Inverter control device, inverter control method, and vehicle including inverter control device

Abstract

The invention relates to an inverter control apparatus, an inverter control method, and a vehicle including the inverter control apparatus. Specifically, the inverter control device can reduce the junction temperature of the inverter by minimizing the maximum value of the phase current flowing through the inverter. The inverter control device comprises a current command output module, a current command conversion module, a switching determination module and a switching module, wherein the current command output module is configured to output a current command corresponding to an input torque command; the current instruction conversion module is configured to receive a current instruction and a zero-sequence current instruction, and perform phase shift on the current instruction to output a phase-shifted current instruction; the switching determination module is configured to output a control signal based on an input motor rotating speed and a torque instruction; the switching module is configured to selectively output one of a current command and a phase shifted current command in response to a control signal.

Description

Inverter control device, inverter control method, and vehicle including inverter control device Technical Field

[0001] This invention relates to inverter control technology, and more specifically, to an inverter control device, an inverter control method, and a vehicle including the inverter control device, which can reduce the junction temperature of an inverter by minimizing the maximum value of the phase current flowing through the inverter. Background Technology

[0002] Maximum Torque Per Ampere (MTPA) control for driving permanent magnet synchronous motors (PMSMs) is a technique for generating maximum torque by supplying a minimum three-phase balanced current. Because it uses the minimum current to produce the same torque, it can minimize copper losses and improve motor efficiency.

[0003] However, when MTPA control is applied to situations where the motor continuously outputs torque in a stationary or extremely low-speed rotating state (e.g., in a hill-dwelling parking state to prevent slippage without braking on a slope), depending on the motor's electrical angle, the current flowing through the motor may be concentrated in one of the three phases, and the heat generated in the power module of the current-conducting phase may be significantly higher than the junction temperature of the other phases.

[0004] Therefore, there is a need for a technology that can reduce the magnitude of the current concentrated in one phase when the vehicle is parked on a ramp, in order to reduce overheating in the power module.

[0005] The background information refers to technical information possessed by the inventor in order to derive the present invention or obtained during the derivation of the present invention, and is not necessarily considered to be publicly known technology disclosed prior to the application of this invention. The subject matter described in this background section is intended to facilitate an understanding of the background of the present invention, and therefore may include subject matter not yet known to those skilled in the art. Summary of the Invention

[0006] This invention aims to solve the above-mentioned problems, and its purpose is to provide an inverter junction temperature reduction technology that can alleviate the phenomenon of heat concentration in a single phase of the power module when the vehicle is parked on a slope (including when the motor is stopped or when the motor is rotating at extremely low speed).

[0007] Another object of the present invention is to provide a maximum torque angle ratio (MTPD) control technique that can generate maximum torque while intentionally allowing the flow of zero-sequence current, which is avoided during motor control, to minimize the maximum value of the phase current.

[0008] Another object of the present invention is to provide an inverter junction temperature reduction technology that can ultimately reduce hardware costs by reducing the junction temperature compared to MTPA at the same torque.

[0009] Another object of the present invention is to provide an inverter control device, an inverter control method, and a vehicle including the inverter control device, which apply the inverter junction temperature reduction technology proposed in this invention.

[0010] The technical objectives of this invention are not limited to the above description, and those skilled in the art will be able to clearly understand other objectives of this invention from the following description.

[0011] As a technical means to achieve the above objectives, the present invention provides an inverter control device, an inverter control method, and a vehicle including the inverter control device, which apply the inverter junction temperature reduction technology proposed in the present invention.

[0012] According to one aspect of the present invention, the above and other objectives can be achieved by providing an inverter control device comprising: a current command output module, a current command conversion module, a switching determination module, and a switching module; the current command output module being configured to output a current command corresponding to an input torque command; the current command conversion module being configured to receive a current command and a zero-sequence current command, and to phase-shift the current command to output a phase-shifted current command; the switching determination module being configured to output a control signal based on an input motor speed and torque command; and the switching module being configured to selectively output one of a current command and a phase-shifted current command in response to the control signal.

[0013] According to the implementation plan, the average of the minimum and maximum phase values ​​of the phase-shifted current command can be 0A.

[0014] According to the implementation plan, the current command conversion module can generate a phase current command based on the current command and the zero-sequence current command, and shift the phase of the phase current command by the average of the maximum and minimum phase values ​​of the phase current command to generate a phase-shifted phase current command.

