On-vehicle charger, electric vehicle, control method, and computer-readable storage medium

Abstract

The present invention relates to an on-board charger, an electric vehicle, a control method and a computer readable storage medium. The on-board charger comprises first and second low voltage DC-DC converters, and a controller. The first low voltage DC-DC converter is configured to be connected between a high voltage battery unit and a low voltage battery unit of a vehicle. The second low voltage DC-DC converter is configured to be connected between the high voltage battery unit and the low voltage battery unit. The controller is configured to control one of the second low voltage DC-DC converter and the first low voltage DC-DC converter to maintain an electrical connection to the high voltage battery unit and the low voltage battery unit, and to control the other of the second low voltage DC-DC converter and the first low voltage DC-DC converter to break the electrical connection to the high voltage and low voltage battery units. The controller is configured to control the first low voltage DC-DC converter to maintain the electrical connection to the high voltage battery unit and the low voltage battery unit at least during a charging process of the high voltage battery unit, and to control the second low voltage DC-DC converter to maintain the electrical connection to the high voltage and low voltage battery units during a non-charging process of the high voltage battery unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chargers, in particular to a vehicle-mounted charger, an electric vehicle, a control method thereof and a computer readable storage medium. BACKGROUND

[0002] In the related art, the power supply system of an electric vehicle includes a high-voltage battery unit and a low-voltage battery unit, for example, the high-voltage battery unit is a power battery unit, and the low-voltage battery unit is a storage battery unit. The vehicle-mounted charger includes a low-voltage DC-DC unit, which is connected between the high-voltage battery unit and the low-voltage battery unit, and is used to convert high-voltage direct current of the high-voltage battery unit, for example, the power battery unit, into low-voltage direct current to supply power to the low-voltage battery unit, for example, the storage battery unit, of the electric vehicle.

[0003] However, during the charging process of the high-voltage battery unit of the vehicle and during the driving process of the vehicle, the low-voltage DC-DC converter needs to be kept in a working state at all times, and the design life of the low-voltage DC-DC converter needs to be consistent with or longer than the life of the vehicle, which results in the need for a longer design life of the low-voltage DC-DC converter, and further results in a higher design cost of the low-voltage DC-DC converter.

[0004] Further, if the low-voltage DC-DC converter fails, the low-voltage battery unit, for example, the storage battery unit, cannot receive power from the high-voltage battery unit, for example, the power battery unit, but the amount of power stored in the storage battery unit itself is very limited and can only supply the electric vehicle for a very short time. Therefore, after a very short time of failure of the low-voltage DC-DC unit, all the electric devices of the entire electric vehicle will be powered off, and the electric vehicle faces a great risk of breaking down, which brings a very serious safety accident hazard. SUMMARY

[0005] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present application is to propose a vehicle-mounted charger which reduces the working life requirement of the low-voltage DC-DC converter and reduces the design cost requirement of the low-voltage DC-DC converter, thereby reducing the cost requirement and design complexity of the entire vehicle-mounted charger.

[0006] Another object of the present application is to propose an electric vehicle.

[0007] Still another object of the present application is to propose a method of controlling the electric vehicle.

[0008] Still another object of the present application is to propose a computer readable storage medium.

[0009] The first aspect of the present application provides a vehicle-mounted charger, comprising: a first low-voltage DC-DC converter, configured to be connected between a high-voltage battery unit and a low-voltage battery unit of a vehicle; a second low-voltage DC-DC converter, configured to be connected between the high-voltage battery unit and the low-voltage battery unit; and a controller, connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter, configured to control one of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter to keep electrical connection with the high-voltage battery unit and the low-voltage battery unit, and control the other of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter to disconnect the electrical connection with the high-voltage battery unit and the low-voltage battery unit. The controller is configured to: control the first low-voltage DC-DC converter to keep the electrical connection with the high-voltage battery unit and the low-voltage battery unit at least during a charging process of the high-voltage battery unit, so as to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and charge the low-voltage battery unit; and control the second low-voltage DC-DC converter to keep the electrical connection with the high-voltage battery unit and the low-voltage battery unit during a non-charging process of the high-voltage battery unit, so as to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the second low-voltage DC-DC converter and charge the low-voltage battery unit.

[0010] Therefore, according to the on-board charger of the embodiment of the present application, by comprising the first low-voltage DC-DC converter, the second low-voltage DC-DC converter and the controller, the first low-voltage DC-DC converter and the second low-voltage DC-DC converter are both used to be connected between the high-voltage battery unit and the low-voltage battery unit of the vehicle, the controller is connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter, the controller is used to control one of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter to keep the electrical connection with the high-voltage battery unit and the low-voltage battery unit, and to disconnect the other of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter from the electrical connection with the high-voltage battery unit and the low-voltage battery unit, and the controller is used to control the first low-voltage DC-DC converter to keep the electrical connection with the high-voltage battery unit and the low-voltage battery unit at least in the charging process of the high-voltage battery unit to convert the high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and charge the low-voltage battery unit, and the controller is used to control the second low-voltage DC-DC converter to keep the electrical connection with the high-voltage battery unit and the low-voltage battery unit in the non-charging process of the high-voltage battery unit to convert the high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the second low-voltage DC-DC converter and charge the low-voltage battery unit, the two low-voltage DC-DC converters alternately play a role to supply power for the low-voltage battery unit by the high-voltage battery unit, which reduces the working life requirement of each low-voltage DC-DC converter, and in the same design cost, the design life of each low-voltage DC-DC converter can be longer (such as 20 years or 600,000 kilometers), or in the same design life, the design cost of each low-voltage DC-DC converter is lower.

[0011] According to some embodiments of the present application, the on-board charger further comprises a switching unit, which is used to be connected between the first low-voltage DC-DC converter and the low-voltage battery unit and used to be connected between the second low-voltage DC-DC converter and the low-voltage battery unit, the controller is connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter through the switching unit, and the controller is used to control the switching unit to selectively turn on the electrical connection of the first low-voltage DC-DC converter or the second low-voltage DC-DC converter with the low-voltage battery unit, so that the high-voltage battery unit charges the low-voltage battery unit through the first low-voltage DC-DC converter or the second low-voltage DC-DC converter.

[0012] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle, and the controller is configured to control the switching unit to, in the driving mode of the vehicle, connect the first low-voltage DC-DC converter to the high-voltage battery unit when the second low-voltage DC-DC converter fails, so as to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and charge the low-voltage battery unit.

[0013] According to some embodiments of the present application, the on-board charger further comprises a switching unit connected between the first low-voltage DC-DC converter and the high-voltage battery unit and connected between the second low-voltage DC-DC converter and the high-voltage battery unit, and the controller is connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter through the switching unit, and the controller is configured to control the switching unit to selectively connect the first low-voltage DC-DC converter or the second low-voltage DC-DC converter to the high-voltage battery unit, so that the high-voltage battery unit charges the low-voltage battery unit through the first low-voltage DC-DC converter or the second low-voltage DC-DC converter.

