Vehicle-mounted charging system and vehicle

Abstract

The invention discloses a vehicle-mounted charging system and a vehicle, and the system comprises a non-isolated charger which is arranged between the AC output side of a power grid and a battery pack and is suitable for charging the battery pack after converting AC provided by the power grid into DC; and the leakage current suppression circuit is connected with the non-isolated charger and is suitable for suppressing the leakage current generated by the non-isolated charger. Therefore, leakage current generated by the non-isolated charger is suppressed by newly adding a leakage current suppression measure, so that the vehicle-mounted charging system is enabled to adapt to various types of vehicles and charging application scene requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicle charging, in particular to a vehicle charging system and a vehicle. BACKGROUND

[0002] An electric vehicle on-board charger (OBC) can be classified as an isolated OBC or a non-isolated OBC according to whether there is electrical isolation between the grid side and the load side. The non-isolated OBC does not require an isolation transformer, which can reduce the BOM cost, system size and weight. In addition, compared with the isolated OBC, the non-isolated OBC has better application prospects due to smaller size, lower system complexity and lower cost.

[0003] However, the related art has a problem that the AC side and the DC side of the non-isolated OBC are directly connected, and a large leakage current exists during operation. Generally, the electric vehicle performs residual current detection during charging, and interrupts the charging process when the leakage current exceeds the detection threshold, which leads to poor user experience. If the protective earth (PE wire) fails, it may even threaten personal safety. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the related art. To this end, a first object of the present application is to provide a vehicle charging system that can suppress the leakage current generated by a non-isolated charger by adding a leakage current suppression measure, thereby adapting the vehicle charging system to various types of vehicles and charging application scenarios.

[0005] A second object of the present application is to provide a vehicle.

[0006] To achieve the above object, the vehicle charging system according to an embodiment of the present application includes: a non-isolated charger disposed between an AC output side of a grid and a battery pack, adapted to convert AC power provided by the grid into DC power and charge the battery pack; and a leakage current suppression circuit connected to the non-isolated charger, adapted to suppress the leakage current generated by the non-isolated charger.

[0007] The vehicle charging system according to an embodiment of the present application is configured to dispose the non-isolated charger between the AC output side of the grid and the battery pack, convert AC power provided by the grid into DC power by the non-isolated charger, and charge the battery pack, and connect the leakage current suppression circuit to the non-isolated charger to suppress the leakage current of the non-isolated charger by the leakage current suppression circuit. Thus, the leakage current generated by the non-isolated charger is suppressed by adding a leakage current suppression measure, thereby adapting the vehicle charging system to various types of vehicles and charging application scenarios.

[0008] In addition, the on-board charging system according to the above embodiments of the present invention may also have the following additional technical features:

[0009] According to one embodiment of the present invention, the non-isolated charger includes: a first filter adapted to filter out common-mode and differential-mode interference between the power grid and the non-isolated charger; a second filter adapted to filter out common-mode and differential-mode interference between the non-isolated charger and the battery pack; and a DC-AC conversion module disposed between the first filter and the second filter, adapted to convert the alternating current provided by the power grid into direct current.

[0010] According to an embodiment of the present invention, the DC-AC conversion module includes: a first H-bridge adapted to convert AC power supplied by the power grid; a second H-bridge adapted to convert AC power supplied by the power grid; and a switch group connected to the first H-bridge and the second H-bridge respectively, adapted to enable the first H-bridge and the second H-bridge to output in series.

[0011] According to one embodiment of the present invention, the first H-bridge includes a first switching transistor, a second switching transistor, a first diode, and a second diode. The first switching transistor and the second switching transistor constitute a high-frequency bridge, and the first diode and the second diode constitute a power frequency bridge.

[0012] According to one embodiment of the present invention, the second H-bridge includes a third switch, a fourth switch, a third diode, and a fourth diode. The third switch and the fourth switch constitute a high-frequency bridge, and the third diode and the fourth diode constitute a power frequency bridge.

[0013] According to one embodiment of the present invention, the first H-bridge and the second H-bridge are configured as two high-frequency bridge symmetrical switches.

[0014] According to one embodiment of the present invention, the switch group includes: a fifth diode, the anode of which is connected to the first H-bridge; a sixth diode, the cathode of which is connected to the first H-bridge; a seventh diode, the anode of which is connected to the second H-bridge, and the cathode of which is connected to the cathode of the fifth diode; and an eighth diode, the cathode of which is connected to the second H-bridge, and the anode of which is connected to the anode of the sixth diode.