[0015] According to the implementation plan, the current command conversion module can perform coordinate axis transformation on the phase-shifted phase current command to output the phase-shifted current command.

[0016] According to the implementation scheme, the current command transformation module may include: a first coordinate axis transformation module, a minimum and maximum value determination module, an average value determination module, and a phase transformation module. The first coordinate axis transformation module is configured to generate a phase current command based on the current command and the zero-sequence current command. The minimum and maximum value determination module is configured to determine a minimum phase value and a maximum phase value based on the phase current command. The average value determination module is configured to determine the average value of the minimum and maximum phase values. The phase transformation module is configured to shift the phase of the phase current command based on the average value of the minimum and maximum phase values ​​to generate a phase-shifted phase current command.

[0017] According to the implementation plan, the phase transformation module can shift the phase of the phase current command by the average of the minimum and maximum phase values.

[0018] According to the implementation plan, the average of the minimum and maximum phase values ​​of the phase current command after phase shifting can be 0A.

[0019] According to the implementation plan, the switching determination module may include a control mode determination module and a control signal output module. The control mode determination module is configured to determine the control mode based on the motor speed and torque command, and output a control mode signal corresponding to the determined control mode. The control signal output module is configured to output a control signal in response to the control mode signal.

[0020] According to the implementation plan, the control mode determination module may include a control mode table, which includes a first control mode signal and a second control mode signal set according to the motor speed and torque commands.

[0021] According to the implementation plan, the control mode determination module can output a first control mode signal to cause the switching module to output a current command, and output a second control mode signal to cause the switching module to output a phase-shifted current command.

[0022] According to another aspect of the present invention, an inverter control method is provided, the inverter control method comprising: outputting a current command corresponding to an input torque command; phase-shifting the current command based on the current command and a zero-sequence current command to output a phase-shifted current command; outputting a control signal based on a motor speed and a torque command; and selectively outputting either the current command or the phase-shifted current command in response to the control signal.

[0023] According to the implementation scheme, the inverter control method may further include: outputting a phase voltage command corresponding to a current command or a phase-shifted current command; and modulating the phase voltage command to output a pulse width modulation (PWM) signal to the inverter.

[0024] According to the implementation plan, the output phase-shifted current command may include: generating a phase current command based on a current command and a zero-sequence current command; determining a minimum phase value and a maximum phase value based on the phase current command; determining the average value of the minimum phase value and the maximum phase value; and generating a phase-shifted phase current command by shifting the phase of the phase current command based on the average value of the minimum phase value and the maximum phase value.

[0025] According to the implementation plan, shifting the phase of the phase current command may include shifting the phase of the phase current command by the average of the minimum and maximum phase values.

[0026] According to the implementation plan, the average of the minimum and maximum phase values ​​of the phase current command after phase shifting can be 0A.

[0027] According to the implementation plan, outputting a phase-shifted current command may include: performing a coordinate axis transformation on the phase-shifted phase current command, and outputting the phase-shifted current command.

[0028] According to the implementation plan, the output control signal may include: determining the control mode based on the motor speed and torque command; outputting a control mode signal corresponding to the control mode; and outputting a control signal in response to the control mode signal.

[0029] According to the implementation scheme, the output control signal may include: outputting a first control mode signal to cause the switching module to output a current command, and outputting a second control mode signal to cause the switching module to output a phase-shifted current command.

[0030] According to another aspect of the present invention, a vehicle is provided that uses an electric motor as a drive source for propulsion. The vehicle includes: an inverter for driving the electric motor and means for controlling the inverter, wherein the means generates a current command corresponding to a torque command; receives a current command and a zero-sequence current command; phase-shifts the current command to generate a phase-shifted current command; and selectively outputs one of the current command and the phase-shifted current command based on the motor speed and the torque command.

[0031] In addition to the apparatus for solving the above-mentioned problems, specific details of various examples according to the invention are included in the following description and drawings. Attached Figure Description

[0032] The above and other objects, features and advantages of the present invention will become clearer from the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 is a schematic diagram of an example motor system including an inverter control device that applies an inverter junction temperature reduction technology according to an embodiment of the present invention.

