Upflow charging circuit and electric vehicle

Abstract

The utility model discloses a current-rising charging circuit and an electric automobile, and relates to the technical field of electric automobile charging, the current-rising charging circuit comprises a charging pile, a battery, a motor controller and a motor which are connected in sequence, the motor controller is connected with a multi-phase winding of the motor through a multi-phase connection point, the current-rising charging circuit further comprises a plurality of switch modules, and the switch modules are connected with the charging pile. Wherein the switch modules comprise a first switch module, a second switch module and a third switch module, one end of the first switch module and one end of the second switch module are respectively connected with the positive electrode of the battery, one end of the third switch module is connected with the positive electrode of the charging pile, and the other end of the first switch module is connected with any connection point in the multiple connection points; and the other end of the second switch module and the other end of the third switch module are respectively connected with the positive input end of the motor controller. According to the invention, the motor controller and the motor can be utilized to enable the charging pile to carry out direct-current fast charging or current-rising charging on the battery, so that the charging efficiency is improved, and the charging duration is shortened.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicle charging, and in particular to a current-boosting charging circuit and an electric vehicle. Background Art

[0002] Currently, electric vehicles are primarily charged using two types of charging: AC and DC. During DC charging, the charging voltage is the voltage between the positive and negative poles of the vehicle's battery, and the charging current is the charging current limit imposed by the DC charging station itself. However, with the continuous advancement of battery technology, the charging current limit of DC charging stations is now far less than the maximum charging current a battery can withstand. When the battery voltage of a vehicle is low, using DC charging will result in a charging power far less than the maximum output power of the charging station due to the voltage limitations of the vehicle battery and the current limitations of the charging station. This will limit the charging rate and unnecessarily extend the charging time. Utility Model Content

[0003] The main purpose of this application is to provide a current-boosting charging circuit and an electric vehicle, aiming to solve the technical problem in the related art that DC charging has current limitation, resulting in a low charging rate.

[0004] To achieve the above objectives, the present application proposes a boost charging circuit, comprising a charging pile, a battery, a motor controller, and a motor connected in sequence, wherein the motor controller is connected to the multi-phase windings of the motor via a multi-phase connection point, and the boost charging circuit further comprises a plurality of switch modules;

[0005] Wherein, the plurality of switch modules include a first switch module, a second switch module and a third switch module;

[0006] One end of the first switch module and one end of the second switch module are respectively connected to the positive pole of the battery, one end of the third switch module is connected to the positive pole of the charging pile, the other end of the first switch module is connected to any connection point in the multi-phase connection point, and the other end of the second switch module and the other end of the third switch module are respectively connected to the positive input end of the motor controller.

[0007] In one embodiment, the boost charging circuit further includes a direct charging switch K1 and a direct charging switch K2;

[0008] The positive electrode of the charging pile is connected to the positive electrode of the battery through the direct charging switch K1, and the negative electrode of the charging pile is connected to the negative electrode of the battery through the direct charging switch K2.

[0009] In one embodiment, the direct charge switch K1 is configured to be closed in the DC fast charge mode and open in the normal drive mode, the boost charge mode, and the battery heating mode;

[0010] The direct charging switch K2 is used to close in the DC fast charging mode, the boost charging mode and the battery heating mode, and to open in the normal driving mode.

[0011] In one embodiment, the first switch module includes a switch K10;

[0012] One end of the switch K10 is connected to the positive electrode of the battery, and the other end of the switch K10 is connected to any one of the multi-phase connection points.

[0013] In one embodiment, the switch K10 is configured to be closed in the boost charging mode and the battery heating mode, and to be opened in the normal driving mode and the DC fast charging mode.

[0014] In one embodiment, the second switch module includes a switch K20;

[0015] One end of the switch K20 is connected to the positive electrode of the battery, and the other end of the switch K20 is connected to the positive input terminal of the motor controller.

[0016] In one embodiment, the switch K20 is configured to be closed in the normal driving mode and open in the DC fast charging mode, the boost charging mode, and the battery heating mode.

