Charging system, control method of charging system and vehicle

Abstract

The embodiment of the invention relates to the technical field of new energy automobiles, and discloses a charging system, a control method of the charging system and a vehicle, in the charging system, a charging port is used for coupling a charging pile, a battery pack is coupled to the charging port, and a motor driving circuit is coupled to the charging port and the battery pack. The first switching device, the second switching device and the fourth switching device are arranged between the charging port and the motor driving circuit, and the third switching device and the fifth switching device are arranged between the battery pack and the motor driving circuit. The control circuit selects a charging mode to charge the battery pack by controlling the conduction states of the first switching device, the second switching device, the third switching device, the fourth switching device and the fifth switching device, and the charging mode comprises at least one of a direct charging mode, a boost charging mode and a current-rising charging mode. By applying the technical scheme, the technical problem that a large number of switching devices need to be additionally arranged when multiple charging modes are integrated in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of new energy vehicle technology, specifically to a charging system, a control method for the charging system, and a vehicle. Background Technology

[0002] With the rapid development of new energy vehicles, a mismatch has emerged between the charging capacity of the battery packs in these vehicles and the discharging capacity of the charging piles, affecting charging efficiency and even preventing charging altogether. Related technologies address this by adding a switch to the motor drive system (also known as the motor drive circuit) to accommodate both boost and buck charging functions.

[0003] However, to match charging stations and integrate multiple charging modes, a large number of switching devices are added to the related technologies. Adding a large number of switching devices increases costs and complicates the control logic. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this application is to provide a charging system, a control method for the charging system, and a vehicle, which aims to solve the technical problem that the integration of multiple charging modes in the prior art requires the addition of a large number of switching devices.

[0005] In a first aspect, embodiments of this application provide a charging system, including: a charging port, a battery pack, a motor drive circuit, a control circuit, a first switching device, a second switching device, a third switching device, a fourth switching device, and a fifth switching device. A charging port is used to couple to a charging pile. A battery pack is coupled to the charging port. A motor drive circuit is coupled to the charging port and the battery pack. A first switching device is disposed between the first end of the charging port and the first end of the motor drive circuit. A second switching device is disposed between the second end of the charging port and the second end of the motor drive circuit. A third switching device is disposed between the first end of the battery pack and the first end of the motor drive circuit. A fourth switching device is disposed between the second end of the charging port and the third end of the motor drive circuit. A fifth switching device is disposed between the first end of the battery pack and the second end of the motor drive circuit. A control circuit is configured to select a charging mode to charge the battery pack by controlling the conduction state of the first, second, third, fourth, and fifth switching devices. The charging mode includes at least one of a direct charging mode, a boost charging mode, and a boost current charging mode.

[0006] In this embodiment, the motor drive circuit is integrated as the core unit of the charging system. By setting five switching devices in the charging system, the motor drive circuit can be reused to meet the motor drive function, and direct charging, boost charging, or boost current charging can be realized through the coordinated control of these five switching devices. In this embodiment, the motor drive circuit can be reused and the charging mode can be switched through the logic control of the switching devices alone, integrating direct charging, boost charging, and boost current charging into one system. In addition, this embodiment reduces the number of switching devices, greatly simplifies the system hardware structure, reduces hardware costs, and improves system integration. The logic control of the switching devices enables flexible switching of charging modes, balancing the functionality and economy of the system and maximizing the utilization of hardware resources.

[0007] In some embodiments, the boost charging mode includes a first charging period and a second charging period after the first charging period. During the first and second charging periods, the battery pack is boost charged. The control circuit is specifically configured to: during the first charging period, control the first and fourth switching devices to be turned on, and control the second, third, and fifth switching devices to be turned off; during the second charging period, control the first, third, and fourth switching devices to be turned on, and control the second and fifth switching devices to be turned off.

[0008] In conjunction with the above embodiments, in boost charging mode, the control circuit can achieve boost charging of the battery pack by controlling the conduction state of each switching device. This embodiment of the application can achieve mode switching by controlling the conduction state of each switching device, thereby improving charging compatibility and efficiency. It can also simplify the hardware structure and reduce costs.

[0009] In some embodiments, the boost charging mode further includes a third charging time period and a fourth charging time period after the third charging time period. The fourth charging time period is before the first charging time period. During the third and fourth charging time periods, the voltage across the charging port is stepped down. Specifically, the control circuit is configured to: control the first, third, and fourth switching devices to be turned on and the second and fifth switching devices to be turned off during the third charging time period; and control the first and fourth switching devices to be turned on and the second, third, and fifth switching devices to be turned off during the fourth charging time period.

[0010] In conjunction with the above embodiments, in boost charging mode, before the first charging time period, the control circuit can also control the voltage across the charging port by controlling the conduction state of each switching device to adapt to the output characteristics of the charging pile. This embodiment of the application can achieve mode switching by controlling the conduction state of each switching device, improving charging compatibility and efficiency. It can also simplify the hardware structure and reduce costs.

[0011] In some embodiments, the boost charging mode includes a fifth charging period and a sixth charging period following the fifth charging period. During the fifth and sixth charging periods, the battery pack is boosted. The control circuit is specifically configured to: during the fifth charging period, control the first, second, and fifth switching devices to be turned on, and the third and fourth switching devices to be turned off; during the sixth charging period, control the fifth switching device to be turned on, and the first, second, third, and fourth switching devices to be turned off.

[0012] In conjunction with the above embodiments, in the boost charging mode, the control circuit can achieve boost charging of the battery pack by controlling the conduction state of each switching device. This embodiment of the application can achieve mode switching by controlling the conduction state of each switching device, thereby improving charging compatibility and efficiency. It can also simplify the hardware structure and reduce costs.

[0013] In some embodiments, the control circuit is specifically configured to select a charging mode to charge the battery pack based on the relationship between the maximum output voltage of the charging pile and a preset voltage threshold.

[0014] In this embodiment, the control circuit adjusts the conduction state of each switching device based on the relationship between the maximum output voltage of the charging pile and a preset threshold, thereby achieving automatic switching between boost, current boost, and direct charging modes. This embodiment can adapt to the output characteristics of different charging piles through mode switching, improving charging compatibility and efficiency. It can also simplify the hardware structure and reduce costs.

[0015] In some embodiments, the preset voltage threshold includes a first voltage threshold and a second voltage threshold, wherein the second voltage threshold is greater than the first voltage threshold. The control circuit is specifically configured to select the direct charging mode when the maximum output voltage of the charging pile is greater than the first voltage threshold and less than or equal to the second voltage threshold.

[0016] In this embodiment, the control circuit divides the charging pile's output voltage range using first and second voltage thresholds. When the charging pile's maximum output voltage falls within the range of the first to second voltage thresholds, a direct charging mode is selected. This adapts to the charging requirements of this voltage range, avoids circuit losses caused by unnecessary mode switching, improves charging efficiency, reduces equipment failures caused by frequent mode switching, ensures a stable charging process, and aligns with the battery's charging characteristics at this voltage range, reducing the risk of abnormal charging and discharging.

[0017] In some embodiments, the control circuit is specifically configured to select a boost charging mode when the maximum output voltage of the charging pile is less than a first voltage threshold.