[0014] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle, and the controller is configured to control the switching unit to, in the driving mode of the vehicle, connect the first low-voltage DC-DC converter to the high-voltage battery unit when the second low-voltage DC-DC converter fails, so as to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and charge the low-voltage battery unit.

[0015] According to some embodiments of the present application, the on-board charger further comprises a power factor correction (PFC) unit configured to connect an external alternating current terminal in the charging mode of the vehicle and configured to convert alternating current voltage from the external alternating current terminal into a first direct current voltage, and a high-voltage DC-DC converter connected to the PFC unit and configured to be connected to the high-voltage battery unit, the high-voltage DC-DC converter being configured to convert the first direct current voltage from the PFC unit into a second direct current voltage and supply the second direct current voltage to the high-voltage battery unit in the charging mode of the vehicle, and the high-voltage battery unit being configured to output the second direct current voltage and supply the second direct current voltage to the first low-voltage DC-DC converter.

[0016] According to some embodiments of the present application, the high-voltage DC-DC converter comprises a primary winding of a transformer, a first secondary winding of the transformer, a second secondary winding of the transformer, a primary switch circuit connected with the primary winding, and a first secondary switch circuit connected with the first secondary winding, wherein an output terminal of the first secondary switch circuit is an output terminal of the high-voltage DC-DC converter. The on-board charger further comprises a second secondary switch circuit connected with the second secondary winding, and the second DC-DC converter comprises the first secondary winding, the first secondary switch circuit, the second secondary winding, and the second secondary switch circuit, wherein an output terminal of the second secondary switch circuit is an output terminal of the second low-voltage DC-DC converter.

[0017] According to some embodiments of the present application, the high-voltage DC-DC converter comprises a primary winding of a transformer, a secondary winding of the transformer, a primary switch circuit connected with the primary winding, and a first secondary switch circuit connected with the secondary winding, wherein an output terminal of the first secondary switch circuit is an output terminal of the high-voltage DC-DC converter. The on-board charger further comprises a second secondary switch circuit connected with the secondary winding, and the second DC-DC converter comprises the secondary winding, the first secondary switch circuit, and the second secondary switch circuit, wherein an output terminal of the second secondary switch circuit is an output terminal of the second low-voltage DC-DC converter.

[0018] According to some embodiments of the present application, the switching unit comprises a first switch connected with an output terminal of the first low-voltage DC-DC converter and a second switch connected with an output terminal of the second low-voltage DC-DC converter. The controller is configured to control one of the first switch and the second switch to be closed and the other one of the first switch and the second switch to be opened, wherein the controller is configured to control the first switch to be closed and the second switch to be opened during a charging process of the high-voltage battery unit, and control the first switch to be opened and the second switch to be closed during a non-charging process of the high-voltage battery unit.

[0019] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of a vehicle, and the controller is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails during the driving mode of the vehicle.

[0020] According to some embodiments of the present application, the switching unit comprises a first switch and a second switch, wherein the first switch is connected with an input terminal of the first low-voltage DC-DC converter, and the second switch is connected with an input terminal of the second low-voltage DC-DC converter. The controller is configured to control one of the first switch and the second switch to be closed and the other of the first switch and the second switch to be opened. The controller is configured to control the first switch to be closed and the second switch to be opened during a charging process of the high-voltage battery unit, and control the first switch to be opened and the second switch to be closed during a non-charging process of the high-voltage battery unit.

[0021] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle. The controller is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

[0022] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle. The controller is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

[0023] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle. The controller is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

[0024] According to some embodiments of the present application, the non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle. The controller is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

[0025] According to some embodiments of the present application, the starting the first low-voltage DC-DC converter comprises: controlling the switching unit to connect the first low-voltage DC-DC converter to the low-voltage battery unit and disconnect the second low-voltage DC-DC converter to the low-voltage battery unit; or controlling the switching unit to connect the first low-voltage DC-DC converter to the high-voltage battery unit and disconnect the second low-voltage DC-DC converter to the high-voltage battery unit.

[0026] According to some embodiments of the present application, the starting the second low-voltage DC-DC converter comprises: controlling the switching unit to disconnect the first low-voltage DC-DC converter to the low-voltage battery unit and connect the second low-voltage DC-DC converter to the low-voltage battery unit; or controlling the switching unit to disconnect the first low-voltage DC-DC converter to the high-voltage battery unit and connect the second low-voltage DC-DC converter to the high-voltage battery unit.

[0027] According to some embodiments of the present application, the method further comprises: in the driving mode of the electric vehicle, determining whether the second low-voltage DC-DC converter is in an abnormal working state; in response to determining that the second low-voltage DC-DC converter is in an abnormal working state, connecting the first low-voltage DC-DC converter to the high-voltage battery unit and the low-voltage battery unit, and issuing an alarm to indicate that the second low-voltage DC-DC converter has failed.

[0028] According to an embodiment of the fourth aspect of the present application, a computer readable storage medium has a computer program stored thereon, which, when executed by a processor, implements the method for controlling an electric vehicle according to any one of the embodiments of the third aspect of the present application.

[0029] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0030] One or more embodiments are illustrated by way of example in the accompanying drawings, which are not intended to be limiting of the present application, and the description below. Like reference numerals and characters designate like elements throughout the drawings, in which:

[0031] Figure 1 is a schematic diagram of the connection of the on-board charger, the high-voltage battery unit, the low-voltage battery unit and the external AC terminal according to an embodiment of the present application.

[0032] Figure 2Fig. 1 is a schematic connection diagram of a vehicle charger and a high-voltage battery unit, a low-voltage battery unit and an external AC terminal according to another embodiment of the present application.

[0033] Figure 3 Fig. 2 is a schematic connection diagram of a vehicle charger and a high-voltage battery unit, a low-voltage battery unit and an external AC terminal according to yet another embodiment of the present application.

[0034] Figure 4 Fig. 3 is a schematic topology diagram of a vehicle charger shown in Fig. 1. Figure 1 Fig. 4 is a schematic topology diagram of a vehicle charger shown in Fig. 2.

[0035] Figure 5 Fig. 5 is a schematic topology diagram of a vehicle charger shown in Fig. 3. Figure 2 Fig. 6 is a schematic topology diagram of a vehicle charger shown in Fig. 4.

[0036] Figure 6 Fig. 7 is a schematic topology diagram of a vehicle charger shown in Fig. 5. Figure 3 Fig. 8 is another schematic topology diagram of a vehicle charger shown in Fig. 6.

[0037] Figure 7 Fig. 9 is another schematic topology diagram of a vehicle charger shown in Fig. 7. Figure 3 Fig. 10 is a schematic block diagram of an electric vehicle according to an embodiment of the present application.