[0015] According to one embodiment of the present invention, during the positive half-cycle of the AC input, the first switch and the fourth switch are controlled to switch at high frequency, the fifth diode and the eighth diode are controlled to conduct, and the sixth diode and the seventh diode are controlled to turn off; and during the negative half-cycle of the AC input, the second switch and the third switch are controlled to switch at high frequency, the sixth diode and the seventh diode are controlled to conduct, and the fifth diode and the eighth diode are controlled to turn off.

[0016] According to one embodiment of the present invention, the non-isolated charger further includes: a first inductor disposed between the first filter and the first H-bridge; and a second inductor disposed between the first filter and the second H-bridge.

[0017] According to one embodiment of the present invention, the non-isolated charger further includes: a first capacitor, one end of which is connected to the first filter; a second capacitor, one end of which is connected to the first filter, and the other end of which is connected to the other end of the first capacitor to form a first midpoint; wherein the leakage current suppression circuit is connected to the first midpoint.

[0018] According to one embodiment of the present invention, the non-isolated charger further includes: a third capacitor, one end of which is connected to the first filter; a fourth capacitor, one end of which is connected to the first filter, and the other end of which is connected to the other end of the third capacitor to form a second midpoint; a fifth capacitor, one end of which is connected to the cathode of the first diode, and the other end of which is connected to the anode of the second diode; and a sixth capacitor, one end of which is connected to the cathode of the third diode, and the other end of which is connected to the cathode of the fourth diode.

[0019] According to one embodiment of the present invention, the non-isolated charger further includes: a seventh capacitor, one end of which is connected to the cathode of the fifth diode; and an eighth capacitor, one end of which is connected to the anode of the eighth diode, and the other end of which is connected to the other end of the seventh capacitor to form a third midpoint; wherein the second midpoint is connected to the third midpoint.

[0020] According to one embodiment of the present invention, the leakage current suppression circuit is an active leakage current suppression circuit, wherein the active leakage current suppression circuit includes: a Y capacitor; an active leakage current suppression excitation circuit adapted to provide an excitation source; a transformer, wherein the primary side of the transformer is connected to the output side of the active leakage current suppression excitation circuit, one side of the secondary side of the transformer is connected to the Y capacitor, and the other side of the secondary side of the transformer is connected to the non-isolated charger.

[0021] According to one embodiment of the present invention, the first diode is replaced with a fifth switch, the second diode is replaced with a sixth switch, the third diode is replaced with a seventh switch, the fourth diode is replaced with an eighth switch, the fifth diode is replaced with a ninth switch, the sixth diode is replaced with a tenth switch, the seventh diode is replaced with an eleventh switch, and the eighth diode is replaced with a twelfth switch.

[0022] According to one embodiment of the present invention, the active leakage current suppression circuit further includes: a Y capacitor; a preprocessing module connected to the AC input side of the power grid, adapted to generate an excitation source for the leakage current suppression module; and a leakage current suppression module disposed between the preprocessing module and the non-isolated charger, adapted to suppress leakage current generated by the non-isolated charger.

[0023] According to one embodiment of the present invention, the preprocessing module includes: a rectifier unit connected to the AC input side of the power grid, adapted to convert the AC power provided by the power grid into DC power; a DC-DC unit connected to the rectifier unit, adapted to perform voltage amplitude conversion on the DC power; a high-frequency inverter unit connected to the DC-DC unit, adapted to convert the DC power into high-frequency AC power; and a filter unit connected to the high-frequency inverter unit, adapted to filter the high-frequency AC power.

[0024] According to one embodiment of the present invention, the leakage current suppression module includes: a transformer, the primary side of which is connected to the filter unit, one side of the secondary side of which is connected to the Y capacitor, and the other side of the secondary side of which is connected to the non-isolated charger; and a controller, which is connected to the high-frequency inverter module and is adapted to acquire leakage current sampling values ​​and adjust the output voltage of the high-frequency inverter module according to the leakage current sampling values.

[0025] To achieve the above objectives, the vehicle proposed in the second aspect of the present invention includes a battery pack and the on-board charging system described in the above-described embodiments of the present invention.

