Double-gun charging system and vehicle

Abstract

The invention provides a double-gun charging system and a vehicle. The double-gun charging system comprises a first charging interface, a second charging interface, an electric heater, a first switch, a third switch, a sixth switch, a seventh switch and an eighth switch. Wherein the first terminal of the first charging interface is connected with the first end of the third switch and the first end of the eighth switch, the second end of the eighth switch is connected with the second end of the first switch, and the first end of the first switch and the second end of the third switch are used for being connected with the positive electrode of a battery pack; the first terminal of the second charging interface is connected with the first end of the seventh switch, and the second end of the seventh switch is connected with the second end of the first switch and the second end of the eighth switch; the first end of the electric heater is connected with the second end of the sixth switch, the first end of the sixth switch is connected with the second end of the first switch and the second end of the eighth switch, and the second terminal of the first charging interface, the second terminal of the second charging interface and the second end of the electric heater are used for being connected with the negative electrode of the battery pack.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to a dual-gun charging system and a vehicle. Background Art

[0002] Currently, commercial vehicle power battery packs with larger capacities, such as 100kWh, 130kWh, and 150kWh, are becoming the mainstream. As the power level increases, the battery capacity also increases accordingly. For large-capacity batteries, faster charging requires a higher charging current.

[0003] For high-capacity battery packs, to meet customer demands for fast charging, the charging current needs to be increased and the charging time shortened. This increase in charging current also requires improvements in the specifications of the electrical components in the charging circuit. This is limited by the specifications of electrical components, such as the rated current limits of contactors and connectors. Currently, mainstream battery systems for commercial electric vehicles on the market mostly use a dual-charger solution, meaning a vehicle has two charging ports connected to a charging station for charging. Compared to single-charger charging, dual-charger charging can save charging time. However, dual-charger charging either results in heating current flowing back into the battery pack or requires a relay capable of providing a larger rated current. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a dual-gun charging system and a vehicle that can solve at least one technical problem pointed out in the above-mentioned prior art.

[0005] One aspect of an embodiment of the present application provides a dual-gun charging system. The dual-gun charging system includes a first charging interface, a second charging interface, an electric heater, a first switch, a third switch, a sixth switch, a seventh switch, and an eighth switch. The first terminal of the first charging interface is connected to the first end of the third switch and the first end of the eighth switch, and the second end of the eighth switch is connected to the second end of the first switch. The first end of the first switch and the second end of the third switch are used to connect to the positive electrode of the battery pack; the first terminal of the second charging interface is connected to the first end of the seventh switch, and the second end of the seventh switch is connected to the second end of the first switch and the second end of the eighth switch; the first end of the electric heater is connected to the second end of the sixth switch, and the first end of the sixth switch is connected to the second end of the first switch and the second end of the eighth switch. The second terminal of the first charging interface, the second terminal of the second charging interface, and the second end of the electric heater are used to connect to the negative electrode of the battery pack.

[0006] Furthermore, the dual-gun charging system also includes a discharge interface, wherein the first terminal of the discharge interface is connected to the second end of the first switch and the second end of the eighth switch, and the second terminal of the discharge interface is used to be connected to the negative pole of the battery pack; the first port of the discharge interface is connected to the second end of the seventh switch and the first end of the sixth switch, and the second port of the discharge interface is connected to the second terminal of the second charging interface and the second end of the electric heater.

[0007] Furthermore, the dual-gun charging system also includes a second switch and a fourth switch, wherein the second terminal of the first charging interface is used to connect to the negative pole of the battery pack through the fourth switch; the second terminal of the discharge interface is used to connect to the negative pole of the battery pack through the second switch.

[0008] Furthermore, the dual-gun charging system further includes a fifth switch and a pre-charging resistor, wherein the fifth switch and the pre-charging resistor are connected in series at both ends of the first switch.

[0009] Furthermore, the dual-gun charging system has a heating-only mode, a heating-and-charging mode, and a charging-only mode, wherein, when only the first charging interface is used to charge the battery pack, when the dual-gun charging system is in the heating-only mode, the first switch and the third switch are disconnected, and the second switch, the fourth switch, the sixth switch, and the eighth switch are closed; when the dual-gun charging system is in the heating-and-charging mode, the first switch is disconnected, and the second switch, the third switch, the fourth switch, the sixth switch, and the eighth switch are closed; when the dual-gun charging system is in the charging-only mode, the second switch, the sixth switch, and the eighth switch are disconnected, and the third switch and the fourth switch are closed.