[0038] Figure 8 Fig. 11 is a schematic flow chart of a method for controlling an electric vehicle according to an embodiment of the present application.

[0039] Figure 9 Fig. 12 is another schematic flow chart of a method for controlling an electric vehicle according to an embodiment of the present application.

[0040] Figure 10 Fig. 13 is a schematic flow chart of a method for controlling an electric vehicle according to another embodiment of the present application.

[0041] Reference numerals:

[0042] Vehicle charger 1000; first low-voltage DC-DC converter 10; high-voltage battery unit 20;

[0043] Low-voltage battery unit 30; second low-voltage DC-DC converter 40; controller 200; switching unit 50; first switch SI;

[0044] Second switch S2; power factor correction (PFC) unit 60; external AC terminal 70; high-voltage DC-DC converter 80;

[0045] Transformer 100; primary winding 101; first secondary winding 102; second secondary winding 103; primary side switching circuit 104;

[0046] The first auxiliary side switch circuit 105; the second auxiliary side switch circuit 106; an output terminal 1061 of the second auxiliary side switch circuit;

[0047] The output terminal 1051 of the first auxiliary side switch circuit;

[0048] The auxiliary side winding 107; the electric vehicle 2000. DETAILED DESCRIPTION

[0049] The embodiments of the present application are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0050] The embodiments of the present application are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary. Figures 1-7 The embodiments of the present application are described in detail below, and the embodiments described with reference to the accompanying drawings are exemplary.

[0051] As Figures 1-7 As shown in the figure, the on-board charger 1000 according to the embodiments of the present application includes two low-voltage DC-DC converters, i.e., a first low-voltage DC-DC converter 10 and a second low-voltage DC-DC converter 40. The first low-voltage DC-DC converter 10 is used to be connected between a high-voltage battery unit 20 and a low-voltage battery unit 30 of a vehicle, so as to convert high-voltage direct current provided by the high-voltage battery unit 20 into low-voltage direct current, thereby supplying power to the low-voltage battery unit 30; the second low-voltage DC-DC converter 40 is used to be connected between the high-voltage battery unit 20 and the low-voltage battery unit 30, so as to convert high-voltage direct current provided by the high-voltage battery unit 20 into low-voltage direct current, thereby supplying power to the low-voltage battery unit 30. Among the plurality of battery units, the battery unit with a higher working voltage is the high-voltage battery unit 20, and the battery unit with a lower working voltage is the low-voltage battery unit 30. Here, the high-voltage battery unit 20 can be a power battery, and the low-voltage battery unit 30 can be a storage battery.

[0052] The on-board charger 1000 further comprises a controller 200 connected to the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40, the controller 200 being configured to control one of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 10 to maintain electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30, and to control the other of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 10 to break the electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30. In other words, the two low-voltage DC-DC converters are alternately electrically connected between the high-voltage battery unit 20 and the low-voltage battery unit 30, i.e. when one of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 10 is electrically connected between the high-voltage battery unit 20 and the low-voltage battery unit 30 and is working, the other of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 10 is not electrically connected between the high-voltage battery unit 20 and the low-voltage battery unit 30.

[0053] The controller 200 is configured to control the first low-voltage DC-DC converter 10 to maintain electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30 at least during a charging process of the high-voltage battery unit 20, so as to convert high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the first low-voltage DC-DC converter 10 and charge the low-voltage battery unit 30, and to control the second low-voltage DC-DC converter 40 to maintain electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30 during a non-charging process of the high-voltage battery unit 20, so as to convert high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the second low-voltage DC-DC converter 40 and charge the low-voltage battery unit 30.

[0054] Specifically, during a charging process of the high-voltage battery unit 20 (at this time, the vehicle is in a non-running mode), the on-board charger 1000 is connected to the external AC terminal 70 of the external AC charging station to receive alternating current, the received alternating current is converted into high-voltage direct current inside the on-board charger 1000, the high-voltage direct current is provided to the high-voltage battery unit 20, then the high-voltage direct current is provided to the first low-voltage DC-DC converter 10 by the high-voltage battery unit 20, and after passing through the first low-voltage DC-DC converter 10, the high-voltage direct current is converted into low-voltage direct current, which is provided to the low-voltage battery unit 30 to charge the low-voltage battery unit 30. Therefore, it can be seen that the first low-voltage DC-DC converter 10 plays a role during the process of charging the high-voltage battery unit 20 of the vehicle by using the on-board charger 1000.

[0055] In the non-charging process of the high-voltage battery unit 20 (i.e. the vehicle has started, but the high-voltage battery unit 20 is in a non-charging mode), the high-voltage battery unit 20 of the vehicle is the power source of all electrical appliances of the entire vehicle, at this time, the second low-voltage DC-DC converter 40 is electrically connected between the high-voltage battery unit 20 and the low-voltage battery unit 30, the high-voltage direct current provided by the high-voltage battery unit 20 is provided to the second low-voltage DC-DC converter 40, and the second low-voltage DC-DC converter 40 converts the high-voltage direct current into low-voltage direct current to power the low-voltage battery unit 30 of the vehicle, and the low-voltage battery unit 30 powers the electrical appliances in the vehicle. Therefore, it can be seen that in the non-charging state of the high-voltage battery unit 20, the second low-voltage DC-DC converter 40 plays a role in the process of the high-voltage battery unit 20 powering the low-voltage battery unit 30.

[0056] From the above, it can be seen that the first low-voltage DC-DC converter 10 plays a role in the charging process of the high-voltage battery unit 20, at this time the vehicle is in a non-running state; the second low-voltage DC-DC converter 40 plays a role in the process of the high-voltage battery unit 20 powering the low-voltage battery unit 30. Compared with the prior art in which only one low-voltage DC-DC converter is provided in the vehicle charger, the two low-voltage DC-DC converters in the present application can alternately play a role in the process of the high-voltage battery unit 20 powering the low-voltage battery unit 30, and in the entire life cycle of the vehicle, the total working time of each low-voltage DC-DC converter is reduced, which reduces the working life requirement of each low-voltage DC-DC converter, and under the same design cost, the design life of each low-voltage DC-DC converter can be longer, or under the same design life, the design cost of each low-voltage DC-DC converter is lower.

