KR20170060484A - Power supplying device of motor-generator for mild hybrid vehicle and controlling method thferof - Google Patents

Abstract

A motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention is connected to an engine and a belt, and is configured as a field winding type motor generator power supply device. The motor generator power supply device includes a high voltage battery; An inverter for converting a direct current power of the high voltage battery and a three phase power of the motor generator; And a low voltage battery for applying power to the inverter. When an abnormality is detected in the power supplied to the inverter from the high voltage battery or the high voltage battery, the motor generator is driven using the low voltage battery.

Description

TECHNICAL FIELD [0001] The present invention relates to a power supply device for a motor generator of a mild hybrid vehicle, and a control method thereof. BACKGROUND OF THE INVENTION 1. Field of the Invention [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for a motor generator and a control method thereof, and more particularly, to a power supply device for a motor generator applied to a mild hybrid vehicle and a control method thereof.

The rising oil prices and the increasing social interest in the environment have caused the automobile industry to accelerate the fuel efficiency of vehicles and the development of environmentally friendly vehicles. To meet this demand, a mild hybrid system that regenerates the deceleration energy of the vehicle has appeared .

1 is a block diagram of a conventional mild hybrid device. Referring to FIG. 1, a conventional mild hybrid device includes a motor-generator 2 having functions of a motor and a generator and interlocked with an engine 1 and a belt 7, and the motor- The engine 1 is supplied with driving power through the inverter 3 and serves as an auxiliary power for the engine 1. When the generator is in operation, power is generated using the thermal energy generated when the vehicle is braked, And supplies the necessary electricity to the vehicle. Such a mild hybrid device has an advantage that a hybrid system can be implemented by replacing an existing alternator without changing the structure of a conventional internal combustion engine vehicle.

However, in a conventional mild hybrid device, when a failure occurs in the high-voltage battery 4, it becomes impossible to generate a driving force or generate electric power using such a high voltage. As a result, The low-voltage battery 6 can not be charged and the vehicle can not be operated.

The following prior art documents relate to a regenerative braking method in a mild hybrid system in which an integrated motor-generator is automatically switched to a generator mode and a motor mode according to various operating states of a vehicle under running, and the technical gist of the present invention is included not.

Korean Patent Publication No. 10-2007-0030363

In order to solve the above-mentioned problems, a power supply apparatus for a motor generator of a mild hybrid vehicle and a control method thereof according to an embodiment of the present invention aim to solve the following problems.

The present invention provides a motor generator power supply of a mild hybrid vehicle capable of driving a motor generator using a low-voltage battery even if power is not supplied to drive the motor generator when a high-voltage battery fails, and a control method thereof.

The solution to the problem of the present invention is not limited to those mentioned above, and other solutions not mentioned can be clearly understood by those skilled in the art from the following description.

A motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention is connected to an engine and a belt, and is configured as a field winding type motor generator power supply device. The motor generator power supply device includes a high voltage battery; An inverter for converting a direct current power of the high voltage battery and a three phase power of the motor generator; And a low voltage battery for applying power to the inverter. When an abnormality is detected in the power supplied to the inverter from the high voltage battery or the high voltage battery, the motor generator is driven using the low voltage battery.

The inverter includes: a field current supply unit for applying power to a field of the motor generator; And a three-phase current supply unit for applying three-phase power to the windings of the motor generator, wherein the field current supply unit and the three-phase current supply unit selectively supply power by either the high-voltage battery or the low- .

And a relay unit for selecting a power source to be supplied to the field current supply unit and the three-phase current supply unit.

The relay unit includes: a first relay for interrupting supply of power from the low-voltage battery to the field current supply unit and the three-phase current supply unit; And a second relay for interrupting supply of power from the high-voltage battery to the field current supply unit and the three-phase current supply unit.

The inverter may further include a boost converter disposed between the field current supply unit and the relay unit.

A method of controlling a motor generator power supply of a mild hybrid vehicle according to an embodiment of the present invention includes a high voltage battery, an inverter for converting a direct current power source of the high voltage battery and a three phase power source of a field winding motor generator, The inverter includes a field current supply unit for applying power to a field of the motor generator, and a control unit for controlling the motor generator in accordance with the control signal of the motor generator power supply unit. And a three-phase current supply unit for applying an upper supply voltage to the high-voltage battery or the high-voltage battery; Converting the battery connected to the field current supply unit and the three-phase current supply unit from the high-voltage battery to the low-voltage battery when the abnormality is detected; Activating a boost converter that boosts the power of the low-voltage battery and transfers the boosted power to the field current supply unit; And determining the necessity of driving the motor generator.

