CN111098760B

CN111098760B - Device and method for heating battery pack of electric vehicle and electric vehicle

Info

Publication number: CN111098760B
Application number: CN201811259613.1A
Authority: CN
Inventors: 孙韬; 朱道平; 倪攀; 陈毅; 徐勋高
Original assignee: Fafa Automobile China Co ltd
Current assignee: Fafa Automobile China Co ltd
Priority date: 2018-10-26
Filing date: 2018-10-26
Publication date: 2021-12-10
Anticipated expiration: 2038-10-26
Also published as: CN111098760A

Abstract

The embodiment of the invention provides a device and a method for heating a battery pack of an electric automobile and the electric automobile, and belongs to the field of electric automobiles. The device includes: the charging capacity judging and connecting module is used for converting voltage between the battery pack and charging equipment for charging the battery pack so that the charging equipment judges whether the charging of the battery pack is within the charging capacity range of the charging equipment; the heating module is used for receiving charging power of the charging equipment to generate heat energy to heat the battery pack; and the control module is used for controlling the charging capacity judging and connecting module to stop working and starting the heating module so as to heat the battery pack by the heating module under the condition of receiving a signal which is sent by the charging equipment and confirms that the battery pack is in the charging capacity range. Therefore, the battery pack is heated, the application range of the electric automobile is expanded, and the cost is reduced.

Description

Device and method for heating battery pack of electric vehicle and electric vehicle

Technical Field

The invention relates to the field of electric automobiles, in particular to a device and a method for heating a battery pack of an electric automobile and the electric automobile.

Background

The development of electric vehicles has a trend toward high voltage platforms, and there are some technologies for charging batteries of electric vehicles having high voltage. However, when the battery of the electric vehicle is at a low temperature, the battery cannot be charged due to its physicochemical properties, and therefore, the battery needs to be heated first to raise its temperature, and charging can be performed only when the temperature is allowed.

Disclosure of Invention

The object of the invention is to provide a device which can be realized as a battery heating for an electric vehicle.

In order to achieve the above object, an aspect of the present invention provides an apparatus for heating a battery pack of an electric vehicle, the apparatus comprising: the charging capacity judging and connecting module is used for converting voltage between the battery pack and charging equipment for charging the battery pack so that the charging equipment judges whether the charging of the battery pack is within the charging capacity range of the charging equipment; the heating module is used for receiving charging power of the charging equipment to generate heat energy to heat the battery pack; and the control module is used for controlling the charging capacity judging and connecting module to stop working and starting the heating module so as to heat the battery pack by the heating module under the condition of receiving a signal which is sent by the charging equipment and confirms that the battery pack is in the charging capacity range.

Optionally, the charging capability determining module includes: the voltage reduction circuit comprises a first coil, a first switch tube, a second switch tube and a first capacitor, wherein the first coil, the first switch tube, the second switch tube and the first capacitor are used for connecting the charging equipment and the battery pack, and the voltage reduction circuit is used for reducing the voltage of the battery pack so that the charging equipment can judge whether the battery pack is charged in the charging capacity range of the battery pack according to the reduced voltage; the first switch module is used for connecting the voltage reduction circuit and the charging equipment and controlling the connection or disconnection between the voltage reduction circuit and the charging equipment; and the second switch module is used for connecting the battery pack and the voltage reduction circuit and controlling the connection or disconnection between the voltage reduction circuit and the battery pack, wherein the control module controls the charging capacity judgment connection module to stop working by controlling the first switch module and/or the second switch module.

Optionally, the first switch module includes a first relay and/or a second relay, wherein the first relay is connected between the voltage reduction circuit and the positive pole of the charging device, and the second relay is connected between the voltage reduction circuit and the negative pole of the charging device.

Optionally, the second switch module includes a third relay and/or a fourth relay, wherein the third relay is connected between the voltage reduction circuit and the positive pole of the battery pack, and the fourth relay is connected between the voltage reduction circuit and the negative pole of the battery pack.

Optionally, the heating module comprises: a second coil for receiving charging power of the charging device to generate heat energy for heating the battery pack; and a third switching module, configured to connect the second coil and the charging device to control connection or disconnection between the second coil and the charging device, where the control module controls the heating module to start by controlling the third switching module.

Optionally, the third switching module includes a fifth relay and/or a sixth relay, where the fifth relay is used to connect the second coil and the positive electrode of the charging device, and the sixth relay is used to connect the second coil and the negative electrode of the charging device.

Optionally, in a case where the charging capability judgment connection module includes the voltage reduction circuit and the heating module includes the second coil, the first coil and the second coil are coils in a motor of the electric vehicle, the first switching tube and the second switching tube are switching tubes in an inverter of the electric vehicle, the heating module further includes a switching tube in the inverter, the second coil is connected to a third switching module via a switching tube in the inverter, and in a case where the control module controls the charging capability judgment connection module to stop operating, the control module is further configured to: before the heating module is started, transmitting a discharging signal to the inverter, so that the inverter forms a discharging circuit with a second capacitor and a coil in the motor by controlling a switching tube included in the inverter, the second capacitor is discharged, and whether the relation between the discharging voltage of the second capacitor and the voltage output by the charging equipment meets a first preset condition or not is monitored; transmitting a motor zero torque signal to the inverter such that the inverter controls the motor to not generate torque after the heating module is activated; and controlling to start a thermal management controller of the electric vehicle so as to transfer heat energy generated by the second coil to the battery pack; the condition that the control module controls the heating module to be started is that the relation between the discharge voltage of the second capacitor and the voltage output by the charging equipment is monitored to meet a first preset condition.

Optionally, the apparatus further comprises: the insulation detection module is connected between the positive electrode and the negative electrode of the charging equipment and the vehicle body ground and is used for: detecting the insulation resistance of a circuit formed by the charging equipment and the charging capability judging and connecting module or the heating module respectively in the working process of the charging capability judging and connecting module or the heating module; and transmitting a signal to the control module under the condition that the detected insulation resistance exceeds a preset value, so that the control module controls to disconnect the connection between the charging capacity judging and connecting module or the heating module and the charging equipment.

In addition, the invention also provides an electric automobile which comprises the device.

In addition, another aspect of the present invention also provides a method for heating a battery pack of an electric vehicle, the method including: the charging equipment judges whether the battery pack is charged within the charging capacity range of the battery pack; under the condition that a signal which is sent by the charging equipment and confirms that the battery pack is in the charging capacity range of the battery pack is received, transmitting a discharging signal to an inverter so that the inverter discharges a second capacitor through a control discharging circuit, and monitoring whether the relation between the discharging voltage of the second capacitor and the voltage output by the charging equipment meets a preset condition or not; under the condition that the relation between the discharge voltage of the second capacitor and the voltage output by the charging equipment meets a preset condition, starting the heating module to heat the battery pack; transmitting a motor zero torque signal to the inverter such that the inverter controls the motor to not generate torque after the heating module is activated; and controlling to start a thermal management controller of the electric vehicle so that heat energy generated by the second coil is transferred to the battery pack.

