Electric vehicle

Abstract

An electric vehicle includes an electric machine having a plurality of windings, a dual inverter having a first DC terminal and a second DC terminal and connected to the electric machine, a charging terminal to which a charging voltage is applied, and a plurality of nodes. The plurality of nodes include a first node formed between a positive electrode of the charging terminal and the other end of any one of the plurality of windings, a second node formed between a negative electrode of the charging terminal and a negative electrode of the first DC terminal, a third node formed between the negative electrode of the charging terminal and a negative electrode of the second DC terminal, and a second node formed at the second node. And a fourth node between the third node and the negative electrode of the charging terminal.

Description

Technical Field

[0001] The present invention relates to an electric vehicle having multiple batteries connected to a dual inverter. Background Technology

[0002] In recent years, with increasing public awareness of environmental protection, the number of environmentally friendly vehicles equipped with electric motors as their power source is rising. Environmentally friendly vehicles are also known as electric vehicles, with representative examples including hybrid vehicles (HEVs) and electric vehicles (EVs).

[0003] For small or light electric vehicles, cost competitiveness requires consideration of not only reducing the cost of high-voltage batteries but also reducing the cost of power electronic (PE) components. Among high-voltage power electronic components, the high-voltage battery is the most expensive; minimizing its capacity can reduce the price of the power electronic components. However, reducing the capacity of the high-voltage battery will not only shorten the electric vehicle's driving range but also reduce the output of the motor and inverter.

[0004] Therefore, a motor drive system with multiple independent batteries as voltage sources may be useful.

[0005] The matters described above as background art are intended to enhance the understanding of the background of the present invention, and should not be construed as an admission that they correspond to prior art known to those skilled in the art. Summary of the Invention

[0006] Therefore, the present invention was made in view of the above-mentioned problems, and the object of the present invention is to provide an electric vehicle capable of forming a charging path for charging multiple batteries (e.g., all) connected to dual (e.g., even number) inverters when the charging conditions of multiple batteries are different.

[0007] The purpose of this invention is not limited to the above-described purpose, and those skilled in the art can understand other tasks not mentioned from the following description.

[0008] According to one aspect of the invention, the above and other objectives can be achieved by providing an electric vehicle comprising: a motor having a plurality of windings corresponding to a plurality of phases; a first inverter having a first DC terminal connected to a first battery and a plurality of branches connected to one end of the plurality of windings (e.g., each winding); a second inverter having a second DC terminal connected to a second battery and a plurality of branches connected to the other end of the plurality of windings (e.g., each winding); a charging terminal to which a charging voltage of an external charging device is applied when the external charging device is connected; and a plurality of nodes including a first node formed between the positive terminal of the charging terminal and the other end of any one of the plurality of windings, a second node formed between the negative terminal of the charging terminal and the negative terminal of the first DC terminal, a third node formed between the negative terminal of the charging terminal and the negative terminal of the second DC terminal, and a fourth node formed between the second node, the third node and the negative terminal of the charging terminal.

[0009] For example, the electric vehicle may further include a controller configured to control a first inverter and a second inverter based on the voltage of a first battery and a second battery, as well as a maximum charging voltage applicable to the charging terminals, thereby determining the charging paths for the first battery and the second battery.

[0010] For example, the voltage of the first battery can be equal to or higher than the voltage of the second battery, and the controller can control the first inverter and the second inverter based on the voltage of the second battery and the maximum charging voltage.

[0011] For example, the controller can control the first inverter and the second inverter such that when the maximum charging voltage is equal to or higher than the voltage of the second battery, a charging path is formed in which the second battery is directly charged using the charging voltage and the first battery is charged using the voltage of the second battery.

[0012] For example, the controller can control the first inverter and the second inverter so that the current caused by the charging voltage is transmitted to the second battery via the first node and the second inverter.

[0013] For example, the controller can control the switching state of the second inverter, such that the branch of the second inverter connected to the first node is connected to the positive terminal of the second DC terminal.

[0014] For example, the controller can control the first inverter and the second inverter such that the voltage of the second battery is converted to match the voltage of the first battery through the plurality of windings.

[0015] For example, the controller can control the switching state of the second inverter so that multiple branches of the second inverter are connected to the positive terminal of the second DC terminal, and the controller can control the switching state of the first inverter so that the voltage of the second battery is converted to match the voltage of the first battery through the multiple windings.