[0017] In one embodiment, the third switch module includes a switch K31, a switch K32 and a diode D1;

[0018] One end of the switch K31 and one end of the switch K32 are respectively connected to the positive electrode of the charging pile, the other end of the switch K31 is connected to the positive electrode of the diode D1, and the cathode of the diode D1 and the other end of the switch K32 are respectively connected to the positive input end of the motor controller.

[0019] In one embodiment, the switch K31 is configured to be closed in the battery heating mode and open in the normal driving mode, the DC fast charging mode, and the boost charging mode;

[0020] The switch K32 is configured to be closed in the boost charging mode and opened in the normal driving mode, the DC fast charging mode, and the battery heating mode.

[0021] In addition, to achieve the above-mentioned purpose, the present application also proposes an electric vehicle, comprising:

[0022] The battery, motor controller and motor; and the boost charging circuit as described above formed by connecting to an external charging pile.

[0023] One or more technical solutions proposed in this application have at least the following technical effects:

[0024] A boost charging circuit is proposed, comprising a charging pile, a battery, a motor controller and a motor connected in sequence, wherein the motor controller is connected to the multi-phase winding of the motor through a multi-phase connection point. On this basis, different mode switching is realized through multiple switch modules. Specifically, the switching of normal driving mode, DC fast charging mode, boost charging mode and battery heating mode is realized by turning on and off three switch modules, namely a first switch module with one end connected to the positive pole of the battery and the other end connected to any connection point in the multi-phase connection point, a second switch module with one end connected to the positive pole of the battery and the other end connected to the positive input terminal of the motor controller, and a third switch module with one end connected to the positive pole of the charging pile and the other end connected to the positive input terminal of the motor controller. In the existing DC charging circuit that can only perform direct charging, the motor controller and the motor are used to enable the charging pile to perform DC fast charging or boost charging on the battery. The newly added boost charging function can increase the charging current of the entire vehicle battery and increase the charging power, thereby improving the charging efficiency and shortening the charging time. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0027] Figure 1 A connection diagram of a DC charging system in the related art;

[0028] Figure 2 This is a connection diagram of an embodiment of a current boost charging circuit provided by the present application;

[0029] Figure 3 A circuit topology diagram of another embodiment of the current boost charging circuit provided by the present application;

[0030] Figure 4 for Figure 3 Equivalent schematic diagram of the switch on-off control of the circuit in normal driving mode;

[0031] Figure 5 for Figure 3 Equivalent schematic diagram of the switch on-off control of the middle circuit in DC fast charging mode;

[0032] Figure 6 for Figure 3Equivalent schematic diagram of the switch on-off control of the middle circuit in the boost charging mode;

[0033] Figure 7 for Figure 6 Schematic diagram of the corresponding inductor charging state in the boost charging mode;

[0034] Figure 8 for Figure 6 Schematic diagram of the inductor freewheeling state in the corresponding boost charging mode;

[0035] Figure 9 for Figure 3 Equivalent schematic diagram of the on-off control of the mid-circuit in battery heating mode;

[0036] Figure 10 for Figure 9 Schematic diagram of the inductive charging state when charging the battery in the corresponding battery heating mode;

[0037] Figure 11 for Figure 9 Schematic diagram of the inductor freewheeling state during battery charging in the corresponding battery heating mode;

[0038] Figure 12 for Figure 9 Schematic diagram of the inductor charging state during battery discharge in the corresponding battery heating mode;

[0039] Figure 13 for Figure 9 Schematic diagram of the inductor freewheeling state when the battery is discharged in the corresponding battery heating mode. The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.

