A high machine sodium-lithium hybrid power system

Abstract

The application relates to a high-machine sodium-lithium hybrid power system, which comprises connected lithium battery units and sodium battery units; the lithium battery unit comprises a lithium battery module, a first shunt, a first BMS unit, a first fuse, a first DC / DC conversion unit, a first total positive control unit, a first total positive relay, a first heating film, a first heating control relay and a first heating control unit, wherein the sodium battery unit is connected with the first shunt, the first BMS unit and the first total positive relay respectively. The application adopts a master-slave control architecture, takes the lithium battery unit as the master and the sodium battery unit as the slave, can fully exert the respective advantages of the sodium battery and the lithium battery, greatly improves the overall performance of the battery system, can cope with the requirements of super-low-temperature outdoor application, meets the temperature adaptation of-40 DEG C to 55 DEG C, greatly improves the environmental temperature adaptability, and makes the coverage of the product wider.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a high-performance sodium-lithium hybrid power system. Background Technology

[0002] Hydrogen fuel cells are one of the new power systems in recent years. Their technology, products, and safety have been validated, and they have attracted much attention as a power source for vehicle systems, achieving initial scale in the international market. Because there is a certain lag between the full reaction of the hydrogen fuel cell and the continuous provision of a stable power supply to the electric motor, and vehicles cannot wait for a period of time after starting before being used again, a lithium battery is usually designed in conjunction with a hydrogen fuel cell system to serve as a transitional power source.

[0003] Existing vehicle power systems generally use the same material system (lithium iron phosphate) in series or parallel to form a PACK solution. Their normal environmental temperature resistance is 0℃ to 55℃, and this range can only be broadened by external auxiliary heating. However, due to the performance limitations of the chemical material (lithium iron phosphate), and the fact that the environmental resistance of external auxiliary heating equipment is only -20℃ to 55℃, exceeding these temperatures restricts the equipment's application or causes it to shut down. In the extremely cold regions of Northeast China (-40℃), there is still widespread demand for aerial work platforms; however, current equipment is limited in application under these conditions, especially at -40℃, where it completely shuts down. Restoring battery discharge performance through auxiliary heating relies on an external power source; however, lithium iron phosphate batteries become completely inoperable below -30℃, and when the equipment is used outdoors, no suitable power source can be found for external heating. Therefore, lithium iron phosphate batteries have poor low-temperature chemical activity, with discharge performance dropping sharply below -20℃ and completely losing chemical activity below -30℃.

[0004] Sodium-ion batteries have excellent low-temperature resistance. However, due to their material properties, sodium-ion batteries have a wide voltage range (1.5V to 3.95V), which makes them unsuitable for direct application in high-voltage systems (they cannot drive motor controllers in the low-voltage range), resulting in approximately 30% of the charge remaining unreleased in the low-capacity range. Utility Model Content

[0005] Based on this, this utility model provides a sodium-lithium hybrid power system for high-performance engines, aiming to solve the problems of poor low-temperature chemical activity, wide voltage range, and inability to meet the application requirements of high-performance engine systems in existing vehicle power systems.

[0006] To achieve the above objectives, the present invention proposes the following technical solution: a high-performance sodium-lithium hybrid power system, comprising a lithium battery unit and a sodium battery unit connected together; the lithium battery unit includes a lithium battery module, a first shunt, a first BMS unit, a first fuse, a first DC / DC converter, a first positive control unit, a first positive relay, a first heating film, a first heating control relay, and a first heating control unit; the lithium battery module is connected to the first shunt, the first BMS unit, and the first fuse respectively; the first BMS unit is connected to the first shunt, the first fuse, the first DC / DC converter, and the first heating control unit respectively; the first heating film is connected to the first DC / DC converter and the first heating control relay respectively; the first heating control relay is connected to the first heating control unit; the first positive relay is connected to the first positive control unit, the first fuse, the first heating control relay, and the sodium battery unit respectively; the sodium battery unit is connected to the first shunt and the first BMS unit respectively.