[0016] For example, the controller can control the first inverter and the second inverter so that the phase currents applied to the plurality of windings have the same amplitude.

[0017] For example, the controller can control the first inverter and the second inverter such that when the maximum charging voltage is lower than the voltage of the second battery, a charging path is formed in which the first battery is charged using the charging voltage and the second battery is charged using the voltage of the first battery.

[0018] For example, the controller can control the first inverter and the second inverter such that the current caused by the charging voltage is transmitted to the first battery via the first node, the winding of the plurality of windings connected to the first node, and the first inverter.

[0019] For example, the controller can control the switching state of the branch connected to the first node in a plurality of branches of the first inverter, so that the charging voltage is converted to match the voltage of the first battery through the winding connected to the first node in a plurality of windings.

[0020] For example, the controller can control the first inverter and the second inverter such that the current caused by the voltage of the first battery is transmitted to the second battery via the windings of the plurality of windings that are not connected to the first node and the second inverter.

[0021] For example, the controller can control the switching state of the branches of the first inverter that are not connected to the first node, so that the voltage of the first battery is converted to match the voltage of the second battery through the windings of the multiple windings that are not connected to the first node.

[0022] For example, the controller can control the first inverter and the second inverter so that the phase currents applied to the plurality of windings have the same amplitude.

[0023] For example, the electric vehicle may further include: a first switch that, when in the ON state, electrically connects a first node and the positive terminal of a charging terminal; a second switch that, when in the ON state, electrically connects a second node and the negative terminal of a charging terminal; and a third switch that, when in the ON state, electrically connects a third node and the negative terminal of a charging terminal. Attached Figure Description

[0024] The above and other objects, features, and advantages of the present invention will be understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 This is a schematic diagram illustrating the configuration of an electric vehicle according to an embodiment of the present invention; and

[0026] Figure 2 , Figure 3 , Figure 4 and Figure 5 This is a schematic diagram illustrating the charging path of an electric vehicle according to an embodiment of the present invention. Detailed Implementation

[0027] The specific structural and functional descriptions of the embodiments of the present invention disclosed in this application are for the purpose of explaining the embodiments of the present invention. The embodiments of the present invention can be implemented in various forms and should not be construed as limited to the embodiments described in this application.

[0028] Since embodiments of the invention can be modified in various ways and have various forms, specific embodiments will be shown in the drawings and described in detail in the application. However, this is not intended to limit embodiments of the concept according to the invention to a specific disclosed form, but should be understood to include (e.g., all) variations, equivalents, and alternatives included within the spirit and technical scope of the invention.

[0029] Unless otherwise stated, terms, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Commonly used terms, such as those defined in dictionaries, shall be interpreted as consistent with their meaning in the context of the relevant art. These terms shall not be interpreted in an ideal or overly formal manner unless otherwise defined herein.

[0030] In the following description, the embodiments disclosed herein will be described in detail with reference to the accompanying drawings. However, the same or similar components will be given the same reference numerals, and redundant descriptions thereof will be omitted.

[0031] In the following description of the embodiments, the term "preset" discloses that the value of a parameter is predetermined when it is used in a process or algorithm. According to the embodiments, the value of a parameter may be set at the start of the process or algorithm, or it may be set during a period of execution of the process or algorithm.

[0032] The terms “module” and “unit or component” used to refer to components are used in this document to help understand components and should not be considered to have a specific meaning or function.

[0033] In the following description of the embodiments disclosed in this application, detailed descriptions of known functions and configurations included herein will be omitted where such descriptions may obscure the subject matter of the invention. Furthermore, the accompanying drawings are provided to facilitate understanding of the embodiments disclosed herein, without limiting the technical spirit disclosed herein, and include variations, equivalents, and alternatives included within the spirit and scope of the invention.

[0034] The terms "first" and / or "second" are used to describe various components, but these components are not limited by these terms. These terms are used to distinguish one component from another.

[0035] When a component is “joined” or “connected” to another component, it should be understood that a third component may exist between the two components, although that component may (e.g., directly) join or connect to the other component. When a component is “directly joined” or “directly connected” to another component, it should be understood that there are no elements between the two components.

