Battery charging circuit, equipment and vehicle

Abstract

The utility model discloses a battery charging circuit, battery charging equipment and a vehicle, and relates to the technical field of electric driving systems. The battery module is connected with the charging module through the direct charging unit, the battery module, the electric driving module, the boosting unit and the charging module are sequentially connected, and the charging module is connected with charging equipment; the high-low voltage switching module has a first state and a second state; in the first state, the direct charging unit charges the battery module through charging voltage of charging equipment accessed by the charging module; and in the second state, the boost unit charges the battery module after boosting the charging voltage accessed by the charging module under the driving of the electric drive module. On the premise that the integrity of the battery is not damaged, flexible switching of high-voltage charging and low-voltage charging is achieved so as to improve the reliability of the battery.

Description

Technical Field

[0001] The utility model relates to the technical field of electric drive systems, and in particular to a battery charging circuit, equipment and a vehicle. Background Art

[0002] With the rapid development of new energy vehicles, the voltage of power batteries continues to increase to meet the demand for efficient charging. However, there are still a large number of low-voltage charging piles on the market that cannot directly adapt to high-voltage batteries, which brings challenges to the charging of new energy vehicles.

[0003] At present, a common battery charging solution is to control the series and parallel connection of high-voltage power batteries constructed by multiple low-voltage power batteries through relays to meet the charging requirements of different voltages. Specifically, when high-voltage power supply is required, all low-voltage power batteries are controlled by relays to be connected in series to increase the voltage; when only the voltage provided by the low-voltage charging pile is required, all power batteries are also required to be controlled by relays to be connected in parallel to match the voltage of the low-voltage charging pile. However, this battery charging solution has certain defects. Since the existing battery charging solution needs to separate the entire high-voltage power battery into multiple low-voltage power batteries, the integrity of the high-voltage power battery is destroyed, thereby reducing the reliability of battery power supply.

[0004] Therefore, how to achieve flexible switching between high and low voltage charging to improve battery reliability without destroying the integrity of the battery is a technical problem that needs to be solved urgently. Utility Model Content

[0005] The main purpose of the utility model is to provide a battery charging circuit, a device and a vehicle, aiming to achieve flexible switching between high and low voltage charging to improve battery reliability without destroying the integrity of the battery.

[0006] To achieve the above object, the utility model provides a battery charging circuit, the battery charging circuit includes a battery module, an electric drive module, a high-low voltage switching module and a charging module, the high-low voltage switching module includes a direct charging unit and a boost unit;

[0007] The battery module is connected to the charging module through the direct charging unit, the battery module, the electric drive module, the boost unit and the charging module are connected in sequence, and the charging module is connected to a charging device;

[0008] The high and low voltage switching module has a first state and a second state;

[0009] In the first state, the direct charging unit charges the battery module by connecting the charging module to the charging voltage of the charging device;

[0010] In the second state, the boost unit charges the battery module after boosting the charging voltage connected to the charging module under the drive of the electric drive module.

[0011] In one embodiment, the boost unit includes a first contactor, a second contactor, a third contactor, a fourth contactor, an inductor, a first capacitor, and a filter circuit;

[0012] The first end of the electric drive module is connected to the movable end of the first contactor, the fixed end of the first contactor is connected to the first end of the inductor, the second end of the inductor is respectively connected to the first end of the first capacitor and the first end of the filter circuit, the second end of the first capacitor is respectively connected to the fixed end of the third contactor and the second end of the filter circuit, and the movable end of the third contactor is connected to the second end of the electric drive module;

[0013] The first end of the filter circuit is connected to the active end of the second contactor, the fixed end of the second contactor is connected to the positive output end of the charging module, the second end of the filter circuit is respectively connected to the second end of the first capacitor and the active end of the fourth contactor, and the fixed end of the fourth contactor is connected to the negative output end of the charging module.

[0014] In one embodiment, the filter circuit includes a second capacitor and a third capacitor;

[0015] The first end of the second capacitor is the first end of the filter circuit, and is respectively connected to the second end of the inductor and the active end of the second contactor;

[0016] The second end of the second capacitor is connected to the first end of the third capacitor and then grounded;

[0017] The second end of the third capacitor is the second end of the filter circuit, and is respectively connected to the second end of the first capacitor and the active end of the third contactor.

[0018] In one embodiment, the direct charging unit includes a fifth contactor and a sixth contactor;

[0019] The active end of the fifth contactor is connected to the positive input end of the battery module, and the active end of the sixth contactor is connected to the negative input end of the battery module;

[0020] The fixed end of the fifth contactor is connected to the positive output end of the charging module, and the fixed end of the sixth contactor is connected to the negative output end of the charging module.