[0010] Furthermore, the dual-gun charging system has a heating-only mode, a heating-and-charging mode, and a charging-only mode, wherein, when only the second charging interface is used to charge the battery pack, when the dual-gun charging system is in the heating-only mode, the first switch is disconnected, and the sixth switch and the seventh switch are closed; when the dual-gun charging system is in the heating-and-charging mode, the first switch and the second switch, the sixth switch, and the seventh switch are closed; when the dual-gun charging system is in the charging-only mode, the first switch, the second switch, and the seventh switch are closed, and the sixth switch is disconnected.

[0011] Furthermore, the dual-gun charging system has a heating-only mode, a heating-and-charging mode, and a charging-only mode, wherein, when the first charging interface and the second charging interface are used simultaneously to charge the battery pack, when the dual-gun charging system is in the heating-only mode, the first switch and the third switch are disconnected, and the second switch, the fourth switch, the sixth switch, the seventh switch, and the eighth switch are closed; when the dual-gun charging system is in the heating-and-charging mode, the first switch, the second switch, the third switch, the fourth switch, the sixth switch, and the seventh switch are closed, and the eighth switch is disconnected; when the dual-gun charging system is in the charging-only mode, the first switch, the second switch, the third switch, the fourth switch, and the seventh switch are closed, and the sixth switch and the eighth switch are disconnected.

[0012] Furthermore, when the lowest temperature of the battery cells of the battery pack is lower than a first temperature threshold and the highest temperature of the battery cells is not greater than a second temperature threshold, the dual-gun charging system enters the heating-only mode, wherein the second temperature threshold is greater than the first temperature threshold.

[0013] Furthermore, when the minimum temperature of the battery cell of the battery pack is higher than the third temperature and lower than the fourth temperature threshold, and the maximum temperature of the battery cell is not greater than the second temperature threshold, the dual-gun charging system enters the heating and charging mode, wherein the third temperature threshold is greater than the first temperature threshold, the fourth temperature threshold is greater than the third temperature threshold, and the second temperature threshold is greater than the fourth temperature threshold.

[0014] Furthermore, when the minimum temperature of the battery cell of the battery pack is not less than the fifth temperature threshold, the maximum temperature of the battery cell is not less than the second temperature threshold, or the average temperature of the battery cell is not less than the sixth temperature threshold, the dual-gun charging system enters the charging-only mode, wherein the fifth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is greater than the fifth temperature threshold, and the second temperature threshold is greater than the sixth temperature threshold.

[0015] Another aspect of the present application provides a vehicle, which includes a battery pack and the dual-charger charging system described above, wherein the battery pack is charged by the dual-charger charging system.

[0016] The dual-gun charging system and vehicle of one or more embodiments of the present application can solve the problem of heating current being injected into the battery pack during the low-temperature heating phase of dual-gun charging by adding an eighth switch between the front end of the third switch and the rear end of the first switch, thereby reducing design costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a schematic diagram of the architecture of a single-gun charging system in the related art.

[0018] Figure 2 This is a schematic diagram of the architecture of a dual-gun charging system in the related art.

[0019] Figure 3 This is a schematic diagram of the architecture of another dual-gun charging system in the related art.

[0020] Figure 4 This is a schematic diagram of the architecture of a dual-gun charging system according to an embodiment of the present application.

[0021] Figure 5 This is a flowchart of the dual-gun charging system according to one embodiment of the present application. DETAILED DESCRIPTION

[0022] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of devices consistent with certain aspects of the present application, as detailed in the appended claims.

[0023] Figure 1 The schematic diagram of the structure of a single-gun charging system 100 in the related art is disclosed. Figure 1 As shown, in the single-charger charging system 100, the third switch KM3 (i.e., the main positive relay for fast charging) is connected to the rear end of the first switch KM1 (i.e., the main positive relay for discharging), i.e., the end closest to the discharge port C. When the battery pack BAT is at a low temperature, for example, below -20°C, and only the battery pack BAT is heated, the first switch KM1 is disconnected, and the heating current flows through the charging station, the first charging port A, the third switch KM3, and the sixth switch KM6 to the PTC (electric heater) for heating. No heating current is injected into the battery pack BAT. However, due to the current rating limit of the connector of the first charging port A, the single-charger charging system 100 cannot continuously charge at a high rate, resulting in a longer charging time compared to a dual-charger charging system.

[0024] The dual-charger system has two charging ports on the vehicle: the first charging port A and the second charging port B. The dual-charger system can be configured in two different configurations depending on the wiring position of the third switch KM3 (i.e., the fast-charging main positive relay).

[0025] Figure 2 The schematic diagram of the architecture of a dual-gun charging system 200 in the related art is disclosed. Figure 2In the dual-charger charging system 200 shown, the third switch KM3 is connected to the front end of the first switch KM1, that is, close to the positive terminal of the battery pack BAT. During dual-charger charging, the third switch KM3 and the first switch KM1 form a parallel branch to charge the battery pack BAT.