[0036] Unless the context clearly indicates otherwise, elements described in the singular are intended to include multiple elements.

[0037] In this specification, it will be further understood that the terms "comprising" or "including" specify the presence of the said feature, value, step, operation, component, part or combination thereof, but do not exclude the presence or addition of one or more other features, values, steps, operations, components or combinations thereof.

[0038] Furthermore, the units or control units included in the names of such as motor control unit (MCU) and hybrid control unit (HCU) can be used when naming control devices that control specific vehicle functions, and may not indicate general-purpose functional units.

[0039] A controller may include a communication device that communicates with other controllers or sensors to control the functions of the controller, a memory that stores an operating system, logic instructions, input / output information, etc., and one or more processors that perform determination, calculation, and decision-making to control the functions (e.g., as necessary).

[0040] Reference Figure 1 An electric vehicle according to an embodiment of the present invention includes a motor 100, dual inverters (e.g., a first inverter 210 and a second inverter 220), a first battery B1, a second battery B2, charging terminals Ch1 and Ch2, a plurality of switches Sw, and a controller 300.

[0041] Reference Figure 1The motor 100 has multiple windings L1, L2 and L3 corresponding to the first phase a, the second phase b and the third phase c.

[0042] The dual inverter includes a first inverter 210 and a second inverter 220, which are connected to the two ends of a plurality of windings L1, L2, and L3 (e.g., each winding). Specifically, the first inverter 210 has DC links D1 and D1' connected to one end of the plurality of windings L1, L2, and L3 (e.g., each winding) and a plurality of branches S11-S12, S21-S22, and S31-S32, and the second inverter 220 has second DC links D2 and D2' connected to the other end of the plurality of windings L1, L2, and L3 (e.g., each winding) and a plurality of branches S11'-S12', S21'-S22', and S31'-S32'. The branch is connected to the upper switching elements S11, S21, S31, S11', S21' and S31' and the lower switching elements S12, S22, S32, S12', S22' and S32', each of which can be implemented as a transistor such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT).

[0043] Charging terminals Ch1 and Ch2 may have a positive terminal Ch1 connected to the positive terminal D1 of the first DC terminal and a negative terminal Ch2 connected to the negative terminal D2' of the second DC terminal. An external charging device 20 may be connected to charging terminals Ch1 and Ch2 to apply a charging voltage, and (for example, in this case) relays RLY1 and RLY2 may be disposed between charging terminals Ch1 and Ch2 and the first DC terminal D1 and the second DC terminal D2'.

[0044] The first battery B1 is connected to the first DC terminals D1 and D1', and the second battery B2 is connected to the second DC terminals D2 and D2'. Both batteries can be charged by applying a charging voltage to the charging terminals Ch1 and Ch2. In this configuration, the first and second batteries B1 can be charged independently; for example, only the first battery B1 can be charged, or only the second battery B2 can be charged. Furthermore, the first and second batteries B1 can have different types and specifications, and therefore can have different voltages.

[0045] In an embodiment of the present invention, the first battery B1 and the second battery B2 can be charged together. In particular, even when the charging conditions of the first battery B1 and the second battery B2 are different, both the first battery B1 and the second battery B2 can be charged.

[0046] In order to form a charging path that can charge both the first battery B1 and the second battery B2 as described herein, the electric vehicle according to the embodiment may include a plurality of nodes, including a first node nd1 formed between the positive terminal Ch1 of the charging terminal and the other end of one of the plurality of windings L1, L2 and L3, a second node nd2 formed between the negative terminal Ch2 of the charging terminal and the negative terminal D1' of the first DC terminal, a third node nd3 formed between the negative terminal Ch2 of the charging terminal and the negative terminal D2' of the second DC terminal, and a fourth node nd4 formed between the second node nd2, the third node nd3 and the negative terminal Ch2 of the charging terminal.

[0047] Multiple switches can be provided between the motor 100, the first inverter 210, the second inverter 220, and the charging terminals Ch1 and Ch2 (for example, in this case), and when the multiple switches are turned on, a charging path can be formed through each node nd1, nd2, nd3, and nd4. More specifically, the multiple switches may include a first switch Sw1 electrically connecting the first node nd1 and the positive terminal Ch1 of the charging terminal when turned on, a second switch Sw2 electrically connecting the second node nd2 and the negative terminal Ch2 of the charging terminal when turned on, and a third switch Sw3 electrically connecting the third node nd3 and the negative terminal Ch2 of the charging terminal when turned on.