[0021] In one embodiment, the electric drive module includes M-phase motor windings, bridge arm units paired with the motor windings of each phase, a fourth capacitor, a fifth capacitor, and a sixth capacitor;

[0022] The first end of each phase of the motor winding is connected to the midpoint of the bridge arm of the paired bridge arm unit, the second end of each phase of the motor winding is connected to each other, the first end of the fourth capacitor is connected to the first side of each bridge arm unit, and the second end of the fourth capacitor is connected to the second side of each bridge arm unit;

[0023] The first end of the fifth capacitor is connected to the first end of the fourth capacitor and the positive contact end of the battery module, and the second end of the fifth capacitor is connected to the first end of the sixth capacitor and then grounded;

[0024] The second end of the motor winding of each phase is the first end of the electric drive module, and is connected to the boost unit;

[0025] The second end of the sixth capacitor is the second end of the electric drive module, and is respectively connected to the second end of the fourth capacitor, the boost unit, and the negative contact end of the battery module.

[0026] In one embodiment, the bridge arm unit includes an upper bridge arm and a lower bridge arm, the upper bridge arm is connected to the lower bridge arm, and the connection intersection of the upper bridge arm and the lower bridge arm constitutes the bridge arm midpoint of the bridge arm unit.

[0027] In one embodiment, the battery module includes a power battery, a seventh contactor, an eighth contactor, a ninth contactor, and a buffer resistor;

[0028] The positive electrode of the power battery is connected to the active end of the seventh contactor and the active end of the ninth contactor respectively, and the negative electrode of the power battery is connected to the active end of the eighth contactor;

[0029] The ninth contactor is connected in series with the buffer resistor and then connected to the fixed end of the seventh contactor;

[0030] The positive electrode of the power battery is the positive input terminal of the battery module, and the negative electrode of the power battery is the negative input terminal of the battery module, which are respectively connected to the direct charging unit;

[0031] The fixed end of the seventh contactor is the positive contact end of the battery module, and the negative contact end of the eighth contactor is the negative contact end of the battery module, which are respectively connected to the electric drive module.

[0032] In one embodiment, the charging module includes a tenth contactor and an eleventh contactor;

[0033] The fixed end of the tenth contactor is connected to the positive electrode of the charging device, and the fixed end of the eleventh contactor is connected to the negative electrode of the charging device;

[0034] The active end of the tenth contactor is the positive output end of the charging module, and is connected to the direct charging unit and the boost unit respectively;

[0035] The active end of the eleventh contactor is the negative output end of the charging module, and is connected to the direct charging unit and the boost unit respectively.

[0036] In addition, to achieve the above-mentioned purpose, the present application also provides a battery charging device, which at least includes the battery charging circuit described in any one of the above items.

[0037] In addition, to achieve the above objectives, the present application also provides a vehicle, which at least includes any one of the battery charging circuits described above, or the battery charging device described above.

[0038] The high-low voltage switching module provided in the utility model has a first state when the charging device is a high-voltage charging pile, and a second state when the charging device is a low-voltage charging pile, that is, the high-low voltage switching module provided in the present application can be compatible with the charging of the battery module by the high-voltage charging pile and the low-voltage charging pile without destroying the integrity of the battery. Specifically, after the high-low voltage switching module automatically switches to the first state when the high-voltage charging pile is charged, it can automatically enable the direct charging unit to immediately access the charging voltage of the charging device to charge the battery module based on the connection between the battery module and the charging module through the direct charging unit without destroying the integrity of the battery; in addition, after the high-low voltage switching module provided in the present application automatically switches to the second state when the low-voltage charging pile is charged, it can automatically enable the direct charging unit to immediately access the charging voltage of the charging device to charge the battery module based on the connection between the battery module, the electric drive module, the boost unit and the charging module in sequence without destroying the integrity of the battery, so that the boost unit can charge the battery module after boosting the charging voltage connected to the charging module under the drive of the electric drive module, which not only realizes the flexible switching of high and low voltage charging, but also effectively avoids the risk of poor battery reliability caused by the relay added to the series-parallel power battery in the prior art, and significantly improves the battery reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0040] Figure 1A schematic diagram of a prior art circuit related to a battery charging circuit provided in this application;

[0041] Figure 2 A circuit diagram of an embodiment of a battery charging circuit provided in the present application;

[0042] Figure 3 A circuit diagram related to another embodiment of the battery charging circuit provided by the present application;

[0043] Figure 4 A circuit diagram of another embodiment of a battery charging circuit provided in the present application;

[0044] Figure 5 A schematic diagram of a filter circuit involved in an embodiment of the present application;

[0045] Figure 6 This is another schematic diagram of a filter circuit involved in an embodiment of the present application;

[0046] Figure 7 This is another schematic diagram of a filter circuit involved in the embodiment of the present application.

