Vehicle power conversion device and method

Abstract

The present disclosure provides a vehicle power conversion device that can reduce the overall system size by integrating a motor controller that generates electric power and a power supply device that converts electric power. The vehicle power conversion device includes a drive motor connected to an engine, a power converter that selectively converts electric power in a plurality of modes to generate electric power related to the operation of the drive motor, and a first battery that supplies electric power for conversion or receives converted electric power.

Description

Technical Field

[0001] This disclosure relates to an electric power conversion technology, and more particularly, to a vehicle electric power conversion device and method. Background Technology

[0002] Typically, in hybrid systems used in hybrid vehicles, the lack of electricity ultimately necessitates increasing the capacity of the alternator and battery. This requires increased wiring / harness and / or increased vehicle weight. Specifically, in mild hybrid systems, the drive motor and engine are connected by a belt, and the inverter used to drive the drive motor is integrated with the drive motor to form a mild hybrid starter generator (MHSG).

[0003] In addition, the power generated by the MHSG is used to charge the 48V battery or supply it to the vehicle's electrical loads via a DC-DC converter, which acts as a power supply device, or to charge the 12V auxiliary battery. The inverter consists of three phases, each operating as a parallel switch. Furthermore, the converter that converts the 48V battery power to 12V is a buck converter, which is configured as a parallel module.

[0004] Because mild hybrid systems use high current, they require parallel configuration. Furthermore, they have the limitation of being difficult to configure based on the size and / or configuration of the additional 48V dedicated components compared to the base vehicle. Additionally, the final output efficiency decreases with each stage of power conversion.

[0005] The descriptions in this section are provided only to help understand the context of this disclosure and may include content previously unknown to those skilled in the art to which this disclosure pertains. Summary of the Invention

[0006] This disclosure provides a vehicle power conversion device and method that can reduce overall size by integrating a motor controller for generating electricity and a power supply device for converting electricity. Furthermore, this disclosure also provides a vehicle power conversion device and method that can improve output efficiency through control of the integrated components.

[0007] To achieve this objective, this disclosure provides a vehicle power conversion device that can reduce its size by integrating a motor controller for generating electricity and a power supply device for converting electricity. The vehicle power conversion device may include: a drive motor connected to an engine; a power converter configured to selectively convert electricity in multiple modes to generate electricity relevant to the operation of the drive motor; and a first battery configured to supply the converted electricity or receive the converted electricity.

[0008] A power converter may include an inverter and a converter integrated into one unit. The inverter may be configured to supply alternating current (AC) to a drive motor, and the converter may be configured to convert AC to direct current (DC). Furthermore, the power converter may include a switching network configured to perform power control between the converter and the inverter. The switching network may include: a first switching block that cuts off power transmission to the output side of the converter; and a second switching block that, during converter operation, disconnects the converter's output from a phase output of the inverter, and the first and second switching blocks may be connected in series.

[0009] Furthermore, multiple modes are available, including a high-power operation mode requiring high power and a general operation mode that does not require high power. The converter can operate after being disconnected from one phase output of the inverter. High-power generation has a power path in the order of drive motor, inverter, and first battery, while torque assistance has a power path in the order of first battery, inverter, and drive motor.

[0010] Additionally, in high-power operation mode, when power transmission to the converter's output is cut off, power is supplied to the electrical load from a second battery. The inverter may include multiple power elements symmetrically arranged for each phase, which may be connected in parallel. A first switching block may be positioned among the multiple power elements in a phase to be shared with the converter.

[0011] The converter may include the remaining power elements of a plurality of power elements shared with the inverter, a second switching block connected to the remaining power elements, and an inductor connected in series with the second switching block. Each of the first and second switching blocks has a back-to-back structure with a plurality of switching elements connected back-to-back.

[0012] Another exemplary embodiment of this disclosure provides a vehicle power conversion method, which may include: selecting multiple modes; and when multiple modes are selected, a power converter converts power to generate power related to the operation of a drive motor, and the power converter may be configured to receive power from a first battery, or the power converter may be configured to supply power to the first battery.

