KR102625324B1 - Dc-dc converter for vehicle applying and control method of the same - Google Patents

Abstract

The present invention relates to a direct current converter for a vehicle. The direct current converter for a vehicle according to an embodiment of the present invention is connected to a high-voltage battery, an inverter, a solar cell module, and a low-voltage battery. The direct current converter boosts the input voltage. Or a conversion unit that outputs by force; and a plurality of switching units that switch according to control and selectively connect the high-voltage battery, the solar cell module, the low-voltage battery, and the inverter.

Description

Direct current converter for vehicles and its control method {DC-DC CONVERTER FOR VEHICLE APPLYING AND CONTROL METHOD OF THE SAME}

The present invention relates to a direct current converter for a vehicle, and more specifically, to a direct current converter for a vehicle implemented to perform different functions by changing the electrical path depending on the mode, and a control method thereof.

A solar cell is a photoelectric conversion device that converts sunlight into electrical energy. Unlike other energy sources, solar cells are infinite and environmentally friendly, so their importance is increasing over time and their field of use is also expanding. The automobile industry is also taking advantage of this trend, developing and releasing cars equipped with solar cells and systems that utilize the electrical energy output from them.

Republic of Korea Patent Publication No. 10-2012-0086923 discloses a solar energy utilization system for automobiles. According to the solar energy utilization system for cars, when the car's engine is running, solar energy is accumulated in the battery mounted on the car, and when the engine is stopped and the outside temperature is low, car parts that require preheating are used by solar energy. It can be preheated, and if the engine is stopped and the outside temperature is appropriate, ventilation of the cabin can be achieved by solar energy. If the engine is stopped and the outside temperature is high, solar energy can be accumulated in the battery.

This solar energy utilization system for automobiles is limited to utilizing solar energy for battery charging, preheating automobile parts, and ventilation of the vehicle compartment, and there is a lack of research on utilization through linkage with the driving system of hybrid vehicles.

Therefore, the present invention was proposed to solve the problems of the prior art as described above, and the purpose of the present invention is to provide a direct current converter for a vehicle implemented to perform different functions by changing the electrical path depending on the mode, and the same. It provides a control method.

The technical problem of the present invention is not limited to the matters mentioned above, and from the following description, anyone skilled in the art to which the present invention pertains will be able to clearly understand other problems intended by the present invention. will be.

The direct current converter for a vehicle according to an embodiment of the present invention to achieve the above object is connected to a high-voltage battery, an inverter, a solar cell module, and a low-voltage battery. The direct current converter boosts or steps down the input voltage. A conversion unit that outputs; and a plurality of switching units that switch according to control and selectively connect the high-voltage battery, the solar cell module, the low-voltage battery, and the inverter.

The plurality of switching units may include: a first switching unit connected between the high voltage battery and the inverter; a second switching unit connected between the conversion unit and the inverter; a third switching unit connected between the solar cell module and the conversion unit; and a fourth switching unit connected between the low-voltage battery and the conversion unit.

One side of the first switching unit is connected to the high voltage battery, and the other side of the first switching unit is connected to the inverter.

One side of the second switching unit is connected to the conversion unit, and the other side of the second switching unit is connected between the first switching unit and the inverter.

One side of the third switching unit is connected to the solar cell module, and the other side of the third switching unit is connected to the conversion unit.

One side of the fourth switching unit is connected to the low-voltage battery, and the other side of the fourth switching unit is connected to the third switching unit and the conversion unit.

Under the first mode, the first switching unit is switched on, and the second to fourth switching units are switched off.

Under the first mode, the inverter drives the motor based on the voltage output from the high-voltage battery, or the inverter charges the high-voltage battery based on the voltage generated by driving the motor.

Under the second mode, the first to third switching units are switched on, and the fourth switching units are switched off.

Under the second mode, the converter boosts the voltage output from the solar cell module to charge the high-voltage battery.

Under the third mode, the first, second and fourth switching units are switched on, and the third switching unit is switched off.

Under the third mode, the converter boosts the voltage output from the low-voltage battery to charge the high-voltage battery.

Under the fourth mode, the first and third switching units are switched off, and the second and fourth switching units are switched on.

Under the fourth mode, the converter boosts the voltage output from the low-voltage battery, and the inverter drives the motor based on the boosted voltage, or the converter steps down the voltage generated when the motor is driven. Charge the low-voltage battery.

