Pre-charging circuit, on-board charger and vehicle

Abstract

The present disclosure relates to the field of vehicle technology, and provides a pre-charging circuit, an on-board charger and a vehicle, wherein the pre-charging circuit includes: a first switch, the first switch includes a first contact point and a second contact point, the second contact point is connected to the first end of the power supply device; a second switch, the second switch includes a third contact point and a fourth contact point, the fourth contact point is connected to the power supply device; a PFC circuit, the PFC circuit is connected to the first switch and the second switch K2; a first capacitor, the first capacitor is connected to the PFC circuit; a high-voltage circuit, the high-voltage circuit is respectively connected to the first capacitor and the PFC circuit; a second capacitor, the second capacitor is connected to the first contact point, and the second capacitor is connected to the fourth contact point; a high-voltage battery pack, the high-voltage battery pack is respectively connected to the high-voltage circuit, the second capacitor and the high-voltage circuit; a low-voltage circuit, the low-voltage circuit is respectively connected to the high-voltage circuit, the second capacitor, the high-voltage battery pack and the low-voltage battery pack. The present disclosure can simplify the pre-charging process by directly pre-charging the bus capacitor.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle technology, and in particular, to a pre-charging circuit, an on-board charger and a vehicle. Background Art

[0002] Before a vehicle is charged using an on-board charger (OBC), the charging gun usually needs to charge the PFC (Power Factor Correction) capacitor in the on-board charger to prevent the high current from short-circuiting and damaging the internal circuit of the on-board charger. Currently, the pre-charging circuit of an on-board charger usually uses a pre-charging resistor and a relay in parallel, but this method results in a high volume and cost of the pre-charging circuit. Summary of the invention

[0003] The main purpose of the present disclosure is to provide a pre-charging circuit, an on-board charger and a vehicle, aiming to solve the above-mentioned technical problems.

[0004] According to a first aspect of an embodiment of the present disclosure, a pre-charging circuit is provided, the pre-charging circuit comprising:

[0005] A first switch K1, wherein the first switch K1 comprises a first contact point and a second contact point, wherein the second contact point is connected to a first end of a power supply device;

[0006] A second switch K2, wherein the second switch K2 comprises a third contact point and a fourth contact point, and the fourth contact point is connected to the second end of the power supply device;

[0007] A power factor correction PFC circuit, wherein a first end of the PFC circuit is connected to the first switch K1, and a second end of the PFC circuit is connected to the second switch K2;

[0008] a first capacitor C1, wherein a first end of the first capacitor C1 is connected to a third end of the PFC circuit;

[0009] A high-voltage circuit, a first end of which is respectively connected to the first capacitor C1 and the PFC circuit;

[0010] a second capacitor C2, wherein a first end of the second capacitor C2 is connected to the first contact point, and a second end of the second capacitor C2 is connected to the fourth contact point;

[0011] A high-voltage battery pack Bat1, wherein the high-voltage battery pack Bat1 is connected to the high-voltage circuit and the second capacitor C2 respectively;

[0012] A low voltage circuit, wherein a first end of the low voltage circuit is respectively connected to the high voltage circuit, the second capacitor C2 and the high voltage battery pack Bat1, and a second end of the low voltage circuit is connected to the low voltage battery pack Bat2.

[0013] Optionally, the PFC circuit includes:

[0014] a first inductor L1, wherein a first end of the first inductor L1 is connected to the first switch K1;

[0015] A first switch tube Q1 and a third switch tube Q3, wherein a midpoint of a first bridge arm formed by the first switch tube Q1 and the third switch tube Q3 is connected to a second end of the first inductor L1;

[0016] The second switch tube Q2 and the fourth switch tube Q4, the midpoint of the second bridge arm formed by the second switch tube Q2 and the fourth switch tube Q4 is connected to the second switch K2, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are respectively connected to the first capacitor C1.

[0017] Optionally, the high voltage circuit comprises:

[0018] a fifth switch tube Q5 and a sixth switch tube Q6, wherein the fifth switch tube Q5 and the sixth switch tube Q6 are connected to the PFC circuit and the first capacitor C1 respectively, and the fifth switch tube Q5 and the sixth switch tube Q6 form a third bridge arm;

[0019] A third capacitor C3 and a fourth capacitor C4, wherein the third capacitor C3 is connected to the fifth switch tube Q5, and the fourth capacitor C4 is connected to the sixth switch tube Q6;

[0020] The first transformer T1, the positive end of the primary winding of the first transformer T1 is connected to the midpoint of the third capacitor C3 and the fourth capacitor C4, and the negative end of the primary winding of the first transformer T1 is connected to the midpoint of the third bridge arm.

[0021] Optionally, the high voltage circuit further includes:

[0022] A unidirectional charging circuit, the unidirectional charging circuit includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, the anode of the first diode D1 is connected to the cathode of the third diode D3, the midpoint between the anode of the first diode D1 and the cathode of the third diode D3 is connected to the positive end of the secondary winding of the first transformer T1, the anode of the second diode D2 is connected to the cathode of the fourth diode D4, and the midpoint between the anode of the second diode D2 and the cathode of the fourth diode D4 is connected to the negative end of the secondary winding of the first transformer T1.

