Hydrogen-sodium combined battery system for a forklift truck

Abstract

The application relates to a hydrogen-sodium combined battery system for a forklift, which comprises a sodium battery module, a shunt, a BMS unit, a first fuse, a second fuse, a DC / DC conversion unit, a heating film, a heating control relay and a heating control unit; the sodium battery module is connected with the shunt, the BMS unit and the first fuse respectively; the BMS unit is connected with the shunt, the first fuse, the DC / DC conversion unit and the heating control unit respectively; the heating film is connected with the DC / DC conversion unit and the heating control relay respectively; the heating control relay is connected with the heating control unit and the first fuse respectively; and the second fuse is connected with the first fuse and the DC / DC conversion unit respectively. The system adopts hydrogen-sodium combination, has better performance than a lithium ion battery, is more in line with the actual demand of application working conditions, and has lower cost.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a sodium hydrogen combined battery system for forklifts. Background Technology

[0002] Hydrogen fuel cells are one of the new power systems emerging in recent years. Their technology, products, and safety have been validated, and they have attracted considerable attention as a power source for forklift 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 supply of stable power to the motor, and vehicles cannot be used again after startup, a lithium battery is usually designed as a transitional unit in the design of hydrogen fuel cell systems. Forklifts are characterized by high instantaneous power output during forking, and the transitional battery's capacity cannot be designed too large due to its positioning, but it must still meet the maximum forking power requirements of the forklift. Therefore, high-rate cells need to be selected when designing the battery.

[0003] Currently, most forklifts use lithium-ion batteries, and existing lithium-hydrogen hybrid solutions also employ lithium iron phosphate chemistry, using high-rate, square aluminum-cased cells. These square aluminum-cased cells are bundled into modules. Forklifts have high power demands during startup, requiring the battery to discharge at a high rate, resulting in significant heat generation and a rapid temperature rise in the battery module. In contrast, in lithium-hydrogen hybrid solutions, the lithium battery pack only needs to buy time for the hydrogen fuel cell to complete its reaction during startup. Therefore, the battery pack capacity is typically smaller, with insufficient design dimensions, making it impossible to incorporate liquid cooling or other auxiliary heat dissipation equipment. This often leads to over-temperature alarms in high-temperature environments. Furthermore, due to the poor low-temperature performance of lithium iron phosphate batteries, maintaining high-rate performance relies solely on auxiliary heating devices, requiring additional discharge heating functionality. In addition, the high cost of high-rate cells significantly increases production costs. Utility Model Content

[0004] Based on this, this utility model provides a sodium hydrogen combined battery system for forklifts, which aims to solve the problems of existing forklift battery systems in high-temperature application scenarios, such as high temperature alarms, the need for auxiliary heating devices to maintain the continuous operation of high-rate cells, the inability to incorporate auxiliary heating devices in the reserved space of the battery pack, and the high cost of high-rate cells.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a sodium-hydrogen combined battery system for forklifts, comprising a sodium battery module, a shunt, a BMS unit, a first fuse, a second fuse, a DC / DC converter unit, a heating film, a heating control relay, and a heating control unit; the sodium battery module is connected to the shunt, the BMS unit, and the first fuse; the BMS unit is connected to the shunt, the first fuse, the DC / DC converter unit, and the heating control unit; the heating film is connected to the DC / DC converter unit and the heating control relay; the heating control relay is connected to the heating control unit and the first fuse; and the second fuse is connected to the first fuse and the DC / DC converter unit.

[0006] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a total positive control unit and a total positive relay, wherein the total positive relay is connected to the total positive control unit, the first fuse, the BMS unit, and the heating control relay.

[0007] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a charging control unit and a charging relay, wherein the charging relay is connected to the charging control unit, the first fuse, and the BMS unit, respectively.

[0008] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a precharge control unit and a precharge control relay, wherein the precharge control relay is connected to the precharge control unit, the first fuse, and the heating control relay, respectively.

