Three-phase boost charging circuit and electric vehicle

Abstract

The utility model discloses a three-phase boost charging circuit and an electric automobile, and relates to the technical field of electric automobile charging, the three-phase boost charging circuit comprises a charging pile, a battery, a motor controller and a motor which are connected in sequence, and further comprises five switch modules, one end of the first switch module and one end of the second switch module are connected with the positive electrode of the battery, and the other end of the first switch module is connected with the negative electrode of the battery; one end of the fifth switch module is connected with the positive electrode of the charging pile, one end of the third switch module and one end of the fourth switch module are connected with the other end of the fifth switch module, and the other end of the first switch module and the other end of the fourth switch module are connected with a neutral point of a multi-phase winding of the motor. The other end of the second switch module and the other end of the third switch module are connected with the positive input end of the motor controller. According to the invention, the charging pile can carry out direct-current fast charging, current-rising charging or voltage-rising fast charging on the battery, the charging efficiency is improved, the charging time is shortened, and the low-voltage charging pile is used for charging the battery of a high-voltage vehicle type.

Description

Technical Field

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

[0002] Currently, electric vehicle charging methods primarily include AC charging and DC charging. 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 the battery can withstand. When the battery voltage of a vehicle is low, using DC charging will result in the charging power being 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. Furthermore, as the voltage level of automotive batteries continues to increase, earlier low-voltage charging stations are no longer able to meet the charging needs of high-voltage vehicle batteries. Utility Model Content

[0003] The main purpose of this application is to provide a three-phase boost charging circuit and an electric vehicle, aiming to solve the technical problems in related technologies of DC charging having current limitation, resulting in low charging rate and low-voltage charging piles being unable to meet the charging requirements of high-voltage batteries.

[0004] To achieve the above objectives, the present application proposes a three-phase 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 three-phase boost charging circuit further comprises a plurality of switch modules;

[0005] The plurality of switch modules include a first switch module, a second switch module, a third switch module, a fourth switch module and a fifth 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 fifth switch module is connected to the positive pole of the charging pile, one end of the third switch module and one end of the fourth switch module are respectively connected to the other end of the fifth switch module, the other end of the first switch module and the other end of the fourth switch module are respectively connected to the neutral point of the multi-phase winding, 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 three-phase boost charging circuit further includes a direct charging switch K1 and a direct charging switch K2;

[0008] The positive pole of the charging pile is connected to the positive pole of the battery through the direct charging switch K1, and the negative pole of the charging pile is connected to the negative pole of the battery through the direct charging switch K2. The negative pole of the charging pile is also connected to the connection point of the negative pole of the battery and the negative input terminal of the motor controller.

[0009] In one embodiment, the first switch module includes a switch K10;

[0010] 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 the neutral point of the multi-phase winding.

[0011] In one embodiment, the second switch module includes a switch K20;

[0012] 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.

[0013] In one embodiment, the third switch module includes a switch K30;

[0014] One end of the switch K30 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K30 is connected to the positive input end of the motor controller.

[0015] In one embodiment, the switch K30 is configured to be turned on in the boost charging mode and the battery heating mode, and turned off in the normal driving mode, the DC fast charging mode, and the boost charging mode.

[0016] In one embodiment, the fourth switch module includes a switch K40;

[0017] One end of the switch K40 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K40 is connected to the neutral point of the multi-phase winding.

[0018] In one embodiment, the fifth switch module includes a switch K51, a switch K52 and a diode D2;

[0019] One end of the switch K51 and one end of the switch K52 are respectively connected to the positive electrode of the charging pile, the other end of the switch K51 is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 and the other end of the switch K52 are both connected to one end of the third switch module and one end of the fourth switch module.

[0020] In one embodiment, the switch K51 is configured to be turned on in the battery heating mode and turned off in the normal driving mode, the DC fast charging mode, the boost charging mode, and the boost charging mode;

[0021] The switch K52 is configured to be turned on in the current boost charging mode and the voltage boost charging mode, and to be turned off in the normal driving mode, the DC fast charging mode, and the battery heating mode.

[0022] In addition, to achieve the above-mentioned purpose, the present application also proposes an electric vehicle, comprising:

[0023] The battery, motor controller and motor; and the three-phase boost charging circuit as described above, which is connected to an external charging pile.