[0007] In a preferred embodiment, the lithium battery unit further includes a second fuse, one end of which is connected to the first DC / DC conversion unit, and the other end is connected between the first shunt and the sodium battery unit.

[0008] In a preferred embodiment, the lithium battery unit further includes a first precharge control unit and a first precharge control relay, wherein the first precharge control relay is connected to the first precharge control unit, the first fuse, and the first heating control relay.

[0009] In a preferred embodiment, a first resistor is provided between the first precharge control relay and the first heating control relay, and the first resistor is connected to the first precharge control relay and the first heating control relay respectively.

[0010] In a preferred embodiment, the lithium battery unit further includes a first power supply control unit and a first power supply relay, wherein the first power supply relay is connected to the first power supply control unit, the first fuse, and the first DC / DC conversion unit.

[0011] In a preferred embodiment, the lithium battery unit further includes a first total negative control unit and a first total negative relay, wherein the first total negative relay is connected to the first total negative control unit, the first shunt, the second fuse, and the sodium battery unit.

[0012] In a preferred embodiment, the lithium battery unit further includes a first self-reset button, which is connected to the first fuse, the first DC / DC conversion unit, and the first BMS unit.

[0013] In a preferred embodiment, a first diode is provided between the first BMS unit and the first DC / DC conversion unit, and the first diode is connected to the first BMS unit and the first DC / DC conversion unit respectively.

[0014] In a preferred embodiment, the lithium battery unit further includes a second diode, which is connected to the first BMS unit.

[0015] In a preferred embodiment, the lithium battery unit further includes a first indicator light, which is connected to the first BMS unit.

[0016] In a preferred embodiment, the lithium battery unit further includes a first charging / discharging positive terminal interface and a first charging / discharging negative terminal interface, one end of the first charging / discharging positive terminal interface being connected to the first main positive relay, and one end of the first charging / discharging negative terminal interface being connected to the first main negative relay.

[0017] In a preferred embodiment, the first BMS unit is provided with a first matching resistor, which is connected to the sodium battery unit.

[0018] In a preferred embodiment, the lithium battery module includes several lithium battery cells connected in series; the lithium battery cells are cylindrical lithium battery cells.

[0019] In a preferred embodiment, the sodium battery unit includes a sodium battery module, a second shunt, a second BMS unit, a third fuse, a second DC / DC converter, a second positive control unit, a second positive relay, a second heating film, a second heating control relay, and a second heating control unit. The sodium battery module is connected to the second shunt, the second BMS unit, and the third fuse. The second BMS unit is connected to the second shunt, the third fuse, the second DC / DC converter, and the second heating control unit. The second heating film is connected to the second DC / DC converter and the second heating control relay. The second heating control relay is connected to the second heating control unit. The second positive relay is connected to the second positive control unit, the third fuse, the second heating control relay, and the first positive relay. The second shunt is connected to the first negative relay. The second BMS unit is connected to the first BMS unit.

[0020] In a preferred embodiment, the sodium battery unit further includes a fourth fuse, one end of which is connected to the second DC / DC conversion unit, and the other end is connected between the second shunt and the first main negative relay.

[0021] In a preferred embodiment, the sodium battery unit further includes a second precharge control unit and a second precharge control relay, wherein the second precharge control relay is connected to the second precharge control unit, the third fuse, and the second heating control relay, respectively.

[0022] In a preferred embodiment, a second resistor is provided between the second precharge control relay and the second heating control relay, and the second resistor is connected to the second precharge control relay and the second heating control relay respectively.

[0023] In a preferred embodiment, the sodium battery unit further includes a second power supply control unit and a second power supply relay, wherein the second power supply relay is connected to the second power supply control unit, the third fuse, and the second DC / DC conversion unit, respectively.

[0024] In a preferred embodiment, the sodium battery unit further includes a second total negative control unit and a second total negative relay, the second total negative relay being connected to the second total negative control unit, the second shunt, the fourth fuse, and the first total negative relay, respectively.

[0025] In a preferred embodiment, the sodium battery unit further includes a second self-reset button, which is connected to the third fuse, the second DC / DC conversion unit, and the second BMS unit.