[0048] When multiple switches as described herein are turned on, controller 300 can control first inverter 210 and second inverter 220 based on the voltages of first battery B1 and second battery B2 and the maximum charging voltage applicable to charging terminals Ch1 and Ch2, thereby forming a charging path for charging first battery B1 and second battery B2 (e.g., both).

[0049] In this implementation, controller 300 can be implemented as a motor control unit (MCU) and can be connected to a battery management system (BMS) in the vehicle to obtain voltage and charging current commands for the first battery B1 and the second battery B2. Alternatively, controller 300 can be implemented as a higher-level controller such as a vehicle control unit (VCU) or hybrid power control unit (HCU), having the functions of both the motor control unit (MCU) and the battery management system (BMS). Furthermore, the maximum charging voltage is the maximum value of the charging voltage applicable to charging terminals Ch1 and Ch2, and its value can be determined according to the specifications of the external charging device connected to the charging terminals. Controller 300 can obtain the maximum charging voltage, for example, through communication with the external charging device.

[0050] The controller 300 can determine the charging path of the first battery B1 and the second battery B2 by controlling the switching states of the first inverter 210 and the second inverter 220. Here, the switching state control of the first inverter 210 and the second inverter 220 can be performed by controlling the on / off state of the upper and lower switching elements of branches S11-S12, S21-S22, S31-S32, S11'-S12', S21'-S22', and S31'-S32' included in the first inverter 210 and the second inverter 220 using switching signals Sa, Sb, and Sc for each phase. The controller 300 (e.g., in this case) can control the current flowing through phases a, b, and c to have the same value, thereby preventing the connected motor 100 from rotating while the first battery B1 and the second battery B2 are being charged by the first inverter 210 and the second inverter 220.

[0051] According to an electric vehicle having multiple switches Sw and a controller 300 (e.g., as described herein), even if the charging conditions of the first battery B1 and the second battery B2, which serve as dual voltage sources in a dual-inverter structure with dual voltage sources, are different, both the first battery B1 and the second battery B2 can be charged with a single power source. Therefore, it is recommended to charge the batteries with (e.g., optimal) efficiency in various charging scenarios depending on the charging conditions of the first battery B1 and the second battery B2.

[0052] Here, the charging conditions of the first battery B1 and the second battery B2 can be determined based on the voltage of the first battery B1 and the second battery B2, the charging current command, and the relationship between the voltage and the maximum charging voltage.

[0053] In the following text, reference will be made to Figures 2 to 5 This describes a specific control method for effectively charging both the first battery B1 and the second battery B2 when the charging conditions for the first battery B1 and the second battery B2 are different.

[0054] Figure 2 , Figure 3 , Figure 4 and Figure 5 This is a schematic diagram illustrating the charging path of an electric vehicle according to an embodiment of the present invention.

[0055] First, refer to Figure 2 and Figure 3 According to the implementation scheme, the controller 300 can control the first inverter 210 and the second inverter 220 based on the lower of the voltages of the first battery B1 and the second battery B2 and the maximum charging voltage. The voltages of the first battery B1 and the second battery B2 may vary depending on the implementation scheme, but in the following description, it may be assumed, for example, that the voltage of the second battery B2 is lower than the voltage of the first battery B1.

[0056] More specifically, the controller 300 can control the first inverter 210 and the second inverter 220 such that when the maximum charging voltage is higher than the voltage of the second battery B2, a charging path is formed (e.g., directly) to charge the second battery B2 using the charging voltage and to charge the first battery B1 using the voltage of the second battery B2.

[0057] Reference Figure 2 The controller 300 can control the first inverter 210 and the second inverter 220 such that the current caused by the charging voltage is transmitted to the second battery B2 through the first node nd1 and the second inverter 220. More specifically, the controller 300 (e.g., in this case) can turn on the relevant switching element of the second inverter 220 such that the branches S31'-S32' connected to the first node nd1 are connected to the positive terminal D2 of the second DC terminal, thereby enabling the current caused by the charging voltage to be transmitted (e.g., directly) to the second battery B2 without passing through the multiple windings L1, L2 and L3.