[0041] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application, the directional indications are only used to explain the relative positional relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, if there are descriptions of "first", "second", etc. in the embodiments of the present application, 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 defined as "first" and "second" can 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 schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or schemes that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that ordinary technicians in this field can implement them. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0042] With the increasing popularity of new energy electric vehicles, the demand for rapid recharging is growing. Currently, electric vehicle charging methods primarily include AC charging and DC charging. DC charging involves connecting a DC charging station directly to the positive and negative terminals of the vehicle's battery via a mains connection. Due to its high charging power and rapid recharging, DC charging has become a mainstream method for electric vehicle charging.

[0043] Reference Figure 1 , Figure 1 The figure is a connection diagram of a DC charging system in the related art, which is a charging system for electric vehicles. Figure 1 As shown, the positive and negative poles of the charging pile are connected to the positive and negative poles of the battery through switches K1 and K2. The positive pole of the battery is also connected to the positive input terminal of the motor controller through a main switch K3. When the entire vehicle needs to be charged, the main switch K3 is specifically disconnected, and switches K1 and K2 are closed, so that the battery is directly connected to the charging pile and charged. At this time, the electric vehicle is in DC fast charging mode. In this DC charging mode, the charging current is limited by the charging pile, and the charging voltage is also limited by the battery voltage. It can be seen that in the current DC charging process, the charging voltage is the voltage between the positive and negative poles of the entire vehicle battery, and the charging current is the charging limit current limited by the DC charging pile itself.

[0044] However, with the continuous advancement of battery technology, the current limit of DC charging piles is now far less than the maximum charging current that the battery can withstand. When the battery voltage of the vehicle is low, using DC charging will result in the charging power being far less than the maximum output power of the charging pile due to the voltage limit of the vehicle battery and the current limit of the charging pile. This will limit the charging rate and unnecessarily extend the charging time.

[0045] To address the above problems, the present application provides a current boosting charging circuit and an electric vehicle. The present application and the following embodiments are described below with reference to the accompanying drawings.

[0046] The present application proposes a current-boosting charging circuit.

[0047] In one embodiment of the present application, refer to Figure 2 , Figure 2 This is a connection diagram of an embodiment of a boost charging circuit. The boost charging circuit may include a charging pile, a battery, a motor controller, and a motor connected in sequence. The motor controller is connected to the multi-phase windings of the motor via a multi-phase connection point. The boost charging circuit may also include multiple switch modules.

[0048] Wherein, the plurality of switch modules include a first switch module, a second switch module and a third switch module;

[0049] One end of the first switch module and one end of the second switch module are respectively connected to the positive pole of the battery, one end of the third switch module is connected to the positive pole of the charging pile, the other end of the first switch module is connected to any connection point in the multi-phase connection point, and the other end of the second switch module and the other end of the third switch module are respectively connected to the positive input end of the motor controller.

[0050] It should be noted that the charging pile refers to the DC charging pile outside the electric vehicle, and the battery refers to the entire battery of the electric vehicle. The battery, motor controller and motor can all be set inside the electric vehicle. Among them, the motor can be a three-phase motor with a three-phase winding. Correspondingly, the power circuit inside the motor controller can be a three-phase bridge arm circuit. The lead wire of each phase bridge arm circuit serves as an output end of the motor controller and is connected to one phase winding of the three-phase winding through a connection point. The three-phase output of the motor controller can be connected to the three-phase winding of the motor through the three-phase connection points respectively. Figure 2 As shown in .

[0051] In addition, it should be noted that the first switch module, the second switch module, and the third switch module can directly use one or more switch devices to achieve on-off, or can use a switch circuit or switch chip to achieve on-off. When multiple switch devices are used, they can also have other electronic devices such as diodes required to achieve accurate on-off action, which is not specifically limited here. The on-off control of the above three switch modules can be controlled by an external control circuit or control device according to actual needs. Alternatively, a controller can be provided in the boost charging circuit to output control instructions to each switch module to achieve on-off control of each switch module. It is understandable that when the controller outputs the control instruction and whether the control instruction is a closing instruction or an opening instruction can be set according to actual needs and is not specifically limited here.

