Rapid charging system for lithium battery of industrial vehicle

Abstract

The utility model relates to the technical field of lithium battery systems, in particular to an industrial vehicle lithium battery quick charging system, which comprises a first battery pack, a second battery pack and a relay group, and during discharging, the relay group can enable the first battery pack and the second battery pack to be connected in parallel; and during charging work, the relay group can enable the first battery pack and the second battery pack to be connected in series. After series connection, the total voltage of the system is improved, and a charging power supply with a higher voltage level can be connected, so that higher charging power is obtained under the same charging current, the charging time is remarkably shortened, and the requirements of frequent charging and high-efficiency energy complementation of vehicles are met.

Description

A fast charging system for lithium batteries in industrial vehicles Technical Field

[0001] This utility model relates to the field of lithium battery system technology, and in particular to a fast charging system for lithium batteries in industrial vehicles. Background Technology

[0002] With the development of new energy technologies, industrial vehicles (such as electric forklifts, electric stackers, and electric tractors) are increasingly using battery systems as their power source. For system safety and stability considerations, most mainstream industrial vehicles currently employ low-voltage, high-capacity battery system structures, such as 48V or 72V. The advantages of such systems are their relatively simple structure and high safety, but they also bring some significant problems.

[0003] First, the low-voltage platform limits the increase in charging power. Currently, the power of widely used industrial vehicle chargers is around 20kW. Considering that the upper limit of safe current is generally no more than 200A, the lower the charging voltage, the longer the charging time. This cannot meet the fast charging requirements of frequent operation scenarios, and greatly affects the vehicle's utilization efficiency and range.

[0004] Secondly, to improve charging speed, some technical solutions propose using dual-gun simultaneous charging or parallel chargers. However, these methods require special design for the battery pack and place higher demands on the synchronous control and safety protection of the charging system, resulting in a more complex system structure, significantly increased costs, and inconvenient operation in practical use, making them difficult to promote.

[0005] Existing industrial vehicle battery systems face significant technical bottlenecks in terms of charging efficiency and system complexity. There is an urgent need for a battery system switching solution that is structurally sound, highly efficient in charging, flexible in use, and has good compatibility, in order to meet the actual needs of industrial vehicles for fast and safe charging. Summary of the Invention

[0006] The purpose of this invention is to address the significant technical bottlenecks in charging efficiency and system complexity of existing industrial vehicle battery systems, as mentioned in the background art, and to propose a fast charging system for industrial vehicle lithium batteries.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An industrial vehicle lithium battery fast charging system includes a first battery pack, a second battery pack, and a relay group. During discharge, the relay group enables the first battery pack and the second battery pack to be connected in parallel; during charging, the relay group enables the first battery pack and the second battery pack to be connected in series.

[0009] The system includes a third circuit, a sixth circuit, a ninth circuit, a seventh circuit, and a fourth circuit; the relay group includes relays K3, K4, K6, and K7.

[0010] One end of the third circuit is connected to one end of the sixth circuit and the other end is connected to the positive terminal of the charging circuit. The third circuit is equipped with the K3 relay. The other end of the sixth circuit is connected to the positive terminal of the second battery pack. The negative terminal of the second battery pack is connected to the positive terminal of the first battery pack through the ninth circuit. The ninth circuit is equipped with the K7 relay. One end of the seventh circuit is connected to the negative terminal of the first battery pack and the other end is connected to one end of the fourth circuit. The seventh circuit is equipped with the K6 relay. The other end of the fourth circuit is connected to the negative terminal of the charging circuit. The fourth circuit is equipped with the K4 relay.

[0011] The sixth circuit is provided with a second fuse; and / or, the seventh circuit is provided with a second shunt.

[0012] The system includes a first circuit, a second circuit, a fifth circuit, an eighth circuit, and a tenth circuit; the relay group includes K1 relay, K2 relay, and K5 relay.

[0013] One end of the first circuit is connected to the positive discharge terminal, and the other end is connected to one end of the tenth circuit and one end of the fifth circuit. The other end of the tenth circuit is connected to one end of the sixth circuit and one end of the third circuit. The tenth circuit is equipped with a K2 relay. The other end of the fifth circuit is connected to one end of the ninth circuit and the positive terminal of the first battery pack. The fifth circuit is equipped with the K1 relay.