[0023] Optionally, the high voltage circuit further includes:

[0024] A bidirectional charging circuit, the bidirectional charging circuit comprising a fifth capacitor C5, a sixth capacitor C6, a seventh switch tube Q7 and an eighth switch tube Q8, the midpoint of the fifth capacitor C5 and the sixth capacitor C6 being connected to the positive end of the secondary winding of the first transformer T1, the midpoint of a fourth bridge arm formed by the seventh switch tube Q7 and the eighth switch tube Q8 being connected to the negative end of the secondary winding of the first transformer T1, the seventh switch tube Q7 being respectively connected to the first ends of the fifth capacitor C5 and the second capacitor C2, and the eighth switch tube Q8 being respectively connected to the second ends of the sixth capacitor C6 and the second capacitor C2.

[0025] Optionally, the pre-charging circuit further includes:

[0026] A third switch K3, wherein a first end of the third switch K3 is respectively connected to the high voltage circuit, the second capacitor C2 and the low voltage circuit, and a second end of the third switch K3 is connected to the high voltage battery pack Bat1.

[0027] Optionally, the low-voltage circuit includes a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a twelfth switch tube Q12, a second transformer T2, a thirteenth switch tube Q13 and a fourteenth switch tube Q14;

[0028] The midpoint of the fifth bridge arm composed of the ninth switch tube Q9 and the eleventh switch tube Q11 is connected to the negative end of the primary winding of the second transformer T2, the midpoint of the sixth bridge arm composed of the tenth switch tube Q10 and the twelfth switch tube Q12 is connected to the positive end of the primary winding of the second transformer T2, the ninth switch tube Q9 and the tenth switch tube Q10 are respectively connected to the high-voltage battery pack Bat1, and the eleventh switch tube Q11 and the twelfth switch tube Q12 are respectively connected to the third switch K3;

[0029] The first end of the thirteenth switch tube Q13 is connected to the positive end of the secondary winding of the second transformer T2, the first end of the fourteenth switch tube Q14 is connected to the negative end of the secondary winding of the second transformer T2, and the second end of the thirteenth switch tube Q13 and the second end of the fourteenth switch tube Q14 are respectively connected to the low-voltage battery group Bat2.

[0030] Optionally, the low voltage circuit further includes:

[0031] A second inductor L2, wherein a first end of the second inductor L2 is connected to the low-voltage battery pack Bat2, and a second end of the second inductor L2 is connected to a center tap of a secondary winding of the second transformer T2;

[0032] A seventh capacitor C7, wherein a first end of the seventh capacitor C7 is respectively connected to the second inductor L2 and the low-voltage battery pack Bat2.

[0033] Optionally, the pre-charging circuit is configured as:

[0034] Controlling the first switch K1 to connect the first contact point, and controlling the second switch to connect the fourth contact point, so that the first switch K1 and the second switch K2 are connected to the DC side;

[0035] The low voltage circuit is controlled to charge the first capacitor C1 and the second capacitor C2.

[0036] According to a second aspect of an embodiment of the present disclosure, there is provided an on-board charger, the on-board charger comprising the pre-charging circuit described in any one of the first aspects.

[0037] According to a third aspect of an embodiment of the present disclosure, a vehicle is provided, the vehicle comprising the on-board charger according to the second aspect.

[0038] In the above technical solution proposed in the embodiment of the present disclosure, the pre-charging circuit may include a first switch K1, a second switch K2, a PFC circuit, a first capacitor C1, a high-voltage circuit, a second capacitor C2, a high-voltage battery pack Bat1, a low-voltage circuit and a low-voltage battery pack Bat2, wherein the first switch K1 includes a first contact point and a second contact point, the second contact point is connected to the first end of the power supply device, the second switch K2 includes a third contact point and a fourth contact point, the fourth contact point is connected to the second end of the power supply device, the first end of the PFC circuit is connected to the first switch K1, the second end of the PFC circuit is connected to the second switch K2, and the first The first end of capacitor C1 is connected to the third end of the PFC circuit, the first end of the high-voltage circuit is respectively connected to the first capacitor C1 and the PFC circuit, the first end of the second capacitor C2 is connected to the first contact point, the second end of the second capacitor C2 is connected to the fourth contact point, the high-voltage battery pack Bat1 is respectively connected to the high-voltage circuit and the second capacitor C2, the first end of the low-voltage circuit is respectively connected to the high-voltage circuit, the second capacitor C2 and the high-voltage battery pack Bat1, and the second end of the low-voltage circuit is connected to the low-voltage battery pack Bat2. Based on the pre-charging circuit, the embodiment of the present disclosure can directly pre-charge the PFC bus capacitor, thereby simplifying the pre-charging process.

[0039] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0041] Figure 1 is a block diagram of a pre-charging circuit according to an exemplary embodiment.

[0042] Figure 2 is a diagram showing an example of current flow in a pre-charging circuit according to an exemplary embodiment.

[0043] Figure 3 is a schematic diagram showing a pre-charging circuit including a unidirectional charging circuit according to an exemplary embodiment.

[0044] Figure 4 is a schematic diagram showing a pre-charging circuit including a bidirectional charging circuit according to an exemplary embodiment.

