battery pack discharge process is as follows: In the first step, when the battery pack U1 is in a discharging state and the voltage of the battery pack U1 is greater than or equal to the load voltage, the battery pack U1 is discharged through the fifth MOS tube Q5 and the sixth MOS tube Q6; In the second step, when the battery pack U1 is in a discharging state and the voltage of the battery pack U1 is less than the load voltage, during the time period t0-t1, the first MOS tube Q1 and the second MOS tube Q2 are turned on, the third MOS tube Q3, the fourth MOS tube Q4, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, and the battery pack U1 discharges the load through Q1 and Q2; during the time period t1-t2, the first MOS tube Q1 and the second MOS tube Q2 are turned off, the third MOS tube Q3 and the fourth MOS tube Q4 are turned on, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off During the period t2-t3, the first MOS tube Q1 and Q2 are turned on, the third MOS tube Q3 and the fourth MOS tube Q4 are turned off, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, and the battery pack U1 discharges the load through Q1 and Q2 again; during the period t3-t4, the first MOS tube Q1 and the second MOS tube Q2 are turned off, the third MOS tube Q3 and the fourth MOS tube Q4 are turned on, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, and the battery pack U1 discharges the load through Q3 and Q4 again. This process will cycle in a preset cycle (i.e., a predetermined time period) until the battery pack voltage is fully discharged.

[0020] This alternating conduction mode can achieve a boosting effect, ensuring that the battery pack U1 can continuously discharge the load. The fifth MOS tube Q5 and the sixth MOS tube Q6 remain closed throughout the process, which means that they do not participate in the discharge process at this stage. This control strategy achieves a boosting effect by alternately conducting different MOS tubes, ensuring that the battery can continuously supply power to the load at different voltages.

[0021] In some embodiments, when the battery pack U1 is in a charging state, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, and the first MOS tube Q1 and the second MOS tube Q2 and the third MOS tube Q3 and the fourth MOS tube Q4 are alternately turned on and off according to a predetermined time period, and the battery module U1 is charged through the second MOS tube Q2, the fourth MOS tube Q4, the second inductor L2, the first MOS tube Q1, the third MOS tube Q3 and the first inductor L1.

[0022] For example, Figure 4 is a charging voltage curve diagram of a sodium ion battery provided by an embodiment of the present invention, see Figure 4 , during the T0-T2 time period, the battery pack voltage is less than or equal to the power input voltage, that is, during the battery pack charging process, the input battery voltage needs to be adjusted.

[0023] Figure 5 is a timing diagram of a charging control signal of a sodium ion battery provided by an embodiment of the present invention, see Figure 5 , the battery pack charging process is as follows: In the time period t0-t1, the first MOS tube Q1 and the second MOS tube Q2 are turned on, the third MOS tube Q3 and the fourth MOS tube Q4 are turned off, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, the current flows into the second inductor L2 through MOS Q2, and then returns to the positive pole of the power supply through MOS Q4. At this time, the second inductor L2 stores energy; in the time period t1-t2, the first MOS tube Q1 and the second MOS tube Q2 are turned off, the third MOS tube Q3 and the fourth MOS tube Q4 are turned on, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, the energy stored in the second inductor L2 is released to the battery, and new energy begins to be stored in the first inductor L1; in the time period t2-t3, the first MOS tube Q1 and the second MOS tube Q2 are turned on, the third MOS tube Q3 and the fourth MOS tube Q4 are turned off, the fifth MOS tube Q5 and the sixth MOS tube Q6 are turned off, the energy stored in the first inductor L1 is released to the battery, and new energy begins to be stored in the second inductor L2.

[0024] In this charging scheme, the alternating on and off of the MOS tube realizes the charging of the battery module U1, while the first inductors L1 and L2 help maintain the continuity and stability of the current. This method can not only effectively manage the energy transmission during the charging process, but also optimize the charging efficiency and speed by adjusting the switching frequency and duty cycle of the MOS tube.

[0025] In some embodiments, when the battery pack U1 is in a static state, the first MOS transistor Q1, the second MOS transistor Q2, the third MOS transistor Q3, the fourth MOS transistor Q4, the fifth MOS transistor Q5 and the sixth MOS transistor Q6 are all turned off. The entire circuit is designed to minimize static power consumption to ensure that the system can maintain minimum energy consumption even during a long period of static state.

[0026] In some embodiments, the first MOS transistor Q1 , the second MOS transistor Q2 , the third MOS transistor Q3 , the fourth MOS transistor Q4 , the fifth MOS transistor Q5 , and the sixth MOS transistor Q6 are all N-channel enhancement type MOS transistors.