Through above-mentioned technical scheme, the battery package is connected to battery charging outfit via the ability of charging judgement connecting module, battery charging outfit judges whether the battery package is in its ability of charging within range, under the condition that the battery package is in battery charging outfit's ability of charging within range, battery charging outfit signals to control module, control module starts heating module, heating module is connected with battery charging outfit, heating module receives battery charging outfit's charging electric power after being started and produces heat energy and heat for the battery package, so, realized heating for the battery package, make electric automobile can use in the colder area of weather, electric automobile's range of application has been enlarged. In addition, the battery pack is heated by the charging equipment, and a battery pack heater is not required to be additionally arranged for the electric automobile, so that the cost is reduced.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

fig. 1 is a schematic connection diagram of an apparatus for heating a battery pack of an electric vehicle according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of the connection of the BUCK circuit;

fig. 3 is a schematic connection diagram of an apparatus for heating a battery pack of an electric vehicle according to another embodiment of the present invention;

FIG. 4 is a schematic diagram of the connection of an insulation detection module in a circuit according to another embodiment of the present invention;

fig. 5 is a logic diagram of a charging device according to another embodiment of the present invention determining whether a battery pack is charged within a charging capability range;

FIG. 6 is a schematic diagram of the basic structure of an electric vehicle;

FIG. 7 is a schematic diagram of the connection between the charging device and the external power source and the battery pack according to an embodiment of the present invention;

fig. 8 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention;

FIG. 9 is a logic diagram of the apparatus of FIG. 8 for charging an electric vehicle;

fig. 10 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention;

FIG. 11 is a logic diagram of the apparatus of FIG. 10 for charging an electric vehicle;

fig. 12 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention;

FIG. 13 is a logic diagram of the apparatus of FIG. 12 for charging an electric vehicle;

fig. 14 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention;

fig. 15 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention; and

fig. 16 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention.

Description of the reference numerals

1 coil 2 first control module

3 at least one pair of control switches 4 DC charging socket

5-wire-harness 6 motor

7 motor controller 8 batteries

9 boost DC/DC device 10 external power supply

11 charging equipment 12 charging capability judges connection module

13 battery pack 14 control module

15 heating module 16 electric machine coil

17 switching tube

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.

One aspect of an embodiment of the present invention provides an apparatus for heating a battery pack of an electric vehicle. Fig. 1 is a schematic connection diagram of an apparatus for heating a battery pack of an electric vehicle according to an embodiment of the present invention. As shown in fig. 1, the apparatus includes a charging capability judgment connection module 12, a heating module 15, and a control module 14. The charging capability determining connection module 12 connects the battery pack 13 and the charging device 1 for charging the battery pack, and is configured to convert a voltage between the battery pack 3 and the charging device 1, so that the charging device 11 determines whether the charging of the battery pack 13 is within a charging capability range. When a battery pack of an electric vehicle is charged using a charging device (e.g., a charging pile, where the charging pile may be a dc charging pile), the voltage of the battery pack may not match the voltage between the charging devices, for example, if the battery pack is a high voltage, e.g., 800V, and the charging device is a low voltage, e.g., 400V, or if the battery pack is a low voltage, e.g., 400V, and the charging device is a high voltage, e.g., 800V, it is necessary to convert the voltage of the battery pack, so that the charging device determines whether the converted voltage is in its output voltage range, determines whether the battery pack requiring charging is charged in its charging capability range, and outputs electric energy to charge the battery pack if it is determined that the battery pack is charged in its charging capability range. The heating module 15 is connected to the charging device 11 and the control module 14, and is configured to receive the charging capability of the charging device 11 to generate heat energy, so as to heat the battery pack 13 by using the generated heat energy. The control module 14 is connected to the charging capability judgment connection module 12 and the heating module 15, and can communicate with the charging device 11. The charging device 11 transmits a corresponding signal to the control module 14 when determining that the charging of the battery pack requiring the charging device is within the charging capability range, and the control module 14 controls the charging capability judgment connection module 12 to stop working, that is, disconnects the connection with the charging device 11 and/or the battery pack 13, so that a loop formed by the charging device 11, the charging capability judgment connection module 12 and the battery pack 13 is disconnected, and the heating module 15 is started, that is, controls the heating module 15 and the charging device 11 to form a loop, so that the heating module 15 receives the charging power of the charging device 11 to generate heat energy, thereby heating the battery pack 13.

The battery package judges that connection module is connected to battery charging outfit via the charging capacity, battery charging outfit judges whether the battery package is in its charging capacity within range, under the condition that the battery package is in battery charging outfit's charging capacity within range, battery charging outfit signals to control module, control module starts heating module, heating module is connected with battery charging outfit, heating module receives battery charging outfit's charging electric power after being started and produces heat energy and heat for the battery package, thus, realized heating for the battery package, make electric automobile can use in the colder area of weather, electric automobile's range of application has been enlarged. In addition, the battery pack is heated by the charging equipment, and a battery pack heater is not required to be additionally arranged for the electric automobile, so that the cost is reduced.

Optionally, in the embodiment of the present invention, the charging capability determining connection module includes a voltage reducing circuit, a first switch module, and a second switch module. The voltage reduction circuit comprises a first coil connected between the charging equipment and the battery pack, a first switch tube, a second switch tube and a first capacitor, and is used for reducing the voltage of the battery pack, so that the charging equipment judges whether the reduced voltage is in the output voltage range of the charging equipment or not, judges whether the charging is in the charging capacity range of the battery pack or not according to the reduced voltage, namely the voltage of the charging equipment is lower than that of the battery pack, the voltage of the battery pack needs to be reduced, and the charging equipment can judge whether the charging is in the charging capacity range of the battery pack or not. The first switch module is connected between the voltage reduction circuit and the charging equipment and used for controlling connection or disconnection between the voltage reduction circuit and the charging equipment. The second connecting module is connected between the battery pack and the voltage reduction circuit and used for controlling connection or disconnection between the battery pack and the voltage reduction circuit. The control module controls the charging capacity judging and connecting module to stop working by controlling the first switch module and/or the second switch module, namely, the disconnection between the voltage reduction circuit and the charging equipment and/or the disconnection between the voltage reduction circuit and the battery pack.

Optionally, in an embodiment of the present invention, the voltage-reducing circuit is a BUCK circuit. Specifically, the first switch tube and the second switch tube respectively comprise an IGBT and a parasitic diode, and the first coil, the IBGT in the first switch tube, the parasitic diode in the second switch tube and the first capacitor form a BUCK circuit. When the BUCK circuit is formed, the IGBT of the first switch tube is switched on, and the IGBT of the second switch tube is switched off, so that the IGBT of the first switch tube is switched into the circuit, and the parasitic diode of the second switch tube is switched into the circuit. The connection diagram of the BUCK circuit can be as shown in FIG. 2, u_dCorresponding to the voltage of the battery pack, VT corresponds to IGBT in the first switch tube, VD corresponds to parasitic diode in the second switch tube, L corresponds to the first coil, C corresponds to the first capacitor, u corresponds to the second capacitor_oCorresponding to the voltage of the charging device.