[0045] Figure 5 The present invention is a flow chart showing a pre-charging circuit for pre-charging a capacitor according to an exemplary embodiment.

[0046] Figure 6 The figure is a block diagram of a vehicle charger according to an exemplary embodiment.

[0047] Figure 7 is a block diagram of a vehicle according to an exemplary embodiment. DETAILED DESCRIPTION

[0048] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0049] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0050] Here, exemplary embodiments will be described in detail, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present disclosure.

[0051] In the description of the present disclosure, the terms used, such as "first", "second", etc., are used to distinguish similar objects and are not necessarily understood as a specific order or sequence. In addition, in the description with reference to the accompanying drawings, the same symbols in different drawings represent the same elements unless otherwise stated.

[0052] The embodiments described in some embodiments of the present disclosure below do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0053] In the related art, the pre-charging circuit usually relies on the inverter function of the bidirectional on-board charger, and cannot pre-charge the unidirectional on-board charger. Specifically, due to cost reasons, the unidirectional on-board charger is not equipped with an inverter circuit, so it is impossible to use the inverter function of the high-voltage DCDC (Direct Current to Direct Current) to pre-charge the PFC bus capacitor.

[0054] In addition, the pre-charging of the high-voltage side capacitor usually relies on the reverse pre-charging function of the low-voltage DCDC. Therefore, the DCDC needs to be controlled when pre-charging the capacitor, that is, the voltage of the high-voltage side capacitor is pre-charged to the voltage of the power battery. Moreover, the pre-charging of the PFC bus capacitor relies on the inversion function of the high-voltage DCDC. Only by controlling the high-voltage DCDC can the voltage of the PFC bus capacitor be pre-charged to the target voltage. It can be seen that the relevant technology requires two steps to realize the pre-charging of the capacitor, which will increase the complexity of the pre-charging control.

[0055] In order to solve the above problems, the embodiment of the present disclosure proposes a pre-charging circuit, based on which the relay (K3) can be cut off under abnormal circumstances to achieve a power-off protection function, and on an on-board charger without an inverter function, reverse pre-charging of the PFC bus capacitor can also be achieved, thereby providing pre-charging for a unidirectional on-board charger.

[0056] Figure 1 is a block diagram of a pre-charging circuit according to an exemplary embodiment. Figure 1 As shown, the pre-charging circuit 100 may include a first switch K1, a second switch K2, a PFC circuit 110, a first capacitor C1, a high voltage circuit 120, a second capacitor C2, a high voltage battery pack Bat1, a low voltage circuit 130 and a low voltage battery pack Bat2.

[0057] The first switch K1 may include a first contact point (contact point 1) and a second contact point (contact point 2), the second contact point is connected to the first end of the power supply device, and the second switch K2 may include a third contact point (contact point 3) and a fourth contact point (contact point 4), the fourth contact point may be connected to the second end of the power supply device. Here, the charging device may be a charging gun, which may charge the battery pack through the charging port.

[0058] The first end of the power factor correction PFC circuit 110 may be connected to the first switch K1, and the second end of the PFC circuit 110 may be connected to the second switch K2. The PFC circuit 110 is used to improve the energy efficiency of the on-board charger and the stability of the power grid.

[0059] In addition, the third terminal of the PFC circuit 110 may be connected to the first terminal of the first capacitor C1, and the first capacitor C1 may be a bus capacitor C Bus , where bus capacitance C Bus Used to filter out high-frequency harmonics of input current, smooth output voltage, and protect circuits from sudden voltage changes, etc.

[0060] In some implementations, the high voltage circuit 120 may be a high voltage direct current (HV DC) circuit, and a first end of the high voltage circuit 120 may be connected to the first capacitor C1 and the PFC circuit 120 .

[0061] As can be seen from the above introduction, the pre-charging circuit 100 may further include a second capacitor C2, which may be a high-voltage electrical equipment capacitor C HV , a first end of the second capacitor C2 can be connected to the first contact point (1 contact point) of the first switch K1, and a second end of the second capacitor C2 can be connected to the fourth contact point (4 contact point) of the second switch K2.

[0062] In addition, the high-voltage battery pack Bat1 can be connected to the high-voltage circuit 120 and the second capacitor C2 respectively. Specifically, the first end of the high-voltage battery pack Bat1 can be connected to the first end of the high-voltage circuit 120 and the first end of the second capacitor C2 respectively, and the second end of the high-voltage battery pack Bat1 can be connected to the second end of the high-voltage circuit 120 and the second end of the second capacitor C2 respectively.

[0063] In addition, the high-voltage battery pack Bat1 can also be connected to the low-voltage circuit 130, that is, the third end of the high-voltage battery pack Bat1 can be connected to the low-voltage circuit 130. Here, the low-voltage circuit 130 can be a low voltage direct current (LV DC) circuit, and the first end of the low-voltage circuit 130 can be connected to the high-voltage circuit 120, the second capacitor C2 and the high-voltage battery pack Bat1 respectively, and the second end of the low-voltage circuit 130 can be connected to the low-voltage battery pack Bat2.

