Charging system, charging method, vehicle-mounted charger and vehicle

Abstract

The invention provides a charging system and method, a vehicle-mounted charger and a vehicle, and the method comprises the steps: switching the charging mode of the vehicle from a vehicle-mounted wired charging mode to a wireless charging mode through a mode switching switch, or switching the charging mode from the wireless charging mode to the vehicle-mounted wired charging mode, a rectification switch circuit, an inverter, an isolation circuit, a transformer and a rectifier can be reused for charging. According to the invention, the cost and the size of the charging system can be reduced by increasing the multiplexing number of components; moreover, the charging modes are switched through the mode switching switch, so that the redundancy of the charging system can be reduced, and the overall efficiency is improved. Since the rectification switch circuit, the inverter, the isolation circuit, the transformer and the rectifier comprise inductive elements and high-frequency full-bridge circuits, further multiplexing of the circuit module can be realized by multiplexing the inductive elements with large volume and high-cost high-frequency full-bridge circuits in the charging system, so that the cost can be reduced, and the space can be saved.

Description

Technical Field

[0001] The present application relates to the field of charging technology, and in particular to a charging system and a charging method, an on-board charger and a vehicle. Background Art

[0002] Compared with traditional cars, electric vehicles (EVs) have made significant improvements in starting speed, vehicle system intelligence, and ride comfort, but the development of electric vehicles has also put forward higher requirements for battery power supply technology. For electric vehicles equipped with on-board wired chargers and wireless chargers, the relevant technology basically requires redundant design of two charging systems, which not only increases costs but also leads to reduced efficiency; and the simultaneous installation of two charging systems will greatly increase the cost, occupied volume and complexity of the vehicle charging system. In addition, although the circuit modules of wired charging and wireless charging are relatively similar in power conversion function, power level, and voltage level, the relevant technology has not fully utilized this similarity to reuse circuit modules, which makes the relevant technology insufficient in the reuse of components, resulting in higher costs and larger charging systems. Summary of the invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a charging system and a charging method, an on-board charger and a vehicle, so as to solve the technical problems existing in the prior art.

[0004] To achieve the above objectives and other related objectives, the present application provides a charging system, the charging system comprising:

[0005] The rectifier switch circuit is used to control the on / off of the circuit and the direction of the current, and to rectify the input power supply;

[0006] an inverter, connected to the rectifier switch circuit, for converting direct current into alternating current;

[0007] An isolation circuit, connected to the inverter, for electrical isolation;

[0008] A transformer, used for voltage conversion, wherein the primary side of the transformer is connected to the isolation circuit, and the secondary side of the transformer is connected to the rectifier;

[0009] Rectifiers, which convert AC power into DC power;

[0010] A mode switching switch is used to switch the vehicle's charging mode from an on-board wired charging mode to a wireless charging mode, or to switch the vehicle's charging mode from a wireless charging mode to an on-board wired charging mode; wherein, in the on-board wired charging mode or the wireless charging mode, the rectifier switch circuit, the inverter, the isolation circuit, the transformer and the rectifier are reused for charging.

[0011] In one embodiment of the present application, the mode switching switch includes a relay.

[0012] In one embodiment of the present application, the charging system further includes: an electromagnetic interference filter for suppressing the generation and / or propagation of electromagnetic interference, the input end of the electromagnetic interference filter is connected to the input power supply, and the output end of the electromagnetic interference filter is connected to the rectifier switch circuit.

[0013] In one embodiment of the present application, the charging system also includes: a power factor correction circuit for rectifying the input power supply; the input end of the power factor correction circuit is connected to the output end of the electromagnetic interference filter, and the output end of the power factor correction circuit is connected to the rectification switch circuit.

[0014] In one embodiment of the present application, when in the wireless charging mode, the charging system also includes: a primary compensation circuit, a primary coil, a secondary coil, and a secondary compensation circuit; wherein the input end of the primary compensation circuit is connected to the output end of the power factor correction circuit, the primary coil is connected to the output end of the primary compensation circuit, the secondary coil is connected to the primary coil, the input end of the secondary compensation circuit is connected to the secondary coil, and the output end of the secondary compensation circuit is connected to the rectifier switch circuit.

[0015] In one embodiment of the present application, the rectifier switch circuit includes a field effect transistor and a diode.

[0016] In one embodiment of the present application, the output end of the rectifier is connected to a load, and the load includes a battery management system and / or a battery pack.

