Motor drive device and control method thereof

Abstract

The present application relates to a motor drive device and a control method thereof, wherein the device includes a first inverter; a second inverter; a plurality of third switching elements, one end of each of the third switching elements being connected to a corresponding second end of a winding different from each other in a plurality of windings, and the other end being connected to the other end of each of the remaining third switching elements; and a controller configured to drive the motor in a first drive mode or a second drive mode based on a back electromotive force value of the motor, a torque command, and a motor temperature, wherein the plurality of third switching elements are configured to control the first switching elements to drive the motor when turned on, or to control both the first switching elements and the second switching elements to drive the motor when turned off, as needed.

Description

Technical Field

[0001] The embodiments of the present invention relate to a motor drive device and a control method thereof capable of effectively driving a motor while taking into account motor temperature. Background Technology

[0002] Typically, one end of the winding of each phase in a motor is connected to an inverter, and the other end is connected to the other end of the winding of other phases, thus forming a Y-type connection.

[0003] When driving the motor, the switching elements in the inverter are turned on and off by pulse width modulation, applying line voltage to the windings of the Y-connected motor to generate alternating current, thereby producing torque.

[0004] The fuel efficiency (or electrical efficiency) of environmentally friendly vehicles, such as electric vehicles powered by the torque generated by such motors, is determined by the power conversion efficiency of the inverter-motor system. Therefore, to improve fuel efficiency, it is important to maximize the power conversion efficiency of the inverter and the efficiency of the motor.

[0005] The efficiency of an inverter-motor system is primarily determined by the inverter's voltage utilization rate. When the vehicle's operating point, determined by the relationship between motor speed and torque, is established within a range with high voltage utilization, the vehicle's fuel efficiency can be improved.

[0006] However, when increasing the number of motor windings to increase the motor's maximum torque, the range with higher voltage utilization is moved away from the low torque region, which is the vehicle's primary operating point, potentially reducing fuel efficiency. Furthermore, from a fuel efficiency perspective, when the primary operating point is designed to fall within the range with higher voltage utilization, the vehicle's starting performance may be limited.

[0007] Therefore, in related technologies, a technique has been introduced that utilizes two inverters and a switching mechanism to drive a single motor in two different modes. This approach improves voltage utilization at critical operating points, thereby increasing fuel efficiency while generating higher maximum torque.

[0008] The foregoing is intended only to help understand the background of the present invention and is not intended to imply that the present invention falls within the scope of related technologies known to those skilled in the art. Summary of the Invention

[0009] The embodiments of the present invention aim to provide a motor drive device and a method for controlling the motor drive device, and to effectively drive the motor by appropriately selecting one of two drive modes, namely, Y-connected or open, of the motor windings based on the temperature of the motor.

[0010] The technical aspects to be achieved by the embodiments of the present invention are not limited to the above-mentioned technical aspects. Other technical aspects not mentioned will be clearly understood by those skilled in the art through the following description.

[0011] To achieve the above objectives, a motor drive device for driving a motor having a plurality of corresponding windings can be provided. As an apparatus according to a disclosed embodiment, the apparatus includes: a first inverter comprising a plurality of first switching elements and connected to first ends of the plurality of windings; a second inverter comprising a plurality of second switching elements and connected to second ends of the plurality of windings; a plurality of third switching elements, the first ends of which are connected to the second ends of each of the plurality of windings, and the second ends of which are connected to each other; and a controller operatively connected to the first inverter, the second inverter, and the plurality of third switching elements, and configured to drive the motor in a first drive mode or a second drive mode based on the motor's back electromotive force (EMF) value, torque command, and motor temperature. In the first drive mode, the plurality of third switching elements are turned on, and the first switching elements are controlled by the controller to drive the motor; in the second drive mode, the plurality of third switching elements are turned off, and both the first and second switching elements are controlled by the controller to drive the motor.