[0013] According to this disclosure, by integrating a mild hybrid power conversion component, size can be reduced and / or efficiency can be improved. Furthermore, another effect of this disclosure is that by using an inverter parallel switch as the main switch of the converter, all existing converter parallel switches can be eliminated, and the number of parallel magnets can also be reduced, thereby reducing size. Moreover, yet another effect of this disclosure is that by differentiating and operating modes such as high-power operation and 12V power operation according to the needs of the vehicle's electrical components, power conversion efficiency is improved. Attached Figure Description

[0014] The objects, features, and advantages of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 This is a block diagram illustrating the configuration of a vehicle power conversion device according to an exemplary embodiment of the present disclosure;

[0016] Figure 2 This illustrates exemplary embodiments according to this disclosure. Figure 1 A block diagram showing the configuration of the power converter;

[0017] Figure 3 This illustrates exemplary embodiments according to this disclosure. Figure 2 A block diagram showing the detailed configuration of the components;

[0018] Figure 4 This is a flowchart illustrating a power conversion process according to an exemplary embodiment of the present disclosure;

[0019] Figure 5 This illustrates an exemplary embodiment according to the present disclosure. Figure 4 A diagram illustrating the power flow under high-power operation mode; and

[0020] Figure 6 This illustrates an exemplary embodiment according to the present disclosure. Figure 4 A diagram illustrating the power flow under normal operating conditions. Detailed Implementation

[0021] It is understood that the term “vehicle” or “of a vehicle” or other similar terms as used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including various boats and vessels, aircraft, etc., and include hybrid vehicles, electric vehicles, combustion plug-in hybrid vehicles, hydrogen-powered vehicles and other alternative fuel (e.g., fuels derived from resources other than petroleum) vehicles.

[0022] Although exemplary embodiments are described as using multiple units to perform exemplary processes, it is understood that exemplary processes may also be performed by one or more modules. Furthermore, it is understood that the term controller / control unit refers to a hardware device that includes a memory and a processor and is specifically programmed to perform the processes described herein. The memory is configured to store modules, and the processor is specifically configured to run said modules to perform one or more processes further described below.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as used herein. It will be further understood that, when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0024] Unless otherwise specified or apparent from the context, as used herein, the term “about” is understood to mean within the normal tolerance range in the field, such as within 2 standard deviations of the mean. “About” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. All numerical values ​​provided herein are modified by the term “about” unless the context clearly indicates otherwise.

[0025] This disclosure can have various modifications and exemplary embodiments, and specific embodiments are shown in the accompanying drawings and described in detail in the description. However, it should be understood that this is not intended to limit this disclosure to the specific embodiments, and this disclosure includes all modifications, equivalents, and alternatives that are included within the spirit and scope of this disclosure.

[0026] In describing each drawing, the same reference numerals are used for the same components. Terms such as "first" and "second" may be used to describe various components, but these components should not be limited by these terms. These terms are used only to distinguish one component from others. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component. The term "and / or" includes a combination of or any one of a plurality of related descriptive items.

[0027] Unless otherwise defined, all terms used herein, including technical or scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Terms such as those defined in general dictionaries shall be interpreted as having a meaning consistent with the meaning in the context of the relevant art, and shall not be interpreted as having an idealized or overly formal meaning, unless the term is expressly defined to have such meaning in this application.

[0028] In the following, a vehicle power conversion apparatus and method according to exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0029] Figure 1 This is a block diagram illustrating the configuration of a vehicle power conversion device 100 according to an exemplary embodiment of the present disclosure. (Refer to...) Figure 1 The vehicle power conversion device 100 may include an engine 10, a power converter 110, a drive motor 120, a first battery 130, an electrical load 140, and a second battery 150.

[0030] Engine 10 can be a continuously variable valve timing (CVVT), double overhead camshaft (DOHC), gasoline direct injection (GAI), or multi-point injection (MPI) engine using gasoline as fuel; a common rail direct injection (CRDI), high-direction turbo intercooler (HTI), or variable geometry turbocharger (VGT) engine using diesel as fuel; or a liquid propane injection (LPi) engine using gas as fuel, etc. The power converter 110 can be configured to drive drive motor 120 by converting three-phase AC power generated by drive motor 120 to DC power, or conversely, converting DC power to three-phase AC power. In other words, the power converter 110 can be configured to convert the three-phase AC power generated by the drive motor 120 into DC power and supply the DC power to the first battery 120, the electrical load 140, and the second battery 150.

[0031] Furthermore, the power converter 110 can be configured to convert the DC power stored in the first battery 130 into three-phase AC power and supply the three-phase AC power to the drive motor 120. The power converter 110 can also be configured to boost the DC power stored in the first battery 130 and supply the boosted DC power to the drive motor 120, or to step down the DC power and supply the stepped-down DC power to the second battery 150 and / or the electrical load 140.

[0032] The drive motor 120 can be driven to start the engine 10. Furthermore, the drive motor 120 can be configured to perform the function of generating electricity through the rotation of the engine 10. The drive motor 120 may include a permanent magnet type and an electromagnet. In other words, the stator (not shown) includes a permanent magnet type, and the rotor (not shown) includes an electromagnet. Therefore, firstly, an excitation current is allowed to flow to pre-magnetize the electromagnet of the rotor to drive the drive motor 120.