[0017] The present application also provides a charging method, the method comprising the following steps:

[0018] In response to the first charging instruction, switching the charging mode of the vehicle from the on-board wired charging mode to the wireless charging mode to perform wireless charging on the vehicle; or,

[0019] In response to the second charging instruction, switching the charging mode of the vehicle from the wireless charging mode to the on-board wired charging mode to perform wired charging on the vehicle;

[0020] When the charging mode of the vehicle is in the on-vehicle wired charging mode or the wireless charging mode, the rectifying switch circuit, the inverter, the isolation circuit, the transformer and the rectifier are reused for charging;

[0021] Wherein, the rectifier switch circuit is configured to control the on-off of the circuit and the direction of the current, and to rectify the input power supply;

[0022] an inverter, connected to the rectifier switch circuit and configured to convert direct current into alternating current;

[0023] an isolation circuit, connected to the inverter and configured to perform electrical isolation;

[0024] A transformer configured to perform voltage conversion, wherein a primary side of the transformer is connected to the isolation circuit, and a secondary side of the transformer is connected to a rectifier;

[0025] A rectifier is configured to convert alternating current into direct current.

[0026] The present application also provides a vehicle charger, which includes a charging system as described in any one of the above.

[0027] The present application also provides a vehicle, which includes the on-board charger as described above.

[0028] As described above, the present application provides a charging system and a charging method, a vehicle charger and a vehicle, which have the following beneficial effects: the present application switches the charging mode of the vehicle from the vehicle-mounted wired charging mode to the wireless charging mode, or switches the charging mode of the vehicle from the wireless charging mode to the vehicle-mounted wired charging mode by providing a mode switching switch, and can reuse the rectifier switch circuit, inverter, isolation circuit, transformer and rectifier for charging. Therefore, the present application can reduce costs and reduce the volume of the charging system by increasing the number of components reused; and the present application switches the charging mode through the mode switching switch, which can reduce the redundancy of the charging system to improve the overall efficiency. In addition, since the rectifier switch circuit, inverter, isolation circuit, transformer and rectifier contain inductive elements and high-frequency full-bridge circuits, the present application can further reuse circuit modules by reusing the inductive elements that account for a large volume in the charging system and the high-cost high-frequency full-bridge circuit, thereby reducing costs and saving space. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the hardware principle of a charging system provided in an embodiment of the present application;

[0030] Figure 2 A circuit connection diagram of a charging system provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of circuit connections of a charging system provided by an embodiment of the present application in a vehicle-mounted wired charging mode;

[0032] Figure 4 A schematic diagram of circuit connections of a charging system in a wireless charging mode provided by an embodiment of the present application;

[0033] Figure 5 A schematic diagram of steady-state operating waveforms of input voltage and inductor current of a charging system provided by an embodiment of the present application under rated operating conditions in an on-vehicle wired charging mode;

[0034] Figure 6 The figure is a schematic diagram of steady-state operating waveforms of input voltage and inductor current of a charging system provided in an embodiment of the present application under rated conditions in a wireless charging mode. DETAILED DESCRIPTION

[0035] The following is an explanation of the embodiments of the present application by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied by other different specific embodiments, and the details in this specification can also be based on different viewpoints and applications, without departing from the spirit of the present application. Various modifications or changes are made. It is understood that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. In addition, it is understood that the illustrations provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and only the components related to the present application are shown in the drawings rather than the number, shape and size of the components during the actual implementation. The type, quantity and ratio of each component during its actual implementation can be a random change, and its component layout type may also be more complicated.

[0036] Figure 1 A schematic diagram of the hardware principle of a charging system is shown in FIG. Figure 1 As shown, Figure 1Three charging modes for electric vehicles (EVs) are shown, namely, high-voltage DC fast charging mode, onboard wired charging (OBC) mode, and wireless charging (WPT) mode. For the high-voltage DC fast charging mode, the ground-side charging piles are mostly based on three-phase power factor correction circuits (PFC), which are connected to the vehicle side after rectification to high-voltage DC, and then connected to the battery management system (BMS) and high-voltage battery through one or several DC isolation circuits. The energy storage device. For the OBC mode, the ground side often only provides a "port" function connected to the power grid, and the circuit modules for charging the high-voltage battery are all located at the vehicle side. The circuit modules from the grid side to the energy storage device are EMI (Electromagnetic Interference, EMI for short) filter, PFC rectifier, high-frequency inverter, and DCDC isolation circuit. For the WPT mode, its components are highly similar to those of the OBC mode. The difference is that the transformer in the DCDC isolation circuit becomes a coupler for high-frequency magnetic field energy transmission, so the positions of its components on the ground and vehicle sides are also different. At the same time, although the circuit modules of the OBC mode and the WPT mode are similar in terms of power conversion function, power level, and voltage level, the relevant technologies have not fully utilized this similarity to reuse circuit modules, which makes the relevant technologies insufficient in terms of component reuse, resulting in higher costs and larger charging systems.