[0026] When the battery pack BAT is at a low temperature, for example, below -20°C, before using dual charging plugs or only the first charging port A to charge the battery pack BAT, it is necessary to first heat only the battery pack BAT. This is because, depending on battery characteristics, when the battery pack BAT temperature is below a predetermined temperature threshold (for example, -20°C, the specific value depends on the specific battery characteristics), charging the battery pack BAT may cause lithium deposition, short circuits, capacity decay, and other safety risks. When only heating the battery pack BAT, the first switch KM1, the second switch KM2, the third switch KM3, the fourth switch KM4, and the sixth switch KM6 are closed (the seventh switch KM7 is also closed when using dual charging plugs). The heating current flows from the charging pile through the first charging port A, the third switch KM3, the first switch KM1, the discharge port C, and the sixth switch KM6 to the PTC (electric heater) for heating. However, at this time, the heating current will flow back into the battery pack BAT through the fuse FU.

[0027] Figure 3 A schematic diagram of the architecture of another dual-gun charging system 300 in the related art is disclosed. Figure 3 The dual-gun charging system 300 shown in FIG. Figure 2 In the dual-charger charging system 200 shown, a third switch KM3 is connected to the rear end of the first switch KM1. When charging with the first charging port A, the third switch KM3 and the first switch KM1 are connected in series to charge the battery pack BAT. When charging with two charging guns, the third switch KM3 acts as a branch to converge with the seventh switch KM7 connected to the second charging port B, and then charges the battery pack BAT through the first switch KM1.

[0028] When charging the battery pack BAT at a low temperature, for example, below -20°C, before using dual charging guns or only using the first charging interface A to charge the battery pack BAT, it is necessary to heat the battery pack BAT first. At this time, the first switch KM1 is disconnected, and the second switch KM2, the third switch KM3, the fourth switch KM4 and the sixth switch KM6 are closed (wherein, the seventh switch KM7 is also closed when using dual charging guns). The heating current is from the charging pile through the first charging interface A, the third switch KM3, the discharge interface C, and the sixth switch KM6 to enter the PTC (electric heater) for heating. At this time, since the first switch KM1 is disconnected, the heating current will not flow into the battery pack BAT through the fuse FU.

[0029] As mentioned above, during dual-charger charging, the third switch KM3 acts as a branch, converging the current with the seventh switch KM7 connected to the second charging port B, before charging the battery pack BAT through the first switch KM1. This requires the rated current of the first switch KM1 to be greater than the rated current of the third switch KM3. For example, if the total current of dual-charger charging is 460A (amperes) and the current of each charging port is 230A, the rated current of the first switch KM1 must be at least 500A, and the rated current of the third switch KM3 must be at least 300A. In terms of cost, a 500A relay is much more cost-effective than a 300A relay.

[0030] If adopted Figure 2 The dual-gun charging system 200 shown in the figure has a total dual-gun charging current of 460A and a current of 230A for each charging port. Since the third switch KM3 and the first switch KM1 are connected in parallel to charge the battery pack BAT during dual-gun charging, the first switch KM1 and the third switch KM3 can be selected with the same rated current, not less than 300A, to meet the demand, which is more cost-effective. Figure 3 The dual-gun charging system 300 shown is low cost.

[0031] After the above Figure 2 and Figure 3 Comparison of the two options, Figure 2 The dual-gun charging system 200 shown has the risk of heating current being poured into the battery pack BAT, but is superior to the relay in terms of cost. Figure 3 The dual-gun charging system 300 is shown; Figure 3 The dual-gun charging system 300 shown can solve the risk of heating current being injected into the battery pack BAT, but the cost of the relay is relatively high.

[0032] In view of this, in order to solve the risk of heating current being injected into the battery pack BAT when the dual-gun charging system only heats the battery pack BAT while taking into account the cost, the present application provides an improved dual-gun charging system 400.

[0033] The following describes in detail the dual-gun charging system and vehicle of each embodiment of the present application in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments and implementations can be combined with each other.

[0034] Figure 4 The schematic diagram of the architecture of a dual-gun charging system 400 according to one embodiment of the present application is disclosed. Figure 4 As shown, the dual-charger charging system 400 of the present application includes a first charging port A, a second charging port B, an electric heater, a first switch KM1, a third switch KM3, a sixth switch KM6, a seventh switch KM7 and an eighth switch KM8.