[0033] The engine 10 and drive motor 120 can be connected to the crankshaft of the engine 10 via a connecting device. Therefore, during regenerative braking, the drive motor 120 can be reverse-driven by the rotation of the engine 10 to generate electricity. The connecting device 121 can be a belt, spur gear, sprocket, etc. The first battery 130 can be used as a main battery to receive DC power from the power converter 110 and charge it using the received DC power, or to supply DC power stored in the power converter 110. The first battery 130 can have an output voltage of approximately 48V, but is not limited to this.

[0034] The first battery 130 can be a supercapacitor or a lithium-ion battery. In addition to the above, the first battery 130 can also be a high-voltage battery for electric vehicles, such as a nickel-metal hydride battery, a lithium polymer battery, or an all-solid-state battery. Furthermore, the first battery 130 can be a single battery cell, or a battery pack of such battery cells connected in series and / or parallel. The battery cell can be designed as a cylindrical battery cell, a prismatic battery cell, or a pouch battery cell. A pouch battery cell includes a flexible cover made of a thin film, and the electrical components of the battery cell are housed within this cover.

[0035] To achieve optimal space utilization within a single battery cell, pouch-shaped battery cells are specifically used. Pouch-shaped battery cells are also characterized by their light weight and large capacity. The edges of the aforementioned pouch-shaped battery cell include sealing joints (not shown). In other words, the sealing joints connect two thin films in each of the battery cells, and these films include additional components within the resulting cavity.

[0036] The second battery 150 is typically a lead-acid battery used as an auxiliary battery, but is not limited to this; it can also be a nickel-metal hydride battery, a lithium polymer battery, a lithium-ion battery, a supercapacitor, etc. Therefore, the second battery 150 can be charged by receiving DC power from the first battery 130. The output voltage of the second battery 150 can be approximately 12V, but is not limited to this.

[0037] The vehicle controller 20 can be configured to execute a high-power operation mode or a normal operation mode in response to a driver's command. Furthermore, the vehicle controller 20 can be configured to use auxiliary battery status information from the second battery 150 and battery status information from the first battery 130 to determine the charge level. Battery status information can include State of Charge (SOC), State of Health (SOH), Depth of Discharging (DOD), State of Function (SOF), etc. Figure 1 The engine 10 shown includes an engine controller (not shown), and the drive motor 120 does not include a motor controller and can be separated by a power converter. The electrical load 140 may be an electrical component such as a lamp.

[0038] Figure 2 It is shown Figure 1 A block diagram showing the configuration of the power converter 110. (Refer to...) Figure 2 The power converter 110 may include an inverter 210, a switching network 220, and a converter 230. The inverter 210 may be configured to convert direct current (DC) to three-phase alternating current (AC) and supply the three-phase AC to the drive motor 120, or to receive three-phase AC and convert it to DC. The inverter 210 uses a pulse width modulation (PWM) inverter as a voltage-source inverter, but is not limited to this, and may also use a current-source inverter by modifying some components. The PWM inverter may be configured to use a pulse width modulation (PWM) control method to simultaneously regulate voltage and frequency to rectify DC voltage.

[0039] Converter 230 can be configured to perform buck or boost functions. In other words, converter 230 can be configured to buck the DC power supplied by inverter 210 and supply the bucked DC power to the first battery 130 and / or electrical load 140. For example, converter 230 can be configured to convert 48V supplied by inverter 210 to 12V and supply 12V to the first battery 130, second battery 150, electrical load 140, etc. Furthermore, converter 230 can be configured to boost the DC power supplied by the first battery 130 and supply the boosted DC power to inverter 210. For example, converter 230 can be configured to convert 12V supplied by the first battery 130 to 48V and supply 48V to inverter 210.

[0040] Therefore, converter 230 can be a DC-DC converter and can be a bidirectional low DC-DC converter (LDC). Of course, converter 230 may include boost and / or buck circuitry. Switching network 220 is associated with the power control between inverter 210 and converter 230.

[0041] Figure 3 It is shown Figure 2 A block diagram showing the detailed configuration of components 210, 220, and 230 is provided. (Refer to...) Figure 3 The inverter 210 can have a three-phase structure and two power elements 310 connected in parallel. Therefore, during high-power generation or general drive, the inverter 210 can operate by distributing current to each power element 310. The high power is approximately 17 to 20 kVA / liter.