[0018] In this embodiment, when the maximum output voltage of the charging pile is less than the first voltage threshold, the boost charging mode is selected, which can increase the output voltage to the battery's compatibility range, meet the basic charging voltage requirements of the battery pack, avoid the problem that the low voltage cannot directly charge the battery, ensure the effective start of the charging process, adapt to the low voltage output condition of the charging pile, and improve the compatibility of the charging system with charging piles of different output voltages.

[0019] In some embodiments, the control circuit is specifically configured to select a boost charging mode when the maximum output voltage of the charging pile is greater than a second voltage threshold.

[0020] In this embodiment, when the maximum output voltage of the charging pile is greater than the second voltage threshold, the boost charging mode is selected to adapt to the high voltage output condition of the charging pile. By boosting the current, the charging current demand of the battery pack is made up, avoiding the charging inefficiency problem caused by high voltage and low current, improving the charging rate in the high voltage range, and conforming to the charging characteristics of the battery in the high voltage range, ensuring the safety and stability of the charging process under this condition.

[0021] In some embodiments, the motor drive circuit includes: a bridge arm circuit and a motor winding. The first and second ends of the bridge arm circuit are coupled as the first and second ends of the motor drive circuit, respectively. The bridge arm circuit includes a multi-phase bridge arm. The midpoint of the multi-phase bridge arm is correspondingly coupled to the first end of the multi-phase motor winding in the motor winding. The second end of the multi-phase motor winding is shared. The motor winding includes a first-phase motor winding, a second-phase motor winding, and a third-phase motor winding. The multi-phase bridge arm includes: a first-phase bridge arm, a second-phase bridge arm, and a third-phase bridge arm. The first end of the first-phase motor winding is coupled to the midpoint of the first-phase bridge arm. The first end of the first-phase motor winding also serves as the third end of the motor drive circuit. The control circuit is specifically configured to: control any one phase bridge arm (excluding the first phase bridge arm) in the multi-phase bridge arm to perform single-phase charging of the battery pack, or control any two phase bridge arms (excluding the first phase bridge arm) in the multi-phase bridge arm to perform dual-phase charging of the battery pack.

[0022] In this embodiment, the charging system utilizes the bridge arm circuit and motor windings of the motor drive circuit to achieve single-phase and dual-phase charging by controlling the conduction combinations of different bridge arms. No additional charging-related bridge arm or winding structures are required. Multi-mode charging is achieved by reusing the inherent components of the motor drive circuit, maximizing hardware resource reuse. This allows for flexible switching of charging modes to adapt to different scenario requirements by controlling the bridge arms, further improving system integration and reducing redundant components. Furthermore, the charging system utilizes any two bridge arms (excluding the first phase) and their corresponding motor windings in a multi-phase bridge arm configuration to achieve diverse charging modes by controlling different bridge arm combinations (single-phase / dual-phase). No additional bridge arm or winding hardware is required; multi-mode charging is achieved by reusing the inherent components of the motor drive circuit, improving system integration, reducing redundant components, and lowering costs.

[0023] In an exemplary embodiment, when the charging mode is boost charging mode, the control circuit is further configured to: during a first charging time period, control the upper half of the second phase bridge arm to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the first phase motor winding and the second phase motor winding; during a second charging time period, control the lower half of the second phase bridge arm to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile, the first phase motor winding, and the second phase motor winding perform single-phase charging of the battery pack; or, during the first charging time period, control the upper half of the second phase bridge arm to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile, the first phase motor winding, and the second phase motor winding perform single-phase charging of the battery pack; or, during the first charging time period, control the upper half of the second phase bridge arm to conduct along the second phase bridge arm to the midpoint of ... The first half of the second phase bridge arm is connected to the midpoint of the second phase bridge arm, and the upper half of the third phase bridge arm is connected to the midpoint of the third phase bridge arm, so that the charging pile charges the first phase motor winding, the second phase motor winding, and the third phase motor winding. During the second charging time period, the lower half of the second phase bridge arm is controlled to be connected to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm is connected to the midpoint of the third phase bridge arm, so that the charging pile, the first phase motor winding, the second phase motor winding, and the third phase motor winding perform dual-phase charging of the battery pack.

[0024] When the charging mode is boost charging, the charging system alternately executes the control strategies corresponding to the first and second charging time periods. During the first charging time period, the charging pile charges the motor windings, which are used for energy storage. During the second charging time period, the charging pile and motor windings are connected in series to charge the battery pack in single-phase / dual-phase mode. Boosting the voltage by storing energy in the motor windings solves the problem of insufficient charging from low-voltage charging piles, improving the adaptability of the charging system to accommodate different charging piles. Furthermore, compared to traditional charging methods, single-phase charging results in a larger equivalent inductance between the first and second phase motor windings, improving charging efficiency; dual-phase charging further enhances charging efficiency. This application achieves stable charging under high-voltage scenarios through timing control, ensuring the safety and reliability of charging.

[0025] In some embodiments, an energy storage circuit is also included, coupled between a first end and a second end of the charging port.

[0026] In this embodiment, the charging system also includes an energy storage circuit. When the output voltage of the charging pile is in different ranges, the newly added energy storage circuit of the charging system is coupled to both ends of the charging port, further enhancing the charging adaptability and stability.

[0027] In an exemplary embodiment, when the charging mode is boost charging mode, the control circuit is further configured to: during a third charging time period, control the lower half of the second phase bridge arm to conduct along the midpoint of the second phase bridge arm to the second end of the second phase bridge arm, so that the battery pack charges the energy storage circuit, the first phase motor winding, and the second phase motor winding; during a fourth charging time period, control the upper half of the second phase bridge arm to conduct along the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, so that the first phase motor winding and the second phase motor winding perform single-phase charging of the energy storage circuit; or, during the third charging time period, control the lower half of the second phase bridge arm to conduct along the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, so that the first phase motor winding and the second phase motor winding perform single-phase charging of the energy storage circuit; or, during a third charging time period, control the lower half of the second phase bridge arm to conduct along the midpoint of the second phase bridge arm to ... The lower half of the third phase bridge arm is connected from the midpoint to the second end of the second phase bridge arm, and the lower half of the third phase bridge arm is connected from the midpoint to the second end of the third phase bridge arm, so that the battery pack charges the energy storage circuit, the first phase motor winding, the second phase motor winding, and the third phase motor winding. During the fourth charging period, the upper half of the second phase bridge arm is controlled to be connected from the midpoint to the first end of the second phase bridge arm, and the upper half of the third phase bridge arm is connected from the midpoint to the first end of the third phase bridge arm, so that the first phase motor winding, the second phase motor winding, and the third phase motor winding perform bi-phase charging of the energy storage circuit.

[0028] When the charging mode is boost charging, before the first charging period, the charging system alternately executes the control strategies corresponding to the third and fourth charging periods to reduce the voltage across the energy storage circuit, meeting the battery pack's charging needs in low-voltage charging scenarios. During the third charging period, the battery pack charges the energy storage circuit and motor windings; the first and second phase motor windings are used for voltage division and energy storage. During the fourth charging period, the motor windings charge the energy storage circuit in a single-phase / dual-phase manner to ensure the voltage across the energy storage circuit is lower than the charging pile's maximum output voltage, adapting to low-voltage charging scenarios. Furthermore, compared to traditional charging methods, single-phase charging results in a larger equivalent inductance between the first and second phase motor windings, while dual-phase charging improves charging efficiency.