[0012] In the disclosed implementation, the controller may be further configured to determine a first drive mode or a second drive mode based on a map selected from a plurality of maps, each map having a predefined drive mode, each drive mode being determined based on the motor's inverse EMF value and a corresponding torque command.

[0013] In the disclosed implementation, each of the plurality of mappings may correspond to a different temperature range from each other.

[0014] In the disclosed implementation, the controller may be configured to determine a first drive mode or a second drive mode based on a mapping map in the plurality of mapping maps that corresponds to a motor temperature range including the motor temperature.

[0015] In the disclosed embodiments, each of the plurality of mapping diagrams may have a first axis corresponding to the anti-EMF value of the motor and a second axis corresponding to the torque command, and each of the plurality of mapping diagrams may include a first region for a first drive mode and a second region for a second drive mode defined within the area bounded by the first axis and the second axis.

[0016] In the disclosed embodiments, among the plurality of mapping maps, the mapping map corresponding to a higher motor temperature range may have a second region that is larger than the second region of the mapping map corresponding to a lower motor temperature range.

[0017] In the disclosed implementation, the plurality of mapping diagrams can be set based on the current specifications of a plurality of third switching elements.

[0018] In the disclosed implementation, when the torque command of the motor is greater than the limit torque of the first drive mode determined based on the current specifications of a plurality of third switching elements, each of the plurality of mapping diagrams may correspond to the second drive mode.

[0019] In the disclosed implementation, the controller may be configured to determine the motor's anti-EMF value based on the voltage of a battery configured to store the motor's power and the motor's rotational speed.

[0020] According to another embodiment, a motor drive device for driving a motor having a plurality of corresponding windings can be provided. As another device for achieving the above-mentioned objective, the device includes: a first inverter including a plurality of first switching elements and connected to a first end of the plurality of windings; a second inverter including a plurality of second switching elements and connected to a second end of the plurality of windings; a plurality of third switching elements, the first ends of which are connected to a second end of each of the plurality of windings, and the second ends of which are connected to each other; and a controller configured to drive the motor by controlling the state of each of the plurality of first switching elements, the plurality of second switching elements, and the plurality of third switching elements, wherein the first switching elements, the second switching elements, and the third switching elements are respectively controlled by the controller with reference to a mapping corresponding to the motor temperature and selected from a plurality of pre-prepared mappings, and controlled based on the motor's inverse EMF value and torque command. In another disclosed embodiment, the controller may be configured to drive the motor in a first drive mode or a second drive mode, wherein the motor is referenced to a mapping diagram corresponding to motor temperature and driven based on the motor's inverse EMF value and torque command. In the first drive mode, a plurality of third switching elements are turned on, and the first switching elements are controlled by the controller to drive the motor. In the second drive mode, the plurality of third switching elements are turned off, and both the first and second switching elements are controlled by the controller to drive the motor.

[0021] In another disclosed embodiment, each of the plurality of mappings may correspond to a different temperature range from each other.

[0022] In another disclosed embodiment, the controller may be configured to determine a first drive mode or a second drive mode based on a mapping map in the plurality of mapping maps corresponding to a motor temperature range including the motor temperature.

[0023] In another disclosed embodiment, each of a plurality of mappings having a first axis corresponding to the anti-EMF value of the motor and a second axis corresponding to the torque command may include a first region for a first drive mode and a second region for a second drive mode defined within the area bounded by the first axis and the second axis, wherein, in the plurality of mappings, the mapping corresponding to a higher motor temperature range has a second region larger than the second region of the mapping corresponding to a lower motor temperature range.

[0024] In another disclosed embodiment, the plurality of mapping diagrams may be configured based on the current specifications of a plurality of third switching elements.

[0025] In another disclosed embodiment, each of the plurality of mappings may have a region divided into a first region and a second region, based on the torque generated by the current utilizing the current specifications of the plurality of third switching elements within a corresponding motor temperature range.