[0014] One end of the second circuit is connected to the negative terminal of the discharge circuit, and the other end is connected to one end of the fourth circuit, one end of the eighth circuit, and one end of the seventh circuit. The other end of the eighth circuit is connected to the negative terminal of the second battery pack. The eighth circuit is equipped with the K5 relay.

[0015] The fifth circuit is provided with a first fuse; and / or the eighth circuit is provided with a first shunt.

[0016] The first battery pack includes at least a first cell and a second cell, which are connected in series; and / or the second battery pack includes at least a third cell and a fourth cell, which are connected in series.

[0017] This invention proposes a fast-charging system for lithium batteries in industrial vehicles. The advantages are as follows: In discharge mode, a relay group controls the internal circuit, connecting the first and second battery packs in parallel. At this time, the voltages of the two battery packs remain consistent, and the output current is shared, increasing the overall output capacity and meeting the high-power, high-current continuous operation requirements of industrial vehicles. The parallel structure also reduces the discharge load on individual battery packs, extending battery life. In charging mode, the relay group switches the wiring method, connecting the first and second battery packs in series. The series connection increases the total system voltage, allowing access to higher voltage charging power supplies, thereby achieving greater charging power at the same charging current, significantly shortening charging time, and meeting the needs of frequent vehicle charging and high-efficiency recharging. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the structure of this utility model;

[0019] Figure 2 is a schematic diagram of the open and closed state structure of the relay group during discharge of this utility model;

[0020] Figure 3 is a schematic diagram of the open and closed state structure of the relay group during charging of this utility model.

[0021] In the diagram: Circuit 1, Circuit 2, Circuit 3, Circuit 4, Circuit 5, Circuit 6, Circuit 7, Circuit 8, Circuit 9, Battery 10, Battery 11, Circuit 12. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0023] Referring to Figures 1-3, an industrial vehicle lithium battery fast charging system includes a first battery pack 10, a second battery pack 11, and a relay group. During discharge, the relay group enables the first battery pack 10 and the second battery pack 11 to be connected in parallel; during charging, the relay group enables the first battery pack 10 and the second battery pack 11 to be connected in series.

[0024] In discharge mode, the relay group controls the internal circuitry, connecting the first battery pack 10 and the second battery pack 11 in parallel. At this time, the voltages of the two battery packs remain consistent, and the output current is shared, increasing the overall output capacity and meeting the high-power, high-current continuous operation requirements of industrial vehicles. The parallel structure also reduces the discharge load on individual battery packs, extending battery life.

[0025] During charging operation, the relay group switches the wiring method, connecting the first battery pack 10 and the second battery pack 11 in series. This series connection increases the total system voltage, allowing access to a higher voltage charging power source. This results in greater charging power at the same charging current, significantly shortening charging time and meeting the needs of frequent vehicle charging and high-efficiency refueling.

[0026] Referring to Figure 3, the system includes a third circuit 3, a sixth circuit 6, a ninth circuit 9, a seventh circuit 7, and a fourth circuit 4. The relay group includes relays K3, K4, K6, and K7. One end of the third circuit 3 is connected to one end of the sixth circuit 6 and the other end is connected to the positive terminal of the charging circuit. A relay K3 is installed in the third circuit 3. The other end of the sixth circuit 6 is connected to the positive terminal of the second battery pack 11. The negative terminal of the second battery pack 11 is connected to the positive terminal of the first battery pack 10 through the ninth circuit 9. A relay K7 is installed in the ninth circuit 9. One end of the seventh circuit 7 is connected to the negative terminal of the first battery pack 10 and the other end is connected to one end of the fourth circuit 4. A relay K6 is installed in the seventh circuit 7. The other end of the fourth circuit 4 is connected to the negative terminal of the charging circuit. A relay K4 is installed in the fourth circuit 4.

[0027] The positive terminal of the charging circuit is input through the third circuit 3, which is equipped with a K3 relay. When the K3 relay is closed, the third circuit 3 is connected to the sixth circuit 6, and current flows from the third circuit 3 into the sixth circuit 6. The sixth circuit 6 is connected to the positive terminal of the second battery pack 11, so the charging current first enters the second battery pack 11. The negative terminal of the second battery pack 11 is connected to the positive terminal of the first battery pack 10 through the ninth circuit 9, which is equipped with a K7 relay. When the K7 relay is closed, a series path is formed between the second battery pack 11 and the first battery pack 10.