[0024] One or more technical solutions proposed in this application have at least the following technical effects:

[0025] A three-phase 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 through a first switch module having one end connected to the positive pole of the battery and the other end connected to the neutral point of the multi-phase winding, a second switch module having one end connected to the positive pole of the battery and the other end connected to the positive input terminal of the motor controller, a third switch module having 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, a fourth switch module having one end connected to the positive pole of the charging pile and the other end connected to the neutral point of the multi-phase winding, and a fourth switch module having one end connected to the positive pole of the charging pile and the other end connected to the neutral point of the multi-phase winding. The switching of five switch modules, including the fifth switch module connected to the third switch module and the fourth switch module, is used to realize the switching of normal driving mode, DC fast charging mode, boost charging mode, boost charging mode and battery heating mode. 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, boost 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. In addition, the newly added boost charging function can increase the charging voltage of the entire vehicle battery, so that the low-voltage charging pile can also charge the battery of high-voltage vehicle models, thereby meeting more practical application needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] 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.

[0027] 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.

[0028] Figure 1 A connection diagram of a DC charging system in the related art;

[0029] Figure 2 This is a connection diagram of an embodiment of a three-phase boost charging circuit provided by the present application;

[0030] Figure 3 A circuit topology diagram of another embodiment of the three-phase boost charging circuit provided by the present application;

[0031] Figure 4 for Figure 3 Equivalent schematic diagram of the switch on-off control of the circuit in normal driving mode;

[0032] Figure 5 for Figure 3 Equivalent schematic diagram of the switch on-off control of the middle circuit in DC fast charging mode;

[0033] Figure 6 for Figure 3 Equivalent schematic diagram of the switch on-off control of the middle circuit in the boost charging mode;

[0034] Figure 7 for Figure 6 Schematic diagram of the corresponding inductor charging state in the boost charging mode;

[0035] Figure 8 for Figure 6 Schematic diagram of the inductor freewheeling state in the corresponding boost charging mode;

[0036] Figure 9 for Figure 3 Equivalent schematic diagram of the on-off control of the mid-circuit in battery heating mode;

[0037] Figure 10 for Figure 9 Schematic diagram of the inductive charging state when charging the battery in the corresponding battery heating mode;

[0038] Figure 11 for Figure 9 Schematic diagram of the inductor freewheeling state during battery charging in the corresponding battery heating mode;

[0039] Figure 12 for Figure 9 Schematic diagram of the inductor charging state during battery discharge in the corresponding battery heating mode;

[0040] Figure 13 for Figure 9 Schematic diagram of the inductor freewheeling state during battery discharge in the corresponding battery heating mode;

[0041] Figure 14 for Figure 3 Equivalent schematic diagram of the switch on-off control of the circuit in boost charging mode;

[0042] Figure 15 for Figure 14 Schematic diagram of the inductor charging state in the corresponding boost charging mode;

[0043] Figure 16 for Figure 14 Schematic diagram of the inductor freewheeling state in the corresponding boost charging mode.

[0044] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0045] 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.

[0046] 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.

[0047] 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.

[0048] Reference Figure 1 , Figure 1The 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, and the positive pole of the battery is also connected to the positive pole 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, and there is only one charging method. 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.

[0049] 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 a 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 limitations of the vehicle battery and the current limitations of the charging pile. This will limit the charging rate and unnecessarily extend the charging time. Furthermore, as the voltage level of automotive batteries continues to increase, the earlier low-voltage charging piles can no longer meet the charging needs of high-voltage vehicle batteries.

[0050] To address the above problems, the present application provides a three-phase boost charging circuit and an electric vehicle. The present application and the following embodiments are described below with reference to the accompanying drawings.

[0051] The present application proposes a three-phase boost charging circuit.

[0052] In one embodiment of the present application, refer to Figure 2 , Figure 2 This is a connection diagram of an embodiment of a three-phase boost charging circuit. The three-phase 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 three-phase boost charging circuit may also include multiple switch modules.

[0053] The plurality of switch modules include a first switch module, a second switch module, a third switch module, a fourth switch module and a fifth switch module;

[0054] 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 fifth switch module is connected to the positive pole of the charging pile, one end of the third switch module and one end of the fourth switch module are respectively connected to the other end of the fifth switch module, the other end of the first switch module and the other end of the fourth switch module are respectively connected to the neutral point of the multi-phase winding, 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.