[0042] The power device 310 can use semiconductor switching elements such as field-effect transistors (FETs), metal-oxide-semiconductor FETs (MOSFETs), insulated-gate bipolar transistors (IGBTs), or power rectifier diodes, thyristors, gate-turn-off (GTO) thyristors, triodes for alternating current (TRIACs), silicon controlled rectifiers (SCRs), integrated circuits (ICs), etc. Specifically, the semiconductor element can use bipolar elements, power metal-oxide-semiconductor field-effect transistors (MOSFETs), etc. Due to the high voltage and high current operation of power MOSFETs, power MOSFETs have a double-diffused metal-oxide-semiconductor (DMOS) structure, which differs from that of typical MOSFETs.

[0043] Furthermore, the switching network 220 may include a first switching block 321 and a second switching block 322. The switching element 321-1 also has the same power switch as the inverter. However, for the purposes of understanding, in the exemplary embodiments of this disclosure, the switching element and the switch will be named differently. In other words, the switching element used in the inverter has a higher power per unit than the switch used in the converter, thus being responsible for all the outputs of the converter.

[0044] The first switch block 321 and the second switch block 322 have a back-to-back structure with two switching elements 321-1 connected back-to-back. Due to the loss of directionality, the operation of the switch blocks is similar to that of ordinary switches. Therefore, when the converter 230 is operating, the switch blocks are used to isolate the outputs of the converter 230 and the inverter 210. Furthermore, the first switch block 321 and the second switch block 322 can prevent reverse current.

[0045] Therefore, the switch block can be turned on when 5V is input to the gate and turned off when no 5V is input. Specifically, the first switch block 321 can be configured to cut off power delivery to the output side of the converter 230. The second switch block 322 can be configured to separate the output of the converter 230 from the phase output of the inverter 210 during converter 230 operation. An inductor 330 can be disposed between the first switch block 321 and the second battery 150 and the electrical load 140. Furthermore, the second battery 150 and the electrical load 140 can be connected in parallel.

[0046] Figure 4 This is a flowchart illustrating a power conversion process according to an exemplary embodiment of the present disclosure. (Refer to...) Figure 4 When the driver starts the vehicle, the vehicle controller 20 can be configured to start the engine 10 by operating the drive motor 120 (step S410). Subsequently, the vehicle controller 20 can be configured to determine whether a high-power operation mode is activated (step S420). In particular, the high-power operation mode is a mode in which only the inverter 210 is operated after the converter operation has been stopped when high-power generation or torque assistance is required.

[0047] In step S420, as a result of mode determination, when it is determined that the vehicle controller 20 is in high-power operation mode, the switch network 220 can be activated (step S430) to stop the operation of the converter 230 and execute the operation of the inverter 210 (step S440). Subsequently, it can be determined whether the high-power operation mode has terminated (step S450). As a result of this determination, in step S450, when it is determined that the high-power operation mode has terminated, the vehicle controller 20 can operate in normal operation mode. Subsequently, the vehicle controller 20 can be configured to determine whether the engine has been shut off to terminate the process (step S460).

[0048] Simultaneously, in step S420, as a result of the determination, when it is determined that the vehicle controller 20 is not in high-power operation mode, the mode can be switched to normal operation mode. In particular, the switching network can be operated to isolate and operate the inverter 210 and the converter 230 respectively (steps S440 and S441).

[0049] Figure 5 It shows the basis Figure 4 A diagram illustrating the power flow under high-power operation mode. (Refer to...) Figure 5 The inverter 210 may include three phases, and power elements 310 are disposed on one phase of the three phases. Figure 3 The inverter 210 shares power with the converter 230. Therefore, in high-power operation mode, the sharing relationship can be terminated, and all phases of the three phases of the inverter 210 can be configured to perform parallel operation to switch to high-power mode. In other words, the vehicle can be operated by high-power generation for charging the first battery 130 or by torque assistance for driving the drive motor 120. In the case of high-power generation, the power path 510 can be generated in the order of drive motor 120 -> inverter 210 -> first battery 130. Conversely, in the case of torque assistance, the power path 510 can be generated in the order of first battery 130 -> inverter 210 -> drive motor 120. In particular, the second battery 150 is responsible for supplying power to the electrical load 140.

[0050] Figure 6 It shows the basis Figure 4 A diagram illustrating the power flow during normal operation. Figure 6 This illustrates the operation without high power. In normal operating mode, when power is supplied to the 12V electrical load 140, the switching network 220 can be operated to shut off the second switch block 322 located on the first phase side of the inverter 210, thereby disconnecting the converter 210 from the inverter 230. Therefore, a power path 630 can be generated to supply power from the converter 230 to the electrical load 140. Additionally, a power path 610 can be generated between the first battery 130 and the inverter 210, and a power path 620 can be generated between the first battery 130 and the converter 230.