[0026] According to the vehicle of the present invention, by adopting the on-board charging system described in the foregoing embodiments of the present invention, the leakage current generated by the non-isolated charger can be suppressed by adding leakage current suppression measures, thereby making the on-board charging system adaptable to various types of vehicles and charging application scenarios.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a block diagram of an on-board charging system according to an embodiment of the present invention;

[0029] Figure 2 This is an electrical schematic diagram of an on-board charging system according to an embodiment of the present invention;

[0030] Figure 3 This is an electrical schematic diagram of an on-board charging system according to an embodiment of the present invention;

[0031] Figure 4 This is an electrical schematic diagram of an on-board charging system according to a specific embodiment of the present invention;

[0032] Figure 5 This is an electrical schematic diagram of an on-board charging system according to another specific embodiment of the present invention;

[0033] Figure 6 A block diagram of an on-board charging system according to another embodiment of the present invention;

[0034] Figure 7 This is an electrical schematic diagram of an on-board charging system according to yet another specific embodiment of the present invention;

[0035] Figure 8 This is a block diagram of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0036] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0037] The on-board charging system and vehicle of the present invention are described below with reference to the accompanying drawings.

[0038] Figure 1 This is a block diagram of an on-board charging system according to an embodiment of the present invention.

[0039] Specifically, in some embodiments of the present invention, such as Figure 1 As shown, the on-board charging system 100 includes: a non-isolated charger 10 and a leakage current suppression circuit 20.

[0040] In this embodiment of the invention, such as Figure 2As shown, the non-isolated charger 10 is located between the AC output side of the power grid and the battery pack, and is suitable for converting the AC power supplied by the power grid into DC power to charge the battery pack; the leakage current suppression circuit 20 is connected to the non-isolated charger 10 and is suitable for suppressing the leakage current generated by the non-isolated charger 10.

[0041] During AC charging of a vehicle, common-mode components from the power grid and common-mode voltage components generated during high-frequency switching of power devices can cause leakage current through the vehicle's Y capacitor. This leakage current returns to the power grid via the PE line, leading to problems such as charging gun malfunction protection. Therefore, in the above embodiments of the present invention, the on-board charging system 100 also adds a leakage current suppression circuit 20 connected to the non-isolated charger 10 to suppress the leakage current generated by the non-isolated charger 10, thereby improving the reliability and compatibility of the on-board charging system 100.

[0042] It should be noted that, in the above embodiments of the present invention, as Figures 2-5 and Figure 7 As shown, the on-board charging system 100 can be further divided into a charging pile end and a vehicle end, wherein the power grid and the grounding resistance R g Located on one side of the charging pile, the battery pack, the non-isolated charger 10, and the leakage current suppression circuit 20 are located on the other side of the vehicle, thus constituting the on-board charging system 100 of this embodiment of the invention.

[0043] Furthermore, in some embodiments of the present invention, such as Figure 2 As shown, the non-isolated charger 20 includes: a first filter 21, a second filter 25, and a DC-AC conversion module 30.

[0044] The first filter 21 is adapted to filter out common-mode and differential-mode interference between the power grid and the non-isolated charger 20; the second filter 25 is adapted to filter out common-mode and differential-mode interference between the non-isolated charger 20 and the battery pack; the DC-AC conversion module 30 is disposed between the first filter 21 and the second filter 25 and is adapted to convert the AC power provided by the power grid into DC power.

[0045] It is understood that, in this embodiment of the present invention, the AC output transmitted from the grid to the non-isolated charger 20 can be filtered out for common-mode and differential-mode interference by the first filter 21, and the DC output transmitted from the non-isolated charger 20 to the battery pack can be filtered out for common-mode and differential-mode interference by the second filter 25.

[0046] Furthermore, in some embodiments of the present invention, such as Figure 3 As shown, the DC-AC conversion module 30 includes: a first H-bridge 22, a second H-bridge 23, and a switch group 24.

[0047] The first H-bridge 22 is adapted to transform the AC power supplied by the power grid; the second H-bridge 23 is adapted to transform the AC power supplied by the power grid; the switch group 24 is connected to the first H-bridge 22 and the second H-bridge 23 respectively, and is adapted to enable the first H-bridge 22 and the second H-bridge 23 to output in series.

[0048] Specifically, in the above embodiments of the present invention, the AC power supplied by the power grid can be converted into DC power through the first H-bridge 22 and the second H-bridge 23, and the first H-bridge 21 and the second H-bridge 22 can be connected in series for output through the switch group 24. Thus, the non-isolated charger 10 of the present invention completes the AC-to-DC conversion and realizes the charging of the battery pack.