[0035] The first charging port A is located on the battery pack, and the second charging port B is located on the main and auxiliary drive assembly. The first and second charging ports A and B can be connected to the vehicle's two charging ports, respectively, via a power harness. The charging station can charge the battery pack BAT directly from the vehicle's charging port via the first charging port A on the battery pack; and / or, the charging station can charge the battery pack BAT from the vehicle's charging port via the second charging port B on the main and auxiliary drive assembly, the seventh switch KM7 within the main and auxiliary drive assembly, and the battery pack's discharge port C.

[0036] The first switch KM1, the third switch KM3, the sixth switch KM6, the seventh switch KM7, and the eighth switch KM8 may include, but are not limited to, relays. The first switch KM1 is a discharge main positive relay, the third switch KM3 is a fast charge main positive relay, and the eighth switch KM8 is, for example, a 20A heating relay.

[0037] The first terminal of the first charging interface A is connected to the first end of the third switch KM3 and the first end of the eighth switch KM8, the second end of the eighth switch KM8 is connected to the second end of the first switch KM1, the first end of the first switch KM1 and the second end of the third switch KM3 are used to be connected to the positive electrode of the battery pack BAT; the second terminal of the first charging interface A is used to be connected to the negative electrode of the battery pack BAT.

[0038] The first terminal of the second charging interface B is connected to the first end of the seventh switch KM7, and the second end of the seventh switch KM7 is connected to the second end of the first switch KM1 and the second end of the eighth switch KM8; the second terminal of the second charging interface B is used to be connected to the negative electrode of the battery pack BAT.

[0039] The first end of the electric heater is connected to the second end of the sixth switch KM6, and the first end of the sixth switch KM6 is connected to the second end of the first switch KM1 and the second end of the eighth switch KM8; the second end of the electric heater is used to be connected to the negative electrode of the battery pack BAT.

[0040] The dual-gun charging system 400 of the present application solves the problem of heating current being injected into the battery pack BAT during the low-temperature heating-only phase of dual-gun charging by adding an eighth switch KM8 between the front end of the third switch KM3 and the rear end of the first switch KM1, thereby reducing design costs.

[0041] In some embodiments, the dual-charger charging system 400 of the present application further includes a fourth switch KM4. The fourth switch KM4 may include, for example, but is not limited to, a relay. The fourth switch KM4 serves as a fast-charging main negative relay. The second terminal of the first charging port A is connected to the negative terminal of the battery pack BAT via the fourth switch KM4.

[0042] In some embodiments, the dual-charger charging system 400 of the present application further includes a discharge interface C. A first terminal of the discharge interface C is connected to the second end of the first switch KM1 and the second end of the eighth switch KM8, and a second terminal of the discharge interface C is used to be connected to the negative electrode of the battery pack BAT; a first port of the discharge interface C is connected to the second end of the seventh switch KM7 and the first end of the sixth switch KM6, and a second port of the discharge interface C is connected to the second terminal of the second charging interface B and the second end of the electric heater.

[0043] In some embodiments, the dual-charger charging system 400 of the present application further includes a second switch KM2. The second switch KM2 may include, for example, but is not limited to, a relay. The second switch KM2 is a discharge main negative relay. The second terminal of the discharge port C is connected to the negative terminal of the battery pack BAT via the second switch KM2.

[0044] In some embodiments, the dual-charger charging system 400 of the present application further includes a fifth switch KM5 and R0. The fifth switch KM5 may include, but is not limited to, a relay. The fifth switch KM5 and R0 are connected in series across the first switch KM1.

[0045] The dual-gun charging system 400 of the present application has a heating-only mode, a heating-and-charging mode, and a charging-only mode.

[0046] In some embodiments, when the minimum temperature of the battery cells of the battery pack BAT is lower than a first temperature threshold and the maximum temperature of the battery cells is not greater than a second temperature threshold, the dual-charger charging system 400 enters a heating-only mode, where the second temperature threshold is greater than the first temperature threshold. The first temperature threshold may be, for example, -20°C, and the second temperature threshold may be, for example, 40°C.

[0047] In some embodiments, when the minimum temperature of the battery cells of the battery pack BAT is higher than a third temperature threshold and lower than a fourth temperature threshold, and the maximum temperature of the battery cells is not higher than a second temperature threshold, the dual-charger charging system 400 enters a heating-while-charging mode, wherein the third temperature threshold is higher than the first temperature threshold, the fourth temperature threshold is higher than the third temperature threshold, and the second temperature threshold is higher than the fourth temperature threshold. The third temperature threshold may be, for example, -15°C, and the fourth temperature threshold may be, for example, 2°C.