Optionally, in an embodiment of the present invention, the first switching module includes a first relay and/or a second relay, wherein the first relay is connected between the voltage reduction circuit and the positive pole of the charging device, and the second relay is connected between the voltage reduction circuit and the negative pole of the charging device.

Optionally, in an embodiment of the present invention, the second switch module includes a third relay and/or a fourth relay, wherein the third relay is connected between the voltage reduction circuit and the positive pole of the battery pack, and the fourth relay is connected between the voltage reduction circuit and the negative pole of the battery pack.

Optionally, in an embodiment of the present invention, the heating module includes a second coil and a third switching module. The second coil is used for receiving charging power of the charging device to generate heat energy to heat the battery pack. The third switching module is connected between the second coil and the charging device and used for controlling connection or disconnection between the second coil and the charging device. The control module controls the heating module to start by controlling the third switch module, namely by controlling the conduction between the second coil and the charging equipment.

Optionally, in an embodiment of the present invention, the third switching module includes a fifth relay and/or a sixth relay, wherein the fifth relay is connected between the second coil and the positive electrode of the charging device, and the sixth relay is connected between the second coil and the negative electrode of the charging device.

Optionally, in the embodiment of the present invention, the first coil included in the step-down circuit of the charging capability judgment connection module and the second coil included in the heating module may be coils in a motor of an electric vehicle, and the first switching tube and the second switching tube included in the charging capability judgment connection module may be switching tubes in an inverter of the electric vehicle. In addition, the heating module further comprises a switch tube in the inverter, and the second coil is connected with the third switch module through the switch tube in the inverter. Under the condition that the control module controls the charging capacity to judge that the connection module stops working, the control module is further used for: before the heating module is started, transmitting a discharging signal to the inverter, enabling the inverter to form a discharging circuit with a second capacitor and a coil in the motor by controlling a switching tube included in the inverter, enabling the second capacitor to discharge, and monitoring whether a relation between discharging voltage of the second capacitor and voltage output by charging equipment meets a first preset condition; transmitting a motor zero torque signal to the inverter so that the inverter controls the motor not to generate a torque after the heating module is started; and controlling to start a thermal management controller of the electric vehicle so as to transfer the heat energy generated by the second coil to the battery pack; the control module controls the heating module to be started under the condition that the relation between the discharge voltage of the second capacitor and the voltage output by the charging equipment is monitored to meet a first preset condition. Optionally, the first preset condition is that a voltage difference between a discharge voltage of the second capacitor and a voltage output by the charging device is less than or equal to 10 volts.

The following provides an exemplary description of an apparatus for heating a battery pack of an electric vehicle according to an embodiment of the present invention with reference to fig. 3. It should be noted that, in fig. 3, the coil in the motor is a three-phase coil, that is, three motor coils 16 are included, and the inverter includes 6 switching tubes 17, where the upper arm includes 3 switching tubes 17, and the lower arm includes 3 switching tubes 17, however, in the embodiment of the present invention, the coil in the motor is not limited to a three-wire coil, the switching tubes in the inverter are not limited to 3 switching tubes in each of the upper and lower arms, the coil in the motor may be a coil of any phase, and the inverter may include any number of switching tubes, as long as the conditions in the embodiment of the present invention are met, the heating for the battery pack can be implemented. Further, in this embodiment, the charging device 11 is a 400-volt charging post, and the voltage of the battery pack 13 is 800 volts.

As shown in fig. 3, K5' represents a first relay, namely a 400v relay, according to the embodiment of the present invention, and the bus on which the relay is located is a 400v bus; k6 represents a second relay, namely a high voltage negative relay, as described in the embodiments of the present invention; s4 represents a third relay described in the embodiments of the present invention, namely, a battery pack main positive (800 v) relay; s5 represents a fourth relay described in the embodiment of the present invention, that is, a battery pack main negative relay; k5 represents a fifth relay described in the embodiments of the present invention, that is, an 800v relay, where the bus is an 800v bus; k6 also represents a sixth relay as described in the embodiments of the present invention.

When it is determined whether the charging of the battery pack 13 is within the charging capability range of the charging device 11, the charging device transmits power to the charging device via the K5', the one-phase motor coil 16 in the motor, the one switch tube 17 in the upper arm, the one switch tube 17 in the lower arm, and the capacitor C2 form a BUCK circuit, wherein the two switch tubes 17 forming the BUCK circuit are two switch tubes 17 having a common end, and specifically, which motor coil 16 and which two switch tubes 17 can be designed according to specific situations, as long as the BUCK circuit can be formed, which is not limited by the present invention.

When the battery pack is heated, the charging device 11 supplies electric power to the outside via the K5, returns the electric power to the negative electrode of the charging device 11 via the switching tube 17 of the upper arm, the switching tube 17 of the lower arm of the motor coil 16, and the K6, and controls the motor to generate no torque. In addition, the capacitor C2 is not switched into the circuit, i.e., K7 is in an open state. Specifically, which switching tube or tubes 17 of the upper bridge arm, which switching tube or tubes 17 of the lower bridge arm, and which phase or phases of the motor coils 16 are adopted can be designed according to specific situations, as long as the control of the motor to generate no torque and the generation of heat energy by the motor coils can be realized, and the invention is not limited thereto.

After the electric vehicle is connected to the charging device 11, the charging device 11 transmits a corresponding signal to the power system controller (i.e., the control module in the embodiment of the present invention), and after receiving the signal, the power system controller controls the switching on of K5', K6, S4, S5, and K7, and transmits a signal to the inverter, so that the inverter controls the switching on or off of the IGBT in the switching tube 17 included in the inverter to form a BUCK circuit with the motor coil 16. Subsequently, the charging device 11 determines whether the converted voltage is within its output voltage range, that is, whether the battery pack 13 whose charging is required is charged is within its charging capability range, and a detailed explanation will be given below as to how the charging device 11 determines whether the battery pack 13 is charged within its charging capability range. When the charging device 11 determines that the battery pack 13 is charged within the charging capability range, the charging device 11 controls the output current to be 0, transmits a corresponding signal to the power system controller, and the power system controller controls the disconnection of S4 and S5 after receiving the signal. In addition, the power system controller transmits a discharge signal to the inverter, so that the inverter forms a discharge circuit with the second capacitor C3 and the motor coil 16 in the motor by controlling the switching tube included in the inverter, so that the second capacitor C3 is discharged. In addition, during the discharging process of the second capacitor C3, the powertrain controller monitors whether the relationship between the discharging voltage of the second capacitor C3 and the voltage output by the charging device 11 meets a first preset condition, such as by monitoring the discharging voltage of the second capacitor C3 and the voltage at the point K5', wherein the first preset condition may be that the voltage difference between the two is less than or equal to 10 volts. When the powertrain controller monitors that the relationship between the voltage across the second capacitor C3 and the voltage output by the charging device 11 meets a first preset condition, meaning that the discharge voltage of the second capacitor C3 matches the voltage output by the charging device, i.e., the original 800v voltage on the electric vehicle drops to 400v, the control switches off K5' and makes K5 conductive, thus, the 800V bus is switched to the 400V bus, so that the voltage output by the charging device 11 is directly applied to the inverter of the 800V bus, the 800V bus where K5 is located is connected to the 400V charging device voltage platform, and transmits a motor zero torque signal to the inverter so that the inverter controls the motor not to generate torque, consumes the whole electric energy on the motor coil 16, as such, the charging power from the charging device 11 received by the motor coil 16 connected in the circuit is used to generate heat energy to heat the battery pack 13. In addition, after the control K5 is closed, the powertrain controller controls to start the thermal management controller of the electric vehicle, so that the heat energy generated by the motor coil 16 is transferred to the battery pack 13, and the heating of the battery pack 13 is realized.