[0047] Description of Figure Numbers:

[0048] 100, battery charging circuit; 10, battery module; 20, electric drive module; 30, high and low voltage switching module; 40, charging module; 301, direct charging unit; 302, boost unit; U2, charging equipment; S1, first contactor; S2, second contactor; S3, third contactor; S4, fourth contactor; S5, fifth contactor; S6, sixth contactor; L1, inductor; C1, first capacitor; C2, second capacitor; C3, third capacitor; C4, fourth capacitor; C5, fifth capacitor; C6, sixth capacitor; C7, seventh capacitor; FC1, filter circuit; X1, differential mode capacitor; L3, common mode inductor; L2, motor winding; 21, bridge arm unit; Q1, switch tube; U1, power battery; S7, seventh contactor; S8, eighth contactor; S9, ninth contactor; R1, buffer resistor; S10, tenth contactor; S11, eleventh contactor.

[0049] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0051] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0052] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the utility model, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0053] With the rapid development of new energy vehicles, high voltage has become an inevitable trend, and the voltage of power batteries has increased to 880V or even higher. However, some charging piles on the market are still low-voltage piles that can only support a maximum charging voltage of 500V. This requires the vehicle to be equipped with a boost charging device to increase the voltage of the low-voltage pile to a high voltage to charge the battery.

[0054] Reference Figure 1 , Figure 1 This is a schematic diagram of the prior art circuit involved in the battery charging circuit provided in this application. Power battery 1 and power battery 2 are 400V battery systems. When powering the electrical equipment, relays K1, K2 and K5 are closed, relays K3 and K4 are disconnected, power battery 1 and power battery 2 are connected in series through relay K2, and the composed power battery 3 is a high-voltage 800V battery system.

[0055] When the charging device charges the battery, if the charging device is a low-voltage 500V series charging pile, the relays K1, K2, K4 and K5 are closed, the relay K3 is disconnected, the power battery 1 and the power battery 2 are connected in parallel, and the power battery 3 formed is still a low-voltage 400V battery system, and the low-voltage 500V series charging pile can directly charge the power battery 3. If the charging device is a high-voltage 800V series charging pile, the relays K1, K2 and K5 are closed, the relays K3 and K4 are disconnected, the power battery 1 and the power battery 2 are connected in series through the relay K2, and the power battery 3 formed is a high-voltage 800V battery system, and the high-voltage 800V series charging pile charges the power battery 3.

[0056] This solution requires the high-voltage 800V battery to be separated into two 400V batteries, which destroys the integrity of the battery and does not conform to the overall route planning of the battery supplier, who has a weak willingness to act. In addition, relays K2, K3 and K4 are added to the original battery system, which reduces the reliability of the battery.

[0057] In view of the above defects, the present invention proposes a battery charging circuit, a device and a vehicle. In addition, the connection relationship of the battery charging circuit provided in the present application includes but is not limited to electrical connection or wireless signal connection.

[0058] The utility model provides a battery charging circuit 100, referring to Figure 2 , Figure 2 A circuit diagram of an embodiment of a battery charging circuit provided in the present application. The battery charging circuit 100 includes a battery module 10, an electric drive module 20, a high-low voltage switching module 30 and a charging module 40. The high-low voltage switching module 30 includes a direct charging unit 301 and a boost unit 302. The charging module 40 is connected to a charging device U2.

[0059] The battery module 10 is connected to the charging module 200 through the direct charging unit 301, the battery module 10, the electric drive module 20, the boost unit 302 and the charging module 40 are connected in sequence, and the charging module 40 is connected to the charging device U2;

[0060] The high and low voltage switching module 30 has a first state and a second state;

[0061] In the first state, the direct charging unit 301 charges the battery module 10 by connecting the charging voltage of the charging device U2 to the charging module 40;

[0062] In the second state, the boost unit 302 charges the battery module 10 after boosting the charging voltage connected to the charging module 200 under the drive of the electric drive module 20 .

[0063] In this embodiment, refer to Figure 2 The battery module 10, electric drive module 20 and charging module 40 used in this application are all reused original electrical components of new energy vehicles. Under the premise of not destroying the battery integrity of the battery module 10, this application can achieve the purpose of compatible high and low voltage charging pile charging by only adding a high and low voltage switching module 30 composed of a direct charging unit 301 and a boost unit 302. It not only effectively saves the cost and volume of the whole vehicle, but also cleverly avoids the problem of reduced battery reliability caused by adding multiple relays to control the series and parallel connection of power batteries in the prior art. That is, the high and low voltage switching module 30 set in this application avoids the battery performance loss or safety hazards that may be caused by the complex relay control mechanism, ensures the battery integrity of the battery module 10, and then effectively improves the battery reliability of the battery module 10.