[0048] In some embodiments, when the minimum temperature of the battery cells of the battery pack BAT is not less than a fifth temperature threshold, the maximum temperature of the battery cells is not less than a second temperature threshold, or the average temperature of the battery cells is not less than a sixth temperature threshold, the dual-charger charging system 400 enters a charge-only mode, wherein the fifth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is greater than the fifth temperature threshold, and the second temperature threshold is greater than the sixth temperature threshold. For example, the fifth temperature threshold may be 15°C, and the sixth temperature threshold may be 21°C.

[0049] Of course, it can be understood that the specific values of the first temperature threshold, the second temperature threshold, the third temperature threshold, the fourth temperature threshold, the fifth temperature threshold and the sixth temperature threshold listed above are only some illustrative examples of the present application. However, the various temperature thresholds of the present application are not limited to those described above, and can be reasonably selected according to the actual situation of the battery pack BAT.

[0050] When charging the battery pack BAT using only the first charging port A, when the dual-charger charging system 400 is in heating-only mode, the first switch KM1 and the third switch KM3 are disconnected, and the second switch KM2, the fourth switch KM4, the sixth switch KM6, and the eighth switch KM8 are closed. The heating current flows from the charging pile through the first charging port A, the eighth switch KM8, the discharge port C, and the sixth switch KM6 to the PTC (electric heater) for heating. At this time, since the first switch KM1 and the third switch KM3 are disconnected, the heating current does not flow into the battery pack BAT through the fuse FU. Therefore, by adding the eighth switch KM8 between the front end of the third switch KM3 and the rear end of the first switch KM1, the dual-charger charging system 400 of the present application can solve the problem of heating current flowing into the battery pack BAT during the low-temperature heating-only phase of dual-charger charging.

[0051] When only the first charging interface A is used to charge the battery pack BAT, when the dual-gun charging system 400 is in the heating and charging mode, the first switch KM1 is disconnected, and the second switch KM2, the third switch KM3, the fourth switch KM4, the sixth switch KM6 and the eighth switch KM8 are closed. After the current flows from the charging pile through the first charging interface A, part of the current enters the PTC (electric heater) through the eighth switch KM8, the discharge interface C, and the sixth switch KM6 to heat the battery pack BAT; the other part of the current flows into the battery pack BAT through the third switch KM3 to charge the battery pack BAT.

[0052] When only the first charging interface A is used to charge the battery pack BAT, when the dual-gun charging system 400 is in the charging-only mode, the second switch KM2, the sixth switch KM6, and the eighth switch KM8 are disconnected, and the third switch KM3 and the fourth switch KM4 are closed. The current flows from the charging pile through the first charging interface A and the third switch KM3 into the battery pack BAT to charge the battery pack BAT.

[0053] When only the second charging interface B is used to charge the battery pack BAT, when the dual-gun charging system 400 is in the heating-only mode, the first switch KM1 is disconnected, the sixth switch KM6 and the seventh switch KM7 are closed, and the heating current enters the PTC (electric heater) through the charging pile, the second charging interface B, the seventh switch KM7, and the sixth switch KM6 to heat the battery pack BAT. At this time, since the first switch KM1 is disconnected, no heating current is fed into the battery pack BAT.

[0054] When only the second charging interface B is used to charge the battery pack BAT, when the dual-gun charging system 400 is in the heating and charging mode, the first switch KM1 and the second switch KM2, the sixth switch KM6 and the seventh switch KM7 are closed. After the current flows from the charging pile through the second charging interface B and the seventh switch KM7, part of the current enters the PTC (electric heater) through the sixth switch KM6 to heat the battery pack BAT; the other part of the current flows into the battery pack BAT through the discharge interface C and the first switch KM1 to charge the battery pack BAT.

[0055] When only the second charging interface B is used to charge the battery pack BAT, when the dual-gun charging system 400 is in the charging-only mode, the first switch KM1, the second switch KM2 and the seventh switch KM7 are closed, and the sixth switch KM6 is disconnected. The current flows from the charging pile through the second charging interface B, the seventh switch KM7, the discharge interface C, and the first switch KM1 into the battery pack BAT to charge the battery pack BAT.

[0056] When the first charging interface A and the second charging interface B are used simultaneously to charge the battery pack BAT, when the dual-gun charging system 400 is in the heating-only mode, the first switch KM1 and the third switch KM3 are disconnected, and the second switch KM2, the fourth switch KM4, the sixth switch KM6, the seventh switch KM7 and the eighth switch KM8 are closed. The branch current from the charging pile after passing through the first charging interface A, the eighth switch KM8 and the discharge interface C is combined with the branch current from the charging pile after passing through the second charging interface B and the seventh switch KM7 and enters the PTC (electric heater) for heating to heat the battery pack BAT.