Optionally, in an embodiment of the present invention, the apparatus for heating a battery pack of an electric vehicle further includes an insulation detection module connected between the positive and negative electrodes of the charging device and a vehicle body ground (i.e., a ground), for: detecting the insulation resistance of a circuit formed by the charging equipment and the charging capability judging and connecting module or the heating module respectively in the working process of the charging capability judging and connecting module or the heating module; and transmitting a signal to the control module under the condition that the detected insulation resistance exceeds a preset value, so that the control module controls to disconnect the charging capacity to judge the connection between the connection module or the heating module and the charging equipment.

Fig. 4 is a schematic diagram of connection of an insulation detection module in a circuit according to another embodiment of the present invention. As shown in fig. 4, the insulation detection module IMD is connected between the positive electrode and the negative electrode of the charging device and the vehicle body ground (i.e., the ground, not shown in the figure), and performs insulation detection to ensure safety when determining whether the battery pack is charged within the charging capability range of the charging device and heating the battery pack.

Fig. 5 is a logic diagram of a charging device according to another embodiment of the present invention for determining whether a battery pack is charged within a charging capability range.

As shown in fig. 5, the vehicle-side voltage, that is, the voltage converted by the charging capability judging connection module is detected. After the voltage is detected, whether the detected voltage is within a normal range is judged. Wherein the normal range includes the following conditions: the voltage difference between the detected voltage and the voltage that the battery pack informs the charging device when the charging device is communicating is less than or equal to 5%; and whether the detected voltage is between a maximum voltage and a minimum voltage that can be output by the charging device. And when the detected voltage is not in the normal range, the charging sequence of the charging equipment is ended, and the charging equipment detects a fault and judges the fault level. When the detected voltage is within the normal range, the charging device adjusts the voltage it outputs. Subsequently, the charging device judges whether the voltage output by the charging device meets a second preset condition, wherein the second preset condition is that the voltage between the voltage output by the charging device and the detected voltage is in a range of +/-1-10V. And if the charging equipment judges that the output voltage meets the second preset condition, controlling the DC relay of the charging equipment to enable the electric energy to be output from the charging equipment, and if the output voltage does not meet the second preset condition, continuously adjusting the output voltage until the output voltage meets the second preset condition.

In addition, another aspect of the embodiments of the present invention provides an electric vehicle, which includes the device for heating a battery pack of the electric vehicle described in the above embodiments.

In addition, another aspect of the embodiments of the present invention further provides a system for heating a battery pack of an electric vehicle, where the system includes the apparatus and the charging device described in the above embodiments.

Another aspect of an embodiment of the present invention also provides an apparatus for charging an electric vehicle. The electric automobile comprises a motor, a motor controller and a battery pack. Fig. 6 is a schematic diagram of the basic structure of an electric vehicle. As shown in fig. 6, the electric vehicle includes a motor 6, a motor controller 7, and a battery pack 8 (the battery pack described here and in the following embodiments is equivalent to the battery pack described in the above embodiments). The motor 6 includes three-phase stator coils, a coil L1, a coil L2, a coil L3 (the coil or stator coil described here and in the following embodiments is equal to the motor coil described in the above embodiments), the motor controller 7 (the motor controller described here and in the following embodiments is equal to the inverter described in the above embodiments), three pairs of control switches (the control switches described here and in the following embodiments are equal to the switch tubes described in the above embodiments, wherein the opening and closing of the control switch tubes is the opening and closing of IGBTs in the control switch tubes), a control switch Q1 and a control switch Q2, the control switch Q3 is connected with the control switch Q4, the control switch Q5 is connected with the control switch Q6, the coil L1 and the control switch Q1 are connected with the common end of the control switch Q2, the coil L2 and the control switch Q3 are connected with the common end of the control switch Q4, and the coil L3 and the control switch Q5 are connected with the common end of the control switch Q6. In addition, the system voltage of the battery pack of the electric automobile is between 550V and 950V. It should be noted that the apparatus for charging an electric vehicle according to the embodiment of the present invention is not limited to charging the electric vehicle shown in fig. 7, and may also be used to charge other electric vehicles satisfying the present invention, for example, an electric vehicle to which a motor including four-phase stator coils is applied, an electric vehicle to which a motor controller including four pairs of control switches is applied, and the like.

Fig. 7 is a schematic diagram illustrating connection between an apparatus for charging an electric vehicle and an external power source and a battery pack according to an embodiment of the present invention. The electric automobile comprises a motor, a motor controller and a battery pack. As shown in fig. 7, the apparatus comprises a coil 1, a first control module 2 and at least one pair of control switches 3. The coil 1 is used for receiving charging power, wherein the charging power may be from an external power source 10, such as a dc charging post, or from another power source that can supply power to the coil 1, which is not limited in this respect. The at least one pair of control switches 3 includes a first control switch and a second control switch connected between the coil 1 and the battery pack 8 for alternately conducting to feed the charging power received by the coil 1 to the battery pack 8. The first control module 2 is used for controlling the first control switch and the second control switch to be alternately conducted according to the current of the coil 1 so as to feed the charging power received by the coil 1 to the battery pack 8. Wherein the coil 1 may be a stator coil in a motor and/or the at least one pair of control switches 3 may be a pair of control switches in a motor controller. In the embodiment of the present invention, the coil 1 may include a stator coil inside the motor, may include a coil (e.g., an additional coil) other than the motor, and may further include a stator coil inside the motor and a coil other than the motor. In the case where the coil 1 includes a stator coil in a motor, the coil may include a stator coil of one phase in the motor, or may include a stator coil of two phases in the motor. The at least one pair of control switches 3 may be a pair of control switches in the motor controller, or may not be a pair of control switches in the motor controller, and for example, a pair of control switches may be added. Under the condition that the coil 1 comprises a coil in the motor and at least one pair of control switches 3 is a pair of control switches in the motor controller, a boost circuit is formed by the motor coil and the control switches of the electric automobile to charge the battery pack of the electric automobile, and boosting DC/DC equipment or other parts do not need to be additionally arranged to charge the battery pack of the electric automobile, so that the cost is reduced.

By means of a stator coil in the motor of the electric automobile and/or a pair of control switches in the motor controller, the charging voltage provided by the external power supply is improved so as to meet the requirements of the electric automobile, therefore, the cost is greatly reduced while the electric automobile is charged, the weight of the electric automobile is reduced, and the influence on the driving range and the efficiency of the electric automobile is reduced. In addition, only a small number of parts need to be added, the occupied space in the electric automobile is small, and the design and arrangement on the electric automobile are facilitated. In addition, while the electric vehicle is charged by means of the components of the electric vehicle itself, the cooling system of the components can also be used, so that the need for a separate cooling system is eliminated.