[0034] Figure 2 is a schematic diagram illustrating the configuration of the controller according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram illustrating the configuration of a current command conversion module according to an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram illustrating the configuration of the switching determination module and the switching module according to an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram illustrating a method for controlling a motor-driven inverter according to an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram illustrating step S510 of Figure 5; and

[0039] Figure 7 is a graph illustrating the limit torque that depends on whether the MTPD control technique according to an embodiment of the present invention is applied. Detailed Implementation

[0040] The advantages and features of the invention, as well as methods for achieving these advantages and features, will become apparent from the following detailed description of embodiments taken in conjunction with the accompanying drawings. However, the invention is not limited to the embodiments disclosed below and can be implemented in many different forms. Rather, these exemplary embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope to those skilled in the art. Therefore, the scope of the invention should be defined by the claims.

[0041] In the accompanying drawings, which are used to explain exemplary embodiments of the invention, the shapes, dimensions, proportions, angles, and quantities shown are given by way of example, and therefore the invention is not limited thereto. Throughout the specification, the same reference numerals denote the same constituent elements. Additionally, in the following description of the invention, detailed descriptions of known functions and configurations incorporated herein will be omitted where such detailed descriptions might make the subject matter of the invention quite unclear. Unless used with the term “only,” the terms “comprising,” “including,” and “having” as used herein do not exclude the presence or addition of other elements. Unless the context clearly indicates otherwise, the singular forms are intended to include the plural forms as well.

[0042] In the explanation of constituent elements, even without explicit description, constituent elements are interpreted as including the error range.

[0043] In describing temporal relationships, when using terms such as "after," "following," "next," or "before" to describe the temporal relationship between two actions, the actions may not occur consecutively unless the terms "directly" or "only" are used.

[0044] Although terms such as "first" and "second" can be used to describe various elements, these terms are only used to distinguish identical or similar elements from one another. Therefore, the first element mentioned below can be a second element within the technical scope of this invention.

[0045] It should be understood that although the terms “first,” “second,” A, B, (a), (b), etc., may be used herein to describe elements of the invention, these terms are only used to distinguish one element from another, and the necessity, order, or sequence of the corresponding elements is not limited by these terms. It should be understood that when an element is referred to as being “connected to,” “linked to,” or “joined” to another element, an element may be “connected to,” “linked to,” or “joined” to another element via another element, although an element may be directly connected to or directly joined to another element.

[0046] "At least one" should be understood as any combination of one or more related elements. For example, "at least one of the first element, the second element, and the third element" means not only the first element, the second element, or the third element, but also a combination of two or more of the first element, the second element, and the third element.

[0047] The various features of this invention can be partially or completely linked and combined with each other, and various technical connections are possible. These various embodiments can be implemented independently of each other or can be implemented in relation to each other.

[0048] For ease of description, the scale of the elements shown in the accompanying drawings differs from the actual scale, and therefore the invention is not limited to the scale shown in the drawings. When the controllers, modules, components, devices, elements, etc. of the present invention are described as having a purpose or performing operations, functions, etc., they should be considered herein as "configured" to satisfy that purpose or perform that operation or function. Each controller, module, component, device, element, etc. may be implemented individually or may include a processor and memory as part of a device, such as a non-transitory computer-readable medium.

[0049] In the following description, an inverter control device, an inverter control method, and a vehicle including the inverter control device according to embodiments of the present invention will be described with reference to the accompanying drawings.

[0050] Figure 1 is a schematic diagram of an example motor system including an inverter control device that applies an inverter junction temperature reduction technology according to an embodiment of the present invention.

[0051] Referring to Figure 1, the motor system can be installed in the vehicle and may include an energy storage device 10, an inverter 20, a motor 30, and a controller 100, but the configuration of the motor system is not limited to this.

[0052] The vehicle can be driven by motor 30, which serves as the drive source, and inverter 20 can drive the motor.

[0053] For example, inverter control devices that employ inverter junction temperature reduction technology can be effectively used to control various types of inverters, such as open-end winding (OEW) inverter / motor systems and multiphase inverter / motor systems.

[0054] The motor system may further include a DC link capacitor 40 and a current sensor 50, and may further include additional components for controlling the operation of the motor.

[0055] The energy storage device 10 is a component (e.g., a battery) for storing electrical energy (for driving the motor 30) in DC form and can output DC power.

[0056] Inverter 20 can be configured to convert DC power supplied from energy storage device 10 into AC power for driving motor.

[0057] For example, inverter 20 may include three branches connected in parallel to the two ends of energy storage device 10, and each branch may include a pair of power modules connected in series with each other.

[0058] Each power module of a pair of power modules can be turned on / off by a pulse width modulation (PWM) signal (S: S1 to S6) provided by the controller 100, and can output a phase (U phase / V phase / W phase) of drive power.