[0026] In a preferred embodiment, a third diode is provided between the second BMS unit and the second DC / DC conversion unit, and the third diode is connected to the second BMS unit and the second DC / DC conversion unit respectively.

[0027] In a preferred embodiment, the sodium battery unit further includes a second indicator light, which is connected to the second BMS unit.

[0028] In a preferred embodiment, the second BMS unit is provided with a second matching resistor, which is connected to the first matching resistor.

[0029] In a preferred embodiment, the sodium battery module includes several sodium battery cells connected in series; the sodium battery cell is a cylindrical sodium battery cell.

[0030] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:

[0031] This application employs a master-slave control architecture, combining lithium-ion battery cells with sodium-ion battery cells. With the lithium-ion battery cells as the master and the sodium-ion battery cells as the slave, it fully leverages the advantages of both batteries. The low-voltage range charge that sodium-ion batteries cannot release is used to activate the chemical activity of lithium-ion batteries, significantly improving the overall performance of the battery system. This allows for operation in environments as low as -40°C, meeting the requirements of ultra-low temperature outdoor applications and satisfying temperature adaptability from -40°C to 55°C, greatly enhancing environmental temperature adaptability and broadening the product's coverage. This system significantly reduces the limitation of auxiliary heating on external power sources. Utilizing the ultra-low temperature discharge performance of sodium ions, it activates the chemical activity of lithium iron phosphate, restoring the battery system's ability to supply power externally. This achieves the on-demand supply requirement of the auxiliary heating circuit, fully meeting the battery performance requirements under the original vehicle electrical architecture. This system fully utilizes the material advantages of the respective chemical systems of sodium and lithium, significantly improving battery performance and environmental resistance. It can cover the temperature tolerance requirements of all domestic climates and essentially cover the temperature tolerance requirements of global applications. This application can be applied to high-performance machinery products, which can not only meet the power system performance and logic strategy requirements under the original equipment vehicle electrical architecture, but also cope with the ever-changing and complex usage environment. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the overall structure of a high-performance sodium-lithium hybrid power system according to an embodiment of the present invention.

[0034] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0035] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0036] It should be noted that if any directional indication (such as up, down, left, right, front, back, top, bottom, etc.) is involved in the embodiments of this utility model, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0037] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] It should be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0039] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0040] Specifically, such as Figure 1As shown, the present invention proposes the following technical solution: a high-performance sodium-lithium hybrid power system, comprising a lithium battery unit 100 and a sodium battery unit 200 connected to each other; the lithium battery unit 100 includes a lithium battery module 101, a first shunt 102, a first BMS unit 103, a first fuse FU1, a first DC / DC converter 104, a first positive control unit 105, a first positive relay RL1, a first heating film 106, a first heating control relay RL4, and a first heating control unit 107; the lithium battery module 101 is connected to the first shunt 102, the first BMS unit 103, and the first fuse FU1 respectively; the first BMS unit 103... The first heating film 106 is connected to the first DC / DC converter 104 and the first heating control unit 107, respectively; the first heating film 106 is connected to the first DC / DC converter 104 and the first heating control relay RL4, respectively; the first heating control relay RL4 is connected to the first heating control unit 107; the first positive relay RL1 is connected to the first positive control unit 105, the first fuse FU1, the first heating control relay RL4, and the sodium battery unit 200, respectively; the sodium battery unit 200 is connected to the first shunt 102 and the first BMS unit 103, respectively.

[0041] In this embodiment, the lithium battery cell and the sodium battery cell have similar structures, differing only in the battery module, the second diode, and the BMS unit interface.

[0042] The first main positive relay RL1 is connected to the main positive adhesion detection port ST2-1 (HV2+) of the first BMS unit 103 to realize main positive adhesion detection. The first main positive relay RL1 is connected to the positive interface P+. The first main positive relay RL1 is located between the first fuse FU1 and the first heating control relay RL4.