[0055] 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 vehicle 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 end of the motor controller can be connected to the three-phase winding of the motor through the three-phase connection points respectively. The common connection point of the three-phase winding in the motor is connected through a section of winding wire ( Figure 2 It is represented by the equivalent inductance) and is connected as the neutral point of the three-phase winding. Figure 2 As shown in .

[0056] In addition, it should be noted that the first switch module, the second switch module, the third switch module, the fourth switch module, and the fifth 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 five switch modules can be controlled by an external control circuit or control device according to actual needs, or a controller can be set in the three-phase boost charging circuit to output control instructions to each switch module to achieve on-off control of each switch module. It can be understood that when the controller outputs the control instruction and whether the control instruction is a connection instruction or a disconnection instruction can be set according to actual needs and is not specifically limited here.

[0057] It can be understood that by turning on and off the above-mentioned five switch modules, the three-phase boost charging circuit can switch between normal driving mode, DC fast charging mode, boost charging mode, battery heating mode and boost charging 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 three-phase boost charging circuit adds boost charging function, boost charging function and battery heating function.

[0058] In one possible implementation, refer to Figure 2 , the three-phase boost charging circuit also includes a direct charging switch K1 and a direct charging switch K2;

[0059] The positive pole of the charging pile is connected to the positive pole of the battery through the direct charging switch K1, and the negative pole of the charging pile is connected to the negative pole of the battery through the direct charging switch K2. The negative pole of the charging pile is also connected to the connection point of the negative pole of the battery and the negative input terminal of the motor controller.

[0060] Among them, the direct charging switch K1 is used to be turned on in the DC fast charging mode, and disconnected in the normal driving mode, boost charging mode, battery heating mode and boost charging mode; the direct charging switch K2 is also used to be turned on in the DC fast charging mode, and disconnected in the normal driving mode, boost charging mode, battery heating mode and boost charging mode.

[0061] It should be noted that when the direct charging switch K1 and the direct charging switch K2 are turned on at the same time and the first switch module, the second switch module, the third switch module, the fourth switch module and the fifth switch module are all disconnected, the three-phase 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 K1 and the direct charging switch K2 are both disconnected.

[0062] Specifically, when only the second switch module is turned on and the first switch module, the third switch module, the fourth switch module, the fifth switch module, the direct charging switch K1 and the direct charging switch K2 are all turned off, the three-phase boost charging circuit enters the normal driving mode. At this time, the battery can provide the driving voltage to the motor controller to enable it to operate normally.

[0063] When the first switch module, the fifth switch module and the third switch module are turned on, and the second switch module, the fourth switch module, the direct charging switch K1 and the direct charging switch K2 are all turned off, the three-phase boost charging circuit enters the boost charging mode or the battery heating mode, and 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 output by a pulse signal provided in the three-phase boost charging circuit to achieve control; when the second switch module, the fifth switch module and the fourth switch module are turned on, and the first switch module, the third switch module, the direct charging switch K1 and the direct charging switch K2 are all turned off, the three-phase boost charging circuit enters the boost charging mode. In this mode, the power tube in the motor controller can also be controlled by on-off to connect the motor controller and the motor winding to the loop to achieve boost charging of the battery; it can be understood that it can also be set according to actual needs, and no specific limitation is made here.

[0064] The three-phase 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 through a first switch module with one end connected to the positive pole of the battery and the other end connected to the neutral point of the multi-phase winding, 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, 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, a fourth switch module with one end connected to the positive pole of the charging pile and the other end connected to the neutral point of the multi-phase winding, and a The switching of five switch modules, including the fifth switch module connected to the third switch module and the fourth switch module, is used to realize the switching of normal driving mode, DC fast charging mode, boost charging mode, boost charging mode and battery heating mode. 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, boost 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. In addition, the newly added boost charging function can increase the charging voltage of the entire vehicle battery, so that the low-voltage charging pile can also charge the battery of high-voltage vehicle models, thereby meeting more practical application needs.

[0065] In another embodiment of the present application, refer to Figure 3 , Figure 3 2 is a circuit topology diagram of another embodiment of a three-phase boost charging circuit, in which the first switch module may include a switch K10;

[0066] 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 the neutral point of the multi-phase winding.

[0067] The switch K10 is used to be turned on in the boost charging mode and the battery heating mode, and to be turned off in the normal driving mode, the DC fast charging mode and the boost charging mode.