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

[0010] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a first power supply control unit and a main negative relay, wherein the main negative relay is connected to the first power supply control unit, the shunt, the BMS unit, and the DC / DC conversion unit, respectively.

[0011] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a second power supply control unit and a power supply control relay, wherein the power supply control relay is connected to the second power supply control unit, the second fuse, and the DC / DC conversion unit, respectively.

[0012] In a preferred embodiment, a self-locking switch is provided between the second fuse and the power supply control relay, and the self-locking switch is connected to the second fuse and the power supply control relay respectively.

[0013] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a key switch; one end of the key switch is connected between the DC / DC conversion unit and the power supply control relay, and the other end is connected between the self-locking switch and the power supply control relay.

[0014] In a preferred embodiment, a first diode is provided between the key switch and the DC / DC conversion unit, and the first diode is connected to both the key switch and the DC / DC conversion unit; a key signal detection interface is provided between the first diode and the key switch.

[0015] In a preferred embodiment, a second diode is provided between the DC / DC conversion unit and the BMS unit, and the second diode is connected to both the DC / DC conversion unit and the BMS unit.

[0016] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a third diode; one end of the third diode is connected between the DC / DC conversion unit and the BMS unit, and the other end is connected to the positive terminal of the charging auxiliary power source.

[0017] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a positive output interface, one end of which is connected between the third diode and the BMS unit.

[0018] In a preferred embodiment, the BMS unit is provided with a first matching resistor and a second matching resistor, the first matching resistor and the second matching resistor being arranged adjacent to each other; the first matching resistor is connected to the debugging interface; and the second matching resistor is connected to the charging interface.

[0019] 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.

[0020] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:

[0021] This application system utilizes a combination of hydrogen and sodium, offering superior performance compared to lithium-ion batteries (maximum continuous discharge 10C, maximum continuous charge 8C, peak discharge 15C), better meeting the actual needs of application conditions, and at a lower cost. Traditional lithium iron phosphate batteries offer 4C charge and 8C discharge capabilities, but can only sustain this for a maximum of 3 minutes and are only usable within the 10–35°C range. Outside this temperature range, the rate performance drops rapidly, especially in low-temperature environments such as -20°C, where the discharge rate drops to only 0.5C, failing to meet the original design requirements. In contrast, this application system can achieve a minimum temperature of -40°C with 3C continuous discharge, covering the environmental requirements of application conditions. This system effectively solves the high-temperature problem in high-temperature application scenarios; the cylindrical sodium battery provides better heat dissipation, and the higher-rate sodium-ion battery generates less heat in this scenario, resulting in a smaller overall temperature rise. Simultaneously, it addresses the application requirements in low-temperature environments, exhibiting good low-temperature performance; the rate performance does not rapidly decline below -10°C, making it suitable for the wide-temperature environment requirements of hydrogen fuel cells. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is a schematic diagram of the overall structure of a sodium hydrogen combined battery system for forklifts according to an embodiment of the present invention.

[0024] 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

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Specifically, such as Figure 1As shown, this utility model embodiment proposes the following technical solution: a sodium-hydrogen combined battery system for forklifts, comprising a sodium battery module 10, a shunt 20, a BMS unit 30, a first fuse FU1, a second fuse FU2, a DC / DC converter unit 40, a heating film 50, a heating control relay HSS6, and a heating control unit 60; the sodium battery module 10 is connected to the shunt 20, the BMS unit 30, and the first fuse FU1; the BMS unit 30 is connected to the shunt 20, the first fuse FU1, the DC / DC converter unit 40, and the heating control unit 60; the heating film 50 is connected to the DC / DC converter unit 40 and the heating control relay HSS6; the heating control relay HSS6 is connected to the heating control unit 60 and the first fuse FU1; the second fuse FU2 is connected to the first fuse FU1 and the DC / DC converter unit 40.

[0031] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a total positive control unit 70 and a total positive relay HSS1, wherein the total positive relay HSS1 is connected to the total positive control unit 70, the first fuse FU1, the BMS unit 30, and the heating control relay HSS6.