[0043] In a preferred embodiment, the lithium battery unit 100 further includes a second fuse FU2, one end of which is connected to the first DC / DC conversion unit 104, and the other end is connected between the first shunt 102 and the sodium battery unit 200.

[0044] In a preferred embodiment, the lithium battery unit 100 further includes a first precharge control unit 108 and a first precharge control relay RL2, wherein the first precharge control relay RL2 is connected to the first precharge control unit 108, the first fuse FU1, and the first heating control relay RL4 respectively.

[0045] In a preferred embodiment, a first resistor R1 is provided between the first precharge control relay RL2 and the first heating control relay RL4, and the first resistor R1 is connected to the first precharge control relay RL2 and the first heating control relay RL4 respectively.

[0046] In a preferred embodiment, the lithium battery unit 100 further includes a first power supply control unit 109 and a first power supply relay RL3, wherein the first power supply relay RL3 is connected to the first power supply control unit 109, the first fuse FU1, and the first DC / DC conversion unit 104. In this embodiment, the first power supply control relay RL3 is disposed between the first fuse FU1 and the first DC / DC conversion unit 104.

[0047] In a preferred embodiment, the lithium battery unit 100 further includes a first total negative control unit 110 and a first total negative relay RL5_H, wherein the first total negative relay RL5_H is connected to the first total negative control unit 110, the first shunt 102, the second fuse FU2, and the sodium battery unit 200. In this embodiment, the first total negative relay RL5_H is connected to a negative terminal interface P-.

[0048] In a preferred embodiment, the lithium battery unit 100 further includes a first self-reset button SB1, which is connected to the first fuse FU1, the first DC / DC conversion unit 104, and the first BMS unit 103.

[0049] In this embodiment, the IN+ interface of the first DC / DC conversion unit 104 is connected to the first self-reset button SB1 and the first power supply control relay RL3, respectively; the IN- interface of the first DC / DC conversion unit 104 is connected to the first total negative relay RL5_H and the first heating film 106.

[0050] In a preferred embodiment, a first diode 111 is provided between the first BMS unit 103 and the first DC / DC conversion unit 104, and the first diode 111 is connected to the first BMS unit 103 and the first DC / DC conversion unit 104 respectively.

[0051] In a preferred embodiment, the lithium battery unit 100 further includes a second diode 112, which is connected to the first BMS unit 103.

[0052] In a preferred embodiment, the lithium battery unit 100 further includes a first indicator light 113, which is connected to the first BMS unit 103.

[0053] In a preferred embodiment, the lithium battery unit 100 further includes a first charging and discharging positive terminal interface P+ and a first charging and discharging negative terminal interface P-. One end of the first charging and discharging positive terminal interface P+ is connected to the first total positive relay RL1, and one end of the first charging and discharging negative terminal interface P- is connected to the first total negative relay RL5_H.

[0054] In a preferred embodiment, a first matching resistor 1031 is provided on the first BMS unit 103, and the first matching resistor 1031 is connected to the sodium battery unit 200.

[0055] In a preferred embodiment, the lithium battery module 101 includes a plurality of lithium battery units 1011 connected in series; the lithium battery unit 1011 is a cylindrical lithium battery unit.

[0056] In this embodiment, the ON position interface of the first BMS unit is connected to the first diode and the ON position interface of the second BMS unit, respectively; one end of the normally powered positive interface (normally powered+) of the first BMS unit is connected between the ON position interface (first BMS unit) and the first diode. The normally powered negative interface of the first BMS unit is connected to the first DC / DC conversion unit, the first indicator light, and the first self-reset button, respectively.

[0057] In this embodiment, the positive and negative interfaces of the first BMS unit are connected to the positive and negative terminals of the first positive control unit, respectively; the positive and negative interfaces of the first BMS unit are connected to the positive and negative terminals of the first power supply control unit, respectively; the positive and negative interfaces of the first BMS unit are connected to the positive and negative terminals of the first power supply control unit, respectively; the positive and negative interfaces of the first BMS unit are connected to the positive and negative terminals of the precharge control unit, respectively; when heating is required, the positive and negative interfaces of the first BMS unit are connected to the positive and negative terminals of the first heating control unit, respectively. The lithium battery module is connected to the ST1, ST2, and ST3 ports of the BMS unit via a 16S voltage / 4NTC temperature sampling signal line. The first fuse FU1 is connected to the positive terminal of the lithium battery module, and the first shunt is connected to the negative terminal of the lithium battery module.