[0026] In another disclosed embodiment, the controller may be configured to determine the motor's anti-EMF value based on the voltage of a battery configured to store the motor's power and the motor's rotational speed.

[0027] According to another disclosed embodiment, a method for controlling a motor drive device can be provided, the motor drive device being configured to drive a motor via a first inverter, a second inverter, and a plurality of third switching elements. The first inverter includes a plurality of first switching elements, and a first end of each of a plurality of corresponding windings of the motor is independently connected to the first inverter. The second inverter includes a plurality of second switching elements, and a second end of each of the plurality of windings is independently connected to the second inverter. One end of each of the plurality of third switching elements is connected to a corresponding second end of a different winding of the plurality of windings, and the other end is connected to the other end of the remaining third switching elements. Interconnection, the method comprising: determining a mapping map corresponding to a motor temperature from a plurality of mapping maps, each of the plurality of mapping maps corresponding to a predetermined temperature range and having a predefined drive mode, wherein each of the drive modes is defined in association with an inverse EMF value of the motor and a corresponding torque command; driving the motor in a first drive mode or a second drive mode, wherein the determined mapping map is referenced and the motor is driven based on the inverse EMF value and torque command of the motor, wherein in the first drive mode, a plurality of third switching elements are turned on and a first switching element is controlled to drive the motor, while in the second drive mode, a plurality of third switching elements are turned off and both the first and second switching elements are controlled to drive the motor.

[0028] As described above, according to the embodiments disclosed in this invention, by applying different mapping diagrams based on the motor temperature of the motor drive device to drive the motor, the operating range of the Y-connected motor drive mode can be expanded, thereby further improving the efficiency of the motor.

[0029] The effects that can be obtained in the embodiments of the present invention are not limited to those described above, and those skilled in the art will clearly understand other effects not mentioned from the following description. Attached Figure Description

[0030] The above and other objects, features, and other advantages of the present invention will become more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0031] Figure 1 This is a circuit diagram illustrating an example of a motor drive device according to one embodiment, the motor drive device including a first inverter, a second inverter, a switching switch, a motor, and a controller for controlling them;

[0032] Figure 2 It is a graph showing the motor limiting output of each drive mode according to the motor speed when the motor drive device according to one embodiment is running in a first drive mode or a second drive mode.

[0033] Figure 3 It is a graph showing the motor limiting torque of each drive mode according to the motor speed when the motor drive device according to one embodiment is running in a first drive mode or a second drive mode.

[0034] Figure 4 An example mapping diagram is shown that indicates the drive mode based on motor temperature T1, corresponding to the torque command and motor anti-EMF value according to one embodiment;

[0035] Figure 5 An example mapping diagram is shown that indicates the drive mode based on motor temperature T2, corresponding to the torque command and motor anti-EMF value according to one embodiment;

[0036] Figure 6 An example mapping diagram is shown that indicates the drive mode based on motor temperature T3, corresponding to the torque command and motor anti-EMF value according to one embodiment;

[0037] Figure 7 An example mapping diagram is shown, indicating the drive mode based on motor temperature T4, corresponding to torque command and motor anti-EMF value according to one embodiment; and

[0038] Figure 8 This is a flowchart illustrating an example process in a controller according to one embodiment of controlling a motor by determining one of the drive modes based on the acquired motor temperature. Detailed Implementation

[0039] In the following description, embodiments disclosed herein will be described in detail with reference to the accompanying drawings. However, regardless of the reference numerals, the same reference numerals will be assigned to the same or similar components, and repeated descriptions will be omitted. The terms "module" and "part" used for components in the following description are given or used interchangeably only for ease of writing and do not inherently have different meanings or functions. Furthermore, in describing embodiments disclosed herein, detailed descriptions of relevant known techniques will be omitted where it is determined that such detailed descriptions might obscure the essence of the embodiments disclosed herein. Moreover, the accompanying drawings are provided only to facilitate understanding of the embodiments disclosed herein; the technical ideas disclosed herein are not limited by the accompanying drawings, and all modifications, including those within the spirit and scope of the invention, should be understood to include equivalent or alternative forms.