[0029] In an exemplary embodiment, when the charging mode is a boost charging mode, the control circuit is further configured to: during the fifth charging time period, control the upper half of the second phase bridge arm to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the battery pack, the first phase motor winding, and the second phase motor winding; during the sixth charging time period, control the lower half of the second phase bridge arm to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the first phase motor winding and the second phase motor winding perform single-phase charging of the battery pack; or, during the fifth charging time period, control the upper half of the second phase bridge arm to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the first phase motor winding and the second phase motor winding perform single-phase charging of the battery pack; or, during the fifth charging time period, control the upper half of the second phase bridge arm to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm. The upper half of the third phase bridge arm is connected from the first end to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm is connected from the first end to the midpoint of the third phase bridge arm, so that the charging pile charges the battery pack, the first phase motor winding, the second phase motor winding, and the third phase motor winding. During the sixth charging time period, the lower half of the second phase bridge arm is controlled to be connected from the second end to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm is connected from the second end to the midpoint of the third phase bridge arm, so that the first phase motor winding, the second phase motor winding, and the third phase motor winding perform bi-phase charging of the battery pack.

[0030] When the charging mode is boost charging, the charging system alternately executes the control strategies corresponding to the fifth and sixth charging time periods. During the fifth charging time period, the charging pile charges the battery pack and motor windings, with the motor windings used for energy storage. During the sixth charging time period, the energy stored in the motor windings is used to charge the battery pack using single-phase / dual-phase methods. By using the energy stored in the motor windings to buffer the high voltage, direct high-voltage charging is prevented from damaging the battery pack, eliminating the need for an additional high-voltage step-down module, significantly improving system integration, and reducing the number of components and costs. Furthermore, compared to traditional charging methods, the equivalent inductance of the first and second phase motor windings is larger during single-phase charging, and dual-phase charging can improve charging efficiency. This application achieves stable charging under high-voltage scenarios through timing control, ensuring the safety and reliability of charging.

[0031] Secondly, this application provides a control method for a charging system, characterized in that it includes: acquiring the input voltage of the charging port, and selecting a charging mode to charge the battery pack by controlling the conduction states of a first switch, a second switch, a third switch, a fourth switch, and a fifth switch according to the magnitude relationship between the input voltage and a preset voltage threshold. The charging mode includes at least one of a direct charging mode, a boost charging mode, and a boost current charging mode.

[0032] In this embodiment, by acquiring the input voltage of the charging port in real time and using a preset voltage threshold as the criterion, the conduction state of each switching device is dynamically adjusted to achieve automatic switching between direct, boost, or boost charging modes. This allows for adaptation to different input voltage scenarios without intervention. This embodiment can ensure accurate matching between the charging mode and the input voltage, thereby improving charging safety and efficiency.

[0033] Thirdly, this application provides a vehicle including the charging system described in the first aspect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the background art, the accompanying drawings used in the embodiments of this application will be described below.

[0035] Figure 1 This is a schematic diagram of the structure of a vehicle disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a charging system disclosed in an embodiment of this application; Figure 3 This is a schematic diagram of the current flow direction of a charging system disclosed in an embodiment of this application; Figure 4 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 5 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 6 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 7 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 8 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 9 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 10 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 11 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 12 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 13 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 14This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 15 This is a schematic diagram of the current flow direction of another charging system disclosed in an embodiment of this application; Figure 16 This is a flowchart illustrating a control method for a charging system disclosed in an embodiment of this application.

[0036] Explanation of reference numerals in the attached figures: 1-Vehicle; 10-Charging system; 101-Charging port; 102-Battery pack; 103-Motor drive circuit; 104-Control circuit; 105-Energy storage circuit; 1031 - Bridge arm circuit; 1032 - Motor winding; K1 - First switching device; K2 - Second switching device; K3 - Third switching device; K4 - Fourth switching device; K5 - Fifth switching device; S11 - First upper half-bridge switch; S12 - First lower half-bridge switch; S21 - Second upper half-bridge switch; S22 - Second lower half-bridge switch; S31 - Third upper half-bridge switch; S32 - Third lower half-bridge switch; D11 - First upper half-bridge diode; D12 - First lower half-bridge diode; D21 - Second upper half-bridge diode; D22 - Second lower half-bridge diode; D31 - Third upper half-bridge diode; D32 - Third lower half-bridge diode; L1 - First phase motor winding; L2 - Second phase motor winding; L3 - Third phase motor winding; C1 - First capacitor; C2 - Second capacitor. Detailed Implementation

[0037] The terms “first,” “second,” etc., are used for descriptive purposes only and have no sequential or technical meaning, nor should they be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0038] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the terms "coupled" and "connected" refer to the flow of current or signal from one conductor to another. A connection between A and B means that current or signal can flow from A to B and vice versa. A connection between A and B includes direct electrical connection and indirect electrical connection. A direct electrical connection between A and B means that A and B are electrically connected through physical contact. An indirect electrical connection between A and B means that A and B are electrically connected through C, where C can be at least one wire or device.

[0039] The embodiments of this application are described below with reference to the accompanying drawings.

[0040] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle disclosed in an embodiment of this application. Vehicle 1 can be, but is not limited to, a pure electric vehicle (PEV / BEV), a hybrid electric vehicle (HEV), a range-extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), or a new energy vehicle.

[0041] In this embodiment, vehicle 1 includes a vehicle body and a charging system 10. The charging system 10 is located at the front-wheel drive and / or rear-wheel drive position of the vehicle body and is fixedly connected to the vehicle body. When vehicle 1 is connected to a power supply device such as a charging pile, the charging pile charges the battery pack in the charging system 10.

[0042] Please see Figure 2 , Figure 2 This is a schematic diagram of a charging system disclosed in an embodiment of this application. The charging system 10 includes: a charging port 101, a battery pack 102, a motor drive circuit 103, and a control circuit 104.

[0043] The charging port 101 is used to couple to the charging pile. The first end of the charging port 101 is used to couple to the first end of the charging pile, and the second end of the charging port 101 is used to couple to the second end of the charging pile.

[0044] The battery pack 102 is coupled to the charging port 101. A third switching device K3 is provided between the first end of the battery pack 102 and the first end of the charging port 101. The second end of the battery pack 102 is coupled to the second end of the charging port 101.

[0045] The first terminal of the motor drive circuit 103 is coupled to the first terminal of the charging port 101. The first switch K1 is disposed between the first terminal of the charging port 101 and the first terminal of the motor drive circuit 103. The second switch K2 is disposed between the second terminal of the charging port 101 and the second terminal of the motor drive circuit 103. The third switch K3 is disposed between the first terminal of the battery pack 102 and the first terminal of the motor drive circuit 103. The fourth switch K4 is disposed between the second terminal of the charging port 101 and the third terminal of the motor drive circuit 103. The fifth switch K5 is disposed between the first terminal of the battery pack 102 and the second terminal of the motor drive circuit 103.

[0046] The charging system 10 also includes an energy storage circuit 105, which is coupled between the first and second ends of the charging port 101.

[0047] The energy storage circuit 105 can use the first capacitor C1 to stabilize the voltage between the two ends of the charging port 101.