[0028] The negative terminal of the first battery pack 10 is connected through the seventh circuit 7, and the seventh circuit 7 is equipped with a K6 relay. When the K6 relay is closed, the current continues to flow from the seventh circuit 7 to the fourth circuit 4. The fourth circuit 4 is equipped with a K4 relay. After the K4 relay is closed, it forms a closed circuit with the charging negative terminal.

[0029] Thus, the charging current flows along the following path: charging positive terminal → third circuit 3 → K3 relay → sixth circuit 6 → second battery pack 11 → ninth circuit 9 → K7 relay → first battery pack 10 → seventh circuit 7 → K6 relay → fourth circuit 4 → K4 relay → charging negative terminal, and the entire system forms a complete series charging loop.

[0030] Each circuit is equipped with relays K3, K4, K6, and K7, which can flexibly and accurately control the current on and off, realize automated control, and facilitate integration into the vehicle's electronic control system. The series charging method increases the total system voltage and achieves higher charging power without increasing the current, thereby significantly shortening the charging time and improving energy replenishment efficiency. This structure avoids the problems of complex switching and cumbersome control logic of traditional dual batteries, improves the stability, safety and maintainability of the system, and is suitable for various industrial vehicle platforms with high charging efficiency requirements.

[0031] Referring to Figure 2, the system includes a first circuit 1, a second circuit 2, a fifth circuit 5, an eighth circuit 8, and a tenth circuit 12. The relay group includes a K1 relay, a K2 relay, and a K5 relay. One end of the first circuit 1 is connected to the positive discharge terminal, and the other end is connected to one end of the tenth circuit 12 and one end of the fifth circuit 5. The other end of the tenth circuit 12 is connected to one end of the sixth circuit 6 and one end of the third circuit 3. The tenth circuit 12 is equipped with a K2 relay. The other end of the fifth circuit 5 is connected to one end of the ninth circuit 9 and the positive terminal of the first battery pack 10. The fifth circuit 5 is equipped with a K1 relay. One end of the second circuit 2 is connected to the negative discharge terminal, and the other end is connected to one end of the fourth circuit 4, one end of the eighth circuit 8, and one end of the seventh circuit 7. The other end of the eighth circuit 8 is connected to the negative terminal of the second battery pack 11. The eighth circuit 8 is equipped with a K5 relay.

[0032] During discharge, relays K1, K2, K5, and K6 are closed, while relays K7, K3, and K4 are open. At this time, the first battery pack 10 and the second battery pack 11 are connected in parallel. The parallel structure effectively reduces the discharge load of a single battery pack, extends battery life, and improves the stability and reliability of the system. Furthermore, the charging and discharging systems do not interfere with each other, improving operational safety. Since the charging and discharging process only requires simple control of the opening and closing states of each relay, it is suitable for the complex and high-frequency use requirements of industrial vehicles and has good engineering practicality and promotion prospects.

[0033] The fifth circuit 5 is equipped with a first fuse; and / or the eighth circuit 8 is equipped with a first shunt; the sixth circuit 6 is equipped with a second fuse; and / or the seventh circuit 7 is equipped with a second shunt.

[0034] The first battery pack 10 includes at least a first battery cell and a second battery cell, which are connected in series; and / or the second battery pack 11 includes at least a third battery cell and a fourth battery cell, which are connected in series.

[0035] The fifth circuit 5 is equipped with a first fuse, which is used to connect the positive terminal of the first battery pack 10 to the discharge positive terminal path. When the system is in the discharge state, the first fuse can provide overcurrent protection for this path. Once the current abnormally increases, the fuse will automatically blow to prevent battery overload or circuit damage, thereby improving the safety guarantee capability during the discharge process.

[0036] The eighth circuit 8 includes a first shunt, located between the negative terminal of the second battery pack 11 and the negative discharge terminal. This shunt can detect the current value passing through this path in real time. The first shunt can feed back the collected current signal to the host computer or battery management system, enabling real-time monitoring and control of the discharge current, which is helpful for energy management and operational status diagnosis.