[0040] Terms including ordinal numbers such as first, second, etc., may be used to describe various elements, but the elements are not limited by these terms. The terms mentioned above are used only for the purpose of distinguishing one component from another.

[0041] When a component is referred to as "connected" or "linked" to another component, it can be directly connected to or linked to another component, but it should be understood that other components may exist in between. On the other hand, when a component is referred to as "directly connected" or "directly linked" to another component, it should be understood that no other components exist in between.

[0042] Unless the context clearly indicates otherwise, singular expressions include plural expressions.

[0043] In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, values, steps, operations, components, parts or combinations thereof described in the specification, and it should be understood that this does not preclude the possibility of adding or having one or more other features, values, steps, operations, components, parts or combinations thereof.

[0044] Furthermore, the term "unit" or "controller" included in names such as "motor control unit (MCU)" is a widely used term to name control devices (controllers) that control specific functions of a vehicle, and does not imply a general-purpose functional unit. For example, each controller may include a communication device, a memory, and one or more processors. The communication device communicates with other controllers or sensors to control the functions it is responsible for; the memory stores the operating system or logic instructions and input / output information; and the one or more processors perform the determinations, calculations, decisions, etc., required to control the functions they are responsible for.

[0045] Figure 1 This is a circuit diagram illustrating an example of a motor drive device according to one embodiment, the motor drive device including a first inverter, a second inverter, a switching switch, a motor, and a controller for controlling them.

[0046] refer to Figure 1 According to one embodiment, the motor drive device may include a first inverter 10, a second inverter 20, a motor 30 having a plurality of windings C1, C2 and C3 respectively corresponding to each, a switching switch 40, a battery 50, a DC capacitor (or DC link capacitor) 60 and a controller 70.

[0047] The first inverter 10 may include a plurality of first switching elements S11, S12, S13, S14, S15, and S16, each pair of which is connected to a corresponding end of a plurality of windings C1, C2, and C3. The second inverter 20 may include a plurality of second switching elements S21, S22, S23, S24, S25, and S26, each pair of which is connected to the corresponding other end of one of the plurality of windings C1, C2, and C3. The switching switch 40 may include a plurality of third switching elements S31, S32, and S33, each of which is connected between the corresponding other end of one of the plurality of windings C1, C2, and C3 and the neutral end of the plurality of windings C1, C2, and C3. The controller 70 can control the on / off states of the first switching elements S11, S12, S13, S14, S15 and S16, the second switching elements S21, S22, S23, S24, S25 and S26, and the third switching elements S31, S32 and S33 based on the motor torque command, the DC link voltage (i.e., the battery voltage) of the first inverter 10 and the second inverter 20, the phase current of the motor, and the motor angle.

[0048] The first inverter 10 may include a plurality of branches 11, 12, and 13, which are supplied with a DC voltage provided by a DC capacitor 60 connected between two opposite ends of the battery 50. Branches 11, 12, and 13 may be electrically connected to corresponding phases of the motor 30, respectively.

[0049] More specifically, the first branch 11 includes two switching elements S11 and S12 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S11 and S12 can be connected to one end of the winding C1 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases. Similarly, the second branch 12 includes two switching elements S13 and S14 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S13 and S14 can be connected to one end of the winding C2 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases. Furthermore, the third branch 13 includes two switching elements S15 and S16 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S15 and S16 can be connected to one end of the winding C3 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases.

[0050] The second inverter 20 may include a plurality of branches 21, 22, and 23, which are supplied with a DC voltage provided by a DC capacitor 60 connected between two opposite ends of the battery 50. Branches 21, 22, and 23 may be electrically connected to corresponding phases of the motor 30, respectively.