[0048] The charging system 10 also includes a second capacitor C2, which is coupled between the first and second terminals of the motor drive circuit 103.

[0049] In this embodiment, the motor drive circuit 103 is fixedly connected to the vehicle body. When the charging port 101 is not connected to a charging pile, the battery pack 102 supplies power to the motor drive circuit 103, which converts electrical energy into mechanical energy to drive the vehicle. When the charging port 101 is connected to a charging pile, the control circuit 104 can control the conduction states of the third switching device K3, the fourth switching device K4, and the fifth switching device K5 to perform boost charging or boost current charging on the battery pack 102. The control circuit 104 can also directly charge the battery pack 102 by controlling the conduction states of the first switching device K1 and the second switching device K2.

[0050] As can be seen from the above, this application reuses the motor drive circuit 103 as the core unit of the charging system 10. The control circuit 104, through the coordinated control of the third switching device K3, the fourth switching device K4, the fifth switching device K5, the first switching device K1, and the second switching device K2, can reuse the motor drive circuit 103 and switch the charging mode by simply controlling the logic of the switching devices. It integrates direct charging, boost charging, and boost current charging, thereby improving the integration of the charging system.

[0051] In the above embodiments, the motor drive circuit 103 includes: a bridge arm circuit 1031 and a motor winding 1032.

[0052] The first and second ends of the bridge arm circuit 1031 are coupled to serve as the first and second ends of the motor drive circuit 103, respectively. The bridge arm circuit 1031 includes a multi-phase bridge arm, the midpoint of which is coupled to the first end of the multi-phase motor winding in the motor winding 1032, and the second end of the multi-phase motor winding is connected to the first end of the multi-phase motor winding.

[0053] The motor winding 1032 includes a first phase motor winding L1. The first end of the first phase motor winding L1 is coupled to the midpoint of the first phase bridge arm in the multi-phase bridge arm. The first end of the first phase motor winding L1 also serves as the third end of the motor drive circuit 103.

[0054] In this embodiment of the application, in order to better illustrate the connection relationship of the charging system, this application takes the motor winding 1032 as a three-phase motor and the bridge arm circuit 1031 as including a three-phase bridge arm as an example to introduce the charging system.

[0055] The multi-phase bridge arm in the bridge arm circuit 1031 includes: a first phase bridge arm, a second phase bridge arm, and a third phase bridge arm. The motor winding 1032 includes: a first phase motor winding L1, a second phase motor winding L2, and a third phase motor winding L3.

[0056] The midpoint of the second phase bridge arm is coupled to the first end of the second phase motor winding L2, and the midpoint of the third phase bridge arm is coupled to the first end of the third phase motor winding L3.

[0057] The first phase bridge arm includes: a first upper half-bridge switch S11 and a first lower half-bridge switch S12; the second phase bridge arm includes: a second upper half-bridge switch S21 and a second lower half-bridge switch S22; and the third phase bridge arm includes: a third upper half-bridge switch S31 and a third lower half-bridge switch S32.

[0058] The midpoint of the first upper half-bridge switch S11 and the first lower half-bridge switch S12 is the midpoint of the first phase bridge arm; the second upper half-bridge switch S21 and the second lower half-bridge switch S22 are the midpoints of the second phase bridge arm; and the third upper half-bridge switch S31 and the third lower half-bridge switch S32 are the midpoints of the third phase bridge arm.

[0059] Each switching transistor is connected in reverse parallel with a diode. Specifically, the first upper half-bridge switching transistor S11 is connected in reverse parallel with the first upper half-bridge diode D11, the first lower half-bridge switching transistor S12 is connected in reverse parallel with the first lower half-bridge diode D12, the second upper half-bridge switching transistor S21 is connected in reverse parallel with the second upper half-bridge diode D21, the second lower half-bridge switching transistor S22 is connected in reverse parallel with the second lower half-bridge diode D22, the third upper half-bridge switching transistor S31 is connected in reverse parallel with the third upper half-bridge diode D31, and the third lower half-bridge switching transistor S32 is connected in reverse parallel with the third lower half-bridge diode D32.

[0060] In some embodiments, the control circuit 104 can perform boost charging, boost current charging, or direct charging on the battery pack 102 by controlling the conduction states of the first switching device K1, the second switching device K2, the third switching device K3, the fourth switching device K4, and the fifth switching device K5, based on the relationship between the maximum output voltage of the charging pile and a preset voltage threshold. The preset voltage threshold includes a first voltage threshold and a second voltage threshold, wherein the second voltage threshold is greater than the first voltage threshold, and the first and second voltage thresholds are determined based on the current voltage between the first and second terminals of the battery pack 102.

[0061] The first voltage threshold can be set to the minimum voltage that the battery pack 102 is currently allowed to charge, specifically, it can be set to the sum of the current voltage of the battery pack 102 and the first threshold. The second voltage threshold can be set to the maximum voltage that the battery pack 102 is currently allowed to charge, specifically, it can be set to the sum of the current voltage of the battery pack 102 and the second threshold. In some examples, when the charging pile is connected to the charging interface 101, the battery pack 102 can read the maximum output voltage of the charging pile. The control circuit 104 selects the charging mode based on the maximum output voltage of the charging pile and the current voltage of the battery pack 102, including: direct charging mode, boost charging mode, and boost current charging mode.

[0062] For example, when the maximum output voltage of the charging pile is less than or equal to a first voltage threshold, the charging mode is determined to be a boost charging mode, and the control circuit 104 performs boost charging on the battery pack 102 by controlling the conduction state of each switching device.

[0063] As an example, the boost charging mode includes a first charging period and a second charging period following the first charging period, during which the battery pack 102 is boost-charged. The boost charging mode also includes a third charging period and a fourth charging period following the third charging period, during which the voltage across the charging port 101 is buck-controlled. The fourth charging period occurs before the first charging period.

[0064] Specifically, during the third charging period, the control circuit 104 controls the first switching device K1, the third switching device K3, and the fourth switching device K4 to be turned on, while the second switching device K2 and the fifth switching device K5 are turned off. During the fourth charging period, the control circuit 104 controls the first switching device K1 and the fourth switching device K4 to be turned on, while the second switching device K2, the third switching device K3, and the fifth switching device K5 are turned off. During the first charging period, the control circuit 104 controls the first switching device K1 and the fourth switching device K4 to be turned on, while the second switching device K2, the third switching device K3, and the fifth switching device K5 are turned off. During the second charging period, the control circuit 104 controls the first switching device K1, the third switching device K3, and the fourth switching device K4 to be turned on, while the second switching device K2 and the fifth switching device K5 are turned off.

[0065] In another example, when the maximum output voltage of the charging pile is greater than the first voltage threshold and less than or equal to the second voltage threshold, the charging mode is determined to be the direct charging mode, and the control circuit 104 directly charges the battery pack 102 by controlling the conduction state of each switching device.

[0066] In another example, when the maximum output voltage of the charging pile is greater than the second voltage threshold, the charging mode is determined to be the boost charging mode, and the control circuit 104 performs boost charging on the battery pack 102 by controlling the conduction state of each switching device.

[0067] As an example, the boost charging mode includes a fifth charging period and a sixth charging period following the fifth charging period, during which the battery pack 102 is boost charged.