[0057] Therefore, according to the on-board charger 1000 of the embodiment of the present application, by comprising the first low-voltage DC-DC converter 10, the second low-voltage DC-DC converter 40 and the controller 200, the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 are both used to be connected between the high-voltage battery unit 20 and the low-voltage battery unit 30 of the vehicle, the controller 200 is connected to the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40, the controller 200 is used to control one of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 10 to keep the electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30, and the other of the second low-voltage DC-DC converter 40 and the first low-voltage DC-DC converter 20 to break the electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30, and the controller 200 is used to control the first low-voltage DC-DC converter 10 to keep the electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30 at least in the charging process of the high-voltage battery unit 20 to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the first low-voltage DC-DC converter 10 and charge the low-voltage battery unit 30, and the controller is used to control the second low-voltage DC-DC converter 40 to keep the electrical connection with the high-voltage battery unit 20 and the low-voltage battery unit 30 in the non-charging process of the high-voltage battery unit 20 to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the second low-voltage DC-DC converter 40 and charge the low-voltage battery unit 30, the two low-voltage DC-DC converters alternately play a role to supply power for the low-voltage battery unit 30 by the high-voltage battery unit 20, which reduces the working life requirement of each low-voltage DC-DC converter, and under the same design cost, the design life of each low-voltage DC-DC converter can be longer (such as 20 years or 600,000 kilometers), or under the same design life, the design cost of each low-voltage DC-DC converter is lower.

[0058] According to some embodiments of the present application, as Figure 1 and Figure 4As shown, the on-board charger 1000 further comprises a switching unit 50, which is connected between the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30 and is connected between the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, and the controller 200 is connected to the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 through the switching unit 50, and the controller 200 is used to control the switching unit 50 to selectively turn on the electrical connection between the first low-voltage DC-DC converter 10 or the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, so that the high-voltage battery unit 20 charges the low-voltage battery unit 30 through the first low-voltage DC-DC converter 10 or the second low-voltage DC-DC converter 40. For example, during the charging of the high-voltage battery unit 20, the switching unit 50 selects to turn on the electrical connection between the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30, so as to ensure that the first low-voltage DC-DC converter 10 converts the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current to power the low-voltage battery unit 30; in the non-charging mode of the high-voltage battery unit 30 (at this time the vehicle has been started), the switching unit 50 selects to turn on the electrical connection between the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, so as to ensure that the second low-voltage DC-DC converter 40 converts the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current to power the low-voltage battery unit 30. By providing the switching unit 50, the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 can be easily alternately operated.

[0059] Further, with reference to Figure 1 、 Figure 3 、 Figure 4 、 Figure 6 and Figure 7In the non-charging mode of the high-voltage battery unit 20, the driving mode of the vehicle is included, and the controller 200 is configured to control the switching unit 50: in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 fails, the electrical connection between the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30 is turned on to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the first low-voltage DC-DC converter 10 and charge the low-voltage battery unit 30. Specifically, in the charging mode of the high-voltage battery unit 20, the first low-voltage DC-DC converter 10 is in operation; in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 does not fail, the second low-voltage DC-DC converter 40 is in operation to output low-voltage direct current to charge the low-voltage battery unit 30; in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 fails, the switching unit 50 is switched to turn on the electrical connection between the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30 and turn off the electrical connection between the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, and at this time, the first low-voltage DC-DC converter 10 outputs low-voltage direct current to charge the low-voltage battery unit 30 and ensure the normal operation of the electrical appliances of the vehicle. In this way, on the one hand, in the case where the second low-voltage DC-DC converter 40 fails during the driving of the vehicle, the first low-voltage DC-DC converter 10 can be switched to work in time to ensure that the low-voltage battery unit 30 of the vehicle can still be powered, thereby ensuring the normal operation of the electrical appliances of the vehicle and avoiding the occurrence of vehicle breakdown accidents and improving the driving safety of the entire vehicle; on the other hand, the service life of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 can be designed to be much shorter than the service life of the vehicle, and therefore the design cost of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 is lower.

[0060] According to further embodiments of the present application, reference is made to Figure 2 and Figure 5The on-board charger 1000 further comprises a switching unit 50 connected between the first low-voltage DC-DC converter 10 and the high-voltage battery unit 20 and connected between the second low-voltage DC-DC converter 40 and the high-voltage battery unit 20, and the controller 200 is connected to the first low-voltage DC-DC converter 20 and the second low-voltage DC-DC converter 30 through the switching unit 50. The controller 200 is configured to control the switching unit 50 to selectively connect the first low-voltage DC-DC converter 10 or the second low-voltage DC-DC converter 40 to the high-voltage battery unit 20, so that the high-voltage battery unit 20 charges the low-voltage battery unit 30 through the first low-voltage DC-DC converter 10 or the second low-voltage DC-DC converter 40. For example, during the charging of the high-voltage battery unit 20, the controller 200 controls the switching unit 50 to connect the first low-voltage DC-DC converter 10 to the high-voltage battery unit 20, so as to ensure that the first low-voltage DC-DC converter 10 works to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current to power the low-voltage battery unit 30; in the non-charging mode of the high-voltage battery unit 20 (at this time, the vehicle is started), the controller 200 controls the switching unit 50 to connect the second low-voltage DC-DC converter 40 to the high-voltage battery unit 20, so as to ensure that the second low-voltage DC-DC converter 40 works to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current to power the low-voltage battery unit 30. By so arranging the switching unit 50, another way of realizing the alternate working of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 is provided.

[0061] Further, with reference to Figure 2 and Figure 5In the non-charging mode of the high-voltage battery unit 20, the driving mode of the vehicle, the controller 200 is configured to control the switching unit 50 to: in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 fails, turn on the electrical connection between the first low-voltage DC-DC converter 10 and the high-voltage battery unit 20 to convert the high-voltage direct current from the high-voltage battery unit 20 into low-voltage direct current through the first low-voltage DC-DC converter 10 and charge the low-voltage battery unit 30. Specifically, in the charging mode of the high-voltage battery unit 20, the first low-voltage DC-DC converter 10 functions; in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 does not fail, the second low-voltage DC-DC converter 40 functions to output low-voltage direct current to charge the low-voltage battery unit 30; in the driving mode of the vehicle, when the second low-voltage DC-DC converter 40 fails, the switching unit 50 is switched to turn on the electrical connection between the first low-voltage DC-DC converter 10 and the high-voltage battery unit 20 and turn off the electrical connection between the second low-voltage DC-DC converter 40 and the high-voltage battery unit 20, at this time, the first low-voltage DC-DC converter 10 outputs low-voltage direct current to charge the low-voltage battery unit 30 and ensure the normal operation of the electrical appliances of the vehicle. In this way, on the one hand, in the case that the second low-voltage DC-DC converter 40 fails during the driving of the vehicle, the first low-voltage DC-DC converter 10 can be switched to work in time to ensure that the low-voltage battery unit 30 of the vehicle can still be powered, thereby ensuring the normal operation of the electrical appliances of the vehicle and avoiding the occurrence of vehicle breakdown accidents and improving the driving safety of the entire vehicle; on the other hand, the service life of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 can be designed to be much shorter than the service life of the vehicle, and therefore the design cost of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 is lower.