[0049] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the first H-bridge 22 includes a first switch S1, a second switch S2, a first diode D1 and a second diode D2. The first switch S1 and the second switch S2 form a high-frequency bridge, and the first diode D1 and the second diode D2 form a power frequency bridge.

[0050] It should be noted that, in this embodiment of the present invention, the first switch S1 and the second switch S2 are semiconductor power devices.

[0051] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the second H-bridge 23 includes a third switch S3, a fourth switch S4, a third diode D3, and a fourth diode D4. The third switch S3 and the fourth switch S4 constitute a high-frequency bridge.

[0052] It should be noted that, in this embodiment of the present invention, the third switch S3 and the fourth switch S4 are semiconductor power devices.

[0053] Furthermore, in some embodiments of the present invention, the first H-bridge 22 and the second H-bridge 23 are configured as two high-frequency bridge symmetrical switches.

[0054] Specifically, in this embodiment of the present invention, in order to suppress the mid-to-high frequency leakage current generated by the on-board charging system 100, the two high-frequency bridge symmetrical switches in the first H-bridge 22 and the second H-bridge 23 can be controlled, that is, the first switch S1 and the fourth switch S4 are controlled by the same set of PWM signals, and the second switch S2 and the third switch S3 are controlled by the same set of PWM signals, so as to ensure that when the DC+ potential of the DC bus positive terminal jumps, there must be a simultaneous jump in the opposite direction and the same amplitude of the DC- potential of the DC bus negative terminal, thereby achieving the effect of canceling the high-frequency leakage current, so that the high-frequency leakage current flowing through the ground wire is zero.

[0055] Furthermore, in some embodiments of the present invention, such as Figure 4As shown, switch group 24 includes: fifth diode D5, sixth diode D6, seventh diode D7 and eighth diode D8.

[0056] In this configuration, the anode of the fifth diode D5 is connected to the first H-bridge 22; the cathode of the sixth diode D6 is connected to the first H-bridge 22; the anode of the seventh diode D7 is connected to the second H-bridge 23, and the cathode of the seventh diode D7 is connected to the cathode of the fifth diode D5; the cathode of the eighth diode D8 is connected to the second H-bridge 23, and the anode of the eighth diode D8 is connected to the anode of the sixth diode D6.

[0057] It is understood that in this embodiment of the present invention, the fifth diode D5, the sixth diode D6, the seventh diode D7 and the eighth diode D8 form a switch group 24. At this time, the first H bridge 22 and the second H bridge 23 can be connected in series by adjusting the switching states of the fifth diode D5, the sixth diode D6, the seventh diode D7 and the eighth diode D8.

[0058] Furthermore, in some embodiments of the present invention, during the positive half-cycle of the AC input, the first switch S1 and the fourth switch S4 are controlled to switch at high frequency, the fifth diode D5 and the eighth diode D8 are controlled to conduct, and the sixth diode D6 and the seventh diode D7 are controlled to turn off. During the negative half-cycle of the AC input, the second switch S2 and the third switch S3 are controlled to switch at high frequency, the sixth diode D6 and the seventh diode D7 are controlled to conduct, and the fifth diode D5 and the eighth diode D8 are controlled to turn off.

[0059] Specifically, in this embodiment of the invention, the first H-bridge 22 and the second H-bridge 23 can be connected in series on the DC bus side via a switch group 24. For example, Figure 4 As shown, taking the DC bus output as 2U as an example, during the positive half-cycle of the AC input, the first switch S1 and the fourth switch S4 are controlled to switch at high frequency. At this time, the fifth diode D5 and the eighth diode D8 are turned on, making the positive terminal of the DC bus DC+ U and the negative terminal of the DC bus DC- -U. At the same time, the sixth diode D6 and the seventh diode D7 are turned off, so that the first H-bridge 22 and the second H-bridge 23 are connected in series for output. Similarly, during the negative half-cycle of the AC input, the second switch S2 and the third switch S3 are controlled to switch at high frequency. At this time, the sixth diode D6 and the seventh diode D7 are turned on, making the positive terminal of the DC bus DC+ U and the negative terminal of the DC bus DC- -U. At the same time, the fifth diode D5 and the eighth diode D8 are turned off, so that the first H-bridge 22 and the second H-bridge 23 are connected in series for output.