[0068] Specifically, during the fifth charging period, the control circuit 104 controls the first switching device K1, the second switching device K2, and the fifth switching device K5 to be turned on, while the third switching device K3 and the fourth switching device K4 are turned off. During the sixth charging period, the control circuit 104 controls the fifth switching device K5 to be turned on, while the first switching device K1, the second switching device K2, the third switching device K3, and the fourth switching device K4 are turned off.

[0069] As can be seen from the above, the first voltage threshold and the second voltage threshold are determined based on the current voltage between the first and second terminals of the battery pack. During the charging process, the real-time voltage of the battery pack 102 will gradually increase as the remaining charge (State of Charge, SOC) of the battery pack 102 increases. The control circuit 104 can accurately match the charging mode through the voltage threshold. The switching of the charging mode is in line with the real-time state of the battery pack, which can avoid unnecessary circuit topology switching and improve charging accuracy and safety.

[0070] In some embodiments, the first switching device K1 and the second switching device K2 can be integrated inside the battery pack 102 or in an external power distribution box, and the third switching device K3, the fourth switching device K4, the fifth switching device K5, and the energy storage circuit 105 can be integrated inside the battery pack 102, inside the motor drive circuit 103, or in an external power distribution box.

[0071] The following description, in conjunction with the accompanying drawings, details three charging modes provided in the embodiments of this application (see attached drawings). Figure 3-15 Control circuit 104 is not shown.

[0072] Example 1: When the maximum output voltage of the charging pile is greater than the first voltage threshold and less than or equal to the second voltage threshold, the control circuit 104 directly charges the battery pack 102 by controlling each switching device.

[0073] Please refer to details. Figure 3 The current flow diagram of the charging system is as follows: Figure 3As shown, the control circuit 104 controls the first switch K1, the second switch K2, and the third switch K3 to be turned on, and the fourth switch K4 and the fifth switch K5 to be turned off, thereby directly charging the battery pack 102.

[0074] In this embodiment, the control circuit 104 divides the charging pile output voltage range using a first and a second voltage threshold. When the voltage is between the two thresholds, only the first, second, and third switching devices are activated, and direct charging is achieved using the multiplexed motor drive circuit 103. This application precisely matches the charging mode using voltage thresholds, avoiding unnecessary circuit topology switching, reducing energy loss and device operating frequency, and improving charging efficiency and device lifespan.

[0075] Example 2: When the maximum output voltage of the charging pile is less than or equal to the first voltage threshold, the charging mode is determined to be the boost charging mode. The control circuit 104 boosts the battery pack 102 by controlling the conduction state of each switching device.

[0076] To prevent the battery pack 102 from failing to connect with the charging pile, before boosting the battery pack 102, the control circuit 104 controls the motor drive circuit 103 to enter buck mode to connect with the charging pile, ensuring that the charging pile can charge the power battery.

[0077] Therefore, when the maximum output voltage of the charging pile is less than or equal to the first voltage threshold, the process is divided into two stages. In the first stage, the control circuit can charge the energy storage circuit 105 (also known as the first capacitor C1) by controlling the conduction state of each switch in the bridge arm circuit 1031, thereby reducing the voltage across the charging port 101 and establishing a handshake with the charging pile. In the second stage, the control circuit can boost the charging of the battery pack 102 by controlling the conduction state of each switch in the bridge arm circuit 1031.

[0078] The first phase consists of alternating third and fourth charging periods, with the third charging period preceding the fourth. The second phase consists of alternating first and second charging periods, with the first charging period preceding the second. The first phase occurs between the second phase, meaning the fourth charging period precedes the first charging period.

[0079] When charging the battery pack 102, the control circuit 104 can control the conduction state of each switch in the bridge arm circuit 1031 to control any one phase bridge arm other than the first phase bridge arm in the multi-phase bridge arm to perform single-phase charging of the battery pack 102, or control any two phase bridge arms other than the first phase bridge arm in the multi-phase bridge arm to perform dual-phase charging of the battery pack 102.

[0080] In some embodiments, the current flow diagram of the charging system 10 during the third charging time period is as follows: Figure 4 As shown, the control circuit 104 controls the first switching device K1, the fourth switching device K4 and the third switching device K3 to be turned on, the second switching device K2 and the fifth switching device K5 to be turned off, and controls the lower half of the second phase bridge arm to be turned on from the midpoint of the second phase bridge arm to the second end of the second phase bridge arm, so that the battery pack 102 charges the energy storage circuit 105, the first phase motor winding L1 and the second phase motor winding L2.

[0081] During the fourth charging period, the current flow diagram of the charging system 10 is as follows: Figure 5 As shown, the first switching device K1 and the fourth switching device K4 are turned on, the second switching device K2, the fifth switching device K5 and the third switching device K3 are turned off, and the upper half of the second phase bridge arm is turned on from the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, so that the first phase motor winding L1 and the second phase motor winding L2 charge the energy storage circuit 105 in a single phase.

[0082] In this embodiment, during the third charging period, the control circuit 104 turns on the second lower half-bridge switch S22 in the control arm circuit 1031, while the other switches are turned off. The battery pack 102 charges the first capacitor C1 and the first phase motor winding L1 and the second phase motor winding L2 in the motor winding 1032. The current flows back to the battery pack 102 through the second lower half-bridge switch S22. At this time, the first capacitor C1 and the motor winding 1032 store electrical energy. During the fourth charging period, the control circuit 104 turns off all the switches in the control arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1 and the second phase motor winding L2 does not change. The current flows to the first capacitor C1 through the second upper half-bridge diode D21. At this time, the first phase motor winding L1 and the second phase motor winding L2 release the stored electrical energy.

[0083] In this embodiment, the charging system 10 alternately executes the control strategies corresponding to the third and fourth charging time periods to reduce the voltage across the energy storage circuit 105, thereby meeting the charging requirements of the battery pack 102 in low-voltage charging scenarios. Compared to traditional charging methods, this embodiment uses single-phase charging, resulting in a larger equivalent inductance between the first-phase motor winding L1 and the second-phase motor winding L2, which improves charging efficiency.

[0084] The current flow diagram of the charging system 10 during the first charging period is shown below. Figure 6As shown, the first switch device K1 and the fourth switch device K4 are turned on, the second switch device K2, the fifth switch device K5 and the third switch device K3 are turned off, and the upper half of the second phase bridge arm is turned on from the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the first phase motor winding L1 and the second phase motor winding L2.

[0085] The current flow diagram of the charging system 10 during the second charging period is shown below. Figure 7 As shown, the first switch device K1, the fourth switch device K4 and the third switch device K3 are turned on, the second switch device K2 and the fifth switch device K5 are turned off, and the lower half of the second phase bridge arm is turned on along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile, the first phase motor winding L1 and the second phase motor winding L2 can charge the battery pack 102 in a single phase.

[0086] In this embodiment, the first charging time period and the second charging time period alternate at a certain frequency. During the first charging time period, the control circuit 104 turns on the second upper half-bridge switch S21 in the control arm circuit 1031, while the other switches are turned off. The battery pack 102 charges the first phase motor winding L1 and the second phase motor winding L2 in the motor winding 1032 through the second upper half-bridge switch S21. At this time, the motor winding 1032 stores electrical energy. During the second charging time period, the control circuit 104 turns off each switch in the control arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1 and the second phase motor winding L2 does not change. The charging pile charges the battery pack 102, and then the current flows to the motor winding 1032 through the second lower half-bridge diode D22. At this time, the current in the first phase motor winding L1 and the second phase motor winding L2 is the same as in the previous state. The charging pile and the motor winding 1032 are connected in series to boost the charging of the battery pack 102.