[0058] Reference Figure 3 The controller 300 can control the first inverter 210 and the second inverter 220 so that the voltage of the second battery B2 is converted to match the voltage of the first battery B1 through multiple windings L1, L2 and L3.

[0059] In this configuration, the controller 300 can control the switching state of the second inverter 220, so that multiple branches S11'-S12', S21'-S22' and S31'-S32' of the second inverter 200 are connected to the positive terminal D2 of the second DC terminal. The controller 300 can also control the switching state of the first inverter 210, so that the voltage of the second battery B2 is converted to match the voltage of the first battery B1 through multiple windings L1, L2 and L3.

[0060] More specifically, the controller 300 can turn on the upper switching elements S11', S21', and S31' of the second inverter 220, so that multiple branches S11'-S12', S21'-S22', and S31'-S32' are connected to the positive terminal D2 of the second DC terminal, and the voltage of the second battery B2 can be converted by (e.g., complementaryly) turning on / off the upper switching elements S11, S21, and S31 and the lower switching elements S12, S22, and S32 included in the multiple branches S11-S12, S21-S22, and S31-S32 of the first inverter 210.

[0061] at the same time, Figure 2 and Figure 3 The charging path shown can be formed simultaneously rather than separately, so the first battery B1 and the second battery B2 are charged together.

[0062] and Figure 2 and Figure 3 Compared to the situation shown, when the maximum charging voltage is lower than the voltage of the second battery, the controller 300 can control the first inverter 210 and the second inverter 220 to form a charging path that uses the charging voltage to charge the first battery B1 and uses the voltage of the first battery B1 to charge the second battery B2, as shown. Figure 4 and Figure 5 As shown.

[0063] Reference Figure 4 The controller 300 can control the first inverter 210 and the second inverter 220 so that the current caused by the charging voltage is transmitted to the first battery B1 through the first node nd1, the winding L3 connected to the first node nd1 among the plurality of windings L1, L2 and L3, and the first inverter 210.

[0064] The controller 300 (for example, in this case) can control the switching state of the branch S31-S32 of the plurality of branches S11-S12, S21-S22 and S31-S32 of the first inverter 210 connected to the first node nd1, such that the charging voltage is converted to match the voltage of the first battery B1 through the winding L3 of the plurality of windings L1, L2 and L3 connected to the first node nd1.

[0065] Reference Figure 5 The controller 300 can control the first inverter 210 and the second inverter 220 so that the voltage of the first battery B1 is transmitted to the second battery B2 through the windings L1 and L2 of the plurality of windings L1, L2 and L3 that are not connected to the first node nd1 and the second inverter 220.

[0066] In this configuration, the controller 300 can control the switching states of branches S11-S12 and S21-S22 of the first inverter 210 that are not connected to the first node nd1, so that the voltage of the first battery B1 is converted to match the voltage of the second battery B2 through windings L1 and L2 of the multiple windings L1, L2 and L3 that are not connected to the first node nd1. Furthermore, the controller 300 can control the upper switching elements S11' and S21' of branches S11'-S12', S21'-S22' and S31'-S32' of the second inverter 220 to be turned on, so that current through windings L1 and L2 can be transmitted to the second battery B2.

[0067] at the same time, Figure 4 and Figure 5 The charging path shown can be formed simultaneously rather than separately, so the first battery B1 and the second battery B2 are charged together.

[0068] According to various embodiments of the present invention as described above, even when the charging conditions of multiple batteries used as dual voltage sources for electric vehicles are different, a single power source can be used to charge (e.g., all) the batteries.

[0069] Furthermore, in various charging scenarios based on the charging conditions of multiple batteries, batteries can be charged with (e.g., optimal) efficiency.

[0070] The effects that can be obtained according to the present invention are not limited to those described above, and those skilled in the art can understand other effects not mentioned herein based on the description herein.

[0071] Although the invention has been described and illustrated with reference to specific embodiments as described above, it will be apparent to those skilled in the art that the invention can be modified and altered in various ways without departing from the technical spirit of the invention as provided in the claims.