[0058] In a preferred embodiment, the sodium battery unit 200 includes a sodium battery module 201, a second shunt 202, a second BMS unit 203, a third fuse FU3, a second DC / DC converter unit 204, a second total positive control unit 205, a second total positive relay S_RL1, a second heating film 206, a second heating control relay S_RL4, and a second heating control unit 207; the sodium battery module 201 is connected to the second shunt 202, the second BMS unit 203, and the third fuse FU3 respectively; the second BMS unit 203 is connected to the second shunt 202, the third fuse FU3, and the second DC / DC converter unit 204 respectively. Unit 204 is connected to the second heating control unit 207; the second heating film 206 is connected to the second DC / DC conversion unit 204 and the second heating control relay S_RL4 respectively; the second heating control relay S_RL4 is connected to the second heating control unit 207; the second total positive relay S_RL1 is connected to the second total positive control unit 205, the third fuse FU1, the second heating control relay S_RL4, and the first total positive relay RL1 respectively; the second shunt 202 is connected to the first total negative relay RL5_H; the second BMS unit 203 is connected to the first BMS unit 103.

[0059] In a preferred embodiment, the sodium battery unit 200 further includes a fourth fuse FU4, one end of which is connected to the second DC / DC conversion unit 204, and the other end is connected between the second shunt 202 and the first total negative relay RL5_H.

[0060] In a preferred embodiment, the sodium battery unit 200 further includes a second precharge control unit 208 and a second precharge control relay S_RL2, wherein the second precharge control relay S_RL2 is connected to the second precharge control unit 208, the third fuse FU3, and the second heating control relay S_RL4, respectively.

[0061] In a preferred embodiment, a second resistor R2 is provided between the second precharge control relay S_RL2 and the second heating control relay S_RL4, and the second resistor R2 is connected to the second precharge control relay S_RL2 and the second heating control relay S_RL4 respectively.

[0062] In a preferred embodiment, the sodium battery unit 200 further includes a second power supply control unit 209 and a second power supply relay S_RL3, wherein the second power supply relay S_RL3 is connected to the second power supply control unit 209, the third fuse FU3, and the second DC / DC conversion unit 204, respectively.

[0063] In a preferred embodiment, the sodium battery unit 200 further includes a second total negative control unit 210 and a second total negative relay S_RL5_H, wherein the second total negative relay S_RL5_H is connected to the second total negative control unit 210, the second shunt 202, the fourth fuse FU4, and the first total negative relay RL5_H, respectively.

[0064] In a preferred embodiment, the sodium battery unit 200 further includes a second self-reset button SB2, which is connected to the third fuse FU3, the second DC / DC conversion unit 204, and the second BMS unit 203, respectively.

[0065] In a preferred embodiment, a third diode 211 is provided between the second BMS unit 203 and the second DC / DC conversion unit 204, and the third diode 211 is connected to the second BMS unit 203 and the second DC / DC conversion unit 204 respectively.

[0066] In a preferred embodiment, the sodium battery unit 200 further includes a second indicator light 212, which is connected to the second BMS unit.

[0067] In a preferred embodiment, the second BMS unit 203 is provided with a second matching resistor 2031, which is connected to the first matching resistor 1031.

[0068] In a preferred embodiment, the sodium battery module 201 includes a plurality of sodium battery units 2011 connected in series; the sodium battery unit 2011 is a cylindrical sodium battery unit.

[0069] In this embodiment, the ON position interface of the second BMS unit is connected to the third diode and the ON position interface of the first BMS unit, respectively; one end of the normally powered positive interface (normally powered +) of the second BMS unit is connected between the ON position interface (second BMS unit) and the third diode. The normally powered negative interface of the second BMS unit is connected to the second DC / DC conversion unit, the second indicator light, and the second self-reset button, respectively.