[0032] In this embodiment, the main positive relay HSS1 is connected to the main positive adhesion detection port H-9 (HV1) of the BMS unit 30 to realize main positive adhesion detection. The main positive relay HSS1 is connected to a discharge positive interface (J1-discharge+). The main positive relay HSS1 is located between the first fuse FU1 and the heating control relay HSS6.

[0033] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a charging control unit 80 and a charging relay HSS2, wherein the charging relay HSS2 is connected to the charging control unit 80, the first fuse FU1, and the BMS unit 30, respectively.

[0034] In this embodiment, the charging relay HSS2 is connected to the charging adhesion detection port H-8 (HV2) of the BMS unit 30 to realize charging adhesion detection. The charging relay HSS2 is connected to the charging positive interface (J1-charging+).

[0035] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a precharge control unit 90 and a precharge control relay HSS5, wherein the precharge control relay HSS5 is connected to the precharge control unit 90, the first fuse FU1, and the heating control relay HSS6.

[0036] In a preferred embodiment, a resistor R1 is provided between the precharge control relay HSS5 and the heating control relay HSS6, and the resistor R1 is connected to the precharge control relay HSS5 and the heating control relay HSS6 respectively.

[0037] In a preferred embodiment, the forklift-use sodium-hydrogen battery system further includes a first power supply control unit 100 and a main negative relay HSS3. The main negative relay HSS3 is connected to the first power supply control unit 100, the shunt 20, the BMS unit 30, and the DC / DC conversion unit 40, respectively. In this embodiment, the main negative relay HSS3 is connected to a charging negative interface J1-charging- and a discharging negative interface J1-discharging-.

[0038] In a preferred embodiment, the forklift-use sodium-hydrogen combined battery system further includes a second power supply control unit 110 and a power supply control relay HSS4, wherein the power supply control relay HSS4 is connected to the second power supply control unit 110, the second fuse FU2, and the DC / DC conversion unit 40. In this embodiment, the power supply control relay HSS4 is disposed between the second fuse FU2 and the DC / DC conversion unit 40.

[0039] In a preferred embodiment, a self-locking switch 120 is provided between the second fuse FU2 and the power supply control relay HSS4. The self-locking switch 120 is connected to both the second fuse FU2 and the power supply control relay HSS4. Emergency stop or self-locking can be achieved through the self-locking switch 120.

[0040] In a preferred embodiment, the forklift-use sodium-hydrogen combined battery system further includes a key switch 130; one end of the key switch 130 is connected between the DC / DC conversion unit 40 and the power supply control relay HSS4, and the other end is connected between the self-locking switch 120 and the power supply control relay HSS4.

[0041] In a preferred embodiment, a first diode 140 is disposed between the key switch 130 and the DC / DC conversion unit 40, and the first diode 140 is connected to both the key switch 130 and the DC / DC conversion unit 40; a key signal detection interface HV3 is disposed between the first diode 140 and the key switch 130. In this embodiment, the IN+ interface of the DC / DC conversion unit 40 is connected to the power supply control relay HSS4 and the first diode 140; the IN- interface of the DC / DC conversion unit 40 is connected to the main negative relay HSS3.

[0042] In a preferred embodiment, a second diode 150 is provided between the DC / DC conversion unit 40 and the BMS unit 30, and the second diode 150 is connected to the DC / DC conversion unit 40 and the BMS unit 30 respectively.

[0043] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a third diode 160; one end of the third diode 160 is connected between the DC / DC conversion unit 40 and the BMS unit 30, and the other end is connected to the positive terminal 24V+ of the charging auxiliary power source.

[0044] In a preferred embodiment, the forklift-use sodium hydrogen combined battery system further includes a positive output interface 24V output+, one end of which is connected between the third diode 160 and the BMS unit 30.