[0064] It should be noted that the first state refers to the state where the charging device U2 is a high-voltage charging pile; the second state refers to the state where the charging device U2 is a low-voltage charging pile.

[0065] Exemplarily, when the charging device U2 is a high-voltage charging pile, the high-low voltage switching module 30 provided in the present application can intelligently enable the direct charging unit 301, so that the charging module 40 is directly connected to the charging voltage of the high-voltage charging pile, thereby providing efficient charging services for the battery module 10. When the charging device U2 is a low-voltage charging pile, the high-low voltage switching module 30 will activate the boost unit 302 under the drive of the electric drive module 20. At this time, the boost unit 302 can not only use the voltage released by the motor windings of each phase in the electric drive module 20, but also combine the voltage released by its own inductance L1, and superimpose it on the charging voltage connected to the charging module 40 to achieve the voltage boosting function, so that under the premise of ensuring the integrity of the battery, it can also connect to the low-voltage charging pile to provide a stable and effective charging voltage for the battery module 10.

[0066] In summary, the utility model realizes the switching of high and low voltage charging without destroying the integrity of the battery, based on the battery module 10 connected to the charging module 40 through the direct charging unit 301 in the high and low voltage switching module 30, and the battery charging circuit constructed by the battery module 10, the electric drive module 20, the boost unit 302 in the high and low voltage switching module 30 and the charging module 40 connected in sequence. Specifically, when the charging device U2 is a high-voltage charging pile, the high and low voltage switching module 30 enables the direct charging unit 301 to charge the battery module 10 through the charging voltage of the charging device U2 connected to the charging module 40; and when the charging device U2 is a low-voltage charging pile, the high and low voltage switching module 30 can also enable the boost unit 302 to boost the charging voltage connected to the charging module 40 under the drive of the electric drive module 20, and then charge the battery module 10. That is, the high-low voltage switching module 30 provided in the battery charging circuit 100 of the present application can automatically select the direct charging mode or the boost charging mode according to the voltage type of the charging pile without destroying the integrity of the battery so as to realize flexible switching of high and low voltage charging, thereby avoiding the phenomenon that the existing battery charging solution needs to destroy the integrity of the battery due to the need to be compatible with high and low voltage charging piles, thereby effectively improving the battery reliability.

[0067] Further, in some feasible embodiments, referring to Figure 3 , Figure 3 A circuit diagram of another embodiment of the battery charging circuit provided in the present application. The boost unit 302 includes a first contactor S1, a second contactor S2, a third contactor S3, a fourth contactor S4, an inductor L1, a first capacitor C1 and a filter circuit FC1;

[0068] The first end of the electric drive module 20 is connected to the movable end of the first contactor S1, the fixed end of the first contactor S1 is connected to the first end of the inductor L1, the second end of the inductor L1 is respectively connected to the first end of the first capacitor C1 and the first end of the filter circuit FC1, the second end of the first capacitor C1 is respectively connected to the fixed end of the third contactor S3 and the second end of the filter circuit FC1, and the movable end of the third contactor S3 is connected to the second end of the electric drive module 20;

[0069] The first end of the filter circuit FC1 is connected to the active end of the second contactor S2, the fixed end of the second contactor S2 is connected to the positive output end of the charging module 40, the second end of the filter circuit FC1 is respectively connected to the second end of the first capacitor C1 and the active end of the fourth contactor S4, and the fixed end of the fourth contactor S4 is connected to the negative output end of the charging module 40.

[0070] In this embodiment, refer to Figure 3When the electric drive module 20 works in the driving mode, that is, when the charging module 40 is not connected to the charging device U2, the electrical isolation between the charging module 40 and the battery module 10 is ensured by disconnecting the first contactor S1, the second contactor S2, the third contactor S3 and the fourth contactor S4, thereby effectively avoiding unnecessary power loss in the driving mode and improving the energy efficiency of the whole vehicle. When the electric drive system works in the auxiliary boost mode, the charging module 40, the boost unit 302, the electric drive module 20 and the battery module 10 are connected in sequence by closing the first contactor S1, the second contactor S2, the third contactor S3 and the fourth contactor S4. At this time, the charging device U2 connected to the charging module 40 can charge the battery module 10 after the boost unit 302 is driven by the electric drive module 20 to boost the voltage. That is, this application is implemented as follows Figure 3 The circuit structure shown not only makes full use of the existing electrical components of the vehicle and reduces the cost of the entire vehicle, but also through the use of the boost unit 302, enables the low-voltage charging pile to provide sufficient charging voltage for the battery module 10 without destroying the integrity of the battery, thereby effectively improving the reliability of the battery module 10.