Preferably, the step of determining necessity of driving the motor generator determines the necessity of driving the motor generator based on at least one of a charging rate of the low-voltage battery, a required power generation amount of the vehicle, and an engine speed of the vehicle.

And controlling the field current supply unit so that power of the boosted low voltage battery is supplied to the field of the motor generator when it is determined that the motor generator needs to be driven.

Monitoring the charging rate of the low-voltage battery after the step of controlling the field current supply unit; And comparing the generated power of the motor generator with the required power of the vehicle.

If the difference between the generated power of the motor generator and the required electric power of the vehicle is less than a predetermined value, the step of controlling the field current supply unit is performed again.

And modifying the target output value of the motor generator when the difference between the generated power of the motor generator and the required power of the vehicle is equal to or greater than a predetermined value.

A motor generator power supply device and a control method therefor of a mild hybrid vehicle according to an embodiment of the present invention are characterized in that when a problem occurs in a high voltage battery that applies a driving force to a motor- And it is expected that the vehicle can be moved to the garage to repair the high voltage battery.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned may be clearly understood by those skilled in the art from the following description.

1 is a block diagram of a general mild hybrid system.
FIG. 2 is a graph showing the magnitude of the counter electromotive force according to the number of revolutions in the case of the motor generator constructed by field winding.
3 is a block diagram illustrating an example of a motor generator power supply of a mild hybrid vehicle.
4 is a block diagram illustrating a motor generator power supply of a mild hybrid vehicle according to an embodiment of the present invention.
5 is a flowchart illustrating a method of controlling a motor generator power supply of a mild hybrid vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout.

In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. It is to be noted that the accompanying drawings are only for the purpose of facilitating understanding of the present invention, and should not be construed as limiting the scope of the present invention with reference to the accompanying drawings.

Hereinafter, a mild hybrid system will be described generally with reference to FIGS. 1 and 2. FIG. FIG. 1 is a block diagram of a general mild hybrid system, FIG. 2 is a graph showing the magnitude of counter electromotive force according to the number of revolutions in the case of a motor generator constructed by a field winding, FIG. 3 is a graph As shown in Fig.

The motor generator 2 shown in Fig. 1 is configured to be interlocked with the engine 1 and the belt 7, and is capable of both a start motor for starting the engine and a generator capable of generating an AC voltage.

Specifically, when functioning as a start motor, the drive power is supplied through the inverter 3 to serve as an auxiliary power for engine power. In the case of functioning as a generator, energy lost by heat generated during vehicle braking is converted into electric energy And supplies it to the high voltage battery (4).

Particularly, the mild hybrid device has an idle stop & go (ISG) function in which when the vehicle is stopped for a long time, the vehicle is automatically turned off and then the vehicle is restarted when the vehicle is started, When the voltage is equal to or higher than the reference voltage, the voltage charged in the high-voltage battery 4 is supplied to the electric low-voltage battery 6 through the DC-DC power converter 5.

The inverter 3 is a constitution for controlling the electric energy to be inputted to or outputted from the motor generator 2 and converts the electric energy supplied from the high voltage battery 4 to supply it to the motor generator 2, And supplies the converted electric energy to the high-voltage battery 4.

Generally, the high-voltage battery 4 is composed of a super-capacitor module constituted by a plurality of super capacitors. The high-voltage battery 4 stores electric energy regeneratively braked in the motor-generator 2 when the vehicle decelerates, And supplies energy to assist the engine torque.

Meanwhile, in the motor generator 2 applied to the mild hybrid system, a claw pole motor, a field winding type motor, and a permanent magnet type motor may be employed. In this motor generator, a back- And in the case of a general hybrid system, it is designed to be controlled by the inverter 3 so as to be transmitted to the high-voltage battery 4 in the form of DC voltage.

In the case of a field winding type motor or a cowl pole motor, power must be supplied to the field winding in order to generate a counter electromotive force generated in proportion to the rotation of the motor. In order to generate a desired back electromotive force, In order to supply a large current as much as possible to the field winding, it is designed to generate a back electromotive force in the form of supplying current using a 48V power supply, that is, a high voltage battery. That is, only when the resistance value of the field winding is normally supplied with the 48V power, the performance required by the hybrid controller of the vehicle can be exerted.