[0052] It can be understood that by turning on and off the above three switch modules, the boost charging circuit can switch between normal driving mode, DC fast charging mode, boost charging mode and battery heating mode. Compared with the DC charging system in the related art that can only switch between normal driving mode and DC fast charging mode, the boost charging circuit adds boost charging function and battery heating function.

[0053] In one possible implementation, refer to Figure 2 , the boost charging circuit also includes a direct charging switch K1 and a direct charging switch K2;

[0054] The positive electrode of the charging pile is connected to the positive electrode of the battery through the direct charging switch K1, and the negative electrode of the charging pile is connected to the negative electrode of the battery through the direct charging switch K2.

[0055] Among them, the direct charging switch K1 is used to close in DC fast charging mode, and to disconnect in normal driving mode, boost charging mode and battery heating mode; the direct charging switch K2 is used to close in DC fast charging mode, boost charging mode and battery heating mode, and to disconnect in normal driving mode.

[0056] It should be noted that when the direct charging switch K1 and the direct charging switch K2 are closed at the same time and the first switch module, the second switch module and the third switch module are all disconnected, the boost charging circuit enters the DC fast charging mode. At this time, the charging pile can directly charge the battery with DC; in other modes, the direct charging switch K2 is closed to connect the corresponding working circuit.

[0057] Specifically, when only the second switch module is turned on and the first switch module, the third switch module, the direct charging switch K1 and the direct charging switch K2 are all disconnected, the boost charging circuit enters the normal driving mode. At this time, the battery can provide driving voltage to the motor controller to enable it to work normally; when the direct charging switch K2, the first switch module and the third switch module are turned on and the second switch module and the direct charging switch K1 are all disconnected, the boost charging circuit enters the boost charging mode or the battery heating mode. The boost charging or battery heating can be achieved by controlling the on-off of the power tube in the motor controller. The on-off control of the power tube can be controlled by an external control circuit or device or a controller separately provided in the boost charging circuit to output a pulse signal to achieve control. The specific setting can be based on actual needs and is not limited here.

[0058] The boost charging circuit of this embodiment includes a charging pile, a battery, a motor controller and a motor connected in sequence. The motor controller is connected to the multi-phase winding of the motor through a multi-phase connection point. On this basis, different mode switching is achieved through multiple switch modules. Specifically, the switching of normal driving mode, DC fast charging mode, boost charging mode and battery heating mode is achieved by turning on and off three switch modules, namely a first switch module with one end connected to the positive pole of the battery and the other end connected to any connection point in the multi-phase connection point, a second switch module with one end connected to the positive pole of the battery and the other end connected to the positive input terminal of the motor controller, and a third switch module with one end connected to the positive pole of the charging pile and the other end connected to the positive input terminal of the motor controller. In the existing DC charging circuit that can only perform direct charging, the motor controller and the motor are used to enable the charging pile to perform DC fast charging or boost charging on the battery. The newly added boost charging function can increase the charging current of the entire vehicle battery and increase the charging power, thereby improving the charging efficiency and shortening the charging time.

[0059] In another embodiment of the present application, refer to Figure 3 , Figure 3 2 is a circuit topology diagram of another embodiment of a boost charging circuit, in which the first switch module may include a switch K10;

[0060] One end of the switch K10 is connected to the positive electrode of the battery, and the other end of the switch K10 is connected to any one of the multi-phase connection points.

[0061] The switch K10 is used to be closed in the boost charging mode and the battery heating mode, and to be opened in the normal driving mode and the DC fast charging mode.

[0062] It should be noted that the connection point can be an interface derived from the winding connecting the motor to the motor controller. The number of multi-phase connection points corresponds to the number of windings in the motor. Here, the motor has a three-phase winding and therefore has three-phase connection points. The other end of the switch K10 can be connected to any of the three-phase connection points, so that the switch K10 can connect the positive terminal of the battery to any phase winding of the motor. The switch K10 can be a controllable switching device.