In the embodiment of the present invention, the first control switch and the second control switch are controlled to be alternately turned on according to the current of the coil, which may be controlled according to a relationship between the current of the coil and a preset current value, wherein the preset current value may be related to the inductance of the coil, the charging characteristic of the battery pack, the initial voltage of the battery pack, the average current of the battery pack, the temperature of the battery pack, and the like; the energy stored in the coil can be determined according to the current, and then the control is carried out according to the relation between the energy and a preset value. Optionally, in an embodiment of the present invention, controlling the first control switch and the second control switch to be alternately turned on according to the current of the coil includes cyclically performing the following operations: controlling the first control switch to be closed and the second control switch to be opened; when the current of the coil is increased to a first preset value, the first control switch is controlled to be switched off, and the second control switch is controlled to be switched on; and when the current of the coil is reduced to a second preset value, controlling the first control switch to be closed and the second control switch to be opened. The first preset value may be related to inductance of the coil, charging characteristics of the battery pack, a starting voltage of the battery pack, a temperature of the battery pack, and the like, and the second preset value may be related to an average current and charging characteristics of the battery pack, and the like.

The following describes in detail an apparatus for charging an electric vehicle according to an embodiment of the present invention, and the electric vehicle shown in fig. 7 is taken as an example for explanation.

Fig. 8 is a schematic connection diagram of an apparatus for charging an electric vehicle according to an embodiment of the present invention. As shown in fig. 8, the device includes one of a coil L1, a coil L2, and a coil L3, and one of three pairs of control switches, and connects the positive electrode of the dc charging socket 4 and the center point of the three-phase stator coil of the motor 6 using the wire harness 5. In this embodiment, in the case where the apparatus includes the coil L1, the electric vehicle is charged by controlling the control switch Q1 and the control switch Q2 to be on; in the case where the device includes a coil L2, the electric vehicle is charged by controlling the control switch Q3 and the control switch Q4; in the case where the device includes the coil L3, the electric vehicle is charged by controlling the control switch Q5 and the control switch Q6. In the embodiment of the present invention, the connection between the dc charging socket 4 and the center point of the three-phase stator coil is not limited to the use of the wire harness, and other components may be used as long as the connection component can achieve the conduction between the dc charging socket 4 and the stator coil of the motor.

In the following, taking as an example that the dc charging post is connected to the dc charging socket 4 via the dc charging gun to charge the electric vehicle, and the device includes the coil L1, the control switch Q1 and the control switch Q2, how to charge the electric vehicle will be described with reference to fig. 9.

After the dc charging pile is started, the dc charging pile outputs a certain voltage value allowed by the dc charging pile according to a charging requirement of the electric vehicle (when the dc charging pile is started, the electric vehicle and the dc charging pile can communicate, and the electric vehicle transmits a charging requirement of the electric vehicle, for example, a charging voltage required to be reached is 600V, to the dc charging pile), and the control switches Q3, Q4, Q5, and Q6 included in the motor controller 7 are all in an off state. The control switch Q1 and the control switch Q2 are opened and closed according to the control request by using the arm operation of the control switch Q1 and the control switch Q2. The operation timings of Q1 and Q2 are as follows.

As shown in fig. 9, initially, the control switch Q1 is in an open state with the control switch Q2. Closing the control switch Q2. After the control switch Q2 is closed, the current of the coil L1 is detected, and whether the current of the coil L1 reaches a first design value (the design value is the first preset value in the embodiment of the present invention) is determined. The first design value is related to, among other things, the inductance of the coil L1, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. In addition, the first design value varies in real time during charging according to the inductance of the coil L1, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. When the current of the coil L1 does not reach the first design value, the current of the coil L1 is determined by continuing to detect the current of the coil. When the current of the coil L1 reaches the first design value, the control switch Q2 is turned off, and the control switch Q1 is turned on. After the control switch Q1 is turned on, the current of the coil L1 is detected, and whether the current of the coil L1 reaches a second design value (the second design value is the second preset value in the embodiment of the present invention) is determined. Wherein the second design value is related to the average current of the battery pack 8 and the charging characteristics, and the second design value is changed in real time according to the average current of the battery pack 8 and the charging characteristics during the charging. Further, in the case where the motor controller 7 includes a capacitor, as shown in fig. 8, the motor controller includes a capacitor C1, and the second design value is also related to the characteristic of the capacitor. In the case where the current of the coil L1 is not reduced to the second design value, the current of the coil L1 is continuously detected and it is determined whether or not the current reaches the second design value. In the case where the current of the coil L1 reaches the second design value, the control switch Q1 is turned off. After the control switch Q1 is turned off, it is determined whether or not the battery pack 8 is fully charged. There are many ways to determine whether the battery pack 8 is fully charged, for example, detecting the voltage of the battery pack 8, and determining whether the voltage of the battery pack 8 reaches a preset voltage value, where the voltage of the battery pack 8 reaching the preset voltage value is that the battery is fully charged; if the voltage of the battery pack 8 does not reach the preset voltage value, it indicates that the battery pack 8 is not fully charged. In the case where the battery pack 8 is not fully charged, the above process is continuously performed in a loop, and the control switch Q1 and the control switch Q2 are alternately turned on until the battery pack 8 is fully charged, that is, the required charge amount is reached. When the battery pack 8 is fully charged, the control switch Q1 and the control switch Q2 are turned off, the charging process is stopped, the dc charging gun is pulled out, the connection with the dc charging socket 4 is disconnected, and the charging is completed. In this embodiment, according to the parameters of the coil and the control switch shown in fig. 8, the voltage of the charging pile can be increased from 500V to 800V, so that the battery pack of the electric vehicle can be charged.

Fig. 10 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention. The difference from the device shown in fig. 8 is that in this embodiment the coils included in the device are two-phase stator coils in the motor of an electric vehicle. As shown in fig. 10, the wire harness 5 connects the positive electrode of the dc charging socket 4 with the input terminal of the coil L1, so that the apparatus for charging an electric vehicle includes the coil L1 and the coil L2 or includes the coil L1 and the coil L3, and charges the electric vehicle by controlling the control switch Q3 and the control switch Q4 or the control switch Q5 and the control switch Q6. In this embodiment, in addition to being connected to the input end of the coil L1, the wire harness 5 may be connected to the input end of the coil L2, the coil in the device includes the coil L1 and the coil L2 or includes the coil L2 and the coil L3, and the electric vehicle is charged by controlling the control switch Q1 and the control switch Q2 or controlling the switch Q5 and the control switch Q6; or the wire harness 5 can be connected to the input end of the coil L3, the coil in the device comprises the coil L1 and the coil L3 or comprises the coil L2 and the coil L3, and the electric automobile is charged by controlling the control switch Q1 and the control switch Q2 or controlling the switch Q3 and the control switch Q4.