[0059] For example, each power module may include a power semiconductor element and a diode, and the power semiconductor element may be configured as an insulated gate bipolar transistor (IGBT), but is not limited thereto.

[0060] A pair of power modules constituting the first branch can form a U-phase power module that outputs U-phase current; a pair of power modules constituting the second branch can form a V-phase power module that outputs V-phase current; and a pair of power modules constituting the third branch can form a W-phase power module that outputs W-phase current.

[0061] According to the implementation plan, the inverter 20 can supply power from the motor 30 to the energy storage device 10.

[0062] The motor 30 is an energy conversion device that generates rotational power based on the three-phase AC power supplied by the inverter 20, and can be any type of motor known in the art.

[0063] For example, motor 30 may be a permanent magnet synchronous motor (PMSM), but is not limited to this.

[0064] According to the implementation plan, the neutral point connection terminal 60 can be connected to the neutral point N that is commonly connected by multiple coils of the motor 30, and external devices can be connected to the neutral point connection terminal 60.

[0065] For example, an external device can receive power output through the neutral point N of the motor 30. For example, an external device can supply power to the neutral point N of the motor 30.

[0066] In other words, the neutral point connection terminal 60 can output power from the motor system to an external device, or can supply power from an external device to the motor system.

[0067] The DC link capacitor 40 is connected to both ends of the energy storage device 10 and can generate a DC link voltage V by being charged by the power output from the energy storage device 10. dc The DC link voltage V dc It can be the input voltage of inverter 20, and it can be input to controller 100.

[0068] The current sensor 50 can be located between the inverter 20 and the motor 30, detecting the three-phase current supplied from the inverter 20 to the motor 30, and outputting the three-phase current detection value i_ sns The three-phase current detection value i_ sns It can be provided to controller 100.

[0069] Additionally, the motor system may further include a position sensor 70 and a temperature sensor 80, wherein the position sensor 70 detects and outputs the position of the rotor of the motor 30, that is, the rotation angle θ of the rotor of the motor, and the temperature sensor 80 detects and outputs the junction temperature Temp of the multiple power modules configured in the inverter 20.

[0070] The rotation angle θ detected by the position sensor 70 and the junction temperature Temp detected by the temperature sensor 80 can be input to the controller 100.

[0071] Figure 2 is a schematic diagram illustrating the configuration of the controller 100 according to an embodiment of the present invention.

[0072] Referring to Figure 2, the controller 100 (or inverter control device) can perform pulse width modulation (PWM) control to appropriately adjust the duty cycle of the power module of the inverter 20 so as to control the torque of the motor 30 to the desired value (torque command) T*. e .

[0073] According to the implementation plan, the controller 100 can perform inverter junction temperature reduction control to alleviate the phenomenon that heat is concentrated in the power module of one phase when the vehicle is parked on a slope (including when the motor is stopped or when the motor is rotating at extremely low speed).

[0074] The controller 100 can perform the following control (hereinafter referred to as "Maximum Torque Per Degree (MTPD) control"): to generate maximum torque by intentionally minimizing the maximum value of the phase current while avoiding the flow of zero-sequence current during motor control.

[0075] According to the implementation plan, the controller 100 may include: a current command output module 110, a current command conversion module 120, a switching determination module 130, a switching module 140, a speed estimation module 150, a coordinate transformation module 160, a current controller 170, and a PWM control module 180, but the configuration of the controller 100 is not limited to this.

[0076] The current command output module 110 can output the input torque command T* based on the current mapping relationship. e Convert to current command i* dq And output current command i* dq For example, the current command i*dq output from the current command output module 110 can be represented as a dq-axis current command.

[0077] The current command conversion module 120 can receive current commands i* dq and zero-sequence current command i* n And for the current command i* dq The phase is shifted to output a phase-shifted current command i*. dqn Here, the zero-sequence current command i* n It can be 0A.

[0078] According to the implementation plan, the current command conversion module 120 can receive current command i* dq and zero-sequence current command i* n The coordinate axis transformation is performed to generate the phase current command. The phase of the phase current command is shifted to the average of the maximum and minimum phase values ​​of the phase current command. Then, the coordinate axis transformation is performed again to output the phase-shifted current command i*. dqn For example, the phase-shifted current command i* output from the current command conversion module 120 dqn It can be represented as a dqn axis current command.

[0079] The switching determination module 130 can be based on the torque command T* e and the motor speed ω output from the speed estimation module 150 rpmThe control signal is output to the switching module 140.