In order to solve the problem that occurs when the 48V power supply, that is, the high voltage battery, fails to operate normally, the above-described mild hybrid system has a high voltage battery (not shown) of the inverter 400 controlling the motor generator 100 DC power conversion apparatus 500 using a 12V battery, that is, a low-voltage battery 300, on the input line of the DC-DC power conversion apparatus 500 shown in FIG.

However, in this case, when the high voltage battery 200 is short-circuited, the high voltage generated by the DC-DC power inverter 500 can not be transmitted to the inverter 400 and the high voltage battery 200, so that further breakage of the high-voltage battery 200 occurs, and a problem that a high voltage can not be formed in the inverter 400 occurs.

In order to solve the problem of the power supply device of the above-described mild hybrid vehicle, a motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention and a control method thereof have been proposed. A motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention will be described. 4 is a block diagram briefly showing a motor generator power supply of a mild hybrid vehicle according to an embodiment of the present invention.

A motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention relates to an apparatus for supplying power to a motor generator of a mild hybrid vehicle constructed as described above. Specifically, as shown in FIG. 4, the high voltage battery 200, the inverter 400, and the low voltage battery 300 are included, and the technical contents thereof have already been described above, and thus a detailed description thereof will be omitted. Meanwhile, when an abnormality is detected in the power source applied to the inverter 400 from the high-voltage battery 200 itself or the high-voltage battery 200, the mild hybrid vehicle according to the embodiment of the present invention may use the low- And the motor generator 100 is driven. The detailed contents of the inverter 400 and the relay unit 700 will be described below in order to realize these technical features.

The inverter 400 of the motor generator power supply of the mild hybrid vehicle according to an embodiment of the present invention includes a field current supply unit 410 and a three-phase current supply unit 420 as shown in FIG. The three-phase current supply unit 120 supplies the three-phase current to the three-phase coil 120 of the motor generator 100. The three-phase current supply unit 410 supplies power to the field coil 110 of the motor generator 100, . That is, the three-phase winding 120 of the motor generator and the field winding 110 are insulated from each other. The field current supply unit 410 and the three-phase current supply unit 420 are configured to selectively receive power from either the high-voltage battery 200 or the low-voltage battery 300. When the abnormality occurs in the high voltage battery 200, the field current supply unit 410 and the three-phase current supply unit 420 receive the power from the high voltage battery 200. However, The phase current supply unit 420 is supplied with power from the low voltage battery 300.

In order to select a power source to be transmitted to the high voltage battery 200 and the low voltage battery 300, the motor generator power supply device of the mild hybrid vehicle according to the embodiment of the present invention may further include a relay unit 700 . The relay unit 700 specifically includes a first relay 710 for interrupting power supply from the low voltage battery 300 to the field current supply unit 410 and the three phase current supply unit 420, And a second relay 720 for interrupting the supply of power to the supply part 410 and the three-phase current supply part 420.

That is, the first relay 710 is normally turned off and the second relay 720 is turned on so that the high voltage battery 200 is supplied from the field current supply unit 410 to the three-phase current supply unit 420 Voltage battery 200 and the first relay 710 is turned on while the second relay 720 is turned off so that the field current supply unit 510 and the third And supplies power to the phase current supply unit 420.

When a problem occurs in the high voltage battery 200, when the power is supplied to the field winding of the motor generator 100 by the power supply of the low voltage battery 300, sufficient back EMF is not generated, The inverter 400 may further include a boost converter 430 disposed between the field current supply unit 410 and the relay unit 700. That is, before the power of the low-voltage battery 300 is transmitted to the field current supply unit 410, the boost converter 430 boosts the voltage (12 V -> 48 V) and supplies the high voltage to the field winding 110 of the motor generator 100 So that sufficient back EMF can be generated. Accordingly, the inverter 400 can be driven regardless of the type of the failure of the high voltage battery 200. Further, since the capacity of the boost converter 430 can be supplied only to the field winding 110, do.

4, the inverter 400 further includes a motor controller 440. The inverter 400 is configured to receive power for driving the inverter 400 itself and is generally connected to the low voltage battery 300 The power is supplied by this.

Hereinafter, with reference to FIG. 5, description will be made of a motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention, and FIG. 5 is a block diagram of a motor generator power supply device of a mild hybrid vehicle according to an embodiment of the present invention. The control method will be described. 5 is a flowchart illustrating a method of controlling a motor generator power supply of a mild hybrid vehicle according to an embodiment of the present invention.