[0057] When the first charging interface A and the second charging interface B are used to charge the battery pack BAT at the same time, when the dual-gun charging system 400 is in the heating and charging mode, the first switch KM1, the second switch KM2, the third switch KM3, the fourth switch KM4, the sixth switch KM6 and the seventh switch KM7 are closed, and the eighth switch KM8 is disconnected. The current is diverted from the charging pile through the second charging interface B and the seventh switch KM7. Part of the current enters the PTC (electric heater) through the sixth switch KM6 for heating to heat the battery pack BAT, and the other part of the current flows into the battery pack BAT through the discharge interface C, the first switch KM1, and the current from the charging pile through the first charging interface A and the third switch KM3 to charge the battery pack BAT.

[0058] When the first charging interface A and the second charging interface B are used at the same time to charge the battery pack BAT, when the dual-gun charging system 400 is in the charging-only mode, the first switch KM1, the second switch KM2, the third switch KM3, the fourth switch KM4 and the seventh switch KM7 are closed, and the sixth switch KM6 and the eighth switch KM8 are disconnected. The branch current from the charging pile after passing through the first charging interface A and the third switch KM3 and the branch current from the charging pile after passing through the second charging interface B, the seventh switch KM7, the discharge interface C and the first switch KM1 merge and flow into the battery pack BAT to charge the battery pack BAT.

[0059] Figure 5 The following discloses a working diagram of a dual-gun charging system according to an embodiment of the present application. Figure 5As shown, in step S501, the charging gun is inserted to charge the vehicle's battery pack BAT. In step S502, the battery management system (BMS) wakes up to perform hardware and high-voltage system self-tests. In step S503, it is determined whether charging conditions are met. If the result is "yes", the process proceeds to step S504; otherwise, the process returns to step S502. In step S504, the charging interface is determined. In step S505, it is determined that charging is being performed using the first charging interface A. In step S506, it is determined whether the minimum cell temperature of the battery pack BAT is less than or equal to 2°C and the maximum cell temperature is less than or equal to 40°C, that is, Tempmin≤2°C & Tempmax≤40°C. If the result is "yes", the process proceeds to step S507. Otherwise, the process proceeds to step S516. In step S507, the heating request is initiated. In step S508, the second switch KM2, the fourth switch KM4, the sixth switch KM6, and the eighth switch KM8 are closed. In step S509, it is determined whether the minimum temperature of the battery cell is less than -20°C, that is, Tempmin<-20°C. In step S510, when the minimum temperature of the battery cell is less than -20°C, the heating-only mode is enabled. Otherwise, the process proceeds to step S512. In step S511, it is determined whether the minimum temperature of the battery cell is greater than or equal to -15°C, that is, Tempmin≥-15°C. In step S512, when the minimum temperature of the battery cell is greater than or equal to -15°C, the third switch KM3 is closed; otherwise, the process returns to step S510. In step S513, the charging-while-heating mode is enabled. In step S514, it is determined whether the minimum cell temperature is greater than or equal to 15°C (Tempmin ≥ 15°C), or whether the maximum cell temperature is greater than or equal to 38°C (Tempmax ≥ 38°C), or whether the average cell temperature is greater than or equal to 21°C (Tempmean ≥ 21°C). If the result of this determination is "yes," the process proceeds to step S515. Otherwise, the process returns to step S513. In step S515, the second switch KM2, the sixth switch KM6, and the eighth switch KM8 are turned off. In step S516, the charge-only mode is enabled. In step S517, it is determined whether the minimum cell temperature is less than -22°C. In step S518, if the minimum cell temperature is less than -22°C, the third switch KM3 is turned off. Otherwise, the process returns to step S513.

[0060] In step S519, it is determined that charging is being performed using the second charging port. In step S520, it is determined whether the minimum cell temperature is less than or equal to 2°C and the maximum cell temperature is less than or equal to 40°C, that is, Tempmin ≤ 2°C & Tempmax ≤ 40°C. If the determination result is "yes," the process proceeds to step S521. Otherwise, the process proceeds to step S516. In step S521, a heating request is initiated. In step S522, the sixth switch KM6 and the seventh switch KM7 are closed. In step S523, it is determined whether the minimum cell temperature is less than -20°C, that is, Tempmin < -20°C. In step S524, if the minimum cell temperature is less than -20°C, the heating-only mode is enabled. Otherwise, the process proceeds to step S526. In step S525, it is determined whether the minimum cell temperature is greater than or equal to -15°C, that is, Tempmin ≥ -15°C. In step S526, if the minimum cell temperature is greater than or equal to -15°C, the first switch KM1 and the second switch KM2 are closed. Otherwise, the process returns to step S524. In step S527, the heating-while-charging mode is enabled. In step S528, a determination is made as to whether the minimum cell temperature is greater than or equal to 15°C (Tempmin ≥ 15°C), or whether the maximum cell temperature is greater than or equal to 38°C (Tempmax ≥ 38°C), or whether the average cell temperature is greater than or equal to 21°C (Tempmean ≥ 21°C). If the determination is "yes," the process proceeds to step S529. In step S529, the sixth switch KM6 is opened, and the process proceeds to step S516. In step S530, a determination is made as to whether the minimum cell temperature is less than -22°C. In step S531, if the minimum cell temperature is less than -22°C, the first switch KM1 and the second switch KM2 are opened. Otherwise, the process returns to step S527.