[0063] For example, when the boost charging circuit is about to enter the boost charging mode or the battery heating mode, the switch K10 can be controlled to close to connect the positive pole of the battery with a phase winding of the motor, so that the circuit in the boost charging mode or the battery heating mode is connected.

[0064] It is understandable that the first switch module uses a simple switch device to achieve on and off, and it is convenient to close or open in the corresponding mode based on actual needs. Not only is the control logic simple, but it can also avoid excessive increase in device costs.

[0065] In one possible implementation, refer to Figure 3 , the second switch module in the boost charging circuit may include a switch K20;

[0066] One end of the switch K20 is connected to the positive electrode of the battery, and the other end of the switch K20 is connected to the positive input terminal of the motor controller.

[0067] The switch K20 is used to be closed in the normal driving mode and opened in the DC fast charging mode, the boost charging mode and the battery heating mode.

[0068] It should be noted that switch K20 can be a controllable switch device. As the main switch located between the battery and the motor controller, switch K20 can be controlled to close when the motor controller needs to operate, that is, when the boost charging circuit needs to enter normal drive mode, to connect the positive terminal of the battery to the positive input terminal of the motor controller, thus facilitating the working circuit in normal drive mode. It should be noted that in this normal drive mode, the first switch module, the third switch module, the direct charging switch K1, and the direct charging switch K2 are all disconnected.

[0069] It can be understood that the second switch module uses a simple switching device to realize the main on and off. When it is turned on, the battery can drive the motor controller normally. When it is turned off, it is convenient for the charging pile to charge or heat the battery. The on and off is convenient and the control logic is simple.

[0070] In one possible implementation, refer to Figure 3 The third switch module in the boost charging circuit may include a switch K31, a switch K32 and a diode D1;

[0071] One end of the switch K31 and one end of the switch K32 are respectively connected to the positive electrode of the charging pile, the other end of the switch K31 is connected to the positive electrode of the diode D1, and the cathode of the diode D1 and the other end of the switch K32 are respectively connected to the positive input end of the motor controller.

[0072] Among them, the switch K31 is used to close in the battery heating mode, and to disconnect in the normal driving mode, DC fast charging mode and boost charging mode; the switch K32 is used to close in the boost charging mode, and to disconnect in the normal driving mode, DC fast charging mode and battery heating mode.

[0073] It should be noted that both the switch K31 and the switch K32 can be controllable switch devices. The switch K31 is connected in series with the diode D1, and the series-connected switch K31 and diode D1 are then connected in parallel with the switch K32 to form a switch circuit as a third switch module.

[0074] For example, when the boost charging circuit is about to enter the boost charging mode, the switch K32 can be specifically controlled to close to connect the positive pole of the charging pile with the positive input terminal of the motor controller, so that in the boost charging mode, the output current of the charging pile is boosted by the motor controller and the motor winding to charge the battery; when the boost charging circuit is about to enter the battery heating mode, the switch K31 can be specifically controlled to close to connect the positive pole of the charging pile with the positive input terminal of the motor controller, so that in the battery heating mode, the battery is heated based on the corresponding battery charging and discharging. In the boost charging mode or the battery heating mode, the on-off control of the power tube in the motor controller can be controlled by an external control circuit or device or a pulse signal output by a controller separately provided in the boost charging circuit. The specific setting can be based on actual needs and is not limited here.

[0075] It is understandable that the third switch module uses simple switch devices and diode devices to realize on-off, and can correspondingly switch between the boost charging mode and the battery heating mode to realize boost charging or heating of the battery.

[0076] For example, in order to more accurately reflect the working process of the boost charging circuit, the following Figure 3 As an example, the refined boost charging circuit shown in Figure 4-13 , and explain its working process in detail.

[0077] Reference Figure 4 , Figure 4 This is an equivalent schematic diagram of the switch on-off control in normal driving mode. By closing switch K20, the direct charging switch K1, direct charging switch K2, switch K10, switch K31 and switch K32 are disconnected, so that the current boost charging circuit enters the normal driving mode; at this time, the battery, motor controller and motor are connected in sequence, and the motor controller enters the normal working state.