[0070] In this embodiment, the positive and negative interfaces of the second BMS unit are connected to the positive and negative terminals of the second positive control unit, respectively. When heating is required, the positive and negative interfaces of the second BMS unit are connected to the positive and negative terminals of the second heating control unit, respectively. The sodium battery module is connected to the ST1, ST2, and ST3 ports of the second BMS unit via a 16S voltage / 4NTC temperature sampling signal line. The third fuse FU1 is connected to the positive terminal of the sodium battery module, and the second shunt is connected to the negative terminal of the sodium battery module.

[0071] In this embodiment, both the first BMS unit and the second BMS unit are equipped with an OC2 (ST1-37) button, which can be pressed and held for 3 seconds to power off and put the device into sleep mode. The BMS units (including the first BMS unit and the second BMS unit) of this application all integrate a GPRS module.

[0072] This application fully leverages the ultra-low temperature tolerance of sodium-ion batteries. Through flexible circuit design, it activates the chemical activity of lithium iron phosphate batteries using low-temperature sodium-ion discharge, restoring their external discharge capability and enabling the device to operate normally at -40℃. The process controls when using the system of this application are as follows:

[0073] 1. Discharge Mode

[0074] This hybrid power system adopts a master-slave control architecture, with the lithium battery unit (A box) as the master and the sodium battery unit (B box) as the slave. The entire battery system can be activated by the start switch of any box. At the moment of activation, the battery pack in box A is woken up first, and the lithium battery in box A performs a self-check. After confirming that there are no abnormalities, it prepares to discharge based on the data uploaded by box B.

[0075] ① Whether parallel discharge is performed after the system starts up requires total voltage detection of A / B.

[0076] ② After the system starts, when it detects that the voltage of the B box (sodium battery) is higher than that of the A box (lithium battery), the external capacitor is pre-charged through the second pre-charge relay S_RL2. After the pre-charge is completed, S_RL1 is closed to enter the discharge state. When the total voltage of the B box (sodium battery) drops to within 3V of the total voltage difference of the A box (lithium battery), the total positive relay RL1 of the A box (lithium battery) is closed to enter the parallel discharge state.

[0077] ③ As the battery power is continuously consumed, the total voltage of the B-box battery (sodium battery) will decrease linearly, while the discharge platform of the A-box (lithium battery) is relatively stable. Within the discharge range of the lithium battery, the sodium battery will not be over-discharged. When the voltage drops below 45V, both batteries will cease discharging.

[0078] 2. Charging Mode

[0079] ① Charging at room temperature

[0080] Under normal application conditions, after the entire battery system has finished discharging, the battery voltages of boxes A and B will be basically the same. The main BMS will identify the charger and complete the charging message docking, and enter the parallel charging state. When the total charging voltage reaches 3.65*nV or above, the charging circuit of box A will be cut off, and box B will continue to be charged separately until it reaches 3.95*nV, ensuring that both boxes A and B are fully charged.

[0081] ② Low-temperature charging

[0082] The BMS can control the heating of the A / B boxes through the RL4 and S_RL4 relays. When the ambient temperature is below 0℃, the BMS sends a preheating request to the charger and simultaneously preheats the A / B boxes. Once the temperature reaches the preset value, the normal charging logic is entered.

[0083] 3. Ultra-low temperature discharge mode

[0084] When the battery pack is located in an extremely cold environment (-30℃ to -40℃), the battery system completes the power supply requirements of the whole vehicle system through three stages: sodium discharge, sodium discharge while preheating lithium battery, and sodium and lithium battery discharge together after preheating.

[0085] Specifically as follows:

[0086] ① When the ambient temperature reaches -40℃, the sodium-ion battery still has a continuous discharge capacity of over 2C. At this time, the discharge logic management of the B-box (sodium battery) can be performed through the BMS to enter the single-group discharge mode, and the equipment can be put into use. Pre-charging is completed by closing the S_RL2 relay, and S_RL1 and S_RL5 are powered on. At the same time, the RL1 and RL5_H A-box (lithium battery) relays are kept open to prevent battery damage after the vehicle is started. This is the sodium battery discharge stage.