A method of controlling a direct current converter for a vehicle according to an embodiment of the present invention is a method of controlling a direct current converter connected to a high-voltage battery, an inverter, a solar cell module, and a low-voltage battery. Depending on the mode, a connection is made between the high-voltage battery and the inverter. a first switching unit, a second switching unit connected between the conversion unit and the inverter, a third switching unit connected between the solar cell module and the conversion unit, and a first switching unit connected between the low-voltage battery and the conversion unit. 4 Control the switching unit to control the DC converter to perform operation for each mode.

Under the first mode, the first switching unit is switched on, and the second to fourth switching units are switched off, so that the inverter drives the motor based on the voltage output from the high voltage battery, or drives the motor. The inverter charges the high voltage battery based on the voltage generated accordingly.

Under the second mode, the first to third switching units are switched on and the fourth switching unit is switched off, and the conversion unit boosts the voltage output from the solar cell module to charge the high voltage battery.

Under the third mode, the first, second, and fourth switching units are switched on, and the third switching unit is switched off, and the conversion unit boosts the voltage output from the low-voltage battery to charge the high-voltage battery.

Under the fourth mode, the first and third switching units are switched off and the second and fourth switching units are switched on, so that the converter boosts the voltage output from the low-voltage battery, and based on the boosted voltage, the converter An inverter drives a motor, or the converter steps down the voltage generated by driving the motor to charge the low-voltage battery.

By using the direct current converter for a vehicle according to a preferred embodiment of the present invention, the efficiency of the 48V drive system can be increased by charging the vehicle's 48V driving battery using the generated power of the solar cell.

In addition, when the 48V driving battery is discharged, vehicle driving stability can be improved because the 48V driving battery can be charged through control of the direct current converter.

In addition, if the 48V driving battery fails, the motor can be driven using the power of the 12V battery through control of the direct current converter, thereby improving vehicle driving stability.

In addition, by using a single DC converter, it is possible to perform multiple functions related to battery charging and emergency (emergency) driving, simplifying the vehicle assembly process by reducing the number of controller parts in the vehicle, making the vehicle lighter, and reducing vehicle costs.

Additionally, since the battery can be charged using the generated power of the solar cell, the battery charging function can be provided in all cases, both when the vehicle is in operation and when it is not in operation.

1 is a diagram showing an example of a direct current converter according to a preferred embodiment of the present invention applied to a vehicle drive system,
Figure 2 is a diagram showing the specific configuration of the direct current converter of Figure 1.
3 and 4 are diagrams for explaining the operation of the direct current converter according to the first mode of the vehicle drive system according to a preferred embodiment of the present invention.
Figure 5 is a diagram for explaining the operation of the direct current converter according to the second mode of the vehicle drive system according to the preferred embodiment of the present invention.
Figure 6 is a diagram for explaining the operation of the direct current converter according to the third mode of the vehicle drive system according to a preferred embodiment of the present invention.
7 and 8 are diagrams for explaining the operation of the direct current converter according to the fourth mode of the vehicle drive system according to the preferred embodiment of the present invention.

Regarding the embodiments of the present invention disclosed in the text, specific structural and functional descriptions are merely illustrative for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms and are not included in the text. It should not be construed as limited to the described embodiments.

Since the present invention can be subject to various changes and can have various forms, specific embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be referred to as a second component, and similarly, the second component may be referred to as a first component without departing from the scope of the present invention.

When a component is said to be “connected” or “connected” to another component, it is understood that it may be directly connected or connected to the other component, but that other components may exist in between. It should be. On the other hand, when a component is said to be “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between. Other expressions that describe the relationship between components, such as “between” and “immediately between” or “neighboring” and “directly adjacent to” should be interpreted similarly.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as “comprise” or “have” are intended to designate the presence of a disclosed feature, number, step, operation, component, part, or combination thereof, and are intended to indicate the presence of one or more other features or numbers, It should be understood that this does not exclude in advance the possibility of the presence or addition of steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Meanwhile, if an embodiment can be implemented differently, functions or operations specified within a specific block may occur differently from the order specified in the flowchart. For example, two consecutive blocks may actually be performed substantially simultaneously, or the blocks may be performed in reverse depending on the functions or operations involved.