[0078] Reference Figure 5 , Figure 5 This is an equivalent schematic diagram of the switch on-off control in DC fast charging mode. By closing the direct charging switch K1 and the direct charging switch K2, and opening the switches K10, K20, K31, and K32, the current-boosting charging circuit enters the DC fast charging mode. At this time, the charging pile is directly connected to the battery to perform DC fast charging on the battery.

[0079] Reference Figure 6 , Figure 6 This is an equivalent schematic diagram of the switch on-off control in the boost charging mode. By closing the direct charging switch K2, switch K10, and switch K32 and disconnecting the direct charging switch K1, switch K20, and switch K31, the boost charging circuit enters the boost charging mode. At this time, the charging pile, motor controller, motor winding, and battery are connected in sequence to form a boost charging loop. Among them, only two-phase bridge arm circuits in the three-phase bridge arm circuit in the motor controller are connected to the boost charging loop. The bridge arm circuit that is not connected is the bridge arm circuit corresponding to any connection point in the multi-phase connection point connected to switch K10. In other words, for any connection point, only the corresponding winding is connected to the boost charging loop. The two-phase bridge arm circuit connected to the boost charging loop is the other two-phase bridge arm circuit in the three-phase bridge arm circuit of the motor controller except the bridge arm circuit corresponding to any connection point. Among them, the boost charging circuit can be operated in Buck circuit mode by adjusting the conduction time of the bridge arm switch tube to increase the current passing through the battery and achieve boost charging.

[0080] Furthermore, when the boost charging circuit is in the boost charging mode, based on each cycle, the upper bridge arms of the two-phase bridge arm circuit connected to the boost charging circuit can be controlled to be simultaneously turned on and the lower bridge arms can be simultaneously turned off, and then the lower bridge arms of the two-phase bridge arm circuit can be controlled to be simultaneously turned on and the upper bridge arms can be simultaneously turned off. In this way, the boost charging circuit has two states within one cycle:

[0081] Reference Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the inductor charging state in the boost charging mode. Figure 8 The schematic diagram of the inductor freewheeling state in the boost charging mode is shown in the figure. The dotted line in the figure indicates the current flow direction. When the boost charging circuit is connected and the charging pile starts working, Figure 7 As shown, in the upper bridge arm conduction stage of each cycle, the current output from the positive electrode of the charging pile passes through the switch K32, the upper bridge arm, the motor winding, the switch K10, the battery, the switch K2 in sequence, and returns to the negative electrode of the charging pile. Among them, the current flows through the battery, and the electrical energy is converted into magnetic field energy and stored in the battery to realize battery charging. At the same time, the winding inductance of the motor is also charged, that is, at this time it is in the inductor charging state of the boost charging mode; Figure 8 As shown, during the conduction phase of the lower bridge arm in each cycle, the winding inductance releases the stored electric energy, which continues to flow in the form of current, specifically flowing through the switch K10, the battery, and the lower bridge arm in sequence, thereby achieving electric energy release and avoiding damage to the motor controller and the motor. That is, at this time, the inductor is in the freewheeling state of the boost charging mode.

[0082] Reference Figure 9 , Figure 9 This is an equivalent schematic diagram of the switch on-off control in the battery heating mode. By closing the direct charging switch K2, switch K10 and switch K31, and disconnecting the direct charging switch K1, switch K20 and switch K32, the current-boosting charging circuit enters the battery heating mode. At this time, the charging pile, diode D1, motor controller, motor winding and battery are connected in sequence to form a battery heating circuit. In this circuit, for each cycle, the battery is continuously charged and discharged, so that the current flows through the internal resistance of the battery to achieve battery heating. As described above, only two-phase bridge arm circuits in the three-phase bridge arm circuit in the motor controller are connected to the battery heating circuit. The bridge arm circuit that is not connected is the bridge arm circuit corresponding to any connection point in the multi-phase connection point connected to switch K10, which will not be repeated here.