[0064] The low voltage battery pack Bat2 is used to pre-charge the first capacitor C1 and the second capacitor C2. The pre-charge current flow direction can be as follows: Figure 2 As shown, based on Figure 2 As we know, the low-voltage battery pack Bat2 can not only HV It can also precharge the PFC bus capacitor C Bus Reverse precharging is performed, and the precharging of the two can be independent of each other. Bus and C1 refer to bus capacitance, C HV and C2 both refer to the capacitors of high-voltage electrical equipment.

[0065] It can be seen that the low-voltage side circuit LV DC (low-voltage circuit 130) in the embodiment of the present disclosure can be connected to the first switch K1, the second switch K2 and the high-voltage electrical equipment capacitor C HV (Second capacitor C2) in parallel, bus capacitor C Bus A first switch K1 and a second switch K2 may be connected in series in the loop from the first capacitor C1 to the mains, so as to connect the capacitor C1 to the high voltage electrical equipment through the first switch K1 and the second switch K2. HV And bus capacitance C Bus Charge.

[0066] In a specific embodiment, Figure 3 The PFC circuit 110 shown may include a first inductor L1, a first switch Q1, a second switch Q2, a third switch Q3 and a fourth switch Q4. The first end of the first inductor L1 may be connected to the first switch K1, and the midpoint of the first bridge arm formed by the first switch tube Q1 and the third switch tube Q3 may be connected to the second end of the first inductor L1.

[0067] In addition, the midpoint of the second bridge arm formed by the second switch tube Q2 and the fourth switch tube Q4 can be connected to the second switch K2, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 can be connected to the first capacitor C1 respectively. Specifically, the first end of the first switch tube Q1 and the second switch tube Q2 can be connected together to form a first bus terminal, and the first bus terminal can be connected to the first end of the first capacitor C1; the second end of the third switch tube Q3 and the fourth switch tube Q4 can be connected together to form a second bus terminal, and the second bus terminal can be connected to the second end of the first capacitor C1.

[0068] Optionally, based on Figure 3 It is known that the high voltage circuit 120 may include a fifth switch tube Q5, a sixth switch tube Q6, a third capacitor C3, a fourth capacitor C4 and a first transformer T1. The fifth switch tube Q5 and the sixth switch tube Q6 are connected to the PFC circuit 110 and the first capacitor C1, respectively, that is, the first end of the fifth switch tube Q5 may be connected to the first end and the first bus terminal of the first capacitor C1, respectively, and the second end of the sixth switch tube Q6 may be connected to the second end and the second bus terminal of the first capacitor C1, respectively. The fifth switch tube Q5 and the sixth switch tube Q6 may form a third bridge arm.

[0069] The third capacitor C3 can be connected to the fifth switch tube Q5, and the fourth capacitor C4 can be connected to the sixth switch tube Q6. Specifically, the first end of the third capacitor C3 can be connected to the first end of the fifth switch tube Q5, and the second end of the fourth capacitor C4 can be connected to the second end of the sixth switch tube Q6. Here, the midpoint of the third capacitor C3 and the fourth capacitor C4 can be connected to the positive end of the primary winding of the first transformer T1, and the third bridge arm composed of the fifth switch tube Q5 and the sixth switch tube Q6 can be connected to the negative end of the primary winding of the first transformer T1.

[0070] In some embodiments, the high voltage circuit 120 may include Figure 3 The unidirectional charging circuit 121 shown may include a first diode D1 , a second diode D2 , a third diode D3 and a fourth diode D4 .

[0071] The anode of the first diode D1 can be connected to the cathode of the third diode D3, the midpoint between the anode of the first diode D1 and the cathode of the third diode D3 can be connected to the positive end of the secondary winding of the first transformer T1, the anode of the second diode D2 can be connected to the cathode of the fourth diode D4, and the midpoint between the anode of the second diode D2 and the cathode of the fourth diode D4 can be connected to the negative end of the secondary winding of the first transformer T1. When the charging circuit included in the high-voltage circuit 120 is unidirectional, the corresponding on-board charger is a unidirectional on-board charger.

[0072] At this time, the current flow direction for precharging the second capacitor C2 can be: low-voltage battery pack Bat2, the primary positive end of the second transformer T2, the twelfth switch tube Q12, the second capacitor C2, the ninth switch tube Q9, and the primary negative end of the second transformer T2. The current flow direction for precharging the first capacitor C1 can be: low-voltage battery pack Bat2, the primary positive end of the second transformer T2, the twelfth switch tube Q12, the first switch K1, the first inductor L1, the first switch tube Q1, the first capacitor C1, the fourth switch tube Q4, the second switch K2, the ninth switch tube Q9, and the primary negative end of the second transformer T2.

[0073] In other embodiments, the high voltage circuit 120 may also include Figure 4 The bidirectional charging circuit 122 shown in the figure may include a fifth capacitor C5, a sixth capacitor C6, a seventh switch tube Q7 and an eighth switch tube Q8. Figure 4 Bat shown HV It can be the high voltage battery pack Bat1, and Bat LV It may be the low voltage battery pack Bat2.