Hereinafter, a direct current converter for a vehicle and a control method thereof according to a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

Figure 1 is a diagram showing an example of a direct current converter according to a preferred embodiment of the present invention applied to a vehicle drive system, and Figure 2 is a diagram showing a specific configuration of the direct current converter of Figure 1.

As shown in FIG. 1, the direct current converter 10 according to a preferred embodiment of the present invention can be applied to a hybrid vehicle (ex, mild type hybrid vehicle), but the application field of the direct current converter 10 is this. It is not limited.

As shown in FIG. 1, the direct current converter 10 includes a high-voltage battery (ex, 48V battery) 20 that outputs a predetermined first voltage, a solar cell module 30, and a predetermined second voltage. It is connected to an inverter (ex, 48V inverter) 60 that controls a low-voltage battery (ex, 12V battery) 40 and an electric load (ex, 48V motor) 50.

Hereinafter, it is referred to as the 'vehicle driving system 1' including the direct current converter 10, high voltage battery 20, solar cell module 30, low voltage battery 40, electric load 50, and inverter 60. do.

In FIG. 1, only the necessary configurations are shown to enhance understanding and convenience of explanation of the present invention. However, of course, various configurations not shown in FIG. 1 can be added.

For example, the vehicle drive system 1 of FIG. 1 may further include a control module (not shown) that controls the components within the vehicle drive system 1, and the control described below is performed by the control module. Let's do it.

The high-voltage battery 20, solar cell module 30, low-voltage battery 40, electric load 50, and inverter 60 in FIG. 1 are components widely used in the technical field to which the present invention pertains, and their detailed configuration is and operations are omitted and described briefly as necessary.

As shown in FIG. 2, the direct current converter 10 includes a conversion unit 11 and a plurality of switching units 12 to 15, but may further include other components depending on design purpose, required specifications, etc. can do.

The converter 11 operates according to design, boosts or steps down the input voltage, and outputs it.

For example, a boost-buck DC-DC converter may be used as the converter 110, but it is not limited thereto, and the internal configuration of the converter 110 may also be implemented in various ways.

The plurality of switching units 12 to 15 are switched according to control to implement electrical connection between the high voltage battery 20, solar cell module 30, low voltage battery 40, and inverter 60.

The first switching unit 12 is located between the high-voltage battery 20 and the inverter 60, and switches under control to perform electrical connection between the high-voltage battery 20 and the inverter 60.

That is, one side of the first switching unit 12 is connected to the high voltage battery 20, and the other side of the first switching unit 12 is connected to the inverter 60.

The second switching unit 13 is located between the conversion unit 11 and the inverter 60, and switches under control to perform electrical connection between the conversion unit 11 and the inverter 60.

That is, one side of the second switching unit 13 is connected to the conversion unit 11, and the other side of the second switching unit 13 is connected between the first switching unit 12 and the inverter 60.

The third switching unit 14 is located between the solar cell module 30 and the conversion unit 11, and switches under control to perform electrical connection between the solar cell module 30 and the conversion unit 11.

That is, one side of the third switching unit 14 is connected to the solar cell module 30, and the other side of the third switching unit 14 is connected to the conversion unit 11.

The fourth switching unit 15 is located between the low-voltage battery 40 and the conversion unit 11, and switches under control to perform electrical connection between the low-voltage battery 40 and the conversion unit 11.

That is, one side of the fourth switching unit 15 is connected to the low-voltage battery 40, and the other side of the fourth switching unit 15 is connected between the third switching unit 14 and the conversion unit 11.

In this way, the vehicle driving system 1 includes a plurality of switching units 12 to 15, and the electrical connection relationship between components is determined depending on the status of the plurality of switching units 12 to 15.

The present invention is characterized by controlling the operation of the vehicle drive system 1 according to mode through control of a plurality of switching units 12 to 15 within the vehicle drive system 1.

For example, when the first and fourth switching units 12 and 15 are switched off and the second and third switching units 13 and 14 are switched on, the solar cell module 30 switches on the inverter 60. ) is electrically connected to.

As another example, when the first switching unit 12 is switched on and the second to fourth switching units 13 to 15 are switched off, the high voltage battery 20 is electrically connected to the inverter 60.