[0062] According to some embodiments of the present application, as shown in Figures 1-7 The on-board charger 1000 further comprises a power factor correction (PFC) unit 60 and a high-voltage DC-DC converter 80. The PFC unit 60 is configured to connect to the external AC terminal 70 in the charging mode of the vehicle and to convert the alternating current voltage from the external AC terminal 70 into a first direct current voltage. The high-voltage DC-DC converter 80 is connected to the PFC unit 60 and configured to be connected to the high-voltage battery unit 20, the high-voltage DC-DC converter 80 is configured to convert the first direct current voltage from the PFC unit 60 into a second direct current voltage in the charging mode of the vehicle and supply the second direct current voltage to the high-voltage battery unit 20, and the high-voltage battery unit 20 is configured to output the second direct current voltage and supply the second direct current voltage to the first low-voltage DC-DC converter 10.

[0063] According to some further embodiments of the present application, the second low-voltage DC-DC converter 40 is used as a redundant low-voltage DC-DC converter, which is implemented based on the prior art of only one low-voltage DC-DC converter being provided, as shown in Figure 1 、 Figure 2 、 Figure 4 and Figure 5 .

[0064] According to some further embodiments of the present application, with reference to Figure 3 and Figure 6 , the high-voltage DC-DC converter 80 comprises the primary winding 101 of the transformer 100, the first secondary winding 102 of the transformer 100, the second secondary winding 103 of the transformer 100, the primary side switching circuit 104 and the first secondary side switching circuit 105, the primary side switching circuit 104 is connected with the primary winding 101, the first secondary side switching circuit 105 is connected with the first secondary winding 102, and the output 1051 of the first secondary side switching circuit 105 is the output terminal of the high-voltage DC-DC converter 80. It can be understood that the output terminal of the high-voltage DC-DC converter 80 is used to be connected with the high-voltage battery unit 20. In addition, the on-board charger 1000 further comprises the second secondary side switching circuit 106 connected with the second secondary winding 103, and the second low-voltage DC-DC converter 40 comprises the first secondary winding 102, the first secondary side switching circuit 105, the second secondary winding 103 and the second secondary side switching circuit 106, and the output terminal 1061 of the second secondary side switching circuit 106 is the output terminal of the second low-voltage DC-DC converter 40. In this way, it can be seen that the high-voltage DC-DC converter 80 and the second low-voltage DC-DC converter 40 share the first secondary winding 102, the second secondary winding 103 and the first secondary side switching circuit 105, in other words, the first secondary winding 102, the second secondary winding 103 and the first secondary side switching circuit 105 in the on-board charger 1000 are multiplexed, and compared with the additional increase of one second low-voltage DC-DC converter, the on-board charger 1000 of the scheme of the present application uses fewer components, so the volume is smaller and the cost is lower.

[0065] Optionally, the high-voltage DC-DC converter 80 is composed of the primary winding 101 of the transformer 100, the first secondary winding 102 of the transformer 100, the second secondary winding 103 of the transformer 100, the primary side switching circuit 104 and the first secondary side switching circuit 105. Optionally, the second low-voltage DC-DC converter 40 is composed of the first secondary winding 102, the first secondary side switching circuit 105, the second secondary winding 103 and the second secondary side switching circuit 106.

[0066] According to some further embodiments of the present application, as shown in Figure 3 andFigure 7 As shown, the high-voltage DC-DC converter 80 comprises the primary winding 101 of the transformer 100, the secondary winding 107 of the transformer 100, the primary side switching circuit 104 connected with the primary winding 101, and the first secondary side switching circuit 105 connected with the secondary winding 107, and an output end 1051 of the first secondary side switching circuit 105 is an output end of the high-voltage DC-DC converter 80. The on-board charger 1000 further comprises a second secondary side switching circuit 106 connected with the secondary winding 107, and the second low-voltage DC-DC converter 40 comprises the secondary winding 107, the first secondary side switching circuit 105, and the second secondary side switching circuit 106, and an output end 1061 of the second secondary side switching circuit 106 is an output end of the second low-voltage DC-DC converter 40. In this way, it can be seen that the high-voltage DC-DC converter 80 and the second low-voltage DC-DC converter 40 share the secondary winding 107 and the first secondary side switching circuit 105, in other words, the secondary winding 107 and the first secondary side switching circuit 105 in the on-board charger 1000 are multiplexed, and compared with the additional increase of a second DC-DC converter, the on-board charger 1000 of the scheme of the present application uses fewer components, and therefore has a smaller size and a lower cost.

[0067] Optionally, the high-voltage DC-DC converter 80 is composed of the primary winding 101 of the transformer 100, the secondary winding 107 of the transformer 100, the primary side switching circuit 104, and the first secondary side switching circuit 105. Optionally, the second low-voltage DC-DC converter 40 is composed of the secondary winding 107, the first secondary side switching circuit 105, and the second secondary side switching circuit 106.

[0068] According to some specific embodiments of the present application, as Figure 1 , Figure 3 , Figure 4 , Figure 6 and Figure 7As shown, the switching unit 50 includes a first switch S1 and a second switch S2, the first switch S1 is connected with the output end of the first low-voltage DC-DC converter 10, and the second switch S2 is connected with the output end of the second low-voltage DC-DC converter 40. The controller 200 is configured to control one of the first switch S1 and the second switch S2 to be closed and the other one of the first switch S1 and the second switch S2 to be opened. Specifically, the controller 200 is configured to control the first switch S1 to be closed and the second switch S2 to be opened during the charging process of the high-voltage battery unit 20, and control the first switch S1 to be opened and the second switch S2 to be closed during the non-charging process of the high-voltage battery unit 20. Specifically, the first switch S1 is connected with the output end of the first low-voltage DC-DC converter 10, i.e., the first switch S1 is connected between the output end of the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30; and the second switch S2 is connected with the output end of the second low-voltage DC-DC converter 40, i.e., the second switch S2 is connected between the output end of the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30. The first switch S1 and the second switch S2 cannot be closed at the same time. During the charging process of the high-voltage battery unit 20, only the first switch S1 is closed, so that the high-voltage battery unit 20 charges the low-voltage battery unit 30 through the first low-voltage DC-DC converter 10; during the non-charging process of the high-voltage battery unit 30 (it should be noted that the vehicle is started at this time), the second switch S2 is closed under the condition that the second low-voltage DC-DC converter 40 is fault-free or undamaged, so that the high-voltage battery unit 20 charges the low-voltage battery unit 30 through the second low-voltage DC-DC converter 40. The first switch S1 and the second switch S2 are configured to realize the alternate working of the first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40, which is simple and feasible, and has low cost.

[0069] According to further embodiments of the present application, as shown in Figure 1 , Figure 3 , Figure 4 , Figure 6 and Figure 7 , the non-charging mode of the high-voltage battery unit 20 includes a driving mode of the vehicle, and the controller 200 is further configured to control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter is faulty in the driving mode of the vehicle. It can be seen that, during the driving of the vehicle, if the second low-voltage DC-DC converter 40 is faulty, the first switch S1 is closed and the second switch S2 is opened, so that the high-voltage battery unit 20 charges the low-voltage battery unit 30 through the first low-voltage DC-DC converter 10, thereby ensuring the normal operation of the electrical appliances of the vehicle during the driving of the vehicle.