[0087] ② The vehicle is powered solely by sodium batteries. Since the capacity of sodium batteries only accounts for one-third of the system, and the voltage of sodium batteries at the end of discharge is too low to power the entire vehicle (about 30% cannot be released), it is necessary to restore the discharge capacity of lithium batteries to ensure the overall range of the vehicle. At this time, the BMS controls the relay of the heating circuit of the A box, RL4 is closed, and the sodium battery supplies power to the outside while preheating the lithium battery. This is the stage of sodium battery discharge and lithium battery preheating at the same time.

[0088] ③ When the lithium battery's own temperature rises to -20℃, the lithium battery has a continuous discharge capability of 0.5C, and the battery system as a whole meets the performance requirements of 2.5C and above. At this time, the BMS closes the RL1 and RL5_H relays to perform parallel discharge (the total voltage difference is within the allowable range). This can meet extreme working conditions such as long-distance uphill climbing and muddy road operation. The battery system has fully recovered and is not affected by the low temperature environment.

[0089] 4. Failure Modes

[0090] For the vehicle controller, although the voltage of sodium-ion batteries is higher than that of lithium batteries after being fully charged, it does not exceed the controller's tolerance range. Therefore, the single-cell operation mode of sodium batteries can meet the vehicle's electrical requirements.

[0091] ① Fault in Box A (lithium battery)

[0092] a) Keep relays RL1, RL2, RL3, RL4, and RL5_H disconnected, and use RL6_H to flash the running light of box A to indicate that the battery in box A is faulty, so that maintenance personnel can replace and repair it in time.

[0093] b) The master BMS controls the slave BMS, and the S_RL2 relay completes the pre-charging, controlling the S_RL1, S_RL2, S_RL3, and S_RL5_H relays to complete the power supply to the whole vehicle.

[0094] ② Box B (Sodium Electrolyte) Malfunction

[0095] a) Keep relays S_RL1, S_RL2, S_RL3, S_RL4, and S_RL5_H disconnected, and use S_RL6_H to make the B-box operation light flash, indicating that the B-box battery is faulty, so that maintenance personnel can replace and repair it in time.

[0096] b) Through direct control of the relays by the main BMS, the RL2 relay completes the pre-charging and controls the operation of the RL1, RL2, RL3, and RL5_H relays to complete the power supply to the whole vehicle.

[0097] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0098] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0099] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A high-performance sodium-lithium hybrid power system, characterized in that, The system includes interconnected lithium battery units and sodium battery units. Each lithium battery unit comprises a lithium battery module, a first shunt, a first BMS unit, a first fuse, a first DC / DC converter, a first positive control unit, a first positive relay, a first heating film, a first heating control relay, and a first heating control unit. The lithium battery module is connected to the first shunt, the first BMS unit, and the first fuse. The first BMS unit is connected to the first shunt, the first fuse, the first DC / DC converter, and the first heating control unit. The first heating film is connected to the first DC / DC converter and the first heating control relay. The first heating control relay is connected to the first heating control unit. The first positive relay is connected to the first positive control unit, the first fuse, the first heating control relay, and the sodium battery unit. The sodium battery unit is connected to the first shunt and the first BMS unit.

2. The high-performance sodium-lithium hybrid power system according to claim 1, characterized in that, The lithium battery unit also includes a second fuse, one end of which is connected to the first DC / DC conversion unit, and the other end is connected between the first shunt and the sodium battery unit; The lithium battery unit further includes a first precharge control unit and a first precharge control relay, wherein the first precharge control relay is connected to the first precharge control unit, the first fuse, and the first heating control relay.