[0083] Furthermore, when the boost charging circuit is in the battery heating mode, based on each cycle of different battery states, the upper bridge arms of the two-phase bridge arm circuit connected to the battery heating circuit can be controlled to be simultaneously turned on and the lower bridge arms can be simultaneously turned off, and then the lower bridge arms of the two-phase bridge arm circuit can be controlled to be simultaneously turned on and the upper bridge arms can be simultaneously turned off. As a result, the battery heating circuit has two states in each cycle under different battery states, that is, a total of four states in the battery heating mode:

[0084] Reference Figure 10 and Figure 11 , Figure 10 This is a schematic diagram of the inductive charging state when charging the battery in battery heating mode. Figure 11 This is a schematic diagram of the inductor freewheeling state when the battery is charging in battery heating mode. The dotted line in the figure indicates the current flow direction. When the battery heating circuit is connected and the charging pile starts working, Figure 10 As shown, in the upper bridge arm conduction stage of each cycle, the current output from the positive electrode of the charging pile passes through the switch K31, the diode D1, the upper bridge arm, the motor winding, the switch K10, the battery, the switch K2, and returns to the negative electrode of the charging pile. The current flows through the battery to charge the battery. At the same time, the winding inductance of the motor is also charged. The capacitor C1 in front of the three-phase bridge arm circuit of the motor controller has the function of energy storage, which can protect the motor and the motor controller from damage caused by the voltage fluctuation of the charging pile output. That is, at this time, the battery is in the inductive charging state when charging in the battery heating mode; as shown in FIG. Figure 11As shown, in the conduction phase of the lower bridge arm in each cycle, the winding inductance releases the stored electric energy, which continues to flow in the form of current, specifically flowing through the switch K10, the battery, and the lower bridge arm in sequence, thereby realizing the electric energy release of the winding inductance, and the battery maintains a charged state under the inductive freewheeling; at the same time, the charging pile, the switch K31, the diode D1, the capacitor C1, and the switch K2 form a loop to realize the energy release of the capacitor C1, and the diode D1 cooperates with the capacitor C1 to prevent the current shock from damaging the battery, that is, the battery is in the inductive freewheeling state when charging in the battery heating mode.

[0085] Reference Figure 12 and Figure 13 , Figure 12 This is a schematic diagram of the inductor charging state when the battery is discharged in battery heating mode. Figure 13 This is a schematic diagram of the inductor freewheeling state when the battery is discharged in battery heating mode. The dotted line in the figure indicates the current flow direction. When the battery heating circuit is connected and the battery starts to discharge, Figure 12 As shown, in the lower bridge arm conduction stage of each cycle, the current output from the positive electrode of the battery passes through the switch K10, the motor winding, and the lower bridge arm in sequence, and then returns to the negative electrode of the battery, wherein the current flows through the motor winding to realize the inductive charging of the winding, and the current output from the positive electrode of the charging pile passes through the switch K31, the diode D1, the capacitor C1, and the switch K2 in sequence, and then returns to the negative electrode of the charging pile, wherein the current flows through the capacitor C1, and the capacitor C1 stores energy to protect the motor and the motor controller from damage caused by the voltage fluctuation output by the charging pile, that is, at this time, the battery is in the inductive charging state when discharging in the battery heating mode; as shown Figure 13 As shown, during the conduction phase of the upper bridge arm in each cycle, the winding inductance releases the stored electric energy, which continues to flow in the form of current, specifically flowing through the upper bridge arm, capacitor C1, battery, and switch K10 in sequence, thereby releasing the electric energy of the winding inductance. The battery remains in a discharged state under the inductive freewheeling, that is, at this time, it is in the inductive freewheeling state when the battery is discharged in the battery heating mode.