[0070] According to further embodiments of the present application, as shown in Figure 2 and Figure 5As shown, the switching unit 50 includes a first switch S1 and a second switch S2, wherein the first switch S1 is connected with the input end of the first low-voltage DC-DC converter 10, and the second switch S2 is connected with the input end of the second low-voltage DC-DC converter 40. The controller 200 is configured to control one of the first switch S1 and the second switch S2 to be closed and the other one of the first switch S1 and the second switch S2 to be opened. The controller 200 is configured to control the first switch S1 to be closed and the second switch S2 to be opened during the charging process of the high-voltage battery unit 20, and control the first switch S1 to be opened and the second switch S2 to be closed during the non-charging process of the high-voltage battery unit 20. Specifically, the first switch S1 is connected with the input end of the first low-voltage DC-DC converter 10, i.e., the first switch S1 is connected between the high-voltage battery unit 20 and the input end of the first low-voltage DC-DC converter 10; the second switch S2 is connected with the input end of the second low-voltage DC-DC converter 40, i.e., the second switch S2 is connected between the high-voltage battery unit 20 and the input end of the second low-voltage DC-DC converter 40. The first switch S1 and the second switch S2 cannot be closed at the same time. During the charging process of the high-voltage battery unit 20, only the first switch S1 is closed to charge the low-voltage battery unit 30 by the first low-voltage DC-DC converter 10; during the non-charging process of the high-voltage battery unit 20 (it should be noted that the vehicle is started at this time), the second switch S2 is closed to charge the low-voltage battery unit 30 by the second low-voltage DC-DC converter 40 in the case that the second low-voltage DC-DC converter 40 is fault-free or undamaged. The first low-voltage DC-DC converter 10 and the second low-voltage DC-DC converter 40 are alternately operated by setting the first switch S1 and the second switch S2, which is simple and feasible, and has low cost.

[0071] According to a further embodiment of the application, as Figure 2 and Figure 5 shown, the non-charging mode of the high-voltage battery unit 20 includes a driving mode of the vehicle, and the controller 200 is further configured to control the first switch S1 to be closed and the second switch S2 to be opened when the second low-voltage DC-DC converter 40 is faulty in the driving mode of the vehicle. It can be seen that, during the driving of the vehicle, if the second low-voltage DC-DC converter 40 is faulty, the first switch S1 is closed and the second switch S2 is opened to charge the low-voltage battery unit 30 by the first low-voltage DC-DC converter 10, so as to ensure that the electrical appliances of the vehicle normally operate during the driving of the vehicle.

[0072] According to the electric vehicle 2000 of the second embodiment of the application, as Figure 8 shown and with reference to Figures 1-7The electric vehicle 2000 according to the embodiment of the present application comprises the on-board charger 1000, the high-voltage battery unit 20 and the low-voltage battery unit 30 according to the embodiment of the first aspect of the present application, wherein the low-voltage battery unit 30 is connected to the low-voltage battery unit 30 through the on-board charger 1000.

[0073] The electric vehicle 2000 according to the embodiment of the present application comprises the on-board charger 1000, the high-voltage battery unit 20 and the low-voltage battery unit 30 according to the embodiment of the first aspect of the present application, wherein the low-voltage battery unit 30 is connected to the low-voltage battery unit 30 through the on-board charger 1000.

[0074] The method for controlling an electric vehicle according to the embodiment of the third aspect of the present application, as shown in Figure 9 , comprises steps S10-S40.

[0075] S10, determining whether the high-voltage battery unit of the electric vehicle is in a charging mode.

[0076] Specifically, in combination with Figures 1-8 , the high-voltage battery unit 20 of the electric vehicle 2000 can be in a charging mode and a non-charging mode. In order to determine whether to control the first low-voltage DC-DC converter 10 or the second low-voltage DC-DC converter 40 to work, it is necessary to determine whether the high-voltage battery unit 20 of the electric vehicle 2000 is in the charging mode.

[0077] S20, in response to determining that the high-voltage battery unit is in the charging mode, starting the first low-voltage DC-DC converter to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current to charge the low-voltage battery unit during the charging process of the high-voltage battery unit.

[0078] For example, in combination with Figures 1-8 , the starting of the first low-voltage DC-DC converter 10 can comprise: controlling the switching unit 50 to turn on the electrical connection of the first low-voltage DC-DC converter 10 to the low-voltage battery unit 30 and turn off the electrical connection of the second low-voltage DC-DC converter 40 to the low-voltage battery unit 30; or controlling the switching unit 50 to turn on the electrical connection of the first low-voltage DC-DC converter 10 to the high-voltage battery unit 20 and turn off the electrical connection of the second low-voltage DC-DC converter 40 to the high-voltage battery unit.

[0079] For example, referring to Figure 1 , Figure 3 , Figure 4 , Figure 6 andFigure 7 When the switching unit 50 is connected between the output of the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30 and between the output of the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, starting the first low-voltage DC-DC converter 10 comprises controlling the switching unit 50 to connect the first low-voltage DC-DC converter 10 to the low-voltage battery unit 30 and to disconnect the second low-voltage DC-DC converter 40 from the low-voltage battery unit 30.

[0080] For example, with reference to Figure 2 , Figure 5 When the switching unit 50 is connected between the input of the first low-voltage DC-DC converter 10 and the high-voltage battery unit 20 and between the input of the second low-voltage DC-DC converter 40 and the high-voltage battery unit 20, starting the first low-voltage DC-DC converter 10 comprises controlling the switching unit 50 to connect the first low-voltage DC-DC converter 10 to the high-voltage battery unit 30 and to disconnect the second low-voltage DC-DC converter 40 from the high-voltage battery unit 30.

[0081] S30, in response to determining that the high-voltage battery unit is in the non-charging mode, determining whether the electric vehicle is started.

[0082] In particular, if it is determined that the high-voltage battery unit 30 is in the non-charging mode, i.e. it is determined that the high-voltage battery unit 30 is not being charged, it is determined whether the electric vehicle 2000 is started, i.e. it is determined whether the electric vehicle 2000 is in the driving mode.

[0083] S40, in response to determining that the electric vehicle is started, starting the second low-voltage DC-DC converter to convert high-voltage direct current from the high-voltage battery unit to low-voltage direct current to charge the low-voltage battery unit, wherein the electric vehicle being started indicates that the high-voltage battery unit of the electric vehicle is in the non-charging mode.