[0051] More specifically, the first branch 21 includes two switching elements S21 and S22 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S21 and S22 can be connected to the other end of the winding C1 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases. Similarly, the second branch 22 includes two switching elements S23 and S24 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S23 and S24 can be connected to the other end of the winding C2 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases. Furthermore, the third branch 23 includes two switching elements S25 and S26 connected in series between the two opposite ends of the DC capacitor 60, and the connection node of the two switching elements S25 and S26 can be connected to the other end of the winding C3 of one phase of the motor 30, thereby enabling input / output of AC power corresponding to one phase of multiple phases.

[0052] One end of each of the plurality of third switching elements S31, S32, and S33 is connected to the corresponding other end of one of the plurality of windings C1, C2, and C3 included in the motor 30, and the other end is interconnected at the neutral terminal of the motor 30 with the other end of each of the remaining third switching elements. The plurality of third switching elements S31, S32, and S33 can employ various switching devices known in the related art, such as MOSFETs, IGBTs, thyristors, relays, etc.

[0053] although Figure 1 Not shown, but the motor drive may further include a so-called Y capacitor (Y-Cap), which has two capacitors connected in series between a positive (+) DC terminal and a negative (-) DC terminal, wherein the connection node between the capacitors is grounded.

[0054] The controller 70 can control the motor 30 drive by switching the switching elements S11, S12, S13, S14, S15, S16, S21, S22, S23, S24, S25 and S26 included in the first inverter 10 and the second inverter 20 through pulse width modulation (PWM) based on the torque command required by the motor 30.

[0055] Furthermore, the controller 70 can control the on / off state of the third switching elements S31, S32, and S33 included in the switching switch 40 according to the motor drive mode. The motor drive mode can include a first drive mode and a second drive mode. In this case, the first drive mode can be referred to as the "closed end winding (CEW) mode", and the second drive mode can be referred to as the "open end winding (OEW) mode".

[0056] More specifically, when the motor 30 is driven in CEW mode, the controller 70 can control the third switching elements S31, S32, and S33 to switch to the ON state, and drive the motor 30 through the first inverter 10 of the two inverters 10 and 20. When in the ON state, the third switching elements S31, S32, and S33 can electrically connect the corresponding other end of each of the plurality of windings C1, C2, and C3 to the neutral terminal of the plurality of windings C1, C2, and C3.

[0057] In contrast, when driving motor 30 in OEW mode, controller 70 can control the third switching elements S31, S32, and S33 to switch to the off state, and drive motor 30 through the two inverters 10 and 20. When in the off state, the third switching elements S31, S32, and S33 can electrically disconnect the corresponding other end of one of the multiple windings C1, C2, and C3 from the neutral terminal of the multiple windings C1, C2, and C3, respectively.

[0058] Figure 2 and Figure 3 These are graphs showing the motor limit output and motor limit torque of the motor drive device according to one embodiment, when the device is running in a first drive mode or a second drive mode, depending on the motor speed.

[0059] refer to Figure 2 When motor 30 is driven in CEW mode, the output may increase with increasing motor speed within the range where motor 30 operates at low speeds (i.e., below ω21). However, when the motor speed is above a certain speed ω21, the motor output may no longer increase even if the motor speed increases. Furthermore, when motor 30 is driven at high speeds (not less than ω23), the output may actually decrease with increasing motor speed. On the other hand, the same phenomenon occurs when motor 30 is driven in OEW mode, but a higher maximum output may be achieved compared to CEW mode (within the range of not less than ω22 but less than ω24).

[0060] refer to Figure 3When motor 30 is driven in CEW mode, it can generate constant torque at low speeds (below ω31), but at high speeds (above ω31), the torque may decrease as the motor speed increases. Meanwhile, when motor 30 is driven in OEW mode, the region where motor 30 can generate maximum torque (below ω32) may be larger compared to the CEW mode (below ω31).