[0071] It should be noted that the auxiliary boost mode can be understood as a mode in which the charging device U2 connected to the charging module 40 is a low-voltage charging pile. The first capacitor C1 can be understood as a filter capacitor, which is used to filter the low-frequency AC signal in the battery charging circuit, so that the ripple voltage of the charging module 40 and the charging device U2 is reduced. The first contactor S1, the second contactor S2, the third contactor S3 and the fourth contactor S4 are all relays, and the first to fourth contactors S1~S4 are used for auxiliary boost in the battery charging circuit, that is, the first to fourth contactors S1~S4 set in this application can be regarded as auxiliary boost contactors.

[0072] Further, in some other feasible embodiments, referring to Figure 4 , Figure 4 A circuit diagram of another embodiment of the battery charging circuit provided in the present application. The filter circuit FC1 includes a second capacitor C2 and a third capacitor C3;

[0073] The first end of the second capacitor C2 is the first end of the filter circuit FC1, and is respectively connected to the second end of the inductor L1 and the active end of the second contactor S2;

[0074] The second end of the second capacitor C2 is connected to the first end of the third capacitor C3 and then grounded;

[0075] The second end of the third capacitor C3 is the second end of the filter circuit FC1, and is respectively connected to the second end of the first capacitor C1 and the active end of the third contactor S3.

[0076] In this embodiment, refer to Figure 4 Since high-frequency electromagnetic interference is generated in the process of driving the boost unit 302 to boost the charging voltage of the charging device U2 through the electric drive module 20, the present application sets the filter circuit FC1 in the boost unit 302 to effectively filter out the high-frequency noise.

[0077] It should be noted that the second capacitor C2 and the third capacitor C3 may be common-mode capacitors for filtering common-mode interference in the battery charging circuit 100 .

[0078] In yet another embodiment, referring to Figure 5 , Figure 5 This is a schematic diagram of a filter circuit involved in the embodiment of the present application. The filter circuit FC1 may also include the following: Figure 5 The seventh capacitor C7 shown may be a differential mode capacitor. In addition, the second capacitor C2 and the third capacitor C3 connected in series are connected in parallel with the seventh capacitor C7, and the seventh capacitor C7 is used to filter the differential mode interference in the battery charging circuit 100.

[0079] In another embodiment, referring to Figure 6 , Figure 6 This is another filter circuit schematic diagram involved in the embodiment of the present application. The filter circuit FC1 may also include: Figure 6 The common-mode inductor L3 shown, the first end of the common-mode inductor L3 is connected to the first end of the second capacitor C2, the second end of the common-mode inductor L3 is connected to the second end of the third capacitor C3, the third end of the common-mode inductor L3 is connected to the active end of the second contactor S2, and the fourth end of the common-mode inductor L3 is connected to the active end of the fourth contactor S4. In the process of driving the boost unit 302 to boost the charging voltage of the charging device U2 through the electric drive module 20, due to the switching of the switch tube in the electric drive module 20 or other factors, common-mode noise may be generated in the battery charging circuit. The common-mode inductor L3 is set in the filter circuit FC1 in the present application to effectively filter out these common-mode noises, thereby ensuring the stability and purity of the output voltage.

[0080] In yet another embodiment, referring to Figure 7 , Figure 7 This is another filter circuit schematic diagram involved in the embodiment of the present application. The filter circuit FC1 may also include a seventh capacitor C7 and a common mode inductor L3 to construct a filter circuit as shown in FIG. Figure 7 The filter circuit shown.

[0081] Further, in some feasible embodiments, the direct charging unit 301 includes a fifth contactor S5 and a sixth contactor S6;

[0082] The active end of the fifth contactor S5 is connected to the positive input end of the battery module 10, and the active end of the sixth contactor S6 is connected to the negative input end of the battery module 10;

[0083] A fixed end of the fifth contactor S5 is connected to the positive output end of the charging module 40 , and a fixed end of the sixth contactor S6 is connected to the negative output end of the charging module 40 .

[0084] It should be noted that the fifth contactor S5 and the sixth contactor S6 can also be understood as relays. The fifth contactor S5 and the sixth contactor S6 can be used in the battery charging circuit to control the shutdown of the direct charging unit 301, and the fifth contactor S5 and the sixth contactor S6 can be characterized as fast charging contactors.