[0084] For example, with reference to Figure 1 , Figure 3 , Figure 4 , Figure 6 and Figure 7 When the switching unit 50 is connected between the output of the first low-voltage DC-DC converter 10 and the low-voltage battery unit 30 and between the output of the second low-voltage DC-DC converter 40 and the low-voltage battery unit 30, starting the second low-voltage DC-DC converter 40 comprises controlling the switching unit 50 to disconnect the first low-voltage DC-DC converter 10 from the low-voltage battery unit 30 and to connect the second low-voltage DC-DC converter 40 to the low-voltage battery unit 30.

[0085] For example, with reference to Figure 2and Figure 5 When the switching unit 50 is connected between the high-voltage battery unit 20 and the input end of the first low-voltage DC-DC converter 10 and between the high-voltage battery unit 20 and the input end of the second low-voltage DC-DC converter 40, starting the second low-voltage DC-DC converter 40 includes controlling the switching unit 50 to disconnect the first low-voltage DC-DC converter 10 from the high-voltage battery unit 20 and connect the second low-voltage DC-DC converter 40 to the high-voltage battery unit 20.

[0086] According to the method for controlling the electric vehicle, by starting the first low-voltage DC-DC converter to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current to charge the low-voltage battery unit during the charging process of the high-voltage battery unit in response to determining that the high-voltage battery unit is in the charging mode, and in response to determining that the electric vehicle is started, starting the second low-voltage DC-DC converter to make the second low-voltage DC-DC converter convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current to charge the low-voltage battery unit in response to determining that the high-voltage battery unit is in the non-charging mode, the two low-voltage DC-DC converters work alternately to ensure that the high-voltage battery unit 20 charges the low-voltage battery unit 30, which reduces the working life requirement of each low-voltage DC-DC converter, and in the case that the second low-voltage DC-DC converter fails during the driving of the electric vehicle, the low-voltage battery unit of the electric vehicle can still be supplied with power by switching to the first low-voltage DC-DC converter in time, so as to ensure that the electric appliances of the electric vehicle work normally, avoid the occurrence of vehicle breakdown accidents, and improve the driving safety of the entire electric vehicle.

[0087] According to some embodiments of the present application, the electric vehicle is started, which includes that the electric vehicle is in the driving mode. For details, please refer to the description of the on-board charger according to the first aspect of the present application, which will not be repeated here.

[0088] According to some further embodiments of the present application, the method for controlling the electric vehicle further includes the following steps S50-S60.

[0089] S50, determining whether the second low-voltage DC-DC converter is in an abnormal working state.

[0090] For example, when the second low-voltage DC-DC converter 40 fails, the second low-voltage DC-DC converter 40 cannot work normally, and at this time, it is determined that the second low-voltage DC-DC converter 40 is in an abnormal working state.

[0091] S60, in response to determining that the second low-voltage DC-DC converter is in an abnormal working state, connecting the first low-voltage DC-DC converter to the high-voltage battery unit and the low-voltage battery unit, and issuing an alarm to indicate that the second low-voltage DC-DC converter has failed.

[0092] Specifically, when it is determined that the second low-voltage DC-DC converter 40 is in an abnormal working state, in order to ensure normal driving and operation of the entire electric vehicle, the first low-voltage DC-DC converter 10 is connected to the high-voltage battery unit 20 and the low-voltage battery unit 30, and the high-voltage battery unit 20 supplies power to the low-voltage battery unit 30 through the first low-voltage DC-DC converter 10, thereby ensuring normal driving of the electric vehicle 2000. In addition, an alarm can be issued to indicate that the second low-voltage DC-DC converter 40 has failed, so as to remind the driver that the second low-voltage DC-DC converter 40 needs to be repaired.

[0093] The computer readable storage medium according to the fourth aspect of the present application has a computer program stored thereon, and the computer program is executed by a processor to implement the method for controlling an electric vehicle according to the third aspect of the present application.

[0094] The computer readable storage medium can be a non-transitory storage medium, including a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like, and can also be a transitory storage medium. The computer readable storage medium can also be distributed in a computer system connected through a network, so that the computer readable code can be distributed and executed.

[0095] It should be noted that the above description is only a preferred embodiment of the present application, and does not limit the present application in any form. Any person skilled in the art can make any modification, change and modification to the above embodiment according to the technical essence of the present application without departing from the scope of the technical solution of the present application.

[0096] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the exemplary description of the above terms does not necessarily refer to the same embodiment or example.

[0097] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely divergences of the principles and application of the present application and that numerous modifications, changes, substitutions, and alterations can be made thereto without departing from the spirit and scope of the present application, which is defined by the following claims and their equivalents.

Claims

1. An on-board charger, characterized by, Comprising: a first low-voltage DC-DC converter for connecting between a high-voltage battery unit and a low-voltage battery unit of a vehicle; a second low-voltage DC-DC converter for connecting between the high-voltage battery unit and the low-voltage battery unit; and a controller connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter for controlling one of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter to maintain electrical connection with the high-voltage battery unit and the low-voltage battery unit and the other of the second low-voltage DC-DC converter and the first low-voltage DC-DC converter to break electrical connection with the high-voltage battery unit and the low-voltage battery unit, wherein the controller is configured to: control the first low-voltage DC-DC converter to maintain electrical connection with the high-voltage battery unit and the low-voltage battery unit at least during a charging process of the high-voltage battery unit to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and to charge the low-voltage battery unit; and control the second low-voltage DC-DC converter to maintain electrical connection with the high-voltage battery unit and the low-voltage battery unit during a non-charging process of the high-voltage battery unit to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the second low-voltage DC-DC converter and to charge the low-voltage battery unit. Further comprising a switching unit for connecting between the first low-voltage DC-DC converter and the low-voltage battery unit and for connecting between the second low-voltage DC-DC converter and the low-voltage battery unit, the controller being connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter through the switching unit, the controller being configured to control the switching unit to selectively connect electrical connection of the first low-voltage DC-DC converter or the second low-voltage DC-DC converter with the low-voltage battery unit so that the high-voltage battery unit charges the low-voltage battery unit through the first low-voltage DC-DC converter or the second low-voltage DC-DC converter.

2. The on-board charger of claim 1, wherein, The non-charging mode of the high-voltage battery unit comprises a driving mode of the vehicle, the controller being configured to control the switching unit to connect electrical connection of the first low-voltage DC-DC converter with the low-voltage battery unit to convert high-voltage direct current from the high-voltage battery unit into low-voltage direct current through the first low-voltage DC-DC converter and to charge the low-voltage battery unit when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

3. The on-board charger of claim 2, wherein, ​ 4. The on-board charger of claim 1, wherein, The on-board charger further comprises a switching unit connected between the first low-voltage DC-DC converter and the high-voltage battery unit and connected between the second low-voltage DC-DC converter and the high-voltage battery unit, the controller is connected to the first low-voltage DC-DC converter and the second low-voltage DC-DC converter through the switching unit, and the controller is configured to control the switching unit to selectively connect the first low-voltage DC-DC converter or the second low-voltage DC-DC converter to the high-voltage battery unit in electrical connection, so that the high-voltage battery unit charges the low-voltage battery unit through the first low-voltage DC-DC converter or the second low-voltage DC-DC converter.