[0060] Therefore, according to the non-isolated charger 10 of the present invention, the first H-bridge 22 and the second H-bridge 23 are connected in series through the switch group 24, so that the withstand voltage of the switching transistors and diodes only needs to be higher than half of the maximum output voltage, which helps to reduce the cost of power devices or reduce the difficulty of device selection in high-voltage chargers.

[0061] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the non-isolated charger 10 also includes: a first inductor L1 and a second inductor L2.

[0062] Specifically, in this embodiment of the present invention, the first inductor L1 is disposed between the first filter 21 and the first H-bridge 22; the second inductor L2 is disposed between the first filter 21 and the second H-bridge 23.

[0063] It should be noted that in this embodiment of the present invention, the first inductor L1 and the second inductor L2 are PFC inductors, which serve to filter, store energy and reduce harmonics.

[0064] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the non-isolated charger 10 also includes: a first capacitor C1 and a second capacitor C2.

[0065] In this circuit, one end of the first capacitor C1 is connected to the first filter 21; one end of the second capacitor C2 is connected to the first filter 21, and the other end of the second capacitor C2 is connected to the other end of the first capacitor C1 to form the first midpoint P1; and the leakage current suppression circuit 20 is connected to the first midpoint P1.

[0066] It is understood that in this embodiment of the present invention, the first capacitor C1 and the second capacitor C2 are capacitors in the pre-stage of the first filter 21.

[0067] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the non-isolated charger 10 also includes: a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, and a sixth capacitor C6.

[0068] Among them, one end of the third capacitor C3 is connected to the first filter 21; one end of the fourth capacitor C4 is connected to the first filter 21, and the other end of the fourth capacitor C4 is connected to the other end of the third capacitor C3 to form the second midpoint P2; one end of the fifth capacitor C5 is connected to the cathode of the first diode D1, and the other end of the fifth capacitor C5 is connected to the anode of the second diode D2; one end of the sixth capacitor C5 is connected to the cathode of the third diode D3, and the other end of the sixth capacitor C6 is connected to the cathode of the fourth diode D4.

[0069] It is understood that in this embodiment of the present invention, the third capacitor C3 and the fourth capacitor C4 are input capacitors, the fifth capacitor C5 is the output capacitor of the first H-bridge 22, and the sixth capacitor C6 is the output capacitor of the second H-bridge 23.

[0070] Furthermore, in some embodiments of the present invention, such as Figure 4 As shown, the non-isolated charger 10 also includes a seventh capacitor C7 and an eighth capacitor C8.

[0071] In this configuration, one end of the seventh capacitor C7 is connected to the cathode of the fifth diode D5; one end of the eighth capacitor C8 is connected to the anode of the eighth diode D8, and the other end of the eighth capacitor C8 is connected to the other end of the seventh capacitor C7, forming the third midpoint P3; and the second midpoint P2 is connected to the third midpoint P3.

[0072] It is understood that in this embodiment of the present invention, the seventh capacitor C7 and the eighth capacitor C8 are the total output capacitors, wherein DC1+ is the positive output terminal of the first H-bridge 22, DC1- is the negative output terminal of the first H-bridge 22, DC2+ is the positive output terminal of the second H-bridge 23, DC2- is the negative output terminal of the second H-bridge 23, DC+ is the positive terminal of the DC bus, DC- is the negative terminal of the DC bus, CY2 is the Y capacitor of the positive terminal of the DC bus to the vehicle ground, and CY3 is the Y capacitor of the negative terminal of the DC bus to the vehicle ground, so as to form a common-mode leakage current loop.

[0073] Therefore, according to the embodiment of the non-isolated charger 10 of the present invention, DC-side voltage clamping is performed by connecting the second midpoint P2 of the third capacitor C3 and the fourth capacitor C4 to the third midpoint P3 of the seventh capacitor C7 and the eighth capacitor C8, thereby further eliminating high-frequency leakage current.

[0074] Furthermore, in some embodiments of the present invention, such as Figure 5 and Figure 5 As shown, the leakage current suppression circuit 20 is an active leakage current suppression circuit, which includes: Y capacitor CY1, active leakage current suppression excitation circuit and transformer T1.

[0075] Specifically, in this embodiment of the invention, the active leakage current suppression excitation circuit is adapted to provide an excitation source; the primary side of transformer T1 is connected to the output side of the active leakage current suppression excitation circuit, one side of the secondary side of transformer T1 is connected to Y capacitor CY1, and the other side of the secondary side of transformer T1 is connected to non-isolated charger 10.