[0074] Among them, the midpoint of the fifth capacitor C5 and the sixth capacitor C6 can be connected to the positive end of the secondary winding of the first transformer T1, the seventh switch tube Q7 and the eighth switch tube Q8 can form a fourth bridge arm, and the midpoint of the fourth bridge arm can be connected to the negative end of the secondary winding of the first transformer T1. The first end of the seventh switch tube Q7 can be connected to the first end of the fifth capacitor C5 and the first end of the second capacitor C2, respectively, and the second end of the eighth switch tube Q8 can be connected to the second end of the sixth capacitor C6 and the second end of the second capacitor C2, respectively. When the charging circuit included in the high-voltage circuit 120 is bidirectional, the corresponding on-board charger is a bidirectional on-board charger.

[0075] At this time, the current flow direction for precharging the first capacitor C1 and the second capacitor C2 can be similar to that of charging a unidirectional on-board charger. In addition, the disclosed embodiment can also realize the precharging of the first capacitor C1 through a switch tube, and the specific current flow direction can be: low-voltage battery pack Bat2, the primary positive end of the second transformer T2, the twelfth switch tube Q12, the fifth capacitor C5, the positive end of the first transformer T1, the third capacitor C3, the first capacitor C1, the sixth switch tube Q6, the negative end of the first transformer T1, the eighth switch tube Q8, the ninth switch tube Q9, and the primary negative end of the second transformer T2.

[0076] In other embodiments, the pre-charging circuit may further include a third switch K3, a first end of the third switch K3 may be connected to the high voltage circuit 120, the second capacitor C2 and the low voltage circuit 130 respectively, and a second end of the third switch K3 may be connected to the high voltage battery pack Bat1. Here, the low voltage circuit 130 may include a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a twelfth switch tube Q12, a second transformer T2, a thirteenth switch tube Q13 and a fourteenth switch tube Q14.

[0077] Specifically, the ninth switch tube Q9 and the eleventh switch tube Q11 can form a fifth bridge arm, the midpoint of the fifth bridge arm can be connected to the negative end of the primary winding of the second transformer T2, and the tenth switch tube Q10 and the twelfth switch tube Q12 can form a sixth bridge arm, the midpoint of the sixth bridge arm can be connected to the positive end of the primary winding of the second transformer T2.

[0078] In addition, the ninth switch tube Q9 and the tenth switch tube Q10 can be connected to the high-voltage battery pack Bat1 respectively, where the first ends of the ninth switch tube Q9 and the tenth switch Q10 are connected together to form a third bus terminal, which can be connected to the negative electrode of the high-voltage battery pack Bat1. The eleventh switch tube Q11 and the twelfth switch tube Q12 can be connected to the third switch K3 respectively, that is, the second ends of the eleventh switch tube Q11 and the twelfth switch tube Q12 are connected together to form a fourth bus terminal, which can be connected to the third switch K3, the seventh switch tube Q7 and the fifth capacitor C5.

[0079] In addition, the first end of the thirteenth switch tube Q13 can be connected to the positive end of the secondary winding of the second transformer T2, and the second end of the thirteenth switch tube Q13 and the second end of the fourteenth switch tube Q14 can be connected to the low-voltage battery pack Bat2 respectively. Here, the second end of the thirteenth switch tube Q13 and the second end of the fourteenth switch tube Q14 can be connected together to form a fifth bus terminal, which can be connected to the low-voltage battery pack Bat2. The first end of the fourteenth switch tube Q14 can be connected to the negative end of the secondary winding of the second transformer T2.

[0080] Optionally, the low-voltage circuit 130 may further include a second inductor L2 and a seventh capacitor C7, wherein the first end of the second inductor L2 may be connected to the first end of the seventh capacitor C7 and the positive electrode of the low-voltage battery pack Bat2, respectively, and the second end of the second inductor L2 may be connected to the center tap of the secondary winding of the second transformer T2. The first end of the seventh capacitor C7 may be connected to the first end of the second inductor L2 and the positive electrode of the low-voltage battery pack Bat2, respectively, and the second end of the seventh capacitor C7 may be connected to the fifth bus terminal and the negative electrode of the low-voltage battery pack Bat2, respectively. Here, the seventh capacitor C7 may be a low-voltage electrical equipment capacitor C LV .

[0081] In addition, the pre-charging single channel can also include an EMI (Electromagnetic Interference) device, a first end of the electromagnetic interference device can be connected to the positive pole of the charging port, a second end of the electromagnetic interference device can be connected to the negative pole of the charging port, a third end of the electromagnetic interference device can be connected to the second contact point of the first switch K1, and a fourth end of the electromagnetic interference device can be connected to the third contact point of the second switch K2.

[0082] In the embodiment of the present disclosure, the pre-charging circuit 100 can be configured to: control the first switch K1 to connect to the first contact point, and control the second switch to connect to the fourth contact point, so that the first switch K1 and the second switch K2 are connected to the DC side. On this basis, the pre-charging circuit 100 can control the low-voltage circuit 130 to charge the first capacitor C1 and the second capacitor C2.

[0083] Specifically, when charging the high-voltage battery pack Bat1, the embodiment of the present disclosure can charge the first capacitor C1 and the second capacitor through the pre-charging circuit 100. In this process, the first switch K1 and the second switch K2 are controlled to connect to the DC side to charge the high-voltage electrical equipment capacitor C1 through the low-voltage circuit 130. HV (C2) and bus capacitor C Bus (C1) Charging and judging whether the charging is successful. The specific judgment process can be as follows: Figure 5 shown.