Claims

1. An electric vehicle comprising: An electric motor, comprising multiple windings corresponding to multiple phases; The first inverter includes a first DC terminal connected to a first battery and multiple branches connected to one end of each of a plurality of windings; The second inverter includes a second DC terminal connected to the second battery and multiple branches connected to the other end of each of a plurality of windings; A charging terminal, to which the charging voltage of an external charging device is applied when the external charging device is connected; and Multiple nodes, including The first node is formed between the positive terminal of the charging terminal and the other end of any one of the plurality of windings. The second node is formed between the negative terminal of the charging terminal and the negative terminal of the first DC terminal. The third node is formed between the negative terminal of the charging terminal and the negative terminal of the second DC terminal, and The fourth node is formed between the second node, the third node, and the negative terminal of the charging terminal.

2. The electric vehicle of claim 1, further comprising a controller configured to control a first inverter and a second inverter based on the voltage of a first battery and a second battery, and a maximum charging voltage applicable to the charging terminals, thereby determining the charging paths of the first battery and the second battery.

3. The electric vehicle according to claim 2, wherein, The voltage of the first battery is equal to or higher than the voltage of the second battery, and the controller is configured to control the first inverter and the second inverter based on the voltage of the second battery and the maximum charging voltage.

4. The electric vehicle according to claim 3, wherein, The controller is configured to control the first inverter and the second inverter such that when the maximum charging voltage is equal to or higher than the voltage of the second battery, a charging path is formed in which the second battery is directly charged using the charging voltage and the first battery is charged using the voltage of the second battery.

5. The electric vehicle according to claim 4, wherein, The controller is configured to control the first inverter and the second inverter such that the current caused by the charging voltage is transmitted to the second battery via the first node and the second inverter.

6. The electric vehicle according to claim 5, wherein, The controller is configured to control the switching state of the second inverter, such that the branch of the second inverter connected to the first node is connected to the positive terminal of the second DC terminal.

7. The electric vehicle according to claim 4, wherein, The controller is configured to control the first inverter and the second inverter such that the voltage of the second battery is converted to match the voltage of the first battery through the plurality of windings.

8. The electric vehicle according to claim 7, wherein, The controller is configured to control the switching state of the second inverter, such that multiple branches of the second inverter are connected to the positive terminal of the second DC terminal, and to control the switching state of the first inverter, such that the voltage of the second battery is converted to match the voltage of the first battery through the multiple windings.

9. The electric vehicle according to claim 7, wherein, The controller is configured to control the first inverter and the second inverter such that the phase currents applied to the plurality of windings have the same amplitude.

10. The electric vehicle according to claim 3, wherein, The controller is configured to control the first inverter and the second inverter such that when the maximum charging voltage is lower than the voltage of the second battery, a charging path is formed in which the first battery is charged using the charging voltage and the second battery is charged using the voltage of the first battery.

11. The electric vehicle according to claim 10, wherein, The controller is configured to control the first inverter and the second inverter such that the current caused by the charging voltage is transmitted to the first battery via the first node, the winding of the plurality of windings connected to the first node, and the first inverter.

12. The electric vehicle according to claim 11, wherein, The controller is configured to control the switching state of the branch connected to the first node among the multiple branches of the first inverter, such that the charging voltage is converted to match the voltage of the first battery through the winding connected to the first node among the multiple windings.

13. The electric vehicle according to claim 10, wherein, The controller is configured to control the first inverter and the second inverter such that the current caused by the voltage of the first battery is transmitted to the second battery via the windings of the plurality of windings not connected to the first node and the second inverter.

14. The electric vehicle according to claim 13, wherein, The controller is configured to control the switching state of the branches of the first inverter that are not connected to the first node, so that the voltage of the first battery is converted to match the voltage of the second battery through the windings of the multiple windings that are not connected to the first node.

15. The electric vehicle according to claim 10, wherein, The controller is configured to control the first inverter and the second inverter such that the phase currents applied to the plurality of windings have the same amplitude.

16. The electric vehicle according to claim 1, further comprising: The first switch, when in the ON state, electrically connects the first node and the positive terminal of the charging terminal; The second switch, when in the ON state, electrically connects the second node and the negative terminal of the charging terminal; as well as The third switch, when in the ON state, electrically connects the third node and the negative terminal of the charging terminal.

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