[0068] It should be noted that the neutral point can be an interface or winding wire port derived from the common connection point of the motor's multi-phase windings. Here, the motor has a three-phase winding. Therefore, the neutral point of the multi-phase winding can specifically be one end of the winding inductor derived from the common connection point of the three-phase windings. The other end of the switch K10 can be connected to the neutral point of the three-phase windings, allowing the switch K10 to connect the positive electrode of the battery to the three-phase windings of the motor. The switch K10 can be a controllable switching device.

[0069] For example, when the three-phase boost charging circuit is to enter the boost charging mode or the battery heating mode, the switch K10 can be controlled to be turned on to connect the positive pole of the battery and the three-phase winding of the motor, so that the circuit in the boost charging mode or the battery heating mode is connected.

[0070] It is understandable that the first switch module uses a simple switch device to achieve on and off, which is convenient to turn on or off 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.

[0071] In one possible implementation, refer to Figure 3 , the second switch module in the three-phase boost charging circuit includes a switch K20;

[0072] 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.

[0073] The switch K20 is used to be turned on in the normal driving mode and the boost charging mode, and turned off in the DC fast charging mode, the boost charging mode and the battery heating mode.

[0074] It should be noted that switch K20 can be a controllable switch device. Switch K20 serves as the main switch located between the battery and the motor controller. When the motor controller needs to operate, that is, when the three-phase boost charging circuit needs to enter the normal drive mode, switch K20 can be controlled to turn on to connect the positive electrode of the battery and the positive electrode of the motor controller, so that the working circuit in the normal drive mode is conductive. It should be noted that in this normal drive mode, the first switch module, the third switch module, the fourth switch module, the fifth switch module, the direct charging switch K1, and the direct charging switch K2 are all disconnected.

[0075] 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 increase the current / voltage or heat the battery. The on and off is convenient and the control logic is simple.

[0076] In one possible implementation, refer to Figure 3 , the third switch module in the three-phase boost charging circuit includes a switch K30;

[0077] One end of the switch K30 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K30 is connected to the positive input end of the motor controller.

[0078] The switch K30 is used to be turned on in the boost charging mode and the battery heating mode, and turned off in the normal driving mode, the DC fast charging mode and the boost charging mode.

[0079] It should be noted that the switch K30 can be a controllable switch device. One end of the switch K30 is connected to the fifth switch module, and the other end is connected to the positive input terminal of the motor controller. It cooperates with the fifth switch module to switch between the boost charging mode and the battery heating mode.

[0080] For example, when the three-phase boost charging circuit is about to enter the boost charging mode or the battery heating mode, the switch K30 can be specifically controlled to be turned on, so as to connect the positive electrode of the charging pile and the positive input terminal of the motor controller through the fifth switch module and the switch K30, 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, or 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 by a pulse signal output by a controller separately provided in the three-phase boost charging circuit. The specific setting can be based on actual needs and is not limited here.

[0081] It can be understood that the third switch module uses a simple switch device to achieve on and off, and can be combined with the on and off of the first switch module and the fifth switch module to switch between the boost charging mode and the battery heating mode to achieve boost charging or heating of the battery. The on and off are convenient and the control logic is simple.

[0082] In one possible implementation, refer to Figure 3 , the fourth switch module in the three-phase boost charging circuit includes a switch K40;

[0083] One end of the switch K40 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K40 is connected to the neutral point of the multi-phase winding.

[0084] The switch K40 is used to be turned on in the boost charging mode and turned off in the normal driving mode, the DC fast charging mode, the boost charging mode and the battery heating mode.

[0085] It should be noted that the switch K40 can be a controllable switch device. One end of the switch K40 is connected to the fifth switch module, and the other end is connected to the neutral point of the multi-phase winding. It cooperates with the fifth switch module to switch on and off to enter the boost charging mode.

[0086] For example, when the three-phase boost charging circuit enters the boost charging mode, the switch K40 can be specifically controlled to be turned on, so as to connect the positive pole of the charging pile and the neutral point of the multi-phase winding through the fifth switch module and the switch K40, thereby connecting the circuit in the boost charging mode. In the boost charging mode, the output current of the charging pile is boosted by the fifth switch module, the switch K40, the motor winding, and the motor controller to charge the battery. In the boost charging mode, the on-off control of the power tube in the motor controller can be achieved by an external control circuit or device or by a pulse signal output by a controller separately provided in the three-phase boost charging circuit. The specific setting can be based on actual needs and is not limited here.