[0085] Further, in some other feasible embodiments, the electric drive module 20 includes an M-phase motor winding L2, a bridge arm unit 21 paired with each phase of the motor winding L2, a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6;

[0086] The first end of each phase of the motor winding L2 is connected to the midpoint of the bridge arm of the paired bridge arm unit 21, the second ends of the motor winding L2 of each phase are connected to each other, the first end of the fourth capacitor C4 is connected to the first side of each bridge arm unit 21, and the second end of the fourth capacitor C4 is connected to the second side of each bridge arm unit 21;

[0087] The first end of the fifth capacitor C5 is connected to the first end of the fourth capacitor C4 and the positive contact end of the battery module 10, and the second end of the fifth capacitor C5 is connected to the first end of the sixth capacitor C6 and then grounded;

[0088] The second end of the motor winding L2 of each phase is the first end of the electric drive module, and is connected to the boost unit 302;

[0089] The second end of the sixth capacitor C6 is the second end of the electric drive module 20 , and is respectively connected to the second end of the fourth capacitor C4 , the boost unit 302 , and the negative contact end of the battery module 10 .

[0090] In this embodiment, the electric drive module 20 can be understood as an electric drive system, which may include a motor controller, a motor, and a reducer. Since the reducer does not participate in the auxiliary boost, it is not included in the Figure 4 In addition, the motor controller includes at least Figure 4 The bridge arm unit 21-1, the bridge arm unit 21-2 and the bridge arm unit 21-3 are shown. The motor at least includes a motor winding L2-1, a motor winding L2-2 and a motor winding L2-2.

[0091] It should be noted that the M-phase motor winding can be understood as the three-phase motor winding of the motor in the electric drive module 20 .

[0092] Further, in some feasible embodiments, the bridge arm unit 21 includes an upper bridge arm and a lower bridge arm, the upper bridge arm is connected to the lower bridge arm, and the connection intersection of the upper bridge arm and the lower bridge arm constitutes the bridge arm midpoint of the bridge arm unit.

[0093] In this embodiment, both the upper bridge arm and the lower bridge arm are switch tubes, and the drain of the upper bridge arm is connected to the source of the lower bridge arm. In addition, the connection intersection of the drain of the upper bridge arm and the source of the lower bridge arm constitutes the bridge arm midpoint of the bridge arm unit.

[0094] In a specific embodiment, the battery charging circuit provided in the present application regards the upper bridge arm (i.e., the switch tube Q1-1, the switch tube Q1-2, and the switch tube Q1-3) as a diode, and the lower bridge arm (i.e., the switch tube Q1-1, the switch tube Q1-2, and the switch tube Q1-3) as a switch element. Exemplarily, the electric drive module 20 operates in the energy storage mode, and after the lower bridge arm corresponding to each phase motor winding is turned on, the corresponding motor winding and the boost inductor (i.e., the inductor L1) are stored with energy; next, after determining that the working mode of the electric drive module 20 is switched from the energy storage mode to the freewheeling mode, at this time, the lower bridge arm corresponding to each phase motor winding is turned off, so that the energy storage of each phase motor winding and the inductor L1 is released through the corresponding upper bridge arm, so that the high-low voltage switching module 30 activates the boost unit 302 under the drive of the electric drive module 20. At this time, the boost unit 302 can not only utilize the voltage released by the motor windings of each phase in the electric drive module 20, but also combine it with the voltage released by its own inductor L1, and superimpose it on the charging voltage connected to the charging module 40 to achieve the voltage boosting function. Therefore, under the premise of ensuring the integrity of the battery, it can also be connected to a low-voltage charging pile to provide a stable and effective charging voltage for the battery module 10.

[0095] It should be noted that the switch tube is a switch tube that can be turned off with an anti-parallel diode, and the switch tube Q1 includes but is not limited to the following: Figure 4 MOSFET devices, IGBT devices or other semiconductor switch tubes shown. Figure 4 The bridge arm unit 21 - 1 includes a switch tube Q1 - 1 and a switch tube Q1 - 2; the bridge arm unit 21 - 2 includes a switch tube Q1 - 3 and a switch tube Q1 - 4; the bridge arm unit 21 - 3 includes a switch tube Q1 - 5 and a switch tube Q1 - 6.