5. The vehicle charger of claim 4, wherein, The non-charging mode of the high-voltage battery unit includes a driving mode of the vehicle, and the controller is configured to control the switching unit to connect the first low-voltage DC-DC converter to the high-voltage battery unit in electrical connection when the second low-voltage DC-DC converter fails in the driving mode of the vehicle, so that high-voltage direct current from the high-voltage battery unit is converted into low-voltage direct current by the first low-voltage DC-DC converter and the low-voltage battery unit is charged.

6. The on-board charger according to any one of claims 1-5, characterized by, The on-board charger further comprises: a power factor correction (PFC) unit configured to connect an external alternating current (AC) terminal in a charging mode of the vehicle and configured to convert AC voltage from the external AC terminal into a first direct current (DC) voltage; and a high-voltage DC-DC converter connected to the PFC unit and configured to be connected to the high-voltage battery unit, the high-voltage DC-DC converter being configured to convert the first DC voltage from the PFC unit into a second DC voltage and supply the second DC voltage to the high-voltage battery unit in the charging mode of the vehicle, and the high-voltage battery unit being configured to output the second DC voltage and supply the second DC voltage to the first low-voltage DC-DC converter.

7. The vehicle-mounted charger of claim 6, wherein, The high-voltage DC-DC converter comprises a primary winding of a transformer, a first secondary winding of the transformer, a second secondary winding of the transformer, a primary switch circuit connected to the primary winding, and a first secondary switch circuit connected to the first secondary winding, an output terminal of the first secondary switch circuit being an output terminal of the high-voltage DC-DC converter; The on-board charger further comprises a second secondary switch circuit connected to the second secondary winding, and the second low-voltage DC-DC converter comprises the first secondary winding, the first secondary switch circuit, the second secondary winding, and the second secondary switch circuit, an output terminal of the second secondary switch circuit being an output terminal of the second low-voltage DC-DC converter.

8. The vehicle-mounted charger of claim 6, wherein, The high-voltage DC-DC converter comprises a primary winding of a transformer, a secondary winding of the transformer, a primary switch circuit connected with the primary winding, and a first secondary switch circuit connected with the secondary winding, and an output terminal of the first secondary switch circuit is an output terminal of the high-voltage DC-DC converter; The on-board charger further comprises a second secondary switch circuit connected with the secondary winding, and the second low-voltage DC-DC converter comprises the secondary winding, the first secondary switch circuit, and the second secondary switch circuit, and an output terminal of the second secondary switch circuit is an output terminal of the second low-voltage DC-DC converter.

9. The vehicle-mounted charger of claim 2, wherein, The switching unit comprises a first switch and a second switch, wherein the first switch is connected with an output terminal of the first low-voltage DC-DC converter, the second switch is connected with an output terminal of the second low-voltage DC-DC converter, and the controller is configured to control one of the first switch and the second switch to be closed and the other one of the first switch and the second switch to be opened, wherein the controller is configured to: control the first switch to be closed and the second switch to be opened during a charging process of the high-voltage battery unit; and control the first switch to be opened and the second switch to be closed during a non-charging process of the high-voltage battery unit.

10. The vehicle-mounted charger of claim 9, wherein, The non-charging mode of the high-voltage battery unit comprises a driving mode of a vehicle, and the controller is further configured to: control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

11. The vehicle-mounted charger of claim 4, wherein, The switching unit comprises a first switch and a second switch, wherein the first switch is connected with an input terminal of the first low-voltage DC-DC converter, the second switch is connected with an input terminal of the second low-voltage DC-DC converter, and the controller is configured to control one of the first switch and the second switch to be closed and the other one of the first switch and the second switch to be opened, wherein the controller is configured to: control the first switch to be closed and the second switch to be opened during a charging process of the high-voltage battery unit; and control the first switch to be opened and the second switch to be closed during a non-charging process of the high-voltage battery unit.

12. The vehicle-mounted charger of claim 11, wherein, The non-charging mode of the high-voltage battery unit comprises a driving mode of a vehicle, and the controller is further configured to: control the first switch to be closed and the second switch to be opened when the second low-voltage DC-DC converter fails in the driving mode of the vehicle.

13. An electric vehicle, characterized by comprises: the on-board charger according to any one of claims 1-12; a high-voltage battery unit; and a low-voltage battery unit connected to the low-voltage battery unit by the on-board charger.

14. A method for controlling an electric vehicle according to claim 13, characterized in that, comprises the following steps: judging whether a high-voltage battery unit of the electric vehicle is in a charging mode; in response to determining that the high-voltage battery unit is in a charging mode, starting a first low-voltage DC-DC converter to convert high-voltage direct current from the high-voltage battery unit to low-voltage direct current to charge the low-voltage battery unit during charging of the high-voltage battery unit; in response to determining that the high-voltage battery unit is in a non-charging mode, determining whether the electric vehicle is started; in response to determining that the electric vehicle is started, starting the second low-voltage DC-DC converter to convert high-voltage direct current from the high-voltage battery unit to low-voltage direct current to charge the low-voltage battery unit, wherein the electric vehicle being started indicates that the high-voltage battery unit of the electric vehicle is in a non-charging mode.

15. The method of claim 14, wherein, the electric vehicle being started comprises the electric vehicle being in a driving mode.

16. The method of claim 14, wherein, the starting the first low-voltage DC-DC converter comprises: controlling a switching unit to connect the first low-voltage DC-DC converter to the low-voltage battery unit and disconnect the second low-voltage DC-DC converter from the low-voltage battery unit; or controlling a switching unit to connect the first low-voltage DC-DC converter to the high-voltage battery unit and disconnect the second low-voltage DC-DC converter from the high-voltage battery unit.

17. The method of claim 14, wherein, the starting the second low-voltage DC-DC converter comprises: controlling a switching unit to disconnect the first low-voltage DC-DC converter from the low-voltage battery unit and connect the second low-voltage DC-DC converter to the low-voltage battery unit; or controlling a switching unit to disconnect the first low-voltage DC-DC converter from the high-voltage battery unit and connect the second low-voltage DC-DC converter to the high-voltage battery unit.

18. The method according to any one of claims 14-17, characterized by, further comprising: in the driving mode of the electric vehicle, determining whether the second low-voltage DC-DC converter is in an abnormal working state; in response to determining that the second low-voltage DC-DC converter is in an abnormal working state, connecting the first low-voltage DC-DC converter to the high-voltage battery unit and the low-voltage battery unit, and issuing an alarm to indicate that the second low-voltage DC-DC converter has failed.

19. A computer readable storage medium having stored thereon a computer program which, when executed by a processor, carries out the method according to any one of claims 14-18.

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