[0027] In the present application, in the discharge state, when the battery voltage is higher than that required by the load, the fifth MOS tube Q5 and the sixth MOS tube Q6 are directly turned on to supply power to the load, thereby avoiding unnecessary boost conversion losses. When the battery voltage is lower than that required by the load, the boost effect is achieved by alternately turning on the MOS tubes, thereby ensuring that the battery can continuously and stably supply power to the load while improving efficiency. During the charging process, the alternating conduction of the MOS tubes is used to control the current path, making the charging process smoother and controllable, which helps to extend the battery life and improve the charging efficiency. The use of the first inductors L1 and L2 ensures the continuity and stability of the charging current, reduces the impact on the battery, and is beneficial to protecting the health of the battery. Turning off all MOS tubes in a static state can effectively prevent leakage current and other potential safety hazards, thereby enhancing the reliability and safety of the system. The low static power consumption design enables the system to maintain minimum energy consumption even when not in use for a long time, further improving energy efficiency.

[0028] The present application is applicable to loads and power inputs of different voltage levels, showing good adaptability and flexibility, and can provide stable performance in a variety of application scenarios. Compared with the prior art, the loss in the energy conversion process is reduced by intelligently selecting whether a boost is needed and accurately controlling the switching cycle of the MOS tube. Due to the adoption of an optimized charging and discharging strategy, the working time of the battery under extreme conditions is reduced, which helps to slow down the aging of the battery and thus extend its service life. By disconnecting all MOS tube connections in a static state, not only the self-discharge rate is reduced, but also the safety of the system is increased, which is particularly important in equipment working in harsh environments such as high or low temperatures. The design is simple, easy to understand and maintain, and reduces the difficulty of debugging. In summary, the non-isolated boost circuit for sodium-ion batteries provided in the present application not only improves the charging and discharging efficiency, but also enhances safety and reliability.

[0029] It should be noted that the terms used in the present invention are only for describing specific embodiments, rather than limiting the scope of the present application. As shown in the present specification, unless the context clearly indicates an exception, the words "one", "a", "a kind of" and / or "the" do not specifically refer to the singular, but may also include the plural. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of more restrictions, the elements defined by the sentence "include one..." do not exclude the presence of other identical elements in the process, method or device including the elements.

[0030] It should also be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A non-isolated boost circuit for sodium ion batteries, characterized in that: include: A battery pack, a first inductor, a second inductor, a first capacitor, a second capacitor, a first MOS transistor, a second MOS transistor, a third MOS transistor, a fourth MOS transistor, a fifth MOS transistor and a sixth MOS transistor; One end of the second inductor, one end of the first capacitor, the source of the sixth MOS tube and the drain of the first MOS tube are connected to the positive electrode of the battery pack; the other end of the second inductor is connected to the drain of the second MOS tube and the source of the fourth MOS tube; the other end of the first capacitor, the drain of the sixth MOS tube and the drain of the fourth MOS tube are connected to the positive electrode of the load or the power supply; One end of the first inductor, one end of the second capacitor, the drain of the fifth MOS tube and the source of the second MOS tube are connected to the negative electrode of the battery pack; the other end of the first inductor is connected to the source of the first MOS tube and the drain of the third MOS tube; the other end of the second capacitor, the source of the fifth MOS tube and the source of the third MOS tube are connected to the negative electrode of the load or the power supply; The battery pack is a sodium ion battery.

2. A non-isolated boost circuit for sodium ion batteries according to claim 1, characterized in that: When the battery pack is in a discharging state and when the voltage of the battery pack is greater than or equal to the voltage of the load, the fifth MOS tube and the sixth MOS tube are turned on, the first MOS tube, the second MOS tube, the third MOS tube and the fourth MOS tube are turned off, and the battery pack discharges the load through the fifth MOS tube and the sixth MOS tube.

3. The non-isolated boost circuit for sodium ion battery according to claim 1, characterized in that: When the battery pack is in a discharging state and when the voltage of the battery pack is less than the voltage of the load, the first MOS tube and the second MOS tube and the third MOS tube and the fourth MOS tube are alternately turned on and off according to a predetermined time period, and the battery pack discharges the load alternately through the second MOS tube, the fourth MOS tube and the second inductor or the first MOS tube, the third MOS tube and the first inductor.

4. The non-isolated boost circuit for sodium ion battery according to claim 1, characterized in that: When the battery pack is in a charging state, the fifth MOS tube and the sixth MOS tube are turned off, and the first MOS tube and the second MOS tube and the third MOS tube and the fourth MOS tube are alternately turned on and off according to a predetermined time period, and the battery pack is charged through the second MOS tube, the fourth MOS tube and the second inductor or the first MOS tube, the third MOS tube and the first inductor.

5. The non-isolated boost circuit for sodium ion battery according to claim 1, characterized in that: When the battery pack is in a stationary state, the first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube and the sixth MOS tube are all turned off.

6. The non-isolated boost circuit for sodium ion battery according to claim 1, characterized in that: The first MOS tube, the second MOS tube, the third MOS tube, the fourth MOS tube, the fifth MOS tube and the sixth MOS tube are all N-channel enhancement type MOS tubes.

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