[0096] Further, in some feasible embodiments, the battery module 10 includes a power battery U1, a seventh contactor S7, an eighth contactor S8, a ninth contactor S9 and a buffer resistor R1;

[0097] The positive electrode of the power battery U1 is connected to the active end of the seventh contactor S7 and the active end of the ninth contactor S9, respectively, and the negative electrode of the power battery U1 is connected to the active end of the eighth contactor S8;

[0098] The ninth contactor S9 is connected in series with the buffer resistor R1 and then connected to the fixed end of the seventh contactor S7;

[0099] The positive electrode of the power battery U1 is the positive input terminal of the battery module 10, and the negative electrode of the power battery U1 is the negative input terminal of the battery module and is respectively connected to the direct charging unit 301;

[0100] The fixed end of the seventh contactor S7 is the positive contact end of the battery module 10 , and the negative contact end of the eighth contactor S8 is the negative contact end of the battery module 10 , which are respectively connected to the electric drive module 20 .

[0101] It should be noted that the seventh contactor S7, the eighth contactor S8 and the ninth contactor S9 can be understood as relays, wherein the seventh contactor S7 is characterized as a main positive contactor, the eighth contactor S8 is characterized as a main negative contactor, and the ninth contactor S9 is characterized as a buffer contactor.

[0102] Further, in some other feasible embodiments, the charging module 40 includes a tenth contactor S10 and an eleventh contactor S11;

[0103] The fixed end of the tenth contactor S10 is connected to the positive electrode of the charging device U2, and the fixed end of the eleventh contactor S11 is connected to the negative electrode of the charging device U2;

[0104] The active end of the tenth contactor S10 is the positive output end of the charging module U2, which is connected to the direct charging unit 301 and the boost unit 302 respectively;

[0105] The active end of the eleventh contactor S11 is the negative output end of the charging module 40 , and is connected to the direct charging unit 301 and the boost unit 302 , respectively.

[0106] It should be noted that the tenth contactor S10 and the eleventh contactor S11 can be understood as relays, wherein the tenth contactor S10 and the eleventh contactor S11 can both be regarded as charging contactors.

[0107] In a specific embodiment, refer to Figure 4When the electric drive module 20 works in the driving mode, the seventh contactor S7 and the eighth contactor S8 are closed, and the other relays S1 to S6 and S9 to S11 are all disconnected. At this time, the electric drive module 20 drives the wheels to move. When the charging device U2 is a high-voltage charging pile charging the power battery U1, while disconnecting the seventh contactor S7 and the eighth contactor S8, the tenth contactor S10 and the eleventh contactor S11 are also switched from the open state to the closed state, that is, the fifth contactor S5, the sixth contactor S6, the tenth contactor S10 and the eleventh contactor S11 are closed, and the other relays are all disconnected, so that the high-voltage charging pile can directly charge the power battery U2.

[0108] In addition, when the low-voltage charging pile charges the power battery U2, since the voltage of the charging pile is lower than the battery voltage, charging cannot be performed, and the voltage of the charging pile must be boosted first. After closing the seventh contactor S7, the eighth contactor S8, the tenth contactor S10 and the eleventh contactor S11, at this time, the first contactor S1, the second contactor S2, the third contactor S3 and the fourth contactor S4 are closed, and the other relays are disconnected. The system operates in the auxiliary boost mode to enable the boost unit 302 to charge the battery module 10 after boosting the charging voltage connected to the charging module 40 under the drive of the electric drive module 20.

[0109] In summary, the present application proposes a new circuit topology. When a high-voltage battery is charged with a low-voltage charging pile, the electric drive module 20 is used for auxiliary boosting, and the semiconductor switch tube and control unit of the electric drive module 20 are reused. In addition, the M-phase motor winding L2 in the electric drive module 20 can also serve as a part of the inductor, reducing the inductance of the external inductor. When the charging power demand of the whole vehicle is small, the external inductor can also be cancelled. That is, the battery charging circuit provided in the present application not only realizes the flexible switching of high and low voltage charging without destroying the integrity of the battery, but also greatly saves the cost and volume of the whole vehicle, and has a high practical value.

[0110] In addition, the present application also provides a battery charging device, which at least includes the battery charging circuit 100 described in any one of the above items.

[0111] In addition, the present application also provides a vehicle, wherein the battery charging device at least includes the battery charging circuit 100 described in any one of the above items, or the battery charging device described above.

[0112] The above description is only a preferred embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the technical concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A battery charging circuit, the battery charging circuit is applied to a charging device, characterized in that: The battery charging circuit includes a battery module, an electric drive module, a high-low voltage switching module and a charging module, and the high-low voltage switching module includes a direct charging unit and a boost unit; The battery module is connected to the charging module through the direct charging unit, the battery module, the electric drive module, the boost unit and the charging module are connected in sequence, and the charging module is connected to a charging device; The high and low voltage switching module has a first state and a second state; In the first state, the direct charging unit charges the battery module by connecting the charging module to the charging voltage of the charging device; In the second state, the boost unit charges the battery module after boosting the charging voltage connected to the charging module under the drive of the electric drive module.