Claims

1. A vehicle electric power conversion device, comprising: a drive motor connected to an engine; an electric power converter that selectively converts electric power in a plurality of modes to generate electric power related to operation of the drive motor; and a first battery that supplies the electric power used for conversion or receives converted electric power, wherein, in the electric power converter, an inverter and a converter are integrally formed, wherein components of the inverter are partially shared with the converter to reduce a size of the electric power converter.

2. The vehicle electric power conversion device according to claim 1, wherein the inverter supplies alternating current (AC) electric power to the drive motor, and the converter converts the AC electric power to direct current (DC) electric power.

3. The vehicle electric power conversion device according to claim 2, wherein the electric power converter includes a switching network that performs electric power control between the converter and the inverter.

4. The vehicle electric power conversion device according to claim 3, wherein the switching network includes: a first switching block that cuts off electric power transmission to an output side of the converter; and a second switching block that separates an output of the converter from one phase output of the inverter when the converter operates, wherein the first switching block and the second switching block are connected in series.

5. The vehicle electric power conversion device according to claim 3, wherein the plurality of modes include a high-power operation mode and a general operation mode.

6. The vehicle electric power conversion device according to claim 5, wherein the converter operates after being separated from the one phase output of the inverter.

7. The vehicle electric power conversion device according to claim 5, wherein the high-power operation mode is high-power power generation for charging the first battery or torque assist for driving the drive motor, the high-power power generation has a power path in an order of the drive motor, the inverter, and the first battery, and the torque assist has a power path in an order of the first battery, the inverter, and the drive motor.

8. The vehicle electric power conversion device according to claim 7, wherein in a case of the high-power operation mode, when the electric power transmission to the output side of the converter is cut off, electric power is supplied from a second battery to an electric load.

9. The vehicle electric power conversion device according to claim 4, wherein the inverter includes a plurality of power elements that are symmetrical for each phase, the plurality of power elements are connected in parallel, the first switching block is provided between the plurality of power elements in one phase to be shared with the converter, and wherein the converter includes remaining power elements of the plurality of power elements that are shared with the inverter, the second switching block connected to the remaining power elements, and an inductor connected in series to the second switching block.

10. The vehicle electric power conversion device according to claim 4, wherein each of the first switching block and the second switching block has a back-to-back structure in which a plurality of switching elements are connected in a back-to-back manner.

11. A vehicle electric power conversion method, comprising: selecting a plurality of modes; ​ and when the plurality of modes is selected, the power converter converts power to generate power related to operation of driving the motor, wherein the power converter receives the power from a first battery, or the power converter supplies the power to the first battery, wherein in the power converter, an inverter and a converter are integrally formed, wherein components of the inverter are partially shared with the converter to reduce a size of the power converter.

12. The vehicle power conversion method according to claim 11, wherein the inverter supplies alternating current (AC) power to the drive motor, and the converter converts the AC power to direct current (DC) power.

13. The vehicle power conversion method according to claim 12, wherein the power converter includes a switching network that performs power control between the converter and the inverter.

14. The vehicle power conversion method according to claim 13, wherein the switching network includes: a first switching block that cuts off power transmission to an output side of the converter; and a second switching block that separates an output of the converter from one phase output of the inverter when the converter operates, wherein the first switching block and the second switching block are connected in series.

15. The vehicle power conversion method according to claim 13, wherein the plurality of modes include a high-power operation mode and a general operation mode.

16. The vehicle power conversion method according to claim 15, wherein the converter operates after being separated from the one phase output of the inverter.

17. The vehicle power conversion method according to claim 15, wherein the high-power operation mode is a high-power power generation for charging the first battery or a torque assist for driving the drive motor, the high-power power generation has a power path in an order of the drive motor, the inverter, and the first battery, the torque assist has a power path in an order of the first battery, the inverter, and the drive motor.

18. The vehicle power conversion method according to claim 17, wherein in a case of the high-power operation mode, when the power transmission to the output side of the converter is cut off, power is supplied from a second battery to an electrical load.

19. The vehicle power conversion method according to claim 14, wherein the inverter includes a plurality of power elements that are symmetrical for each phase, the plurality of power elements are connected in parallel, the first switching block is provided between the plurality of power elements in one phase to be shared with the converter, and wherein the converter includes remaining power elements of the plurality of power elements that are shared with the inverter, the second switching block connected to the remaining power elements, and an inductor connected in series to the second switching block.

20. The vehicle power conversion method according to claim 14, wherein each of the first switching block and the second switching block has a back-to-back structure in which a plurality of switching elements are connected in a back-to-back manner.

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