[0084] In other words, during the process of the pre-charging circuit 100 controlling the low voltage circuit 130 to charge the first capacitor C1 and the second capacitor C2, it can be configured to: determine the bus capacitor C Bus (C1) or high voltage electrical equipment capacitor C HV (C2) Whether the charging is successful, if the bus capacitance C Bus If the charging is successful, it means that the bus capacitor pre-charging is completed. HV (C2) If charging is successful, the third switch K3 can be controlled to close through the BMS (Battery Management System), that is, the main positive contactor is closed. At this time, the OBC can start working, that is, charging the high-voltage battery pack through the charging gun.

[0085] As a specific implementation method, when determining the bus capacitance C Bus (C1) During the process of whether charging is successful, the embodiment of the present disclosure can determine the bus capacitance C Bus (C1) Whether the voltage satisfies the first preset condition, wherein the first preset condition may include condition 11 and condition 12. Condition 11 may be the bus capacitance C BusWhether the difference between the (C1) voltage and the peak voltage of the mains voltage is less than a first difference threshold range, where the first difference threshold may be 15-30V.

[0086] If it is determined that condition 11 is satisfied, it means that the bus capacitor pre-charge is completed, that is, the first capacitor C1 is pre-charged. On the contrary, if condition 11 is not satisfied, condition 12 is triggered, where condition 12 can be the bus capacitor C Bus Whether the charging time of (C1) has not reached the first upper limit time threshold (preset duration), if it has not reached the first upper limit time threshold, the bus capacitor can continue to be pre-charged. On the contrary, if it reaches the first upper limit time threshold, the pre-charge timeout can be reported, indicating that the high voltage of the whole vehicle has failed.

[0087] In addition, when determining the capacitance C of high-voltage electrical equipment HV (C2) During the process of whether charging is successful, the embodiment of the present disclosure can determine the capacitance C of the high-voltage electrical equipment. HV (C2) Whether the second preset condition is met, wherein the second preset condition may include condition 21, condition 22 and condition 23. Among them, condition 21 may be the capacitance C of the high-voltage electrical equipment. HV Whether the voltage of (C2) is greater than the power battery voltage and greater than a first lower limit threshold, the first lower limit threshold may be 10-20V.

[0088] If condition 21 is met, condition 22 may be triggered, wherein condition 22 may be the capacitance C of the high-voltage electrical equipment. HV The voltage of (C2) is less than the power battery voltage and less than the second upper limit threshold, which can be 40~50V. When condition 22 is met, the third switch K3 can be closed, so that the OBC starts to work, that is, the on-board charger circuit works forward to use the external AC power supply device AC to power the power battery Bat on the vehicle. HV Charging; when condition 22 is not met, the embodiment of the present disclosure can start the low-voltage circuit 130 to reduce the voltage, that is, start the forward operation of the low-voltage circuit 130, and continue to judge conditions 21 and 23. At this time, the current flow direction can be: the second capacitor C2, the twelfth switch tube Q12, the primary positive terminal of the second transformer T2, the low-voltage battery pack Bat2, the primary negative terminal of the second transformer T2, the ninth switch tube Q9, and the second capacitor C2.

[0089] On the contrary, if condition 21 is not met, condition 23 may be triggered, and condition 23 may be the high-voltage electrical equipment capacitor C HV The charging time of the high-voltage electrical equipment is determined to determine whether the charging time has not reached a second upper limit time threshold, which may be 7 to 10 seconds. If the second upper limit time threshold has not been reached, the high-voltage electrical equipment capacitor is continued to be pre-charged.

[0090] Here, the first upper time threshold and the second upper time threshold may be the same or different. When they are different, illustratively, the first upper time threshold may be smaller than the second upper time threshold.

[0091] In addition, if Figure 5 As shown, before the first switch K1 and the second switch K2 are located at the first contact point and the fourth contact point, the embodiment of the present disclosure can first detect whether a charging gun is inserted into the charging port, and if a charging gun is detected to be inserted, the embodiment of the present disclosure is awakened. On this basis, the OBC self-test operation is performed, and the first switch K1 and the second switch K2 are located at the first contact point and the fourth contact point if the self-test is normal.

[0092] It should be noted that, in the embodiment of the present disclosure, the pre-charging of the first capacitor C1 and the pre-charging of the second capacitor C2 can be performed simultaneously, or the first capacitor C1 can be pre-charged first and then the second capacitor C2, or the second capacitor C2 can be pre-charged first and then the first capacitor C1. The embodiment of the present disclosure does not clearly limit which capacitor is pre-charged first and which is pre-charged later, and can be selected according to actual conditions.

[0093] In summary, the embodiment of the present disclosure can simplify the pre-charging process by directly pre-charging the PFC bus capacitor, and the control complexity is small and easy to implement. In addition, the pre-charging circuit 100 can support bidirectional charging topology and unidirectional charging topology, that is, pre-charging can be achieved by adding only one relay (K3) and two wires, which can reduce the volume and cost of pre-charging to a certain extent.

[0094] It should also be noted that the control of the above charging process can be achieved by a pre-charging circuit or by an on-board charger.