[0061] comprehensive Figure 2 and Figure 3 The graph shows that when the motor's operating point, determined by motor speed and torque commands, is in the high-torque, high-output region, the motor 30 needs to be operated in OEW mode. However, in the low-torque, low-power range, CEW mode can achieve higher efficiency than OEW mode. Therefore, to achieve high motor efficiency while generating greater power, it is necessary to switch between the two modes based on torque commands and motor speed.

[0062] The controller 70 within the motor drive unit can determine the inverse EMF value by considering the motor's DC link voltage and motor speed, and can determine the drive mode based on the inverse EMF value and torque command. In this case, the controller 70 can determine the drive mode based on a pre-prepared mapping diagram. The pre-prepared mapping diagram can be a 2D mapping diagram, where the first axis represents the inverse EMF value and the second axis represents the torque command. Each point on the mapping diagram defined by the inverse EMF value and torque command can correspond to either the OEW mode or the CEW mode. Furthermore, since the third switching elements S31, S32, and S33 in the switching switch 40 can have current specifications representing the limiting current value for normal operation, these current specifications can be considered when creating the mapping diagram.

[0063] When driving motor 30, heat is generated through iron losses, copper losses, and friction, so the motor temperature may change at any time. The magnetic characteristics of the motor change with temperature, so motor temperature needs to be considered when creating the mapping map used to determine the drive mode.

[0064] In the following text, see references Figures 4 to 7 It describes multiple mapping diagrams corresponding to different temperature ranges according to the implementation scheme.

[0065] Figures 4 to 7 Example mapping diagrams are shown, indicating drive modes corresponding to torque commands and anti-EMF values ​​of the motor according to an embodiment of the present invention, at motor temperatures T1, T2 (below T1), T3 (below T2), and T4 (below T3), respectively. That is, Figures 4 to 7 The mappings shown correspond to upper limits that are the temperature ranges of the motor temperatures corresponding to each mapping. For example, based on motor temperature T1... Figure 4It can correspond to the temperature range where the motor temperature exceeds T2 but does not exceed T1.

[0066] refer to Figures 4 to 7 As the motor temperature decreases, the area occupied by the CEW pattern in the mapping diagram can expand. Figure 4 In the CEW mode, the maximum torque (limited torque) available corresponds to point A; Figure 5 In the CEW mode, the maximum torque (limited torque) available corresponds to point B; Figure 6 In the CEW mode, the maximum torque (limited torque) achievable corresponds to point C; Figure 7 In the CEW mode, the maximum torque (limited torque) available corresponds to point D. One reason for this is that the magnetic flux generated by the permanent magnets inside the motor decreases as the temperature increases.

[0067] Therefore, when determining the drive mode based on multiple maps created by taking into account the temperatures of individual motors, compared to determining the drive mode based on maps created by taking into account higher motor temperatures (in... Figure 4 Compared to the case where a single mapping is created to determine the drive mode in the case of T1), the area of ​​the motor operating in CEW mode can be expanded, thereby improving motor efficiency.

[0068] Figure 8 This is a flowchart illustrating an example process in a controller according to one embodiment of controlling a motor by determining one of the drive modes based on the acquired motor temperature.

[0069] refer to Figure 8 After receiving the drive command in step S810, in step S820, the controller 70 can obtain the motor temperature from a temperature sensor (not shown) and select a mapping map from multiple mapping maps that corresponds to a temperature range including the motor temperature. Based on the mapping map selected from the multiple mapping maps, in step S840, the drive mode can be determined. This drive mode corresponds to the inverse EMF value and torque command, the inverse EMF value being determined in step S830 using the motor speed and DC link voltage. Accordingly, when it is determined that the operation is in CEW mode, in step S850, the controller 70 can turn on the third switching elements S31, S32, and S33, and drive the motor 30 using only the first inverter 10 of the two inverters 10 and 20. Conversely, when it is determined that the operation is in OEW mode, in step S850, the controller 70 can turn off the third switching elements S31, S32, and S33, and drive the motor 30 using both inverters 10 and 20.