[0061] In step S532, it is determined that charging is being performed simultaneously using both the first charging port A and the second charging port B. In step S533, it is determined whether the minimum cell temperature is less than or equal to 2°C and the maximum cell temperature is less than or equal to 40°C (Tempmin ≤ 2°C & Tempmax ≤ 40°C). If the determination is "yes," the process proceeds to step S534. In step S34, a heating request is initiated. In step S535, the second switch KM2, the fourth switch KM4, the sixth switch KM6, the seventh switch KM7, and the eighth switch KM8 are closed. In step S536, it is determined whether the minimum cell temperature is less than -20°C (Tempmin < -20°C). In step S537, if the minimum cell temperature is less than -20°C, the heating-only mode is enabled. Otherwise, the process proceeds to step S539. In step S538, it is determined whether the minimum cell temperature is greater than or equal to -15°C (Tempmin ≥ -15°C). In step S539, if the minimum cell temperature is greater than or equal to -15°C, the first switch KM1 and the third switch KM3 are closed, and the eighth switch KM8 is opened. Otherwise, the process returns to step S537. In step S540, the heating-while-charging mode is enabled. In step S541, it is determined whether the minimum cell temperature is greater than or equal to 15°C (Tempmin ≥ 15°C), or the maximum cell temperature is greater than or equal to 38°C (Tempmax ≥ 38°C), or the average cell temperature is greater than or equal to 21°C (Tempmean ≥ 21°C). If the result is "yes," the process proceeds to step S542. In step S542, the sixth switch KM6 is opened, and the process proceeds to step S516. In step S543, it is determined whether the minimum cell temperature is less than -22°C. In step S544, if the minimum cell temperature is less than -22°C, the first switch KM1 and the third switch KM3 are opened, and the eighth switch KM8 is closed. Otherwise, return to step S540.

[0062] In step S545, it is determined whether the charging cut-off condition is met. If the charging cut-off condition is met, the process proceeds to step S546. Otherwise, the process returns to step S516. In step S546, charging is stopped.

[0063] The dual-charger system 400 of the present application introduces a low-cost, low-current eighth switch KM8, which is connected via wires to the front end of the third switch KM3, which serves as the main positive switch for fast charging, and the rear end of the first switch KM1, which serves as the main positive switch for discharging. The eighth switch KM8 acts as a heating relay. Since the heating current is generally between 5 and 15A, the eighth switch KM8 of the present application can be a 20A heating relay, which reduces the cost of the third switch KM3. Furthermore, the third switch KM3 and the first switch KM1 in the dual-charger system 400 of the present application can use the same specifications, reducing the number of relays and lowering the cost of relays.

[0064] The present application also provides a vehicle. The vehicle includes a battery pack BAT and the dual-charger charging system 400 described above. The battery pack BAT can be charged by the dual-charger charging system 400.

[0065] The above is a detailed introduction to the dual-gun charging system and vehicle provided in the embodiments of the present application. Specific examples are used herein to illustrate the dual-gun charging system and vehicle in the embodiments of the present application. The description of the above embodiments is only used to help understand the core idea of the present application and is not intended to limit the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the spirit and principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications should also fall within the scope of protection of the claims attached to the present application.

Claims

1. A dual-gun charging system, characterized by: It includes a first charging interface, a second charging interface, an electric heater, a first switch, a third switch, a sixth switch, a seventh switch and an eighth switch, wherein: The first terminal of the first charging interface is connected to the first end of the third switch and the first end of the eighth switch, the second end of the eighth switch is connected to the second end of the first switch, and the first end of the first switch and the second end of the third switch are used to be connected to the positive electrode of the battery pack; The first terminal of the second charging interface is connected to the first end of the seventh switch, and the second end of the seventh switch is connected to the second end of the first switch and the second end of the eighth switch; The first end of the electric heater is connected to the second end of the sixth switch, and the first end of the sixth switch is connected to the second end of the first switch and the second end of the eighth switch. The second terminal of the first charging interface, the second terminal of the second charging interface and the second end of the electric heater are used to be connected to the negative electrode of the battery pack.