[0087] In this embodiment, the problem of insufficient charging in low-voltage charging piles is solved by energy storage and voltage boosting through the motor winding 1032, improving the adaptability of the charging system 10 and enabling it to be adapted to different charging piles. Compared with traditional charging methods, in this embodiment, when using single-phase charging, the equivalent inductance of the first-phase motor winding L1 and the second-phase motor winding L2 is larger, which can improve charging efficiency.

[0088] In other embodiments, the current flow diagram of the charging system 10 during the third charging period is shown below. Figure 8As shown, the control circuit 104 controls the first switching device K1, the fourth switching device K4, and the third switching device K3 to be turned on, and the second switching device K2 and the fifth switching device K5 to be turned off. It also controls the lower half of the second phase bridge arm to be turned on from the midpoint to the second end of the second phase bridge arm, and the lower half of the third phase bridge arm to be turned on from the midpoint to the second end of the third phase bridge arm. This allows the battery pack 102 to charge the energy storage circuit 105, the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3. During the fourth charging period, the current flow diagram of the charging system 10 is as follows: Figure 9 As shown, the first switching device K1 and the fourth switching device K4 are turned on, while the second switching device K2, the fifth switching device K5 and the third switching device K3 are turned off. The upper half of the second phase bridge arm is turned on from the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, and the upper half of the third phase bridge arm is turned on from the midpoint of the third phase bridge arm to the first end of the third phase bridge arm. This causes the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3 to charge the energy storage circuit 105 in a two-phase manner.

[0089] In this embodiment, during the third charging period, the control circuit 104 turns on the second lower half-bridge switch S22 and the third lower half-bridge switch S32 in the control bridge arm circuit 1031, while the other switches are turned off. The battery pack 102 charges the first capacitor C1 and the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3 in the motor winding 1032. The current flows back to the battery pack 102 through the second lower half-bridge switch S22 and the third lower half-bridge switch S32. At this time, the first capacitor C1 and the motor winding 1032 store electrical energy. During the fourth charging period, the control circuit 104 cuts off each switch in the control bridge arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3 does not change. The current flows to the first capacitor C1 through the second upper half-bridge diode D21 and the third upper half-bridge diode D31. At this time, the stored electrical energy is released by the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3.

[0090] In this embodiment, the charging system 10 alternately executes the control strategies corresponding to the third and fourth charging time periods to reduce the voltage across the energy storage circuit 105, thereby meeting the charging requirements of the battery pack 102 in low-voltage charging scenarios. When using dual-phase charging in this embodiment, the charging efficiency can be improved compared to traditional charging methods.

[0091] The current flow diagram of the charging system 10 during the first charging period is shown below. Figure 10As shown, the control circuit 104 controls the first switching device K1 and the fourth switching device K4 to be turned on, and the second switching device K2, the fifth switching device K5 and the third switching device K3 to be turned off. It also controls the upper half of the second phase bridge arm to be turned on from the first end to the midpoint of the second phase bridge arm, and the upper half of the third phase bridge arm to be turned on from the first end to the midpoint of the third phase bridge arm, so that the charging pile charges the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3. The current flow diagram of the charging system 10 during the second charging period is shown below. Figure 11 As shown, the control circuit 104 controls the first switching device K1, the fourth switching device K4 and the third switching device K3 to be turned on, and the second switching device K2 and the fifth switching device K5 to be turned off. It also controls the lower half of the second phase bridge arm to be turned on from the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm to be turned on from the second end of the third phase bridge arm to the midpoint of the third phase bridge arm. This enables the charging pile, the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3 to perform dual-phase charging of the battery pack 102.

[0092] In this embodiment, the first charging time period and the second charging time period are switched alternately at a certain frequency. During the first charging time period, the control circuit 104 turns on the second half-bridge switch S21 and the third upper half-bridge switch S31 in the control bridge arm circuit 1031, while other switches are turned off. The battery pack 102 charges the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3 in the motor winding 1032 through the second upper half-bridge switch S21 and the third upper half-bridge switch S31. At this time, the motor winding 1032 stores electrical energy. During the second charging period, the control circuit 104 cuts off each switch in the control bridge arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3 does not change. The charging pile charges the battery pack 102, and then flows to the motor winding 1032 through the second lower half-bridge diode D22 and the third lower half-bridge diode D32. At this time, the current in the first phase motor winding L1 and the second phase motor winding L2 is the same as in the previous state. The charging pile and the motor winding 1032 are connected in series to boost the charging of the battery pack 102.

[0093] In this embodiment, the problem of insufficient charging in low-voltage charging piles is solved by using energy storage and voltage boosting in the motor winding 1032, thus improving the adaptability of the charging system 10 and enabling it to be compatible with different charging piles. When using dual-phase charging in this embodiment, the charging efficiency is improved compared to traditional charging methods.

[0094] Example 3: When the maximum output voltage of the charging pile is greater than the second voltage threshold, the charging mode is determined to be the boost charging mode. The control circuit 104 controls the conduction state of each switching device to perform boost charging on the battery pack 102.

[0095] The control circuit 104 can control any one phase arm of the multi-phase bridge arm (excluding the first phase arm) to perform single-phase charging of the battery pack 102 by controlling the conduction state of each switch transistor, or control any two phase arms of the multi-phase bridge arm (excluding the first phase arm) to perform dual-phase charging of the battery pack 102.

[0096] When charging the battery pack 102, the control circuit 104 can control the conduction state of each switch in the bridge arm circuit 1031 to control any one phase bridge arm other than the first phase bridge arm in the multi-phase bridge arm to perform single-phase charging of the battery pack 102, or control any two phase bridge arms other than the first phase bridge arm in the multi-phase bridge arm to perform dual-phase charging of the battery pack 102.

[0097] In some embodiments, the current flow diagram of the charging system 10 during the fifth charging time period is as follows: Figure 12 As shown, the control circuit 104 controls the first switching device K1, the second switching device K2 and the fifth switching device K5 to be turned on, the fourth switching device K4 and the third switching device K3 to be turned off, and controls the upper half of the second phase bridge arm to be turned on from the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the battery pack 102, the first phase motor winding L1 and the second phase motor winding L2.

[0098] During the sixth charging period, the current flow diagram of the charging system 10 is as follows: Figure 13 As shown, the control circuit 104 controls the third switch device K3, the fourth switch device K4, the first switch device K1 and the second switch device K2 to be disconnected, and the fifth switch device K5 to be turned on. It also controls the lower half of the second phase bridge arm to be turned on from the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the first phase motor winding L1 and the second phase motor winding L2 can charge the battery pack 102 in a single phase.