[0070] As described above, in one embodiment, the motor drive can acquire the motor temperature from a temperature sensor and determine the drive mode as either CEW mode or OEW mode based on a mapping map corresponding to a temperature range including the motor temperature from multiple mapping maps, thereby effectively driving the motor. This can further improve motor efficiency by expanding the operating area / operating range / drive area in CEW mode. Furthermore, in the above embodiment, the mapping map referenced when determining the motor drive mode assumes that the first axis corresponds to the inverse EMF and the second axis corresponds to the torque command, but this is exemplary and not necessarily limited to this. As another example, by setting the first axis to represent the motor speed (RPM) and the second axis to represent the torque command, the mapping map can be used to define the drive mode for each operating point.

[0071] Although the invention has been described and illustrated with respect to specific embodiments, it will be apparent to those skilled in the art that the invention can be modified or altered in various ways without departing from the spirit of the technology defined by the appended claims.

Claims

1. A motor drive device for driving a motor, the motor having a plurality of corresponding windings, the device comprising: A first inverter includes a plurality of first switching elements and is connected to the first ends of a plurality of windings; The second inverter includes a plurality of second switching elements and is connected to the second ends of a plurality of windings; A plurality of third switching elements, the first end of which is connected to the second end of each of the plurality of windings, and the second ends of the plurality of third switching elements are connected to each other; as well as The controller is operatively connected to a first inverter, a second inverter, and a plurality of third switching elements, and is configured to drive the motor in a first drive mode or a second drive mode based on the motor's back electromotive force, torque command, and motor temperature. In the first drive mode, multiple third switching elements are turned on, and the first switching elements are controlled by the controller to drive the motor. In the second drive mode, multiple third switching elements are turned off, and both the first and second switching elements are controlled by the controller to drive the motor.

2. The motor drive device for driving a motor according to claim 1, wherein, The controller is further configured to determine a first driving mode or a second driving mode based on a mapping selected from multiple mappings, each mapping having a predefined driving mode. Each drive mode in the drive mode is determined based on the back electromotive force of the motor and the corresponding torque command.

3. The motor drive device for driving a motor according to claim 2, wherein, Each of the multiple mapping maps corresponds to a different temperature range from the others.

4. The motor drive device for driving a motor according to claim 3, wherein, The controller is further configured to determine a first driving mode or a second driving mode based on the mapping map corresponding to the motor temperature range including the motor temperature in the plurality of mapping maps.

5. The motor drive device for driving a motor according to claim 3, wherein, Each of the plurality of mapping diagrams has a first axis corresponding to the back electromotive force value of the motor and a second axis corresponding to the torque command. Each of the plurality of mapping diagrams includes a first region for a first driving mode and a second region for a second driving mode, defined within the area bounded by the first axis and the second axis.

6. The motor drive device for driving a motor according to claim 5, wherein, In the plurality of mapping maps, the second region of the mapping map corresponding to the higher motor temperature range is larger than the second region of the mapping map corresponding to the lower motor temperature range.

7. The motor drive device for driving a motor according to claim 3, wherein, The multiple mapping diagrams are set based on the current specifications of multiple third switching elements.

8. The motor drive device for driving a motor according to claim 7, wherein, When the torque command of the motor is greater than the limit torque of the first drive mode determined based on the current specifications of multiple third switching elements, each of the multiple mapping diagrams corresponds to the second drive mode.

9. The motor drive device for driving a motor according to claim 1, wherein, The controller is further configured to determine the back electromotive force of the motor based on the voltage of the battery configured to store the power of the motor and the rotational speed of the motor.