[0045] In this embodiment, the ON position interface of the BMS unit is connected to the second diode 150, the third diode 160, and the positive output interface 24V output+, respectively; one end of the constant-on positive interface (constant-on+) of the BMS unit 30 is connected between the ON position interface and the second diode 150. The constant-on negative interface of the BMS unit 30 is connected to the DC / DC conversion unit 40, the negative terminal of the auxiliary charging power supply 24V-, and the negative output interface 24V output+, respectively. The BMS unit of this application integrates a GPRS module.

[0046] In a preferred embodiment, the BMS unit 30 is provided with a first matching resistor 31 and a second matching resistor 32, the first matching resistor 31 and the second matching resistor 32 are arranged adjacent to each other; the first matching resistor 31 is connected to the debugging interface; and the second matching resistor 32 is connected to the charging interface.

[0047] In a preferred embodiment, the sodium battery module 10 includes several sodium battery units 11 connected in series; the sodium battery unit 11 is a cylindrical sodium battery unit.

[0048] In this embodiment, the main positive control positive interface and main positive control negative interface of the BMS unit are connected to the positive and negative terminals of the main positive control unit; the charging control positive interface and main positive control negative interface of the BMS unit are connected to the positive and negative terminals of the charging control unit; the main negative control positive interface and main negative control negative interface of the BMS unit are connected to the positive and negative terminals of the first power supply control unit; the DC power supply control positive interface and DC power supply control negative interface of the BMS unit are connected to the positive and negative terminals of the second power supply control unit; when pre-charging is required, the heating control positive interface and heating control negative interface of the BMS unit are connected to the positive and negative terminals of the pre-charging control unit; when heating is required, the heating control positive interface and heating control negative interface of the BMS unit are connected to the positive and negative terminals of the heating control unit. The sodium battery module is connected to the BMS unit's A and B ports via a 16S voltage / 4NTC temperature sampling signal line. The first fuse FU1 is connected to the positive terminal of the sodium battery module, and the shunt is connected to the negative terminal of the sodium battery module.

[0049] The process controls when using the system of this application are as follows:

[0050] 1. When high voltage is applied during discharge:

[0051] a) When the ON position is active, the sodium battery module's BMS is powered on at low voltage and wakes up, entering the self-test process. Closing the key switch triggers the ON signal, initiating the self-test process.

[0052] b) After the BMS self-tests without faults, if it detects no charging connection signal, it enters the discharge state.

[0053] c) First close the HSS3 main negative relay, and after pre-charging, close the HSS1 main positive relay after a 20ms delay.

[0054] d) Discharge and high voltage are completed.

[0055] 2. Discharge high voltage energization process:

[0056] a) When HV3 detects <90% total pressure, it will disconnect the HSS1 main positive relay and the HSS3 main negative relay after a 10-minute delay, and the whole vehicle will enter the cleaning mode. The high voltage power-off is completed.

[0057] b) When the BMS is in operation, the emergency stop switch is turned on, the ON position is lost, the BMS is powered off, and the power-down process is completed.

[0058] c) If the fault level is verified, the relay is de-energized.

[0059] 3. High-voltage charging process:

[0060] a) When the BMS is powered on and wakes up, it performs a self-test without any faults and sends a charging message by default. When it detects a response message from the OBC or charger, it enters the charging state and disconnects the discharge relay.

[0061] b) After the charging self-test shows no serious charging faults and the message exchange is correct, close the HSS2 charging relay.

[0062] c) Charging and power-on complete.

[0063] d) If the self-test fails or there is a serious (relay disconnection) fault, the charging relay will not be closed.

[0064] e) The receipt of a charger status message or OBC signal is used as the condition for entering the charging state.

[0065] f) The charger message is a necessary condition for the charging relay to engage during the charging process.

[0066] g) If no charger message is received within ≥5 seconds when an OBC is available, a charging communication failure must be reported.

[0067] 4. Low-temperature charging process:

[0068] Sodium-ion batteries have excellent low-temperature discharge performance, but their charging performance is the same as that of lithium-ion batteries. They cannot be charged below 0°C. When the temperature is below 0°C, the HSS6 heating circuit needs to be closed first to make the battery temperature > 0°C before closing the HSS2 charging relay to start the charging process.