[0037] Therefore, in an exemplary embodiment of the present application, the embodiment provides a charging system that can reuse components, and the charging system includes:

[0038] The rectifier switch circuit is used to control the on / off of the circuit and the direction of the current, and to rectify the input power supply. The rectifier switch circuit includes a field effect transistor and a diode.

[0039] An inverter, connected to the rectifier switch circuit, for converting direct current into alternating current;

[0040] An isolation circuit, connected to the inverter, for electrical isolation;

[0041] A transformer, used for voltage conversion, wherein the primary side of the transformer is connected to the isolation circuit, and the secondary side of the transformer is connected to the rectifier;

[0042] A rectifier is used to convert alternating current into direct current; wherein the output end of the rectifier is connected to a load, which includes but is not limited to a battery management system and / or a battery pack.

[0043] A mode switching switch is used to switch the vehicle's charging mode from an on-board wired charging mode to a wireless charging mode, or to switch the vehicle's charging mode from a wireless charging mode to an on-board wired charging mode; wherein, in the on-board wired charging mode or the wireless charging mode, a rectifier switch circuit, an inverter, an isolation circuit, a transformer and a rectifier are reused for charging.

[0044] In an exemplary embodiment of the present application, the charging system may further include: an electromagnetic interference filter for suppressing the generation and / or propagation of electromagnetic interference, wherein the input end of the electromagnetic interference filter is connected to the input power supply, and the output end of the electromagnetic interference filter is connected to the rectifier switch circuit.

[0045] In an exemplary embodiment of the present application, the charging system may further include: a power factor correction circuit for rectifying the input power supply; the input end of the power factor correction circuit is connected to the output end of the electromagnetic interference filter, and the output end of the power factor correction circuit is connected to the rectification switch circuit.

[0046] In an exemplary embodiment of the present application, when in a wireless charging mode, the charging system may further include: a primary compensation circuit, a primary coil, a secondary coil, and a secondary compensation circuit; wherein the input end of the primary compensation circuit is connected to the output end of the power factor correction circuit, the primary coil is connected to the output end of the primary compensation circuit, the secondary coil is connected to the primary coil, the input end of the secondary compensation circuit is connected to the secondary coil, and the output end of the secondary compensation circuit is connected to the rectifier switch circuit.

[0047] According to the above records, in a specific example, if the mode switching switch is mainly composed of a relay, the corresponding circuit connection diagram of the charging system can be as follows: Figure 2 As shown. Figure 2 In the example, the charging mode of the charging system can be switched between the OBC mode and the WPT mode through the relay Sa. When the relay Sa is switched to the dotted line circuit, the charging system will operate in the OBC mode. When Sa is switched to the solid line circuit, the charging system will operate in the WPT mode. Figure 2 In the embodiment, the rectifier switch circuit may include field effect transistors S1, S2, S3 and S4, and diodes D1 and D2. The isolation circuit (also referred to as an LCC circuit) may include a capacitor Cr, an inductor Lr and an inductor Lm. Therefore, the combination of these two modes not only ensures that the charging system has both the functions of wired charging and wireless charging of electric vehicles, but also can reuse circuit components to the greatest extent.

[0048] Specifically, in the vehicle wired charging OBC mode, Figure 2 The circuit model of the entire charging system in the working circuit module can be simplified as follows: Figure 3 As shown, Figure 3The figure shows a typical OBC circuit. The circuit modules from the grid side to the high-voltage battery end are EMI filter, interleaved parallel totem pole PFC, high-frequency inverter, LLC circuit for DCDC isolation, high-frequency rectifier and output filter capacitors after each level of rectifier. Among them, the interleaved parallel totem pole PFC has a stronger ability to reduce ripple than the non-interleaved single inductor PFC. For the LLC circuit used for DCDC isolation, Cr and Lr are connected in series to resonate, which can reduce the loss of the inverter. Under rated conditions, the resonant circuit will work in the ZVS (Zero Voltage Switch, ZVS for short) mode with weak inductance. When charging an electric vehicle EV through the on-board wired charging OBC mode, Figure 3 All or part of the components within the dashed box are reused components of the charging system.