The following description will be given of how to charge an electric vehicle, taking an example in which the apparatus includes a coil L1 and a coil L2, and a control switch Q3 and a control switch Q4. The control switches Q1, Q2, Q5, Q6 included in the motor controller 7 are all in an off state.

As shown in fig. 11, initially, the control switch Q3 is in an open state with the control switch Q4. Closing the control switch Q4. After the control switch Q4 is closed, the currents of the coil L1 and the coil L2 are detected, and whether the currents of the coil L1 and the coil L2 reach a first design value (the design value is the first preset value in the embodiment of the present invention) is determined. As shown in fig. 10, since coil L1 is connected in series with coil L2, the currents of coil L1 and coil L2 are equal, and whether the currents of coil L1 and coil L2 described herein reach the first design value or not is determined to determine whether the current of the series circuit of coil L1 and coil L2 reaches the first design value or not, it is possible to determine only the current of coil L1 or only the current of coil L2 in addition to the currents of coil L1 and coil L2. Wherein the first design value is related to the inductance of coil L1 and/or coil L2, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. In addition, the first design value varies in real time during charging according to the inductance of the coil L1 and/or the coil L2, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. When the currents of the coil L1 and the coil L2 do not reach the first design value, the current of the coil is continuously detected, and whether the currents of the coil L1 and the coil L2 reach the first design value or not is determined. When the currents of the coil L1 and the coil L2 reach the first design value, the control switch Q4 is turned off and the control switch Q3 is turned on. After the control switch Q3 is turned on, the currents of the coil L1 and the coil L2 are detected, and whether the currents of the coil L1 and the coil L2 reach a second design value (the second design value is a second preset value in the embodiment of the present invention) is determined. Wherein the second design value is related to the average current of the battery pack 8 and the charging characteristics, and the second design value is changed in real time according to the average current of the battery pack 8 and the charging characteristics during the charging. Further, in the case where the motor controller 7 includes a capacitor, as shown in fig. 10, the motor controller includes a capacitor C1, and the second design value is also related to the characteristic of the capacitor. When the currents of the coil L1 and the coil L2 are not reduced to the second design value, the currents of the coil L1 and the coil L2 are continuously detected and it is determined whether or not the currents reach the second design value. When the currents of the coil L1 and the coil L2 reach the second design value, the control switch Q3 is turned off. After the control switch Q3 is turned off, it is determined whether or not the battery pack 8 is fully charged. There are many ways to determine whether the battery pack 8 is fully charged, for example, detecting the voltage of the battery pack 8, and determining whether the voltage of the battery pack 8 reaches a preset voltage value, where the voltage of the battery pack 8 reaching the preset voltage value is that the battery is fully charged; if the voltage of the battery pack 8 does not reach the preset voltage value, it indicates that the battery pack 8 is not fully charged. In the case where the battery pack 8 is not fully charged, the above-described process continues to be cyclically performed, and the control switch Q3 and the control switch Q4 are alternately turned on until the battery pack 8 is fully charged. When the battery pack 8 is fully charged, the control switch Q3 and the control switch Q4 are turned off, and the charging is completed.

Fig. 12 is a schematic connection diagram of an apparatus for charging an electric vehicle according to another embodiment of the present invention. The difference from the device shown in fig. 8 is that, in this embodiment, the coil included in the device is a coil other than the motor of the electric vehicle, and a coil L4 is added between the dc charging jack 4 and the input terminal of the coil L1. As shown in fig. 12, one end of the coil L4 is connected to the positive electrode of the dc charging outlet 4, and the other end of the coil L4 is connected to the input end of the coil L1. Note that, in this embodiment, the other end of the coil L4 may be connected to an input terminal of the coil L2 or an input terminal of the coil L3, in addition to the input terminal of the coil L1. Under the condition that the other end of the coil L4 is connected with the input end of the coil L1, the electric automobile is charged by controlling the control switch Q1 and the control switch Q2; under the condition that the other end of the coil L4 is connected with the input end of the coil L2, the electric automobile is charged by controlling the control switch Q3 and the control switch Q4; when the other end of the coil L4 is connected to the input terminal of the coil L3, the electric vehicle is charged by controlling the control switch Q5 and the control switch Q6. The external coil is used for charging the electric automobile, so that the influence on the stator coil in the motor can be reduced. In addition, with the additional coil, the wiring is relatively flexible.

Next, how to charge the electric vehicle will be described by taking an example in which the apparatus includes the coil L4 and one end of the coil L4 is connected to the input end of the coil L1. The control switches Q3, Q4, Q5, Q6 included in the motor controller 7 are all in an off state.

As shown in fig. 13, initially, the control switch Q1 and the control switch Q2 are in an open state. Closing the control switch Q2. After the control switch Q2 is closed, the current of the coil L4 is detected, and whether the current of the coil L4 reaches a first design value (the design value is the first preset value in the embodiment of the present invention) is determined. The first design value is related to, among other things, the inductance of the coil L4, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. In addition, the first design value varies in real time during charging according to the inductance of the coil L4, the charging characteristics of the battery pack 8, the starting voltage of the battery pack 8 before charging, and the temperature of the battery pack. When the current of the coil L4 does not reach the first design value, the current of the coil L4 is determined by continuing to detect the current of the coil. When the current of the coil L4 reaches the first design value, the control switch Q2 is turned off, and the control switch Q1 is turned on. After the control switch Q1 is turned on, the current of the coil L4 is detected, and whether the current of the coil L4 reaches a second design value (the second design value is the second preset value in the embodiment of the present invention) is determined. Wherein the second design value is related to the average current of the battery pack 8 and the charging characteristics, and the second design value is changed in real time according to the average current of the battery pack 8 and the charging characteristics during the charging. Further, in the case where the motor controller 7 includes a capacitor, as shown in fig. 12, the motor controller includes a capacitor C1, and the second design value is also related to the characteristic of the capacitor. In the case where the current of the coil L4 is not reduced to the second design value, the current of the coil L4 is continuously detected and it is determined whether or not the current reaches the second design value. In the case where the current of the coil L4 reaches the second design value, the control switch Q1 is turned off. After the control switch Q1 is turned off, it is determined whether or not the battery pack 8 is fully charged. There are many ways to determine whether the battery pack 8 is fully charged, for example, detecting the voltage of the battery pack 8, and determining whether the voltage of the battery pack 8 reaches a preset voltage value, where the voltage of the battery pack 8 reaching the preset voltage value is that the battery is fully charged; if the voltage of the battery pack 8 does not reach the preset voltage value, it indicates that the battery pack 8 is not fully charged. In the case where the battery pack 8 is not fully charged, the above-described process continues to be cyclically performed, and the control switch Q1 and the control switch Q2 are alternately turned on until the battery pack 8 is fully charged. When the battery pack 8 is fully charged, the control switch Q1 and the control switch Q2 are turned off, the charging process is stopped, the dc charging gun is pulled out, the connection with the dc charging socket 4 is disconnected, and the charging is completed.