[0080] Therefore, the switching determination module 130 can store data based on the motor speed ω. rpm and torque command T* e The control mode table is set.

[0081] According to the implementation scheme, the control mode table may include: a first control mode signal and a second control mode signal, wherein the first control mode signal is used to cause the switching module 140 to output a current command i*. dq The second control mode signal is used to cause the switching module 140 to output a phase-shifted current command i*. dqn .

[0082] The switching determination module 130 can output a control signal corresponding to the control mode signal to the switching module 140.

[0083] For example, the first control signal can be a low-level electrical signal, and the second control signal can be a high-level electrical signal.

[0084] Switching module 140 can receive current command i* output from current command output module 110. dq and the phase-shifted current command i* output from the current command conversion module 120 dqn .

[0085] The switching module 140 can be controlled by a control signal from the switching determination module 130, and selectively outputs a current command i* based on the control signal. dq and the phase-shifted current command i* dqn one of.

[0086] The speed estimation module 150 can estimate the motor speed ω based on the rotation angle θ output from the position sensor 70. rpm .

[0087] For example, the speed estimation module 150 may include a differentiator and can convert the estimated motor speed ω rpm The output is sent to the switching determination module 130. Additionally, the speed estimation module 150 can output the estimated motor speed ω. rpm The output is sent to the current controller 170.

[0088] The coordinate transformation module 160 can receive the three-phase current detection value i_ detected by the current sensor 50. sns The three-phase current detection value i_ sns Converted to d / q axis current i dqnn It then outputs the result to the current controller 170. For example, the coordinate transformation module 160 can be called a synchronous coordinate phase transformation module or a three-phase / dq coordinate transformation module.

[0089] The current controller 170 can receive current commands i* output from the switching module 140. dq Or current command i* via phase shift dqn And generate the current command i* dq Or current command i* via phase shift dqn The corresponding phase voltage command (or current control value) v* dqn .

[0090] The current controller 170 can generate the phase voltage command v* dqn Output to PWM control module 180.

[0091] The current controller 170 can correct the phase voltage command v* based on feedback information. dqn This is to eliminate torque error.

[0092] For example, the current controller 170 can receive the d / q axis current i from the coordinate transformation module 160. dqnn For example, the current controller 170 can receive the motor speed ω from the speed estimation module 150. rpm .

[0093] The PWM control module 180 can adjust the phase voltage command v* output from the current controller 170 according to the PWM method. dqn Modulation is performed to generate polar voltage commands (S: S1 to S6) as PWM signals, and these commands are output to inverter 20.

[0094] For example, the PWM control module 180 can perform space vector pulse width modulation (SVPWM) to modulate the phase voltage command v*dqn into a polarity voltage command (S: S1 to S6) as a PWM signal, but the modulation method is not limited to this.

[0095] In embodiments of the invention, the controller 100 may be configured to include a non-volatile memory and a processor. The non-volatile memory is configured to store data relating to an algorithm or software instructions for controlling the operation of various components of a vehicle in relation to features of the invention, and the software instructions are configured to reproduce the algorithm. The processor is configured to perform the operations described herein using the data stored in the memory. Here, the memory and processor may be implemented as separate chips or as a single chip integrating the memory and processor. Alternatively, the processor may take the form of one or more processors.

[0096] Figure 3 is a schematic diagram showing the configuration of the current command conversion module 120 according to an embodiment of the present invention.

[0097] Referring to Figure 3, the current command transformation module 120 may include: a first coordinate axis transformation module 121, a minimum / maximum value determination module 122, an average value determination module 123, a phase transformation module 124, and a second coordinate axis transformation module 125.

[0098] The first coordinate axis transformation module 121 can receive current command i* dq and zero-sequence current command i* n And perform coordinate axis transformation to generate phase current command i* phase .

[0099] The minimum / maximum value determination module 122 can receive phase current command i* phase And based on the phase current command i* phase Determine the minimum phase value min(i*) phase ) and maximum phase value max(i* phase ).

[0100] The average value determination module 123 can determine the minimum phase value min(i*). phase ) and maximum phase value max(i* phase The average value of ).

[0101] Phase conversion module 124 can receive phase current command i* phase and the minimum phase value min(i* phase ) and maximum phase value max(i* phase The average value of ) and based on the minimum phase value min(i* phase ) and maximum phase value max(i* phase The average value of the phase current command i* phase The phase is shifted to output the phase-shifted phase current command i** phase .