[0049] In wireless charging WPT mode, Figure 2 The circuit model of the entire charging system in the working circuit module can be simplified as follows: Figure 4 As shown. In this mode, the circuit modules from the grid side to the high-voltage battery are: EMI filter, PFC, high-frequency inverter, primary LCC compensation circuit, primary coil, secondary coil, secondary LCC compensation circuit, high-frequency rectification circuit, LLC circuit for DCDC isolation. The post-stage DCDC circuit adds a first-level voltage regulation function to the WPT mode, which makes the circuit have a wider voltage modulation range than the circuit specified in the relevant standards, and can cope with the wide range of coupling offsets and load fluctuations in the WPT mode. When charging an electric vehicle EV through the wireless charging WPT mode, Figure 4 All or part of the components within the dashed box are reused components of the charging system.

[0050] according to Figures 2 to 4 It can be known that the charging system provided by the present application can have at least two high-frequency inductors and two high-frequency half-bridges, wherein the inductance of the high-frequency inductor is 30uH, and the reused full-bridge frequency is about 400kHz. Among them, when the charging system is in OBC mode and inputs 220V AC voltage, it can output 400V DC; when the charging system is in WPT mode and inputs 85kHz high-frequency AC, it can output 400V DC. Then, simulation verification is performed under steady-state conditions respectively, and the steady-state working waveforms of the input voltage and inductor current of the charging system under rated conditions in OBC mode can be obtained, such as Figure 5 As shown, the power factor of PFC is 99.2% at this time. And the steady-state operating waveforms of the input voltage and inductor current of the charging system under rated conditions in WPT mode can be obtained, as shown in Figure 6 As shown, a completely resonant sinusoidal waveform is presented under the LCC resonant circuit, which proves that the charging system can work stably in all modes.

[0051] In summary, the present application provides a charging system, which switches the charging mode of the vehicle from the on-board wired charging mode to the wireless charging mode, or switches the charging mode of the vehicle from the wireless charging mode to the on-board wired charging mode by providing a mode switching switch, and can reuse the rectifier switch circuit, inverter, isolation circuit, transformer and rectifier for charging. Therefore, the charging system can reduce costs and reduce the volume of the charging system by increasing the number of components reused; and the charging system switches the charging mode through the mode switching switch, which can reduce the redundancy of the charging system to improve the overall efficiency. In addition, since the rectifier switch circuit, inverter, isolation circuit, transformer and rectifier include inductive elements and high-frequency full-bridge circuits, the charging system can further reuse circuit modules by reusing the inductive elements that account for a large volume in the charging system and the high-cost high-frequency full-bridge circuit, thereby reducing costs and saving space.

[0052] In another exemplary embodiment of the present application, the embodiment further provides a charging method, comprising the following steps:

[0053] In response to the first charging instruction, the charging mode of the vehicle is switched from the on-vehicle wired charging mode to the wireless charging mode to perform wireless charging on the vehicle; or,

[0054] In response to the second charging instruction, switching the charging mode of the vehicle from the wireless charging mode to the on-board wired charging mode to perform wired charging on the vehicle;

[0055] When the vehicle is in the on-board wired charging mode or the wireless charging mode, the rectifier switch circuit, the inverter, the isolation circuit, the transformer and the rectifier are reused for charging;

[0056] Wherein, the rectifier switch circuit is configured to control the on-off of the circuit and the direction of the current, and to rectify the input power supply;

[0057] an inverter connected to the rectifier switching circuit and configured to convert direct current into alternating current;

[0058] an isolation circuit, connected to the inverter, configured to perform electrical isolation;

[0059] A transformer configured to perform voltage conversion, a primary side of the transformer connected to the isolation circuit, and a secondary side of the transformer connected to the rectifier;

[0060] A rectifier is configured to convert alternating current into direct current.

[0061] As an example, the first charging instruction and / or the second charging instruction may be obtained by the user by controlling the vehicle or the ground charging pile when the user is about to charge. As another example, the first charging instruction and / or the second charging instruction may be obtained by the user by controlling the vehicle or the ground charging pile during the charging process.

[0062] It can be understood that the charging method provided in this embodiment and the charging system provided in the above embodiment belong to the same concept, wherein the circuit connection or technical principle of the charging system has been described in detail in the above embodiment, so the technical effect of the charging method provided in this embodiment can refer to the embodiment corresponding to the above charging system, which will not be repeated here. In addition, in actual application, the charging method provided in this embodiment can be appropriately adjusted according to the circuit connection or technical principle of the charging system as needed, and the specific adjustment process will not be repeated here.