[0087] It is understandable that the fourth switch module uses a simple switch device to achieve on and off, and can be combined with the second switch module and the fifth switch module to enable the circuit to enter the boost charging mode to achieve boost charging of the battery. This not only simplifies the control logic, but also avoids excessive increase in device costs.

[0088] In one possible implementation, refer to Figure 3 The fifth switch module in the three-phase boost charging circuit includes a switch K51, a switch K52 and a diode D2;

[0089] One end of the switch K51 and one end of the switch K52 are respectively connected to the positive electrode of the charging pile, the other end of the switch K51 is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 and the other end of the switch K52 are both connected to one end of the third switch module and one end of the fourth switch module.

[0090] Among them, switch K51 is used to be turned on in battery heating mode, and disconnected in normal driving mode, DC fast charging mode, boost charging mode and boost charging mode; switch K52 is used to be turned on in boost charging mode and boost charging mode, and disconnected in normal driving mode, DC fast charging mode and battery heating mode.

[0091] It should be noted that both the switch K51 and the switch K52 can be controllable switch devices. The switch K51 is connected in series with the diode D2, and the series-connected switch K51 and diode D2 are then connected in parallel with the switch K52 to form a switch circuit as the fifth switch module.

[0092] For example, when the three-phase boost charging circuit is to enter the boost / boost charging mode, the switch K52 can be specifically controlled to be turned on to connect the positive electrode of the charging pile, the switch K30, and the positive input terminal of the motor controller, so that the output current of the charging pile is boosted by the switch K30, the motor controller, and the motor winding in the boost charging mode to charge the battery; or the positive electrode of the charging pile, the switch K40, and the motor winding are connected to realize that the output current of the charging pile is boosted by the switch K40, the motor winding, and the motor controller in the boost charging mode to charge the battery; when the three-phase boost charging circuit is to enter the battery heating mode, the switch K51 can be specifically controlled to be turned on to connect the positive electrode of the charging pile, the switch K30, and the positive input terminal of the motor controller, so that the battery is heated based on the corresponding battery charging and discharging in the battery heating mode. Among them, 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 three-phase boost charging circuit. The specific setting can be based on actual needs and is not limited here.

[0093] It is understandable that the fifth switch module uses simple switch devices and diode devices to achieve on-off, and can be combined with other switch modules to switch between boost charging mode, boost charging mode and battery heating mode to achieve boost / boost charging or heating of the battery.

[0094] For example, in order to more accurately reflect the working process of the three-phase boost charging circuit, the following Figure 3 As an example, the three-phase boost charging circuit shown in the figure is combined with Figure 4-Figure 16 , and explain its working process in detail.

[0095] Reference Figure 4 , Figure 4 This is an equivalent schematic diagram of the switch on-off control in normal driving mode. By turning on switch K20 and disconnecting the direct charging switch K1, direct charging switch K2, switch K10, switch K30, switch K40, switch K51 and switch K52, the three-phase boost charging circuit enters the normal driving mode; at this time, the battery, motor controller and motor are turned on in sequence, and the motor controller enters the normal working state.

[0096] Reference Figure 5 , Figure 5 This is an equivalent schematic diagram of the switch on-off control in DC fast charging mode. By connecting the direct charging switch K1 and the direct charging switch K2, and disconnecting the switches K10, K20, K30, K40, K51, and K52, the three-phase boost charging circuit enters the DC fast charging mode. At this time, the charging pile is directly connected to the battery for DC fast charging.

[0097] Reference Figure 6 , Figure 6This is an equivalent schematic diagram of the switch on-off control in the boost charging mode. By turning on switch K10, switch K52 and switch K30, and turning off the direct charging switch K1, direct charging switch K2, switch K20, switch K51 and switch K40, the three-phase 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. The three-phase bridge arm circuit in the motor controller is connected to the boost charging loop, and correspondingly, the three-phase winding of the motor is also connected to the boost charging loop. The three-phase boost charging circuit can be operated in the Buck circuit mode by adjusting the conduction time of the switch tube in each phase bridge arm circuit to increase the current passing through the battery and realize boost charging.