[0099] In this embodiment, the fifth charging time period and the sixth charging time period alternate at a certain frequency. During the fifth charging time period, the control circuit 104 turns on the second upper half-bridge switch S21 in the control bridge arm circuit 1031, while other switches are turned off. The battery pack 102 charges the first phase motor winding L1, the second phase motor winding L2, and the battery pack 102 in the motor winding 1032 in series through the second upper half-bridge switch S21. At this time, the battery pack 102 and the motor winding 1032 store electrical energy. During the sixth charging period, the control circuit 104 cuts off each switch in the control bridge arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1 and the second phase motor winding L2 does not change. The battery pack 102 flows to the motor winding 1032 through the second lower half-bridge diode D22. At this time, the current in the first phase motor winding L1 and the second phase motor winding L2 is the same as in the previous state. The motor winding 1032 performs boost charging on the battery pack 102.

[0100] In this embodiment, the high voltage is buffered by energy storage in the motor winding 1032, preventing damage to the battery pack 102 from direct high-voltage charging. This eliminates the need for an additional high-voltage step-down module, significantly improving system integration and reducing component usage and cost. Compared to traditional charging methods, this embodiment uses single-phase charging, resulting in a larger equivalent inductance between the first-phase motor winding L1 and the second-phase motor winding L2, which improves charging efficiency.

[0101] In other embodiments, the current flow diagram of the charging system 10 during the fifth charging period is shown below. Figure 14 As shown, the control circuit 104 controls the first switching device K1, the second switching device K2 and the fifth switching device K5 to be turned on, and the fourth switching device K4 and the third switching device K3 to be turned off. It also controls the upper half of the second phase bridge arm to be turned on from the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the upper half of the third phase bridge arm to be turned on from the first end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the charging pile charges the battery pack 102, the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3.

[0102] During the sixth charging period, the current flow diagram of the charging system 10 is as follows: Figure 15 As shown, the control circuit 104 controls the third switch device K3, the fourth switch device K4, the first switch device K1 and the second switch device K2 to be disconnected, and the fifth switch device K5 to be turned on. It also controls the lower half of the second phase bridge arm to be turned on from the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm to be turned on from the second end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the first phase motor winding L1, the second phase motor winding L2 and the third phase motor winding L3 can perform bi-phase charging of the battery pack 102.

[0103] In this embodiment, the fifth charging time period and the sixth charging time period alternate at a certain frequency. During the fifth charging time period, the control circuit 104 turns on the second upper half-bridge switch S21 and the third upper half-bridge switch S31 in the control bridge arm circuit 1031, while other switches are turned off. The battery pack 102 charges the first phase motor winding L1, the second phase motor winding L2, the third phase motor winding L3 in the motor winding 1032 and the battery pack 102 through the second upper half-bridge switch S21 and the third upper half-bridge switch S31. At this time, the battery pack 102 and the motor winding 1032 store electrical energy. During the sixth charging period, the control circuit 104 cuts off each switch in the control bridge arm circuit 1031. Due to the inductive characteristics of the motor winding 1032, the current direction on the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3 does not change. The battery pack flows to the motor winding 1032 through the second lower half-bridge diode D22 and the third lower half-bridge diode D32. At this time, the current in the first phase motor winding L1, the second phase motor winding L2, and the third phase motor winding L3 is the same as in the previous state. The motor winding 1032 performs boost charging on the battery pack 102.

[0104] In this embodiment, the high voltage is buffered by energy storage in the motor winding 1032, preventing direct high-voltage charging from damaging the battery pack 102. This eliminates the need for an additional high-voltage step-down module, significantly improving system integration and reducing component usage and cost. Compared to traditional charging methods, this embodiment employs dual-phase charging, which improves charging efficiency.

[0105] This application provides a control method for a charging system, applied to the charging system shown in the above embodiments, including: acquiring the input voltage of the charging port, and selecting a charging mode to charge the battery pack by controlling the conduction states of a first switch, a second switch, a third switch, a fourth switch, and a fifth switch according to the magnitude relationship between the input voltage and a preset voltage threshold. The charging mode includes at least one of a direct charging mode, a boost charging mode, and a boost current charging mode.

[0106] In some examples, the flowchart of the control method for the charging system is as follows: Figure 16 As shown.

[0107] First, connect the charging station to the charging interface.

[0108] Obtain the maximum output voltage of the charging pile, and determine the charging mode based on the maximum output voltage of the charging pile.

[0109] When the maximum output voltage of the charging pile is greater than the second voltage threshold, the charging mode is determined to be the boost charging mode.

[0110] If the maximum output voltage of the charging pile is less than or equal to the first voltage threshold, the charging mode is determined to be boost charging mode.

[0111] If the maximum output voltage of the charging pile is greater than the first voltage threshold and less than or equal to the second voltage threshold, the charging mode is determined to be the direct charging mode.

[0112] During the charging process, the relationship between the maximum output voltage of the charging pile and the preset voltage threshold is judged in real time to determine the charging mode until charging is completed or terminated.

[0113] In this embodiment, by acquiring the input voltage of the charging port in real time and using a preset voltage threshold as the criterion, the conduction state of the drive, current boost, and voltage boost switching devices is dynamically adjusted to achieve automatic switching between voltage boost and current boost charging modes. This allows for adaptation to different input voltage scenarios without intervention. This embodiment can ensure accurate matching between the charging mode and the input voltage, thereby improving charging safety and efficiency.

[0114] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Those skilled in the art can understand that implementing all or part of the processes of the above embodiments and making equivalent changes according to the claims of this application still fall within the scope of this application.

Claims

1. A charging system, characterized in that, include: The charging port (101) is used to connect to a charging pile; The battery pack (102) is coupled to the charging port (101). The motor drive circuit (103) is coupled to the charging port (101) and the battery pack (102). The first switching device (K1) is disposed between the first end of the charging port (101) and the first end of the motor drive circuit (103); The second switching device (K2) is disposed between the second end of the charging port (101) and the second end of the motor drive circuit (103); The third switching device (K3) is disposed between the first end of the battery pack (102) and the first end of the motor drive circuit (103); A fourth switching device (K4) is disposed between the second end of the charging port (101) and the third end of the motor drive circuit (103); The fifth switching device (K5) is disposed between the first end of the battery pack (102) and the second end of the motor drive circuit (103); The control circuit (104) is configured to select a charging mode to charge the battery pack (102) by controlling the conduction state of the first switching device (K1), the second switching device (K2), the third switching device (K3), the fourth switching device (K4) and the fifth switching device (K5); the charging mode includes at least one of a direct charging mode, a boost charging mode and a boost current charging mode.

2. The charging system according to claim 1, characterized in that, The boost charging mode includes a first charging period and a second charging period following the first charging period. During the first charging period and the second charging period, the battery pack (102) is boost-charged. The control circuit (104) is specifically configured as follows: During the first charging period, the first switching device (K1) and the fourth switching device (K4) are turned on, while the second switching device (K2), the third switching device (K3), and the fifth switching device (K5) are turned off. During the second charging period, the first switch (K1), the third switch (K3), and the fourth switch (K4) are turned on, while the second switch (K2) and the fifth switch (K5) are turned off.

3. The charging system according to claim 2, characterized in that, The boost charging mode further includes a third charging time period and a fourth charging time period after the third charging time period. The fourth charging time period is before the first charging time period. During the third charging time period and the fourth charging time period, the voltage across the charging port (101) is stepped down. The control circuit (104) is specifically configured as follows: During the third charging period, the first switching device (K1), the third switching device (K3), and the fourth switching device (K4) are turned on, while the second switching device (K2) and the fifth switching device (K5) are turned off. During the fourth charging period, the first switching device (K1) and the fourth switching device (K4) are turned on, while the second switching device (K2), the third switching device (K3), and the fifth switching device (K5) are turned off.