2. The battery charging circuit according to claim 1, characterized in that: The boost unit includes a first contactor, a second contactor, a third contactor, a fourth contactor, an inductor, a first capacitor and a filter circuit; The first end of the electric drive module is connected to the movable end of the first contactor, the fixed end of the first contactor is connected to the first end of the inductor, the second end of the inductor is respectively connected to the first end of the first capacitor and the first end of the filter circuit, the second end of the first capacitor is respectively connected to the fixed end of the third contactor and the second end of the filter circuit, and the movable end of the third contactor is connected to the second end of the electric drive module; The first end of the filter circuit is connected to the active end of the second contactor, the fixed end of the second contactor is connected to the positive output end of the charging module, the second end of the filter circuit is respectively connected to the second end of the first capacitor and the active end of the fourth contactor, and the fixed end of the fourth contactor is connected to the negative output end of the charging module.

3. The battery charging circuit as claimed in claim 2, characterized in that: The filter circuit includes a second capacitor and a third capacitor; The first end of the second capacitor is the first end of the filter circuit, and is respectively connected to the second end of the inductor and the active end of the second contactor; The second end of the second capacitor is connected to the first end of the third capacitor and then grounded; The second end of the third capacitor is the second end of the filter circuit, and is respectively connected to the second end of the first capacitor and the active end of the third contactor.

4. The battery charging circuit as claimed in claim 1, characterized in that: The direct charging unit includes a fifth contactor and a sixth contactor; The active end of the fifth contactor is connected to the positive input end of the battery module, and the active end of the sixth contactor is connected to the negative input end of the battery module; The fixed end of the fifth contactor is connected to the positive output end of the charging module, and the fixed end of the sixth contactor is connected to the negative output end of the charging module.

5. The battery charging circuit as claimed in claim 1, characterized in that: The electric drive module includes M-phase motor windings, bridge arm units paired with the motor windings of each phase, a fourth capacitor, a fifth capacitor and a sixth capacitor, where M is a natural number greater than 2; The first end of each phase of the motor winding is connected to the midpoint of the bridge arm of the paired bridge arm unit, the second end of each phase of the motor winding is connected to each other, the first end of the fourth capacitor is connected to the first side of each bridge arm unit, and the second end of the fourth capacitor is connected to the second side of each bridge arm unit; The first end of the fifth capacitor is connected to the first end of the fourth capacitor and the positive contact end of the battery module, and the second end of the fifth capacitor is connected to the first end of the sixth capacitor and then grounded; The second end of the motor winding of each phase is the first end of the electric drive module, and is connected to the boost unit; The second end of the sixth capacitor is the second end of the electric drive module, and is respectively connected to the second end of the fourth capacitor, the boost unit, and the negative contact end of the battery module.

6. The battery charging circuit as claimed in claim 5, characterized in that: The bridge arm unit includes an upper bridge arm and a lower bridge arm, the upper bridge arm is connected to the lower bridge arm, and the connection intersection of the upper bridge arm and the lower bridge arm constitutes the bridge arm midpoint of the bridge arm unit.

7. The battery charging circuit as claimed in claim 1, characterized in that: The battery module includes a power battery, a seventh contactor, an eighth contactor, a ninth contactor and a buffer resistor; The positive electrode of the power battery is connected to the active end of the seventh contactor and the active end of the ninth contactor respectively, and the negative electrode of the power battery is connected to the active end of the eighth contactor; The ninth contactor is connected in series with the buffer resistor and then connected to the fixed end of the seventh contactor; The positive electrode of the power battery is the positive input terminal of the battery module, and the negative electrode of the power battery is the negative input terminal of the battery module, which are respectively connected to the direct charging unit; The fixed end of the seventh contactor is the positive contact end of the battery module, and the negative contact end of the eighth contactor is the negative contact end of the battery module, which are respectively connected to the electric drive module.

8. The battery charging circuit as claimed in claim 1, characterized in that: The charging module includes a tenth contactor and an eleventh contactor; The fixed end of the tenth contactor is connected to the positive electrode of the charging device, and the fixed end of the eleventh contactor is connected to the negative electrode of the charging device; The active end of the tenth contactor is the positive output end of the charging module, and is connected to the direct charging unit and the boost unit respectively; The active end of the eleventh contactor is the negative output end of the charging module, and is connected to the direct charging unit and the boost unit respectively.

9. A battery charging device, characterized in that: The battery charging device comprises at least the battery charging circuit as claimed in any one of claims 1-8.

10. A vehicle, characterized in that: The vehicle comprises at least the battery charging circuit according to any one of claims 1 to 8, or the battery charging device according to claim 9.

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