[0098] Furthermore, when the three-phase boost charging circuit is in the boost charging mode, based on each cycle, the three upper bridge arms of the three-phase bridge arm circuit connected to the boost charging circuit can be controlled to be turned on simultaneously and the lower bridge arms can be turned off simultaneously, and then the three lower bridge arms in the three-phase bridge arm circuit can be controlled to be turned on simultaneously and the upper bridge arms can be turned off simultaneously. In this way, the boost charging circuit has two states within one cycle:

[0099] 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 K52, the switch K30, the upper bridge arm, the motor winding, the switch K10, the battery, and returns to the negative electrode of the charging pile. 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, the inductor charging state of the boost charging mode is in this state. 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.

[0100] Reference Figure 9 , Figure 9This is an equivalent schematic diagram of the switch on-off control in the battery heating mode. By turning on switch K10, switch K51 and switch K30, and turning off the direct charging switch K1, direct charging switch K2, switch K20, switch K52 and switch K40, the three-phase boost charging circuit enters the battery heating mode. At this time, the charging pile, diode D2, motor controller, motor winding and battery are connected in sequence to form a battery heating loop. In this loop, 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 mentioned above, the three-phase bridge arm circuit in the motor controller is connected to the battery heating loop, and the three-phase winding of the motor is also connected to the battery heating loop, which will not be repeated here.

[0101] Furthermore, when the three-phase boost charging circuit is in the battery heating mode, based on each cycle of different battery states, the three upper bridge arms of the three-phase bridge arm circuit connected to the above-mentioned battery heating circuit can be controlled to be simultaneously turned on and the lower bridge arms can be simultaneously turned off. Then, the three lower bridge arms of the three-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, there are a total of four states in the battery heating mode:

[0102] 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 K51, the diode D2, the switch K30, the upper bridge arm, the motor winding, the switch K10, the battery in sequence, 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 Figure 11 As 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 K51, the diode D2, the switch K30, and the capacitor C1 form a loop to realize the energy release of the capacitor C1, and the diode D2 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.

[0103] 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 K51, the diode D2, the switch K30, and the capacitor C1 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 and continues to flow in the form of current, specifically flowing through the upper bridge arm, switch K30, diode D2, switch K51, charging pile, battery, and switch K10 in sequence, thereby realizing the electric energy release of the winding inductance. The battery remains in a discharged state under the inductive freewheeling. At the same time, the capacitor C1, battery, switch K10, motor winding, and upper bridge arm form a loop to realize the energy release of the capacitor C1, that is, at this time, it is in the inductive freewheeling state when the battery is discharged in the battery heating mode.

[0104] Reference Figure 14 , Figure 14 This is an equivalent schematic diagram of the switch on-off control in the boost charging mode. By turning on switch K20, switch K52 and switch K40, and turning off the direct charging switch K1, direct charging switch K2, switch K10, switch K51 and switch K30, the three-phase boost charging circuit enters the boost charging mode; at this time, the charging pile, motor winding, motor controller and battery are connected in sequence to form a boost charging loop. As described above, the three-phase bridge arm circuit in the motor controller is connected to the boost charging loop, and the three-phase winding of the motor is also connected to the boost charging loop. Among them, the three-phase boost charging circuit can be operated in the Boost circuit mode by adjusting the conduction time of the switch tube in each phase bridge arm circuit to increase the charging voltage reaching the battery and realize boost charging.

[0105] Furthermore, when the three-phase boost charging circuit is in the boost charging mode, based on each cycle, the three lower bridge arms of the three-phase bridge arm circuit connected to the boost charging circuit can be controlled to be turned on at the same time and the upper bridge arms can be turned off at the same time, and then the three upper bridge arms of the three-phase bridge arm circuit can be controlled to be turned on at the same time and the lower bridge arms can be turned off at the same time. In this way, the boost charging circuit has two states within one cycle:

[0106] Reference Figure 15 and Figure 16 , Figure 15 This is a schematic diagram of the inductor charging state in boost charging mode. Figure 16 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 15 As shown, in the lower bridge arm conduction stage of each cycle, the current output from the positive electrode of the charging pile passes through the switch K52, the switch K40, the motor winding, the lower bridge arm in sequence, and returns to the negative electrode of the charging pile. The current flows through the winding inductance of the motor, and the electrical energy is converted into magnetic field energy and stored in the winding inductance, thereby charging the winding inductance. At the same time, the capacitor C1 in front of the three-phase bridge arm circuit of the motor controller has the function of energy storage. The battery, the switch K20, and the capacitor C1 form a loop, and the capacitor C1 can be charged by the battery, that is, the inductor is in the boost charging mode at this time. Figure 16 As shown, during the conduction phase of the upper bridge arm in each cycle, the winding inductance releases the stored electric energy and continues to flow in the form of current, specifically flowing through the upper bridge arm, switch K20, battery, charging pile, switch K52, and switch K40 in sequence, realizing the release of electric energy. The released electric energy is converted into magnetic field energy and stored in the battery, realizing battery charging in the inductive freewheeling state; at the same time, the capacitor C1 releases the stored energy. Under the action of the capacitor C1, the voltage across the battery increases, that is, it is in the inductive freewheeling state of the boost charging mode at this time.

[0107] It can be seen from the above multiple different modes and their corresponding different states that the three-phase 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 current boost charging function, a battery heating function and a boost charging function, and only needs to control the connection of the corresponding circuit through the on and off of the newly added first switch module, the third switch module, the fourth switch module and the fifth switch module. Combined with the electronic control and motor in the whole vehicle, a current boost charging circuit, a battery heating circuit and a boost charging 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. In actual application, even if the output voltage of the charging pile is low, the high-voltage battery can be boosted and charged, meeting the needs of more practical applications.

[0108] The present application also proposes an electric vehicle, which may include a battery, a motor controller and a motor; and a three-phase boost charging circuit formed by connecting the battery, the motor controller and the motor to an external charging pile.

[0109] Among them, the battery, motor controller and motor are all arranged inside the electric vehicle.

[0110] It should be noted that the specific structure of the three-phase boost 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 described one by one here.

[0111] 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 three-phase boost charging circuit, characterized in that: The three-phase boost charging circuit includes 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 three-phase boost charging circuit further includes a plurality of switch modules; Wherein, the plurality of switch modules include a first switch module, a second switch module, a third switch module, a fourth switch module and a fifth 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 fifth switch module is connected to the positive electrode of the charging pile, one end of the third switch module and one end of the fourth switch module are respectively connected to the other end of the fifth switch module, the other end of the first switch module and the other end of the fourth switch module are respectively connected to the neutral point of the multi-phase winding, 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.

2. The three-phase boost charging circuit according to claim 1, wherein: The three-phase boost charging circuit also includes a direct charging switch K1 and a direct charging switch K2; The positive pole of the charging pile is connected to the positive pole of the battery through the direct charging switch K1, and the negative pole of the charging pile is connected to the negative pole of the battery through the direct charging switch K2. The negative pole of the charging pile is also connected to the connection point of the negative pole of the battery and the negative input terminal of the motor controller.

3. The three-phase boost charging circuit according to claim 1, wherein: 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 the neutral point of the multi-phase winding.

4. The three-phase boost charging circuit according to claim 1, wherein: 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.

5. The three-phase boost charging circuit according to claim 1, wherein: The third switch module includes a switch K30; One end of the switch K30 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K30 is connected to the positive input end of the motor controller.

6. The three-phase boost charging circuit according to claim 5, characterized in that: The switch K30 is configured to be turned on in the boost charging mode and the battery heating mode, and turned off in the normal driving mode, the DC fast charging mode, and the boost charging mode.

7. The three-phase boost charging circuit according to claim 1, wherein: The fourth switch module includes a switch K40; One end of the switch K40 is connected to the positive electrode of the charging pile through the fifth switch module, and the other end of the switch K40 is connected to the neutral point of the multi-phase winding.

8. The three-phase boost charging circuit according to claim 1, wherein: The fifth switch module includes a switch K51, a switch K52 and a diode D2; One end of the switch K51 and one end of the switch K52 are respectively connected to the positive electrode of the charging pile, the other end of the switch K51 is connected to the positive electrode of the diode D2, and the negative electrode of the diode D2 and the other end of the switch K52 are both connected to one end of the third switch module and one end of the fourth switch module.

9. The three-phase boost charging circuit according to claim 8, wherein: The switch K51 is used to be turned on in the battery heating mode and turned off in the normal driving mode, DC fast charging mode, boost charging mode and boost charging mode; The switch K52 is used to be turned on in the current boost charging mode and the voltage boost charging mode, and turned off 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 three-phase boost charging circuit as claimed in any one of claims 1 to 9, connected to an external charging pile.

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