[0037] The sixth circuit 6 is equipped with a second fuse, which is used to connect the charging positive terminal to the positive terminal of the second battery pack 11. When the system is charging, the second fuse provides overcurrent protection for the charging path, preventing safety risks caused by charger failure, abnormal voltage, or relay malfunction, and ensuring the stability of the charging process.

[0038] The seventh circuit 7 is equipped with a second shunt, which is connected between the negative terminal of the first battery pack 10 and the charging negative terminal. The second shunt can monitor the charging current of the first battery pack 10, and the current signal can also be used for system management or safety control to improve the controllability and diagnostic capability of the charging process.

[0039] Furthermore, the first battery pack 10 is composed of at least a first cell and a second cell connected in series, and the second battery pack 11 is composed of at least a third cell and a fourth cell connected in series. This series connection of the cells helps to increase the voltage level of a single battery pack, adapting to the voltage requirements of parallel output or series charging, while also standardizing the battery module structure, facilitating system maintenance, expansion, and replacement.

[0040] The entire system is connected to the battery management system, which controls the opening and closing states of each relay according to charging and discharging requirements.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any technical solution, concept, or design obtained by those skilled in the art by making equivalent substitutions or changes based on the technical solution and utility model concept disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A fast charging system for lithium batteries in industrial vehicles, characterized in that, The system includes a first battery pack (10), a second battery pack (11), and a relay group. During discharge, the relay group enables the first battery pack (10) and the second battery pack (11) to be connected in parallel; during charging, the relay group enables the first battery pack (10) and the second battery pack (11) to be connected in series. The system includes a third circuit (3), a sixth circuit (6), a ninth circuit (9), a seventh circuit (7), and a fourth circuit (4). The relay group includes relays K3, K4, K6, and K7. A relay; one end of the third circuit (3) is connected to one end of the sixth circuit (6) and the other end is connected to the positive terminal of the charging circuit. The third circuit (3) is equipped with the K3 relay. The other end of the sixth circuit (6) is connected to the positive terminal of the second battery pack (11). The negative terminal of the second battery pack (11) is connected to the positive terminal of the first battery pack (10) through the ninth circuit (9). The ninth circuit (9) is equipped with the K7 relay. One end of the seventh circuit (7) is connected to the negative terminal of the first battery pack (10) and the other end is connected to one end of the fourth circuit (4). The seventh circuit (7) is equipped with... The system includes a first circuit (1), a second circuit (2), a fifth circuit (5), an eighth circuit (8), and a tenth circuit (12). The relay group includes a K1 relay, a K2 relay, and a K5 relay. One end of the first circuit (1) is connected to the discharge positive terminal, and the other end is connected to one end of the tenth circuit (12) and one end of the fifth circuit (5). The other end of the tenth circuit (12) is connected to one end of the sixth circuit (6). The fifth circuit (5) is connected to one end of the third circuit (3), and the tenth circuit (12) is equipped with a K2 relay. The other end of the fifth circuit (5) is connected to one end of the ninth circuit (9) and the positive terminal of the first battery pack (10). The fifth circuit (5) is equipped with the K1 relay. One end of the second circuit (2) is connected to the negative terminal of the discharge, and the other end is connected to one end of the fourth circuit (4), one end of the eighth circuit (8), and one end of the seventh circuit (7). The other end of the eighth circuit (8) is connected to the negative terminal of the second battery pack (11). The eighth circuit (8) is equipped with the K5 relay.

2. The fast charging system for industrial vehicle lithium batteries according to claim 1, characterized in that, The sixth circuit (6) is provided with a second fuse; and / or, the seventh circuit (7) is provided with a second shunt.

3. The fast charging system for industrial vehicle lithium batteries according to claim 2, characterized in that, The fifth circuit (5) is provided with a first fuse; and / or the eighth circuit (8) is provided with a first shunt.

4. A fast charging system for lithium batteries in industrial vehicles according to any one of claims 1-3, characterized in that, The first battery pack (10) includes at least a first battery cell and a second battery cell, which are connected in series; and / or the second battery pack (11) includes at least a third battery cell and a fourth battery cell, which are connected in series.

Images