[0069] 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.

[0070] 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.

[0071] 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 sodium hydrogen combined battery system for forklifts, characterized in that, The device includes a sodium battery module, a shunt, a BMS unit, a first fuse, a second fuse, a DC / DC converter, a heating film, a heating control relay, and a heating control unit. The sodium battery module is connected to the shunt, the BMS unit, and the first fuse. The BMS unit is connected to the shunt, the first fuse, the DC / DC converter, and the heating control unit. The heating film is connected to the DC / DC converter and the heating control relay. The heating control relay is connected to the heating control unit and the first fuse. The second fuse is connected to the first fuse and the DC / DC converter.

2. The forklift-grade sodium-hydrogen combined battery system according to claim 1, characterized in that, The forklift-use sodium-hydrogen combined battery system also includes a main positive control unit and a main positive relay, wherein the main positive relay is connected to the main positive control unit, the first fuse, the BMS unit, and the heating control relay.

3. The forklift-grade sodium-hydrogen combined battery system according to claim 1, characterized in that, The forklift-use sodium hydrogen combined battery system also includes a charging control unit and a charging relay, the charging relay being connected to the charging control unit, the first fuse, and the BMS unit respectively; The forklift-use sodium hydrogen combined battery system also includes a precharge control unit and a precharge control relay, wherein the precharge control relay is connected to the precharge control unit, the first fuse, and the heating control relay, respectively.

4. The forklift-grade sodium hydrogen combined battery system according to claim 3, characterized in that, A resistor is provided between the precharge control relay and the heating control relay, and the resistor is connected to the precharge control relay and the heating control relay respectively; The forklift-use sodium-hydrogen combined battery system also includes a first power supply control unit and a main negative relay, the main negative relay being connected to the first power supply control unit, the shunt, the BMS unit, and the DC / DC conversion unit, respectively.

5. The sodium hydrogen combined battery system for forklifts according to claim 1, characterized in that, The forklift-use sodium-hydrogen combined battery system also includes a second power supply control unit and a power supply control relay, wherein the power supply control relay is connected to the second power supply control unit, the second fuse, and the DC / DC conversion unit, respectively.

6. The forklift-grade sodium hydrogen combined battery system according to claim 5, characterized in that, A self-locking switch is provided between the second fuse and the power supply control relay, and the self-locking switch is connected to the second fuse and the power supply control relay respectively; The forklift-use sodium-hydrogen combined battery system also includes a key switch; one end of the key switch is connected between the DC / DC conversion unit and the power supply control relay, and the other end is connected between the self-locking switch and the power supply control relay.

7. The forklift-grade sodium hydrogen combined battery system according to claim 6, characterized in that, A first diode is provided between the key switch and the DC / DC conversion unit, and the first diode is connected to both the key switch and the DC / DC conversion unit; a key signal detection interface is provided between the first diode and the key switch; A second diode is provided between the DC / DC conversion unit and the BMS unit, and the second diode is connected to both the DC / DC conversion unit and the BMS unit.

8. The sodium hydrogen combined battery system for forklifts according to claim 1, characterized in that, The forklift-use sodium hydrogen combined battery system also includes a third diode; one end of the third diode is connected between the DC / DC conversion unit and the BMS unit, and the other end is connected to the positive terminal of the charging auxiliary power source. The forklift-use sodium hydrogen combined battery system also includes a positive output interface, one end of which is connected between the third diode and the BMS unit.

9. The sodium hydrogen combined battery system for forklifts according to claim 1, characterized in that, The BMS unit is provided with a first matching resistor and a second matching resistor, which are arranged adjacent to each other; the first matching resistor is connected to the debugging interface; and the second matching resistor is connected to the charging interface.

10. The sodium hydrogen combined battery system for forklifts according to claim 9, characterized in that, 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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