[0102] At this time, the phase transformation module 124 will send the phase current command i* phase The minimum phase shift value min(i*) phase ) and maximum phase value max(i* phase The average value of ) makes the phase current command i** after phase shifting phase The average of the minimum and maximum phase values ​​becomes 0A.

[0103] The second coordinate axis transformation module 125 can receive the phase current command i** after phase shifting. phase And perform coordinate axis transformation to output phase-shifted current command i* dqn .

[0104] According to the implementation plan, the current command conversion module 120 can be based on the current command i* dq and zero-sequence current command i* n To output the phase-shifted current command i* dqn And through phase-shifted current command i* dqn The average of the minimum and maximum phase values ​​can be 0A.

[0105] In the implementation scheme, the phase-shifted current command i* dqn It does not affect the torque because it is related to the input current command i* dq Same. Additionally, due to the zero-sequence current i* n The contribution of the phase-shifted current command i* dqn The average of the minimum and maximum phase values ​​becomes 0A, thus enabling the phase-shifted current command i* to be applied. dqn Minimize the maximum phase value.

[0106] Figure 4 is a schematic diagram showing the configuration of the switching determination module 130 and the switching module 140 according to an embodiment of the present invention.

[0107] Referring to Figure 4, the switching determination module 130 can be based on the motor speed ω. rpm and torque command T* e The control mode is determined, and the control signal corresponding to the determined control mode is output to the switching module 140.

[0108] According to the implementation plan, the switching determination module 130 may include a control mode determination module 131 and a control signal output module 132.

[0109] The control mode determination module 131 can determine the control mode based on the motor speed ω. rpm and torque command T* e To determine the control mode, and output the control mode signal corresponding to the determined control mode.

[0110] Therefore, the control mode determination module 131 can store data based on the motor speed ω. rpm and torque command T* e The control mode table is set.

[0111] According to the implementation scheme, the control mode table may include: a first control mode signal and a second control mode signal, wherein the first control mode signal is used to cause the switching module 140 to output a current command i*. dq The second control mode signal is used to cause the switching module 140 to output a phase-shifted current command i*. dqn .

[0112] Accordingly, based on the motor speed ω rpmand torque command T* e The control mode determination module 131 can output a first control mode signal to cause the switching module 140 to output a current command i*. dq And output a second control mode signal to cause the switching module 140 to output a phase-shifted current command i* dqn .

[0113] The control signal output module 132 can receive the control mode signal provided by the control mode determination module 131 and output the control signal corresponding to the control mode signal to the switching module 140.

[0114] According to the implementation scheme, the control signal output module 132 can output a first control signal in response to a first control mode signal, and output a second control signal in response to a second control mode signal.

[0115] For example, the first control signal can be a low-level electrical signal, and the second control signal can be a high-level electrical signal.

[0116] Switching module 140 can selectively output current command i* in response to a control signal from switching determination module 130. dq and the phase-shifted current command i* dqn one of.

[0117] According to the implementation scheme, the switching module 140 can receive the current command i* output from the current command output module 110. dq and the phase-shifted current command i* output from the current command conversion module 120 dqn .

[0118] For example, the switching module 140 can output a current command i* in response to a first control signal. dq And in response to the second control signal, output a phase-shifted current command i* dqn .

[0119] The switching module 140 may include a switch 141, which is configured to selectively output a current command i* in response to a control signal from the switching determination module 130. dq and the phase-shifted current command i* dqn one of.

[0120] Figure 5 is a schematic diagram illustrating a method for controlling a motor-driven inverter according to an embodiment of the present invention.

[0121] In the following text, the method of controlling the motor drive inverter will be described with reference to the operation of the controller 100 described with reference to Figures 1 to 4.

[0122] The current command output module 110 can output the input torque command T* based on the current mapping relationship. e Convert to current command i* dq And output current command i* dq (Step S500)

[0123] The current command conversion module 120 can receive current commands i* dq and zero-sequence current command i* n For current command i* dq Perform phase shifting and output the phase-shifted current command i* dqn (Step S510).

[0124] The switching determination module 130 can be based on the input motor speed ω rpm and torque command T* e The control signal is output to the switching module 140 (step S520).

[0125] Subsequently, the switching module 140 can output current command i* based on the control signal. dq and the phase-shifted current command i* dqn One of them (step S530).

[0126] The current controller 170 can output current command i* dq Or current command i* via phase shift dqn The corresponding phase voltage command (or current control value) v*dqn (step S540).