[0095] In the embodiment of the present disclosure, the pre-charging circuit may include a first switch K1, a second switch K2, a PFC circuit, a first capacitor C1, a high-voltage circuit, a second capacitor C2, a high-voltage battery pack Bat1, a low-voltage circuit and a low-voltage battery pack Bat2, wherein the first switch K1 includes a first contact point and a second contact point, the second contact point is connected to the first end of the power supply device, the second switch K2 includes a third contact point and a fourth contact point, the fourth contact point is connected to the second end of the power supply device, the first end of the PFC circuit is connected to the first switch K1, the second end of the PFC circuit is connected to the second switch K2, the first end of the first capacitor C1 is connected to the third end of the PFC circuit The first end of the high-voltage circuit is respectively connected to the first capacitor C1 and the PFC circuit, the first end of the second capacitor C2 is connected to the first contact point, the second end of the second capacitor C2 is connected to the fourth contact point, the first end of the high-voltage battery pack Bat1 is respectively connected to the high-voltage circuit and the second capacitor C2, the second end of the high-voltage battery pack Bat1 is connected to the high-voltage circuit, the first end of the low-voltage circuit is respectively connected to the high-voltage circuit, the second capacitor C2 and the high-voltage battery pack Bat1, and the second end of the low-voltage circuit is connected to the low-voltage battery pack Bat2. Based on the pre-charging circuit, the embodiment of the present disclosure can directly pre-charge the PFC bus capacitor, thereby simplifying the pre-charging process.

[0096] Figure 6 1 is a block diagram of an on-board charger according to an exemplary embodiment. The on-board charger 600 is provided with the pre-charging circuit 100 shown in the embodiment of the present disclosure.

[0097] Figure 7 is a block diagram of a vehicle according to an exemplary embodiment. The vehicle 700 is provided with the on-board charger 600 shown in the embodiment of the present disclosure.

[0098] It should be noted that the word "exemplary" is used in this article to represent serving as an example, instance, or diagram. Any aspect or design described as "exemplary" in this article is not necessarily understood to be advantageous compared to other aspects or designs. On the contrary, the use of the word exemplary is intended to present concepts in a specific way. As used in this article, the term "or" is intended to represent an inclusive "or" rather than an exclusive "or". That is, unless otherwise specified or clear from the context, "X applies A or B" is intended to represent any one of the natural inclusive arrangements. That is, if X applies A; X applies B; or X applies both A and B, "X applies A or B" is satisfied under any of the aforementioned examples. In addition, unless otherwise specified or clearly pointed to a singular form from the context, the articles "one" and "an" as used in this application and the appended claims are generally understood to mean "one or more".

[0099] Although terms such as "first", "second" and "third" can be used herein to describe various components, parts, regions, layers or sections, these components, parts, regions, layers or sections are not limited to these terms. On the contrary, these terms are only used to distinguish one component, component, region, layer or section from another component, component, region, layer or section. Therefore, without departing from the teachings of each example, the first component, component, region, layer or section mentioned in the examples described herein may also be referred to as the second component, component, region, layer or section. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may expressly or implicitly include at least one of the features. In the description herein, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0100] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0101] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0102] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A precharge circuit, characterized in that: The pre-charge circuit comprises: A first switch K1, wherein the first switch K1 comprises a first contact point and a second contact point, wherein the second contact point is connected to a first end of a power supply device; A second switch K2, wherein the second switch K2 comprises a third contact point and a fourth contact point, and the third contact point is connected to the second end of the power supply device; A power factor correction PFC circuit, wherein a first end of the PFC circuit is connected to a common point of the first switch K1, and a second end of the PFC circuit is connected to a common point of the second switch K2; a first capacitor C1, wherein a first end of the first capacitor C1 is connected to a third end of the PFC circuit, and a second end of the first capacitor C1 is connected to a fourth end of the PFC circuit; a high-voltage circuit, wherein a first end of the high-voltage circuit is respectively connected in parallel with the first capacitor C1 and the PFC circuit; a second capacitor C2, wherein a first end of the second capacitor C2 is connected to the first contact point, and a second end of the second capacitor C2 is connected to the fourth contact point; A high-voltage battery pack Bat1, wherein the high-voltage battery pack Bat1 is connected in parallel with the high-voltage circuit and the second capacitor C2 respectively; A low voltage circuit, wherein a first end of the low voltage circuit is respectively connected to the high voltage circuit, the second capacitor C2 and the high voltage battery pack Bat1, and a second end of the low voltage circuit is connected to the low voltage battery pack Bat2.

2. precharge circuit according to claim 1, characterized in that, The PFC circuit comprises: a first inductor L1, wherein a first end of the first inductor L1 is connected to a common point of the first switch K1; A first switch tube Q1 and a third switch tube Q3, wherein a midpoint of a first bridge arm formed by the first switch tube Q1 and the third switch tube Q3 is connected to the second end of the first inductor L1; The second switch tube Q2 and the fourth switch tube Q4, the midpoint of the second bridge arm formed by the second switch tube Q2 and the fourth switch tube Q4 is connected to the common point of the second switch K2, and the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 are respectively connected to the first capacitor C1.