3. The high-performance sodium-lithium hybrid power system according to claim 2, characterized in that, A first resistor is provided between the first pre-charge control relay and the first heating control relay, and the first resistor is connected to the first pre-charge control relay and the first heating control relay respectively. The lithium battery unit also includes a first power supply control unit and a first power supply relay, wherein the first power supply relay is connected to the first power supply control unit, the first fuse, and the first DC / DC conversion unit.

4. The high-performance sodium-lithium hybrid power system according to claim 3, characterized in that, The lithium battery unit further includes a first total negative control unit and a first total negative relay, the first total negative relay being connected to the first total negative control unit, the first shunt, the second fuse, and the sodium battery unit respectively; The lithium battery unit also includes a first self-reset button, which is connected to the first fuse, the first DC / DC conversion unit, and the first BMS unit respectively. A first diode is provided between the first BMS unit and the first DC / DC conversion unit, and the first diode is connected to the first BMS unit and the first DC / DC conversion unit respectively. The lithium battery unit also includes a second diode, which is connected to the first BMS unit.

5. The high-performance sodium-lithium hybrid power system according to claim 4, characterized in that, The lithium battery unit also includes a first indicator light, which is connected to the first BMS unit; The lithium battery unit further includes a first charging and discharging positive terminal interface and a first charging and discharging negative terminal interface. One end of the first charging and discharging positive terminal interface is connected to the first main positive relay, and one end of the first charging and discharging negative terminal interface is connected to the first main negative relay. The first BMS unit is provided with a first matching resistor, which is connected to the sodium battery unit; The lithium battery module includes several lithium battery cells connected in series; the lithium battery cells are cylindrical lithium battery cells.

6. The high-performance sodium-lithium hybrid power system according to claim 5, characterized in that, The sodium battery unit includes a sodium battery module, a second shunt, a second BMS unit, a third fuse, a second DC / DC converter, a second positive control unit, a second positive relay, a second heating film, a second heating control relay, and a second heating control unit. The sodium battery module is connected to the second shunt, the second BMS unit, and the third fuse. The second BMS unit is connected to the second shunt, the third fuse, the second DC / DC converter, and the second heating control unit. The second heating film is connected to the second DC / DC converter and the second heating control relay. The second heating control relay is connected to the second heating control unit. The second positive relay is connected to the second positive control unit, the third fuse, the second heating control relay, and the first positive relay. The second shunt is connected to the first negative relay. The second BMS unit is connected to the first BMS unit.

7. The high-performance sodium-lithium hybrid power system according to claim 6, characterized in that, The sodium battery unit also includes a fourth fuse, one end of which is connected to the second DC / DC conversion unit, and the other end is connected between the second shunt and the first main negative relay; The sodium battery unit also includes a second precharge control unit and a second precharge control relay, the second precharge control relay being connected to the second precharge control unit, the third fuse, and the second heating control relay, respectively.

8. The high-performance sodium-lithium hybrid power system according to claim 7, characterized in that, A second resistor is provided between the second pre-charge control relay and the second heating control relay, and the second resistor is connected to the second pre-charge control relay and the second heating control relay respectively; The sodium battery unit also includes a second power supply control unit and a second power supply relay, the second power supply relay being connected to the second power supply control unit, the third fuse, and the second DC / DC conversion unit, respectively.

9. The high-performance sodium-lithium hybrid power system according to claim 8, characterized in that, The sodium battery unit also includes a second total negative control unit and a second total negative relay, the second total negative relay being connected to the second total negative control unit, the second shunt, the fourth fuse, and the first total negative relay respectively; The sodium battery unit also includes a second self-reset button, which is connected to the third fuse, the second DC / DC conversion unit, and the second BMS unit respectively. A third diode is provided between the second BMS unit and the second DC / DC conversion unit, and the third diode is connected to the second BMS unit and the second DC / DC conversion unit respectively.

10. The high-performance sodium-lithium hybrid power system according to claim 9, characterized in that, The sodium battery unit also includes a second indicator light, which is connected to the second BMS unit; The second BMS unit is provided with a second matching resistor, which is connected to the first matching resistor; The sodium battery module includes several sodium battery cells connected in series; the sodium battery cells are cylindrical sodium battery cells.

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