2. The dual-gun charging system according to claim 1, characterized in that: Also includes a discharge interface, wherein The first terminal of the discharge interface is connected to the second end of the first switch and the second end of the eighth switch, and the second terminal of the discharge interface is used to be connected to the negative electrode of the battery pack; The first port of the discharge interface is connected to the second end of the seventh switch and the first end of the sixth switch, and the second port of the discharge interface is connected to the second terminal of the second charging interface and the second end of the electric heater.

3. The dual-gun charging system according to claim 2, characterized in that: Also includes a second switch and a fourth switch, wherein, The second terminal of the first charging interface is used to connect to the negative electrode of the battery pack through the fourth switch; The second terminal of the discharge interface is used to connect to the negative electrode of the battery pack through the second switch.

4. The dual-gun charging system according to any one of claims 1 to 3, characterized in that: It also includes a fifth switch and a pre-charge resistor, wherein, The fifth switch and the pre-charging resistor are connected in series at both ends of the first switch.

5. The dual-gun charging system according to claim 3, characterized in that: The dual-gun charging system has a heating-only mode, a heating-while-charging mode, and a charging-only mode. When only the first charging port is used to charge the battery pack, When the dual-gun charging system is in the heating-only mode, the first switch and the third switch are opened, and the second switch, the fourth switch, the sixth switch, and the eighth switch are closed; When the dual-gun charging system is in the heating-while-charging mode, the first switch is disconnected, and the second switch, the third switch, the fourth switch, the sixth switch, and the eighth switch are closed; When the dual-gun charging system is in the charging-only mode, the second switch, the sixth switch, and the eighth switch are opened, and the third switch and the fourth switch are closed.

6. The dual-gun charging system according to claim 3, characterized in that: The dual-gun charging system has a heating-only mode, a heating-while-charging mode, and a charging-only mode. When only the second charging port is used to charge the battery pack, When the dual-gun charging system is in the heating-only mode, the first switch is open, and the sixth switch and the seventh switch are closed; When the dual-gun charging system is in the heating-while-charging mode, the first switch, the second switch, the sixth switch, and the seventh switch are closed; When the dual-gun charging system is in the charging-only mode, the first switch, the second switch, and the seventh switch are closed, and the sixth switch is open.

7. The dual-gun charging system according to claim 3, characterized in that: The dual-gun charging system has a heating-only mode, a heating-while-charging mode, and a charging-only mode. When the first charging port and the second charging port are used to charge the battery pack at the same time, When the dual-gun charging system is in the heating-only mode, the first switch and the third switch are opened, and the second switch, the fourth switch, the sixth switch, the seventh switch, and the eighth switch are closed; When the dual-gun charging system is in the heating-while-charging mode, the first switch, the second switch, the third switch, the fourth switch, the sixth switch, and the seventh switch are closed, and the eighth switch is open; When the dual-gun charging system is in the charge-only mode, the first switch, the second switch, the third switch, the fourth switch, and the seventh switch are closed, and the sixth switch and the eighth switch are open.

8. The dual-gun charging system according to any one of claims 5 to 7, characterized in that: When the lowest temperature of the battery cells of the battery pack is lower than a first temperature threshold and the highest temperature of the battery cells is not greater than a second temperature threshold, the dual-gun charging system enters the heating-only mode, wherein the second temperature threshold is greater than the first temperature threshold.

9. The dual-gun charging system according to claim 8, characterized in that: When the lowest temperature of the battery cell of the battery pack is higher than the third temperature and lower than the fourth temperature threshold, and the highest temperature of the battery cell is not greater than the second temperature threshold, the dual-gun charging system enters the heating and charging mode, wherein the third temperature threshold is greater than the first temperature threshold, the fourth temperature threshold is greater than the third temperature threshold, and the second temperature threshold is greater than the fourth temperature threshold.

10. The dual-gun charging system according to claim 9, characterized in that: When the minimum temperature of the battery cell of the battery pack is not less than the fifth temperature threshold, the maximum temperature of the battery cell is not less than the second temperature threshold, or the average temperature of the battery cell is not less than the sixth temperature threshold, the dual-gun charging system enters the charging-only mode, wherein the fifth temperature threshold is greater than the fourth temperature threshold, the sixth temperature threshold is greater than the fifth temperature threshold, and the second temperature threshold is greater than the sixth temperature threshold.

11. A vehicle, characterized in that: The invention comprises a battery pack and a dual-gun charging system according to any one of claims 1 to 10, wherein the battery pack is charged by the dual-gun charging system.

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