[0127] The PWM control module 180 can adjust the phase voltage command v* according to the PWM method. dqn Modulation is performed to generate a polarity voltage command (S: S1 to S6) as a PWM signal, and it is output to inverter 20 (step S550).

[0128] Figure 6 is a schematic diagram illustrating step S510 of Figure 5.

[0129] Referring to Figure 6, the current command conversion module 120 can be based on the current command i* dq and zero-sequence current command i* n To generate phase current command i* phase (Step S511).

[0130] The current command conversion module 120 can be based on the phase current command i* phase Determine the minimum phase value min(i*) phase ) and maximum phase value max(i* phase (Step S512), and determine the minimum phase value min(i* phase) and maximum phase value max(i* phase The average value of (step S513).

[0131] Subsequently, the current command conversion module 120 can base its command on the minimum phase value min(i*). phase ) and maximum phase value max(i* phase The average value of ) is used to assign phase current command i* phase The phase is shifted to output the phase-shifted phase current command i**. phase (Step S514).

[0132] In step S514, the current command conversion module 120 can convert the phase current command i* phase The minimum phase shift value min(i*) phase ) and maximum phase value max(i* phase The average value of ) makes the phase current command i** after phase shifting phase The average of the minimum and maximum phase values ​​becomes 0A.

[0133] Subsequently, the current command conversion module 120 can output the phase current command i** after phase shifting. phase The corresponding phase-shifted current command i* dqn (Step S515).

[0134] Figure 7 is a graph illustrating the limit torque that depends on whether the MTPD control technique according to an embodiment of the present invention is applied.

[0135] In Figure 7, A represents the limit torque value when the MTPD control technology according to the embodiment of the present invention is not applied, and B represents the limit torque value when the MTPD control technology according to the embodiment of the present invention is applied.

[0136] The MTPD control technology according to the embodiment of the present invention can alleviate the phenomenon of heat generation concentrated in a single phase of the power module.

[0137] Although the value of the limiting torque is relatively small in the prior art due to the phenomenon of concentrated heat generation (A in Figure 7), when the MTPD control technology according to the embodiment of the present invention is applied, the phenomenon of concentrated heat generation in a power module of one phase can be reduced, and thus the value of the limiting torque can be increased (B in Figure 7).

[0138] According to an embodiment of the present invention, an inverter junction temperature reduction technology can be provided, which can alleviate the phenomenon that heat is concentrated in one phase of the power module when the vehicle is parked on a slope (including when the motor is stopped or when the motor is rotating at extremely low speed).

[0139] In addition, a maximum torque angle ratio (MTPD) control technique can be provided, which can generate maximum torque while intentionally allowing the flow of zero-sequence current, which is avoided during motor control, to minimize the maximum value of the phase current.

[0140] Since the inverter junction temperature reduction technology according to the embodiment of the present invention can reduce the junction temperature of the power module by minimizing the magnitude of the phase current flowing through the inverter, it can reduce the junction temperature compared with MTPA technology at the same torque, and ultimately a reduction in hardware cost can be expected.

[0141] In addition, it is expected that the cost of the power module will be reduced, and the power module cooling system will be simplified, thereby reducing the weight of the cooling system and lowering its cost.

[0142] The MTPD control technology according to the embodiments of the present invention can be effectively applied to control various types of inverters, such as open-end winding (OEW) inverter / motor systems, multiphase inverter / motor systems, etc.

[0143] The effects of the present invention are not limited to those described above, and those skilled in the art can clearly understand other effects not mentioned from the following description.

[0144] The content of the problem to be solved, the means to solve the problem, and the effect do not specify the basic features of the claims. Therefore, the scope of the claims is not limited by the matters described in the content of this invention.

[0145] Although embodiments of the invention have been described in more detail with reference to the accompanying drawings, the invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the inventive spirit. Therefore, the embodiments disclosed in this specification are not intended to limit the inventive spirit, but rather to explain it, and the scope of the inventive spirit is not limited by such embodiments. Thus, it should be understood that the above embodiments are exemplary in all respects and not restrictive. The scope of the invention should be interpreted by the claims, and all ideas within the scope of the claims should be interpreted as included within the scope of the invention.

Claims

1. An inverter control device, comprising: The current command output module is configured to output a current command corresponding to the input torque command; The current command conversion module is configured to receive current commands and zero-sequence current commands, and to phase-shift the current commands to output phase-shifted current commands; the switching determination module is configured to output control signals based on the input motor speed and the input torque commands. And a switching module configured to output either a current command or a phase-shifted current command in response to the control signal.