[0076] Understandably, the active leakage current suppression excitation circuit provides an excitation source for transformer T1. One side of the secondary winding of transformer T1 is connected to Y capacitor CY1 to provide a voltage reference, and the other side of the secondary winding of transformer T1 is connected to the non-isolated charger 10 to inject reverse leakage current into the main circuit, thereby reducing the net leakage current I on the PE line. leak It is zero.

[0077] Therefore, the active leakage current suppression circuit 20 according to the embodiment of the present invention can eliminate the influence of the Y capacitor value offset, thereby matching different vehicle designs and adapting to various working environment conditions, with high flexibility and low requirements for new circuit components, and can meet the application requirements of on-board chargers with high withstand voltage requirements.

[0078] Furthermore, in some embodiments of the present invention, such as Figure 6 As shown, the first diode D1 is replaced with the fifth switch S5, the second diode D2 is replaced with the sixth switch S6, the third diode D3 is replaced with the seventh switch S7, the fourth diode D4 is replaced with the eighth switch S8, the fifth diode D5 is replaced with the ninth switch S9, the sixth diode D6 is replaced with the tenth switch S10, the seventh diode D7 is replaced with the eleventh switch S11, and the eighth diode D8 is replaced with the twelfth switch S12.

[0079] It is understood that in this embodiment of the present invention, the first to eighth diodes in the aforementioned embodiments of the present invention can be replaced with the fifth to twelfth switching transistors, thereby enabling synchronous rectification and bidirectional power transmission.

[0080] Furthermore, in some embodiments of the present invention, the first filter 21 and the second filter 25 can be implemented using different types of filters. For example, the first filter 21 and the second filter 25 can be EMI filters, multi-stage π-type filters, etc., without limitation. Similarly, the first switch S1, the second switch S2, the third switch S3 and the fourth switch S4 can be implemented using any element that can control the switch, such as MOSFET, IGBT, etc., without limitation.

[0081] Furthermore, in other embodiments of the present invention, such as Figure 7 As shown, the active leakage current suppression circuit 20 also includes: a Y capacitor CY1, a preprocessing module, and a leakage current suppression module.

[0082] The preprocessing module is connected to the AC input side of the power grid and is suitable for generating the excitation source of the leakage current suppression module; the leakage current suppression module is located between the preprocessing module and the non-isolated charger and is suitable for suppressing the leakage current generated by the non-isolated charger.

[0083] Furthermore, in some embodiments of the present invention, such as Figure 7 As shown, the preprocessing module includes: a rectifier unit, a DC-DC unit, a high-frequency inverter unit, and a filter unit.

[0084] The rectifier unit is connected to the AC input side of the power grid and is suitable for converting AC power supplied by the power grid into DC power; the DC-DC unit is connected to the rectifier unit and is suitable for converting the voltage amplitude of DC power; the high-frequency inverter unit is connected to the DC-DC unit and is suitable for converting DC power into high-frequency AC power; and the filter unit is connected to the high-frequency inverter unit and is suitable for filtering high-frequency AC power.

[0085] Furthermore, in some embodiments of the present invention, such as Figure 8 As shown, the leakage current suppression module includes: transformer T1 and controller.

[0086] The primary side of transformer T1 is connected to the filter unit, one side of the secondary side of transformer T1 is connected to Y capacitor CY1, and the other side of the secondary side of transformer T1 is connected to the non-isolated charger 10; the controller is connected to the high-frequency inverter module and is suitable for acquiring leakage current sampling values ​​and adjusting the output voltage of the high-frequency inverter module according to the leakage current sampling values.

[0087] Specifically, in the above embodiments of the present invention, the AC input from the power grid is used as the excitation source input. First, the AC power provided by the power grid is converted into DC power by the rectifier unit. Then, the DC power is converted into voltage amplitude by the DC-DC unit. Next, the DC power is converted into high-frequency AC power by the high-frequency inverter unit. Then, the high-frequency AC power is filtered by the filter unit. At the same time, the leakage current sampling value is obtained by the controller, and the output voltage of the high-frequency inverter unit is adjusted according to the leakage current sampling value. Thus, the primary side input of transformer T1 is realized. At this time, one side of the secondary side of transformer T1 is connected to Y capacitor CY1 to provide a voltage reference. The other side of the secondary side of transformer T1 is connected to non-isolated charger 10. Thus, the reverse leakage current is injected into the main circuit to suppress the low-frequency leakage current generated by non-isolated charger 10.