3. precharge circuit according to claim 1, is characterized in that, The high voltage circuit comprises: a fifth switch tube Q5 and a sixth switch tube Q6, wherein the fifth switch tube Q5 and the sixth switch tube Q6 are connected to the PFC circuit and the first capacitor C1 respectively, and the fifth switch tube Q5 and the sixth switch tube Q6 form a third bridge arm; A third capacitor C3 and a fourth capacitor C4, wherein the third capacitor C3 is connected to the fifth switch tube Q5, and the fourth capacitor C4 is connected to the sixth switch tube Q6; The first transformer T1, the positive end of the primary winding of the first transformer T1 is connected to the midpoint of the third capacitor C3 and the fourth capacitor C4, and the negative end of the primary winding of the first transformer T1 is connected to the midpoint of the third bridge arm.

4. precharge circuit according to claim 3, it is characterized in that, The high voltage circuit further comprises: A unidirectional charging circuit, the unidirectional charging circuit comprising a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4, the anode of the first diode D1 is connected to the cathode of the third diode D3, the midpoint between the anode of the first diode D1 and the cathode of the third diode D3 is connected to the positive end of the secondary winding of the first transformer T1, the cathode of the first diode D1 is connected to the cathode of the second diode D2, the cathode of the first diode D1 and the cathode of the second diode D2 are respectively connected to the first end of the second capacitor C2, the anode of the second diode D2 is connected to the cathode of the fourth diode D4, the midpoint between the anode of the second diode D2 and the cathode of the fourth diode D4 is connected to the negative end of the secondary winding of the first transformer T1, the anode of the third diode D3 is connected to the anode of the fourth diode D4, and the anode of the third diode D3 and the anode of the fourth diode D4 are respectively connected to the second end of the second capacitor C2.

5. precharge circuit according to claim 3, it is characterized in that, The high voltage circuit further comprises: A bidirectional charging circuit, the bidirectional charging circuit comprising a fifth capacitor C5, a sixth capacitor C6, a seventh switch tube Q7 and an eighth switch tube Q8, the midpoint of the fifth capacitor C5 and the sixth capacitor C6 being connected to the positive end of the secondary winding of the first transformer T1, the midpoint of a fourth bridge arm formed by the seventh switch tube Q7 and the eighth switch tube Q8 being connected to the negative end of the secondary winding of the first transformer T1, the seventh switch tube Q7 being respectively connected to the first ends of the fifth capacitor C5 and the second capacitor C2, and the eighth switch tube Q8 being respectively connected to the second ends of the sixth capacitor C6 and the second capacitor C2.

6. precharge circuit according to claim 1, characterized in that, The pre-charge circuit also includes: A third switch K3, wherein a first end of the third switch K3 is respectively connected to the high voltage circuit, the second capacitor C2 and the low voltage circuit, and a second end of the third switch K3 is connected to the high voltage battery pack Bat1.

7. precharge circuit according to claim 6, characterized in that, The low voltage circuit includes a ninth switch tube Q9, a tenth switch tube Q10, an eleventh switch tube Q11, a twelfth switch tube Q12, a second transformer T2, a thirteenth switch tube Q13 and a fourteenth switch tube Q14; The midpoint of the fifth bridge arm composed of the ninth switch tube Q9 and the eleventh switch tube Q11 is connected to the negative end of the primary winding of the second transformer T2, the midpoint of the sixth bridge arm composed of the tenth switch tube Q10 and the twelfth switch tube Q12 is connected to the positive end of the primary winding of the second transformer T2, the ninth switch tube Q9 and the tenth switch tube Q10 are respectively connected to the high-voltage battery pack Bat1, and the eleventh switch tube Q11 and the twelfth switch tube Q12 are respectively connected to the third switch K3; The first end of the thirteenth switch tube Q13 is connected to the positive end of the secondary winding of the second transformer T2, the first end of the fourteenth switch tube Q14 is connected to the negative end of the secondary winding of the second transformer T2, and the second end of the thirteenth switch tube Q13 and the second end of the fourteenth switch tube Q14 are respectively connected to the low-voltage battery group Bat2.

8. precharge circuit according to claim 7, it is characterized in that, The low voltage circuit also includes: A second inductor L2, wherein a first end of the second inductor L2 is connected to the positive electrode of the low-voltage battery pack Bat2, and a second end of the second inductor L2 is connected to the center tap of the secondary winding of the second transformer T2; The seventh capacitor C7, the first end of the seventh capacitor C7 is respectively connected to the first end of the second inductor L2 and the positive electrode of the low-voltage battery pack Bat2, and the second end of the seventh capacitor C7 is respectively connected to the negative electrode of the low-voltage battery pack Bat2, the second end of the thirteenth switch tube Q13 and the second end of the fourteenth switch tube Q14.

9. according to any one of claims 1 to 7, it is characterized in that, The pre-charging circuit is configured as follows: Controlling the first switch K1 to connect the first contact point, and controlling the second switch K2 to connect the fourth contact point, so that the first switch K1 and the second switch K2 are connected to the DC side; The low voltage circuit is controlled to charge the first capacitor C1 and the second capacitor C2.

10. A vehicle charger, characterized in that: The invention comprises a pre-charging circuit as claimed in any one of claims 1 to 9.

11. A vehicle, characterized in that: It includes the on-board charger as claimed in claim 10.

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