Hereinafter, the operation of the direct current converter 10 according to the control of the first to fourth switching units 12 to 15 will be described in more detail.

3 and 4 are diagrams for explaining the operation of the direct current converter according to the first mode of the vehicle drive system according to a preferred embodiment of the present invention.

The vehicle driving system 1 shown in FIGS. 3 and 4 operates in the first mode (or 'basic mode'), where the first switching unit 12 is switched on and the second to fourth switching units (13~15) are switched off.

When the vehicle drive system 1 operates in the first mode, control is performed according to MTPT (Maximum Torque Point Tracking).

When the vehicle driving system 1 operates in the first mode, the converter 11 of the direct current converter 10 does not operate, and the inverter 60 operates the motor based on the voltage output from the high-voltage battery 20. 50 (FIG. 3, vehicle driving assistance function) or the inverter 60 charges the high-voltage battery 20 based on the voltage generated by driving the motor 50 (FIG. 4, battery charging function).

Figure 5 is a diagram for explaining the operation of the direct current converter according to the second mode of the vehicle drive system according to the preferred embodiment of the present invention.

The vehicle driving system 1 shown in FIG. 5 operates in the second mode (or 'solar-battery charging mode'), and the first to third switching units 12 to 14 are switched on, The fourth switching unit 15 is switched off.

When the vehicle driving system 1 operates in the second mode, the direct current converter 10 operates in boost mode, and control is performed according to MPPT (Maximum Power Point Tracking).

When the vehicle driving system 1 operates in the second mode, the converter 11 boosts the voltage output from the solar cell module 30 to charge the high voltage battery 20.

Figure 6 is a diagram for explaining the operation of the direct current converter according to the third mode of the vehicle drive system according to a preferred embodiment of the present invention.

The vehicle driving system 1 shown in FIG. 6 operates in the third mode (or 'battery-battery charging mode'), for example, when the high-voltage battery 20 is discharged, the low-voltage battery 40 is used. This may apply to charging the high-voltage battery 20 using.

When the vehicle drive system 1 operates in the third mode, the first, second, and fourth switching units 12, 13, and 15 are switched on, and the third switching unit 14 is switched off.

When the vehicle driving system 1 operates in the third mode, the direct current converter 10 operates in boost mode and control is performed according to MPPT.

When the vehicle driving system 1 operates in the third mode, the converter 11 boosts the voltage output from the low-voltage battery 40 to charge the high-voltage battery 20.

7 and 8 are diagrams for explaining the operation of the direct current converter according to the fourth mode of the vehicle drive system according to the preferred embodiment of the present invention.

The vehicle drive system 1 shown in FIGS. 7 and 8 operates in the fourth mode (or 'emergency drive mode'), for example, when the high-voltage battery 20 fails, the low-voltage battery 40 is used. This may apply to the case of driving the motor 50 using.

When the vehicle drive system 1 operates in the fourth mode, the first and third switching units 12 and 14 are switched off, and the second and fourth switching units 13 and 15 are switched on. .

When the vehicle driving system 1 operates in the fourth mode, the direct current converter 10 operates in boost/buck mode, and control is performed according to MTPT.

When the vehicle driving system 1 operates in the fourth mode, the converter 11 boosts the voltage output from the low-voltage battery 40 (operates in boost mode), and the inverter 60 operates based on the boosted voltage. The low-voltage battery 40 operates by driving the motor 50 (Figure 7, vehicle driving auxiliary function) or by converting the voltage generated by driving the motor 50 (operating in buck mode) to the converter 11. Charge (Figure 8, battery charging function).

Even though all the components constituting the embodiments of the present invention described above are described as being combined or operated in combination, the present invention is not necessarily limited to these embodiments. That is, as long as it is within the scope of the purpose of the present invention, all of the components may be operated by selectively combining one or more of them. In addition, although all of the components may be implemented as independent hardware, some or all of the components are selectively combined to perform some or all of the combined functions in one or more pieces of hardware. It may also be implemented as a computer program with . Additionally, such a computer program can be stored in computer readable media such as USB memory, CD disk, flash memory, etc. and read and executed by a computer, thereby implementing embodiments of the present invention. Recording media for computer programs may include magnetic recording media, optical recording media, and carrier wave media.