2. The inverter control device according to claim 1, wherein, The average of the minimum and maximum phase values ​​of the phase-shifted current command is 0A.

3. The inverter control device according to claim 1, wherein, The current command conversion module is further configured to: generate a phase current command based on the current command and the zero-sequence current command; and shift the phase of the phase current command by the average of the maximum and minimum phase values ​​of the phase current command to generate a phase-shifted phase current command.

4. The inverter control device according to claim 3, wherein, The current command transformation module is further configured to perform coordinate axis transformation on the phase-shifted phase current command to output the phase-shifted current command.

5. The inverter control device according to claim 1, wherein, The current command transformation module includes: a first coordinate axis transformation module configured to generate a phase current command based on the current command and the zero-sequence current command; a minimum and maximum value determination module configured to determine a minimum phase value and a maximum phase value based on the phase current command; an average value determination module configured to determine the average value of the minimum and maximum phase values; and a phase transformation module configured to shift the phase of the phase current command based on the average value of the minimum and maximum phase values ​​to generate a phase-shifted phase current command.

6. The inverter control device according to claim 5, wherein, The phase transformation module is configured to shift the phase of the phase current command by the average of the minimum and maximum phase values.

7. The inverter control device according to claim 5, wherein, The average of the minimum and maximum phase values ​​of the phase-shifted phase current command is 0A.

8. The inverter control device according to claim 1, wherein, The switching determination module includes: a control mode determination module configured to determine the control mode based on motor speed and torque commands, and output a control mode signal corresponding to the determined control mode; and a control signal output module configured to output a control signal in response to the control mode signal.

9. The inverter control device according to claim 8, wherein, The control mode determination module includes a control mode table, which includes a first control mode signal and a second control mode signal set according to the motor speed and torque commands.

10. The inverter control device according to claim 9, wherein, The control mode determination module is configured to: output a first control mode signal to cause the switching module to output a current command, and output a second control mode signal to cause the switching module to output a phase-shifted current command.

11. An inverter control method, comprising: The output current command corresponds to the input torque command; The current command is phase-shifted based on the current command and the zero-sequence current command to output the phase-shifted current command; Control signals are output based on motor speed and torque commands; One of the current command and the phase-shifted current command output in response to a control signal.

12. The inverter control method according to claim 11, further comprising: Output the phase voltage command corresponding to the current command or the phase-shifted current command; The phase voltage command is modulated to output a pulse width modulated signal to the inverter.

13. The inverter control method according to claim 11, wherein, The phase-shifted current command output includes: generating a phase current command based on the current command and the zero-sequence current command; determining the minimum phase value and the maximum phase value based on the phase current command; determining the average value of the minimum phase value and the maximum phase value; and generating a phase-shifted phase current command by shifting the phase of the phase current command based on the average value of the minimum phase value and the maximum phase value.

14. The inverter control method according to claim 13, wherein, Shifting the phase of the phase current command includes shifting the phase of the phase current command by the average of the minimum and maximum phase values.

15. The inverter control method according to claim 13, wherein, The average of the minimum and maximum phase values ​​of the phase-shifted phase current command is 0A.

16. The inverter control method according to claim 13, wherein, The output phase-shifted current command includes: performing coordinate axis transformation on the phase-shifted phase current command and outputting the phase-shifted current command.

17. The inverter control method according to claim 11, wherein, The output control signal includes: determining the control mode based on the motor speed and the input torque command; outputting a control mode signal corresponding to the control mode; and outputting a control signal in response to the control mode signal.

18. The inverter control method according to claim 11, wherein, The output control signals include: outputting a first control mode signal to cause the switching module to output a current command, and outputting a second control mode signal to cause the switching module to output a phase-shifted current command.

19. A vehicle, the vehicle including an electric motor as a drive source, the vehicle comprising: An inverter configured to drive a motor; And a device for controlling the inverter, configured to generate a current command corresponding to a torque command; Receive current command and zero-sequence current command; phase-shift the current command to generate a phase-shifted current command; output one of the current command and the phase-shifted current command based on the motor speed and torque command.

20. The vehicle according to claim 19, wherein, The device is further configured to: output a phase voltage command corresponding to a current command or a phase-shifted current command; and modulate the phase voltage command to output a pulse width modulation signal to the inverter.

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