[0086] It can be seen from the above multiple different modes and their corresponding different states that the boost charging circuit not only has the normal driving function and DC fast charging function that the DC charging system in the relevant technology already has, but also adds a boost charging function and a battery heating function. It only needs to control the connection of the corresponding circuit through the on and off of the newly added first switch module and the third switch module. Combined with the electronic control and motor in the whole vehicle, a boost charging circuit and a battery heating circuit are formed accordingly. Not only is the mode switching simple and low-cost, but it can also increase the charging current and shorten the charging time.

[0087] The present application also proposes an electric vehicle, which may include a battery, a motor controller and a motor; and a boost charging circuit formed by connecting the battery, the motor controller and the motor to an external charging pile.

[0088] Among them, the battery, motor controller and motor are all arranged inside the electric vehicle.

[0089] It should be noted that the specific structure of the current-boosting charging circuit refers to the above embodiments. Since the electric vehicle adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0090] The above are only some embodiments of the present application and are not intended to limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A current boost charging circuit, characterized in that: The device comprises a charging pile, a battery, a motor controller and a motor connected in sequence, wherein the motor controller is connected to the multi-phase winding of the motor via a multi-phase connection point, and the boost charging circuit further comprises a plurality of switch modules; Wherein, the plurality of switch modules include a first switch module, a second switch module and a third switch module; One end of the first switch module and one end of the second switch module are respectively connected to the positive electrode of the battery, one end of the third switch module is connected to the positive electrode of the charging pile, the other end of the first switch module is connected to any connection point of the multi-phase connection points, and the other end of the second switch module and the other end of the third switch module are respectively connected to the positive input terminal of the motor controller.

2. The boost charging circuit according to claim 1, wherein: The boost charging circuit further includes a direct charging switch K1 and a direct charging switch K2; The positive electrode of the charging pile is connected to the positive electrode of the battery through the direct charging switch K1, and the negative electrode of the charging pile is connected to the negative electrode of the battery through the direct charging switch K2.

3. The boost charging circuit according to claim 2, wherein: The direct charging switch K1 is used to close in the DC fast charging mode and disconnect in the normal driving mode, the boost charging mode and the battery heating mode; The direct charging switch K2 is used to be closed in the DC fast charging mode, the boost charging mode and the battery heating mode, and to be opened in the normal driving mode.

4. The boost charging circuit according to any one of claims 1 to 3, characterized in that: The first switch module includes a switch K10; One end of the switch K10 is connected to the positive electrode of the battery, and the other end of the switch K10 is connected to any one of the multi-phase connection points.

5. The boost charging circuit according to claim 4, wherein: The switch K10 is configured to be closed in the boost charging mode and the battery heating mode, and to be opened in the normal driving mode and the DC fast charging mode.

6. The boost charging circuit according to any one of claims 1 to 3, characterized in that: The second switch module includes a switch K20; One end of the switch K20 is connected to the positive electrode of the battery, and the other end of the switch K20 is connected to the positive input terminal of the motor controller.

7. The boost charging circuit according to claim 6, wherein: The switch K20 is configured to be closed in the normal driving mode and opened in the DC fast charging mode, the boost charging mode, and the battery heating mode.

8. The boost charging circuit according to any one of claims 1 to 3, characterized in that: The third switch module includes a switch K31, a switch K32 and a diode D1; One end of the switch K31 and one end of the switch K32 are respectively connected to the positive electrode of the charging pile, the other end of the switch K31 is connected to the positive electrode of the diode D1, and the cathode of the diode D1 and the other end of the switch K32 are respectively connected to the positive input end of the motor controller.

9. The boost charging circuit according to claim 8, wherein: The switch K31 is used to close in the battery heating mode and open in the normal driving mode, DC fast charging mode and boost charging mode; The switch K32 is configured to be closed in the boost charging mode and opened in the normal driving mode, the DC fast charging mode, and the battery heating mode.

10. An electric vehicle, characterized in that: include: Batteries, motor controllers, and motors; and A current-boosting charging circuit as claimed in any one of claims 1 to 9, formed by connecting to an external charging pile.

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