[0063] In another exemplary embodiment of the present application, the embodiment further provides a vehicle charger, which includes a charging system as described in one or some of the above embodiments. It can be explained that since the circuit connection or technical principle of the charging system has been described in detail in the above embodiments, the technical functions and effects of the vehicle charger provided in this embodiment can be referred to the embodiments corresponding to the above charging system, and will not be repeated here.

[0064] In another exemplary embodiment of the present application, the embodiment further provides a vehicle, which includes the on-board charger described in the above embodiment. It can be explained that since the on-board charger and the charging system provided in the above embodiment belong to the same concept, and the circuit connection or technical principle of the charging system has been described in detail in the above embodiment, the technical functions and effects of the vehicle provided in this embodiment can be referred to the embodiment corresponding to the above charging system, and will not be repeated here.

[0065] It is understood that, although the terms first, second, etc. may be used to describe charging instructions, etc. in the embodiments of the present application, these terms are only used to distinguish charging instructions from each other. For example, without departing from the scope of the embodiments of the present application, the first charging instruction may also be referred to as the second charging instruction, and similarly, the second charging instruction may also be referred to as the first charging instruction.

[0066] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A charging system, characterized in that: The charging system comprises: The rectifier switch circuit is used to control the on / off of the circuit and the direction of the current, and to rectify the input power supply; an inverter, connected to the rectifier switch circuit, for converting direct current into alternating current; An isolation circuit, connected to the inverter, for electrical isolation; A transformer, used for voltage conversion, wherein the primary side of the transformer is connected to the isolation circuit, and the secondary side of the transformer is connected to the rectifier; Rectifiers, which convert AC power into DC power; A mode switching switch is used to switch the vehicle's charging mode from an on-board wired charging mode to a wireless charging mode, or to switch the vehicle's charging mode from a wireless charging mode to an on-board wired charging mode; wherein, in the on-board wired charging mode or the wireless charging mode, the rectifier switch circuit, the inverter, the isolation circuit, the transformer and the rectifier are reused for charging.

2. The charging system according to claim 1, characterized in that: The mode switching switch includes a relay.

3. The charging system according to claim 1, characterized in that: The charging system further includes: an electromagnetic interference filter for suppressing the generation and / or propagation of electromagnetic interference, wherein an input end of the electromagnetic interference filter is connected to an input power supply, and an output end of the electromagnetic interference filter is connected to the rectifier switch circuit.

4. The charging system according to claim 3, characterized in that: The charging system also includes: a power factor correction circuit for rectifying an input power supply; an input end of the power factor correction circuit is connected to an output end of the electromagnetic interference filter, and an output end of the power factor correction circuit is connected to the rectification switch circuit.

5. The charging system according to claim 4, characterized in that: When in the wireless charging mode, the charging system also includes: a primary compensation circuit, a primary coil, a secondary coil, and a secondary compensation circuit; wherein the input end of the primary compensation circuit is connected to the output end of the power factor correction circuit, the primary coil is connected to the output end of the primary compensation circuit, the secondary coil is connected to the primary coil, the input end of the secondary compensation circuit is connected to the secondary coil, and the output end of the secondary compensation circuit is connected to the rectifier switch circuit.

6. The charging system according to any one of claims 1 to 5, characterized in that: The rectifying switch circuit includes a field effect transistor and a diode.

7. The charging system according to any one of claims 1 to 5, characterized in that: The output end of the rectifier is connected to a load, and the load includes a battery management system and / or a battery pack.

8. A charging method, characterized in that: The method comprises the following steps: In response to the first charging instruction, switching the charging mode of the vehicle from the on-board wired charging mode to the wireless charging mode to perform wireless charging on the vehicle; or, In response to the second charging instruction, switching the charging mode of the vehicle from the wireless charging mode to the on-board wired charging mode to perform wired charging on the vehicle; When the charging mode of the vehicle is in the on-vehicle wired charging mode or the wireless charging mode, the rectifying switch circuit, the inverter, the isolation circuit, the transformer and the rectifier are reused for charging; Wherein, the rectifier switch circuit is configured to control the on-off of the circuit and the direction of the current, and to rectify the input power supply; an inverter, connected to the rectifier switch circuit and configured to convert direct current into alternating current; an isolation circuit, connected to the inverter and configured to perform electrical isolation; A transformer configured to perform voltage conversion, wherein a primary side of the transformer is connected to the isolation circuit, and a secondary side of the transformer is connected to a rectifier; A rectifier is configured to convert alternating current into direct current.

9. A vehicle charger, characterized in that: The on-board charger comprises a charging system according to any one of claims 1 to 7.

10. A vehicle, characterized in that: The vehicle includes the on-board charger as claimed in claim 9.

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