In addition, in the embodiment of the invention, the device for charging the electric automobile can also comprise a stator coil inside the motor besides the coil outside the motor. As shown in fig. 12, in the case that one end of the coil L4 is connected to the input end of the coil L1, the coil in the device may include the coil L4 and the coil L1 and the coil L2 or the coil L3, and the electric vehicle is charged by controlling the control switch Q3 and the control switch Q4 or controlling the switch Q5 and the control switch Q6. In addition, in the case that one end of the coil L4 is connected to the input end of the coil L2, the coil in the device may include the coil L4 and the coil L2 and the coil L1 or the coil L3, and the electric vehicle is charged by controlling the control switch Q1 and the control switch Q2 or controlling the switch Q5 and the control switch Q6; in the case where one end of the coil L4 is connected to the input end of the coil L3, the coil in the device may include the coil L4 and the coil L3, and the coil L1 or the coil L2, and the electric vehicle may be charged by controlling the control switch Q1 and the control switch Q2, or controlling the switch Q3 and the control switch Q4. The specific control process is similar to the control switch described in the above embodiment, and is not described here again.

Optionally, in an embodiment of the present invention, the apparatus for charging an electric vehicle may further include a switch module. The switch module is arranged in the direct current charging socket and is used for controlling the conduction or the closing between the positive pole and/or the negative pole of the charging socket and the wire harness. Alternatively, the switching module may be a contactor or a relay. As shown in fig. 8 and 10, the apparatus for charging an electric vehicle includes a contactor S1 and a contactor S2, a normally open contact of the contactor S1 is connected in a circuit between the positive electrode of the dc charging socket 4 and the wire harness 5, and a normally open contact of the contactor S2 is connected between the negative electrode of the dc charging socket 4 and a control switch included in the motor controller 7, which is connected to the negative electrode of the battery pack 8. As shown in fig. 12, the apparatus for charging an electric vehicle includes a contactor S1 and a contactor S2, a normally open contact of the contactor S1 is connected in a circuit between the positive electrode of the dc charging socket 4 and one end of the coil L4, and a normally open contact of the contactor S2 is connected between the negative electrode of the dc charging socket 4 and a control switch included in the motor controller 7, which is connected to the negative electrode of the battery pack 8. After the direct current charging pile is started, controlling to electrify coils of a contactor S1 and a contactor S2 respectively so as to close normally open contacts of a contactor S1 and a contactor S2; under the condition of no charging, the contactor S1 is not electrified with the coil of the contactor S2, and the contactor S1 is disconnected with the normally open contact of the contactor S2, so that the user is prevented from being electrocuted when contacting the direct current charging socket 4, and the safety coefficient is improved. The contactor S1 and the contactor S2 described here are merely examples, and other contactors may be included as long as the positive electrode and the negative electrode of the dc charging socket 4 are controlled to be on when charging the electric vehicle, and the positive electrode and the negative electrode of the dc charging socket 4 are controlled to be off when not charging. For example, the contactors S1 and S2 may also include normally closed contacts, and when charging, the normally closed contacts are controlled to be closed so as to conduct the positive electrode and the negative electrode of the dc charging socket 4; when the charging is not performed, the normally closed contact is controlled to be opened, so that the positive electrode and the negative electrode of the direct current charging socket 4 are powered off.

Optionally, in an embodiment of the present invention, the apparatus for charging an electric vehicle may further include the dc charging socket described in the above embodiment.

Optionally, in the embodiment of the present invention, in the case that the device for charging the electric vehicle includes a coil other than the motor and does not include a stator coil in the motor, a switch module may be further included, and the switch is used for switching connection between the stator coil in the motor and a corresponding control switch, so as to reduce influence on the stator coil during charging. Alternatively, the switching module may be a contactor or a relay. As shown in fig. 14, the apparatus for charging an electric vehicle includes a coil L4, excluding a stator coil in the motor 6, one end of the coil L4 being connected to an input terminal of the coil L1, and a contactor S3 connected between the input terminal of the coil L1 and a connection point of the input terminals of the coil L4 and the coil L1. Specifically, a normally open contact of the contactor S3 is connected between the input end of the coil L1 and the connection point, and when the electric vehicle needs to be charged, no current flows in the coil of the contactor S3, and the normally open contact of the contactor S3 is opened, so that current is prevented from flowing to the coil L1 during charging, and the influence on the coil L1 is avoided; in the case where it is not necessary to charge the electric vehicle, the normally open contact of the control contactor S3 is closed so that the motor 9 can be used normally. The contactor S3 is only an example, and may include other contactors as long as the connection between the stator coil and the additional coil in the motor is disconnected when the electric vehicle is charged and the motor is normally used when the electric vehicle is not charged, for example, the contactor may include a normally closed contact, and the normally closed contact is controlled to be opened when the electric vehicle is charged and to be closed when the electric vehicle is not charged.

Furthermore, in an embodiment of the present invention, the apparatus further includes: a boost DC/DC device for charging the battery pack; the first control module is further configured to: detecting whether the boost DC/DC device fails; and controlling the boost DC/DC device to charge the battery pack when the boost DC/DC device is not malfunctioning; wherein the condition that the first control module controls the first control switch and the second control switch to be alternately turned on to feed the charging power received by the coil to the battery pack according to the current of the coil is that the step-up DC/DC device fails. In the case where an independent boost DC/DC device is included, the boost DC/DC device is preferentially used; in the case where the step-up DC/DC device fails, the electric vehicle is charged by controlling the first control switch and the second control switch to be alternately turned on according to the current of the coil to feed the charging power received by the coil to the battery pack. For example, the stand-alone boost DC/DC device may be a DC/DC boost device that implements 500V/800V. As shown in fig. 15 and 16, the step-up DC/DC device is connected between the positive electrode and the negative electrode of the DC charging socket, where the relationship between the coil and the control switch shown in fig. 15 is the same as the relationship between the coil and the control switch shown in fig. 8, and the relationship between the coil and the control switch shown in fig. 16 is the same as the relationship between the coil and the control switch shown in fig. 14. Further, in the apparatus shown in fig. 10 and 12, a step-up DC/DC device may be added in accordance with the method shown in fig. 15 or 16. When the electric automobile needs to be charged, the first control module can detect whether the boost DC/DC equipment fails or not, and when the boost DC/DC equipment is detected not to fail, the boost DC/DC equipment is controlled to charge the battery pack of the electric automobile; upon detection of a failure of the step-up DC/DC device, the electric vehicle is charged by controlling the alternate conduction of the control switch according to the current of the coil according to the relationship between the coil and the control switch shown in fig. 8, 10, 12, or 14.

In addition, the embodiment of the invention also provides an electric automobile which comprises the device for charging the electric automobile in the embodiment.

Accordingly, another aspect of the embodiments of the present invention provides a method for charging an electric vehicle. The electric automobile comprises a motor, a motor controller and a battery pack, and the method comprises the following steps: the first control switch and the second control switch are controlled to be alternately turned on according to the current of the coil to feed the charging power received by the coil to the battery pack, wherein the coil is used for receiving the charging power, the first control switch and the second control switch are connected between the coil and the battery pack, the coil is a stator coil in the motor, and/or the first control switch and the second control switch are a pair of control switches in the motor controller.