10. A motor drive device for driving a motor, the motor having a plurality of corresponding windings, the device comprising: A first inverter includes a plurality of first switching elements and is connected to the first ends of a plurality of windings; The second inverter includes a plurality of second switching elements and is connected to the second ends of a plurality of windings; A plurality of third switching elements, the first end of which is connected to the second end of each of the plurality of windings, and the second ends of the plurality of third switching elements are connected to each other; as well as A controller, operatively connected to a first inverter, a second inverter, and a plurality of third switching elements, is configured to drive a motor by controlling the state of each of the plurality of first, second, and third switching elements. The first, second, and third switching elements are respectively controlled by the controller based on a mapping diagram corresponding to the motor temperature and selected from a plurality of pre-prepared mapping diagrams, and are controlled based on the motor's back electromotive force value and torque command.

11. The motor drive device for driving a motor according to claim 10, wherein, The controller is further configured to drive the motor in a first drive mode or a second drive mode. The motor is referenced to a mapping diagram corresponding to its temperature and is driven based on the motor's back electromotive force and torque command. In the first drive mode, multiple third switching elements are turned on, and the first switching elements are controlled by the controller to drive the motor. In the second drive mode, multiple third switching elements are turned off, and both the first and second switching elements are controlled by the controller to drive the motor.

12. The motor drive device for driving a motor according to claim 11, wherein, Each of the multiple mapping maps corresponds to a different temperature range from the others.

13. The motor drive device for driving a motor according to claim 12, wherein, The controller is further configured to determine a first driving mode or a second driving mode based on the mapping map corresponding to the motor temperature range including the motor temperature in the plurality of mapping maps.

14. The motor drive device for driving a motor according to claim 13, wherein, Each of the multiple mapping diagrams having a first axis corresponding to the back electromotive force value of the motor and a second axis corresponding to the torque command includes a first region defined for a first drive mode and a second region defined for a second drive mode within the area bounded by the first axis and the second axis. In the plurality of mapping maps, the second region of the mapping map corresponding to the higher motor temperature range is larger than the second region of the mapping map corresponding to the lower motor temperature range.

15. The motor drive device for driving a motor according to claim 14, wherein, The multiple mapping diagrams are set based on the current specifications of multiple third switching elements.

16. The motor drive device for driving a motor according to claim 15, wherein, Each of the plurality of mapping diagrams, within a corresponding motor temperature range, has a region divided into a first region and a second region based on the torque generated by the current that reaches the current specifications of the plurality of third switching elements.

17. The motor drive device for driving a motor according to claim 10, wherein, The controller is further configured to determine the back electromotive force of the motor based on the voltage of the battery configured to store the power of the motor and the rotational speed of the motor.

18. A method for controlling a motor drive device, the motor drive device being configured to drive a motor via a first inverter, a second inverter, and a plurality of third switching elements, the first inverter including a plurality of first switching elements, and a first end of each of a plurality of corresponding windings of the motor being independently connected to the first inverter; the second inverter including a plurality of second switching elements, and a second end of each of the plurality of windings being independently connected to the second inverter; one end of each of the plurality of third switching elements being connected to a corresponding second end of a different winding of the plurality of windings, and the other end being interconnected with the other end of each of the remaining third switching elements, the method comprising: A mapping map corresponding to the motor temperature is determined from multiple mapping maps, each of which corresponds to a predetermined temperature range and has a predefined drive mode, wherein each drive mode is defined in association with the motor's back electromotive force value and a corresponding torque command; The motor is driven using either the first or second drive mode from a predefined drive pattern, wherein the determined mapping diagram is referenced, and the motor is driven based on the motor's back electromotive force and torque command. In the first drive mode, multiple third switching elements are turned on, and the first switching elements are controlled by the controller to drive the motor. In the second drive mode, multiple third switching elements are turned off, and both the first and second switching elements are controlled by the controller to drive the motor.

19. The method according to claim 18, wherein, The multiple mapping diagrams are set based on the current specifications of multiple third switching elements.

20. The method according to claim 19, wherein, Each of the plurality of mapping diagrams, within the corresponding motor temperature range, has a region divided into a first region and a second region based on the torque generated by the current that reaches the current specifications of the plurality of third switching elements.

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