[0088] Furthermore, in some embodiments of the present invention, the excitation source input of the active leakage current suppression circuit 20 may include AC input from the mains grid, DC voltage from the battery pack, etc., and the active leakage current suppression circuit 20 may be modified appropriately according to the type of excitation source, without being specifically limited here.

[0089] It should be noted that in the above embodiments of the present invention, by adding leakage current suppression measures, the leakage current value on the PE line is obtained, and a reverse leakage current is generated according to the leakage current value, so as to inject the reverse leakage current into the circuit to suppress the low-frequency leakage current; and the high-frequency bridge in the H-bridge is controlled to adopt a symmetrical switching strategy and DC side voltage clamping to suppress the high-frequency leakage current generated in the circuit, thereby making the non-isolated OBC practical. In addition, the two H-bridges are connected in series to output through the switching group to reduce the requirement for the withstand voltage of the components.

[0090] In summary, the on-board charging system according to embodiments of the present invention places a non-isolated charger between the AC output side of the power grid and the battery pack. The non-isolated charger converts the AC power supplied by the power grid into DC power to charge the battery pack. Simultaneously, a leakage current suppression circuit is connected to the non-isolated charger to suppress its leakage current. Therefore, by adding leakage current suppression measures, the leakage current generated by the non-isolated charger is suppressed, thereby making the on-board charging system adaptable to various types of vehicles and charging application scenarios.

[0091] Figure 8 This is a block diagram of a vehicle according to an embodiment of the present invention.

[0092] Specifically, in some embodiments of the present invention, such as ​ As shown, the vehicle 1000 includes a battery pack 200 and an on-board charging system 100 as described in the above embodiment of the present invention.

[0093] It should be noted that the specific implementation of the vehicle in the embodiments of the present invention can be found in the specific implementation of the on-board charging system in the foregoing embodiments of the present invention. To reduce redundancy, it will not be repeated here.

[0094] In summary, the vehicle according to the embodiments of the present invention, by adopting the on-board charging system described in the foregoing embodiments of the present invention, can suppress the leakage current generated by the non-isolated charger by adding leakage current suppression measures, thereby making the on-board charging system adaptable to various types of vehicles and charging application scenarios.

[0095] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0096] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0097] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0098] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0099] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0100] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A vehicle-mounted charging system, characterized in that, The system includes: A non-isolated charger is disposed between the AC output side of the power grid and the battery pack, and is suitable for converting the AC power provided by the power grid into DC power to charge the battery pack; A leakage current suppression circuit is connected to the non-isolated charger and is adapted to suppress the leakage current generated by the non-isolated charger.

2. The on-board charging system according to claim 1, characterized in that, The non-isolated charger includes: The first filter is adapted to filter out common-mode and differential-mode interference between the power grid and the non-isolated charger; The second filter is adapted to filter out common-mode and differential-mode interference between the non-isolated charger and the battery pack; A DC-AC conversion module is disposed between the first filter and the second filter, and is adapted to convert the alternating current provided by the power grid into direct current.

3. The on-board charging system according to claim 2, characterized in that, The DC-AC conversion module includes: The first H-bridge is adapted to transform the alternating current supplied by the power grid; The second H-bridge is adapted to transform the alternating current supplied by the power grid; A switch group, which is connected to the first H-bridge and the second H-bridge respectively, is adapted to enable the first H-bridge and the second H-bridge to output in series.

4. The on-board charging system according to claim 3, characterized in that, The first H-bridge includes a first switch, a second switch, a first diode, and a second diode. The first switch and the second switch constitute a high-frequency bridge, and the first diode and the second diode constitute a power frequency bridge.

5. The on-board charging system according to claim 4, characterized in that, The second H-bridge includes a third switch, a fourth switch, a third diode, and a fourth diode. The third switch and the fourth switch constitute a high-frequency bridge, and the third diode and the fourth diode constitute a power frequency bridge.

6. The on-board charging system according to claim 5, characterized in that, The first H-bridge and the second H-bridge are configured as two high-frequency bridge symmetrical switches.

7. The on-board charging system according to claim 5, characterized in that, The switch group includes: The fifth diode, wherein the anode of the fifth diode is connected to the first H-bridge; The sixth diode, the cathode of which is connected to the first H-bridge; The seventh diode, the anode of which is connected to the second H-bridge, and the cathode of which is connected to the cathode of the fifth diode; The eighth diode has its cathode connected to the second H-bridge and its anode connected to the anode of the sixth diode.