The specific working principle and benefits of the method for charging an electric vehicle provided by the embodiment of the invention are similar to those of the device for charging an electric vehicle provided by the embodiment of the invention, and will not be described again here.

In addition, the embodiment of the present invention also provides a machine-readable storage medium, where the machine-readable storage medium has instructions stored thereon, and the instructions are used to cause a machine to execute the method described in the foregoing embodiment.

In conclusion, by means of the stator coil in the motor of the electric automobile and/or the pair of control switches in the motor controller, the charging voltage provided by the external power supply is increased so as to meet the requirements of the electric automobile, so that the cost is greatly reduced while the electric automobile is charged, the weight of the electric automobile is reduced, and the influence on the driving range and the efficiency of the electric automobile is reduced. In addition, only a small number of parts need to be added, the occupied space in the electric automobile is small, and the design and arrangement on the electric automobile are facilitated. In addition, while the electric vehicle is charged by means of the components of the electric vehicle itself, the cooling system of the components can also be used, so that the need for a separate cooling system is eliminated. When the control switch in the motor control and an additional coil are used for charging the electric automobile, the influence on the stator coil in the motor can be reduced.

Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details of the above embodiments, and various simple modifications can be made to the technical solutions of the embodiments of the present invention within the technical idea of the embodiments of the present invention, and the simple modifications all belong to the protection scope of the embodiments of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, the embodiments of the present invention do not describe every possible combination.

Those skilled in the art will understand that all or part of the steps in the method according to the above embodiments may be implemented by a program, which is stored in a storage medium and includes several instructions to enable a single chip, a chip, or a processor (processor) to execute all or part of the steps in the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

In addition, any combination of various different implementation manners of the embodiments of the present invention is also possible, and the embodiments of the present invention should be considered as disclosed in the embodiments of the present invention as long as the combination does not depart from the spirit of the embodiments of the present invention.

Claims

1. An apparatus for heating a battery pack of an electric vehicle, the apparatus comprising:

the charging capacity judging and connecting module is used for converting voltage between the battery pack and charging equipment for charging the battery pack so that the charging equipment judges whether the charging of the battery pack is within the charging capacity range of the charging equipment;

the heating module is used for receiving charging power of the charging equipment to generate heat energy to heat the battery pack; and

the control module is used for controlling the charging capacity judging and connecting module to stop working and starting the heating module so as to heat the battery pack by the heating module under the condition of receiving a signal which is sent by the charging equipment and confirms that the battery pack is in the range of the charging capacity of the battery pack;

wherein, the connection module is judged to the ability of charging includes: the voltage reduction circuit comprises a first coil, a first switch tube, a second switch tube and a first capacitor, wherein the first coil, the first switch tube, the second switch tube and the first capacitor are used for connecting the charging equipment and the battery pack, and the voltage reduction circuit is used for reducing the voltage of the battery pack so that the charging equipment judges whether the charging of the battery pack is in the charging capacity range of the battery pack according to the reduced voltage;

the heating module includes: a second coil for receiving charging power of the charging device to generate heat energy for heating the battery pack; the third switching module is used for connecting the second coil and the charging equipment so as to control the connection or disconnection between the second coil and the charging equipment;

the first coil and the second coil are coils in a motor of the electric automobile, the first switching tube and the second switching tube are switching tubes in an inverter of the electric automobile, the heating module further comprises a switching tube in the inverter, and the second coil is connected with the third switching module through the switching tube in the inverter;

under the condition that the control module controls the charging capacity judging and connecting module to stop working, the control module is further used for: before the heating module is started, a discharging signal is transmitted to the inverter, so that the inverter forms a discharging circuit with a second capacitor and a coil in the motor by controlling a switching tube included in the inverter, the second capacitor is discharged, and whether the relation between the discharging voltage of the second capacitor and the voltage output by the charging equipment meets a preset condition or not is monitored.

2. The apparatus of claim 1, wherein the charging capability determining connection module further comprises:

the first switch module is used for connecting the voltage reduction circuit and the charging equipment and controlling the connection or disconnection between the voltage reduction circuit and the charging equipment; and

a second switch module for connecting the battery pack and the voltage reduction circuit and controlling the connection or disconnection between the voltage reduction circuit and the battery pack,

the control module controls the charging capacity judging and connecting module to stop working by controlling the first switch module and/or the second switch module.

3. The apparatus of claim 2, wherein the first switching module comprises a first relay and/or a second relay, wherein the first relay is connected between the voltage reduction circuit and a positive pole of the charging device, and the second relay is connected between the voltage reduction circuit and a negative pole of the charging device.

4. The apparatus of claim 2, wherein the second switching module comprises a third relay and/or a fourth relay, wherein the third relay is connected between the voltage reduction circuit and the positive pole of the battery pack, and the fourth relay is connected between the voltage reduction circuit and the negative pole of the battery pack.

5. The device of claim 1, wherein the control module controls the heating module to be activated by controlling the third switch module.

6. The apparatus of claim 5, wherein the third switching module comprises a fifth relay and/or a sixth relay, wherein the fifth relay is configured to connect the second coil and a positive pole of the charging device, and the sixth relay is configured to connect the second coil and a negative pole of the charging device.

7. The apparatus according to claim 1, wherein in a case where the control module controls the charging capability judgment connection module to stop operating, the control module is further configured to:

transmitting a motor zero torque signal to the inverter such that the inverter controls the motor to not generate torque after the heating module is activated; and

controlling to start a thermal management controller of the electric vehicle so that heat energy generated by the second coil is transferred to the battery pack;

the condition that the control module controls the heating module to be started is that the relation between the discharge voltage of the second capacitor and the voltage output by the charging equipment is monitored to meet a preset condition.

8. The apparatus of claim 1, further comprising:

the insulation detection module is connected between the positive electrode and the negative electrode of the charging equipment and the vehicle body ground and is used for:

detecting the insulation resistance of a circuit formed by the charging equipment and the charging capability judging and connecting module or the heating module respectively in the working process of the charging capability judging and connecting module or the heating module; and

and under the condition that the detected insulation resistance exceeds a preset value, transmitting a signal to the control module so that the control module controls to disconnect the connection between the charging capacity judging and connecting module or the heating module and the charging equipment.

9. An electric vehicle, characterized in that it comprises a device according to any one of claims 1-8.

10. A method for heating a battery pack of an electric vehicle, the method heating the battery pack according to the apparatus of any one of claims 1-8, the method comprising:

the charging equipment judges whether the battery pack is charged within the charging capacity range of the battery pack;

under the condition that a signal which is sent by the charging equipment and confirms that the battery pack is in the charging capacity range of the battery pack is received, transmitting a discharging signal to an inverter so that the inverter discharges a second capacitor through a control discharging circuit, and monitoring whether the relation between the discharging voltage of the second capacitor and the voltage output by the charging equipment meets a preset condition or not;

under the condition that the relation between the discharge voltage of the second capacitor and the voltage output by the charging equipment meets a preset condition, starting the heating module to heat the battery pack;

and controlling to start a thermal management controller of the electric automobile so as to transfer the heat energy generated by the second coil to the battery pack.