As above, the direct current converter for a vehicle and its control method according to the present invention have been described according to embodiments, but the scope of the present invention is not limited to the specific embodiments, and those skilled in the art Various alternatives, modifications, and changes may be made within the scope of what is self-evident to the user.

Accordingly, the embodiments described in the present invention and the accompanying drawings are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments and the attached drawings. . The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

1: Vehicle drive system
10: DC converter
11: conversion unit
12, 13, 14, 15: first to fourth switching units
20: high voltage battery
30: solar cell module
40: low voltage battery
50: electrical load
60: inverter

Claims (12)

In a direct current converter connected to a high-voltage battery, inverter, solar cell module, and low-voltage battery,
The direct current converter is,
A converter that boosts or steps down the input voltage and outputs it; and
Consisting of a plurality of switching units that are switched according to control and selectively connect the high-voltage battery, the solar cell module, the low-voltage battery, and the inverter,
The plurality of switching units,
A first switching unit connected between the high voltage battery and the inverter;
a second switching unit connected between the conversion unit and the inverter;
a third switching unit connected between the solar cell module and the conversion unit; and
Comprising a fourth switching unit connected between the low-voltage battery and the conversion unit
Direct current converter for vehicles.
delete According to claim 1,
One side of the first switching unit is connected to the high voltage battery, and the other side of the first switching unit is connected to the inverter,
One side of the second switching unit is connected to the conversion unit, and the other side of the second switching unit is connected between the first switching unit and the inverter,
One side of the third switching unit is connected to the solar cell module, and the other side of the third switching unit is connected to the conversion unit,
One side of the fourth switching unit is connected to the low-voltage battery, and the other side of the fourth switching unit is connected to the third switching unit and the conversion unit.
Direct current converter for vehicles. According to claim 1,
Under the first mode, the first switching unit is switched on, and the second to fourth switching units are switched off,
The inverter drives a motor based on the voltage output from the high-voltage battery, or allows the inverter to charge the high-voltage battery based on the voltage generated by driving the motor.
Direct current converter for vehicles. According to claim 1,
Under the second mode, the first to third switching units are switched on, and the fourth switching unit is switched off,
The converter boosts the voltage output from the solar cell module to charge the high-voltage battery.
Direct current converter for vehicles. According to claim 1,
Under the third mode, the first, second and fourth switching units are switched on, and the third switching unit is switched off,
The converter boosts the voltage output from the low-voltage battery to charge the high-voltage battery.
Direct current converter for vehicles. According to claim 1,
Under the fourth mode, the first and third switching units are switched off, and the second and fourth switching units are switched on,
The converter boosts the voltage output from the low-voltage battery, and the inverter drives the motor based on the boosted voltage, or the converter steps down the voltage generated by driving the motor to charge the low-voltage battery. to do so
Direct current converter for vehicles. In the control method of a direct current converter connected to a high-voltage battery, inverter, solar cell module, and low-voltage battery,
Depending on the mode, a first switching unit connected between the high voltage battery and the inverter, a second switching unit connected between the conversion unit and the inverter, a third switching unit connected between the solar cell module and the conversion unit, and Controlling the fourth switching unit connected between the low-voltage battery and the conversion unit to control the DC converter to perform operation for each mode.
Control method of a vehicle direct current converter. According to claim 8,
Under the first mode, the first switching unit is switched on, and the second to fourth switching units are switched off, so that the inverter drives the motor based on the voltage output from the high voltage battery, or drives the motor. causing the inverter to charge the high-voltage battery based on the voltage generated accordingly.
Control method of a vehicle direct current converter. According to claim 8,
Under the second mode, the first to third switching units are switched on and the fourth switching unit is switched off, so that the conversion unit boosts the voltage output from the solar cell module to charge the high voltage battery.
Control method of a vehicle direct current converter. According to claim 8,
In the third mode, the first, second, and fourth switching units are switched on, and the third switching unit is switched off, so that the conversion unit boosts the voltage output from the low-voltage battery to charge the high-voltage battery.
Control method of a vehicle direct current converter. According to claim 8,
Under the fourth mode, the first and third switching units are switched off and the second and fourth switching units are switched on, so that the converter boosts the voltage output from the low-voltage battery, and based on the boosted voltage, the converter An inverter drives a motor, or the converter steps down the voltage generated by driving the motor to charge the low-voltage battery.
Control method of a vehicle direct current converter.

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