8. The on-board charging system according to claim 7, characterized in that, During the positive half-cycle of the AC input, the first and fourth switching transistors are controlled to switch at high frequency, the fifth and eighth diodes are controlled to conduct, and the sixth and seventh diodes are controlled to turn off. During the negative half-cycle of the AC input, the second and third switching transistors are controlled to switch at high frequency, the sixth and seventh diodes are controlled to conduct, and the fifth and eighth diodes are controlled to turn off.

9. The on-board charging system according to claim 8, characterized in that, The non-isolated charger also includes: The first inductor is disposed between the first filter and the first H-bridge; The second inductor is disposed between the first filter and the second H-bridge.

10. The on-board charging system according to claim 9, characterized in that, The non-isolated charger also includes: A first capacitor, one end of which is connected to the first filter; A second capacitor, one end of which is connected to the first filter, and the other end of which is connected to the other end of the first capacitor to form a first midpoint; The leakage current suppression circuit is connected to the first midpoint.

11. The on-board charging system according to claim 10, characterized in that, The non-isolated charger also includes: A third capacitor, one end of which is connected to the first filter; A fourth capacitor, one end of which is connected to the first filter, and the other end of which is connected to the other end of the third capacitor to form a second midpoint; A fifth capacitor, one end of which is connected to the cathode of the first diode, and the other end of which is connected to the anode of the second diode; A sixth capacitor, one end of which is connected to the cathode of the third diode, and the other end of which is connected to the cathode of the fourth diode.

12. The on-board charging system according to claim 11, characterized in that, The non-isolated charger also includes: The seventh capacitor, one end of which is connected to the cathode of the fifth diode; The eighth capacitor has one end connected to the anode of the eighth diode and the other end connected to the other end of the seventh capacitor to form a third midpoint. The second midpoint is connected to the third midpoint.

13. The on-board charging system according to any one of claims 1-12, characterized in that, The leakage current suppression circuit is an active leakage current suppression circuit, wherein the active leakage current suppression circuit includes: Y capacitor; An active leakage current suppression excitation circuit is suitable for providing an excitation source; The transformer has its primary side connected to the output side of the active leakage current suppression excitation circuit, one side of the secondary side of the transformer connected to the Y capacitor, and the other side of the secondary side of the transformer connected to the non-isolated charger.

14. The on-board charging system according to claim 7, characterized in that, The first diode is replaced with the fifth switch, the second diode is replaced with the sixth switch, the third diode is replaced with the seventh switch, the fourth diode is replaced with the eighth switch, the fifth diode is replaced with the ninth switch, the sixth diode is replaced with the tenth switch, the seventh diode is replaced with the eleventh switch, and the eighth diode is replaced with the twelfth switch.

15. The on-board charging system according to claim 14, characterized in that, The leakage current suppression circuit further includes: Y capacitor; A preprocessing module, which is connected to the AC input side of the power grid, is adapted to generate the excitation source for the leakage current suppression module; A leakage current suppression module is disposed between the preprocessing module and the non-isolated charger, and is adapted to suppress the leakage current generated by the non-isolated charger.

16. The on-board charging system according to claim 15, characterized in that, The preprocessing module includes: A rectifier unit, connected to the AC input side of the power grid, is adapted to convert the AC power supplied by the power grid into DC power; A DC-DC unit, which is connected to the rectifier unit, is adapted to perform voltage amplitude conversion on the DC power; A high-frequency inverter unit, which is connected to the DC-DC unit, is adapted to convert the direct current into high-frequency alternating current; A filtering unit is connected to the high-frequency inverter unit and is adapted to filter the high-frequency alternating current.

17. The on-board charging system according to claim 16, characterized in that, The leakage current suppression module includes: A transformer, wherein the primary side of the transformer is connected to the filter unit, one side of the secondary side of the transformer is connected to the Y capacitor, and the other side of the secondary side of the transformer is connected to the non-isolated charger; A controller, connected to the high-frequency inverter module, is adapted to acquire leakage current sampling values ​​and adjust the output voltage of the high-frequency inverter module according to the leakage current sampling values.

18. A vehicle, characterized in that, The vehicle includes a battery pack and an on-board charging system as claimed in any one of claims 1-17.

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