4. The charging system according to claim 4, characterized in that, The boost charging mode includes a fifth charging time period and a sixth charging time period after the fifth charging time period. During the fifth charging time period and the sixth charging time period, the battery pack (102) is boosted. The control circuit (104) is specifically configured as follows: During the fifth charging period, the first switching device (K1), the second switching device (K2), and the fifth switching device (K5) are turned on, while the third switching device (K3) and the fourth switching device (K4) are turned off. During the sixth charging period, the fifth switching device (K5) is turned on, while the first switching device (K1), the second switching device (K2), the third switching device (K3), and the fourth switching device (K4) are turned off.

5. The charging system according to claim 1, characterized in that, The control circuit (104) is specifically configured as follows: Based on the relationship between the maximum output voltage of the charging pile and the preset voltage threshold, the charging mode is selected to charge the battery pack (102).

6. The charging system according to claim 5, characterized in that, The preset voltage threshold includes: a first voltage threshold and a second voltage threshold; the second voltage threshold is greater than the first voltage threshold, and the control circuit (104) is specifically configured as follows: When the maximum output voltage of the charging pile is greater than the first voltage threshold and less than or equal to the second voltage threshold, the charging mode is selected as the direct charging mode.

7. The charging system according to claim 6, characterized in that, The control circuit (104) is specifically configured as follows: When the maximum output voltage of the charging pile is less than the first voltage threshold, the charging mode is selected as boost charging mode.

8. The charging system according to claim 6, characterized in that, The control circuit (104) is specifically configured as follows: When the maximum output voltage of the charging pile is greater than the second voltage threshold, the charging mode is selected as the boost charging mode.

9. The charging system according to claim 4, characterized in that, The motor drive circuit (103) includes: a bridge arm circuit (1031) and a motor winding (1032). The first and second ends of the bridge arm circuit (1031) are respectively used as the first and second ends of the motor drive circuit (103). The bridge arm circuit (1031) includes a multi-phase bridge arm, the midpoint of which is correspondingly coupled to the first end of the multi-phase motor winding (1032) in the motor winding (1032); the second end of the multi-phase motor winding (1032) is also connected. The motor winding (1032) includes a first-phase motor winding (L1), a second-phase motor winding (L2), and a third-phase motor winding (L3). The multi-phase bridge arm includes a first-phase bridge arm, a second-phase bridge arm, and a third-phase bridge arm. The first end of the first-phase motor winding (L1) is coupled to the midpoint of the first-phase bridge arm. The first end of the first-phase motor winding (L1) also serves as the third end of the motor drive circuit (103). The control circuit (104) is specifically configured to: control any one phase arm of the multi-phase bridge arm other than the first phase bridge arm to perform single-phase charging of the battery pack (102), or control any two phase arms of the multi-phase bridge arm other than the first phase bridge arm to perform dual-phase charging of the battery pack (102).

10. The charging system according to claim 9, characterized in that, When the charging mode is the boost charging mode, the control circuit (104) is further configured to: During the first charging period, the upper half of the second phase bridge arm is controlled to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the first phase motor winding (L1) and the second phase motor winding (L2). During the second charging period, the lower half of the second phase bridge arm is controlled to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile, the first phase motor winding (L1) and the second phase motor winding (L2) can charge the battery pack (102) in a single phase. Alternatively, during the first charging period, the upper half of the second phase bridge arm is controlled to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the upper half of the third phase bridge arm is controlled to conduct along the first end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the charging pile charges the first phase motor winding (L1), the second phase motor winding (L2) and the third phase motor winding (L3). During the second charging period, the lower half of the second phase bridge arm is controlled to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm is controlled to conduct along the second end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the charging pile, the first phase motor winding (L1), the second phase motor winding (L2), and the third phase motor winding (L3) can perform dual-phase charging of the battery pack (102).

11. The charging system according to claim 10, characterized in that, The device also includes an energy storage circuit (105) coupled between the first and second ends of the charging port (101).

12. The charging system according to claim 11, characterized in that, When the charging mode is the boost charging mode, the control circuit (104) is further configured to: During the third charging period, the lower half of the second phase bridge arm is controlled to conduct along the midpoint of the second phase bridge arm to the second end of the second phase bridge arm, so that the battery pack (102) charges the energy storage circuit (105), the first phase motor winding (L1) and the second phase motor winding (L2). During the fourth charging period, the upper half of the second phase bridge arm is controlled to conduct along the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, so that the first phase motor winding (L1) and the second phase motor winding (L2) charge the energy storage circuit (105) in a single phase. Alternatively, during the third charging period, the lower half of the second phase bridge arm is controlled to conduct along the midpoint of the second phase bridge arm to the second end of the second phase bridge arm, and the lower half of the third phase bridge arm is controlled to conduct along the midpoint of the third phase bridge arm to the second end of the third phase bridge arm, so that the battery pack (102) charges the energy storage circuit (105), the first phase motor winding (L1), the second phase motor winding (L2) and the third phase motor winding (L3); During the fourth charging period, the upper half of the second phase bridge arm is controlled to conduct along the midpoint of the second phase bridge arm to the first end of the second phase bridge arm, and the upper half of the third phase bridge arm is controlled to conduct along the midpoint of the third phase bridge arm to the first end of the third phase bridge arm, so that the first phase motor winding (L1), the second phase motor winding (L2) and the third phase motor winding (L3) perform bi-phase charging of the energy storage circuit (105).

13. The charging system according to claim 9, characterized in that, When the charging mode is the boost charging mode, the control circuit (104) is further configured to: During the fifth charging period, the upper half of the second phase bridge arm is controlled to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the charging pile charges the battery pack (102), the first phase motor winding (L1) and the second phase motor winding (L2). During the sixth charging period, the lower half of the second phase bridge arm is controlled to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, so that the first phase motor winding (L1) and the second phase motor winding (L2) charge the battery pack (102) in a single phase. Alternatively, during the fifth charging period, the upper half of the second phase bridge arm is controlled to conduct along the first end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the upper half of the third phase bridge arm is controlled to conduct along the first end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the charging pile charges the battery pack (102), the first phase motor winding (L1), the second phase motor winding (L2) and the third phase motor winding (L3); During the sixth charging period, the lower half of the second phase bridge arm is controlled to conduct along the second end of the second phase bridge arm to the midpoint of the second phase bridge arm, and the lower half of the third phase bridge arm is controlled to conduct along the second end of the third phase bridge arm to the midpoint of the third phase bridge arm, so that the first phase motor winding (L1), the second phase motor winding (L2) and the third phase motor winding (L3) perform dual-phase charging of the battery pack (102).

14. A control method for a charging system, characterized in that, include: Obtain the input voltage of the charging port; Based on the relationship between the input voltage and the preset voltage threshold, the charging mode is selected to charge the battery pack by controlling the conduction states of the first switch, the second switch, the third switch, the fourth switch and the fifth switch; the charging mode includes at least one of the following: direct charging mode, boost charging mode and boost current charging mode.

15. A vehicle, characterized in that, Includes the charging system as described in any one of claims 1-3.

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