The control method of the motor generator power supply of the mild hybrid vehicle according to the embodiment of the present invention is similar to that of the motor generator power supply of the mild hybrid vehicle according to the embodiment of the present invention, (S200) of switching the input power source of the inverter 400 to the low-voltage battery 300 (S100). The control method of the high-voltage battery 200 will be described in detail with reference to FIG. A step S300 of activating the boost converter, and a step S400 of judging the necessity of driving the motor generator.

The step S100 of detecting the abnormality of the high-voltage battery 200 may be detected through the current / voltage sensor of the input or output terminal of the high-voltage battery 200. The high-voltage battery 200 itself, It is determined whether or not an abnormality occurs in the power source applied to the inverter 400 from the inverter 200.

When the abnormality is detected in the high voltage battery 200 and the power generated by the high voltage battery 200 in the step S100, the power connected to the field current supply unit 410 and the three-phase current supply unit 420 of the inverter 400, (200) to the low-voltage battery 300 (S200) is performed. In order to perform the power switching step S200, the relay unit 700 described above should be included.

When the power supply of the low-voltage battery 300 is applied to the field current supply unit 410 and the three-phase current supply unit 420 in the power supply switching step S200, sufficient back electromotive force required for driving the motor generator 100 Voltage battery 300 and the field current supply unit 410 so as to increase the power supplied to the field-power supply unit 410, The step S300 of activating the boost converter 430 is performed.

After the step S300 of activating the boost converter 430, a step S400 of determining whether the motor generator 100 needs to be driven is performed. Specifically, the necessity of driving the motor generator 100 is determined based on at least one of the state of charge (SOC) of the low-voltage battery 300, the required power generation amount of the vehicle, and the engine speed of the vehicle. For example, if it is determined that the charging rate of the low-voltage battery 300 is sufficient to supply power to the vehicle load for a long period of time, it is not necessary to drive the motor generator 100, have.

When it is determined in step S400 that the motor generator needs to be driven, the power of the low voltage battery 300 boosted by the boost converter 430 is supplied to the field winding 110 of the motor generator 100 (S500) of controlling the field current supply unit 410 so that the field current can be supplied may be further performed. During the control of the field current supply unit 410, a step S600 of monitoring the charging rate of the low-voltage battery 300 is performed. Thereafter, the generated power of the motor generator 100 and the required power of the vehicle are compared Step S700 is performed.

When the difference between the generated power of the motor generator 100 and the required electric power of the vehicle is less than the predetermined value a, the step S500 of controlling the field current supply unit 410 is performed again, The motor generator 100 is maintained in a constant state. Conversely, when the difference between the generated power of the motor generator 100 and the required power of the vehicle is equal to or greater than a preset value a, a step S800 of modifying the target output value of the motor generator 100 is performed, When the generated power of the generator 100 is very large while the required power of the vehicle is small, charging of the low-voltage battery 200 may be unnecessary, so that it is also possible to control the power supply from the low-voltage battery 200 to be stopped will be.

The embodiments and the accompanying drawings described in the present specification are merely illustrative of some of the technical ideas included in the present invention. Therefore, it is to be understood that the embodiments disclosed herein are not intended to limit the scope of the present invention but to limit the scope of the present invention. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. It should be interpreted.

100: Motor generator
200: High voltage battery
300: Low voltage battery
400: Inverter
700: relay part

Claims (11)

1. A motor generator power supply of a mild hybrid vehicle interlocked with an engine and a belt, the motor generator power supply comprising:
High voltage battery;
An inverter for converting a direct current power of the high voltage battery and a three phase power of the motor generator;
A low voltage battery for applying power to the inverter;
Lt; / RTI >
And drives the motor generator using the low-voltage battery when an abnormality is detected in the power supplied to the inverter from the high-voltage battery or the high-voltage battery.
2. The inverter according to claim 1,
A field current supply unit for applying power to a field of the motor generator; And
A three-phase current supply unit for applying three-phase power to a winding of the motor generator;
Lt; / RTI >
Wherein the field current supply unit and the three-phase current supply unit are selectively supplied with power by either the high-voltage battery or the low-voltage battery.
3. The method of claim 2,
A relay unit for selecting a power source to be supplied to the field current supply unit and the three-phase current supply unit;
The motor generator power supply of the mild hybrid vehicle.
The apparatus as claimed in claim 3,
A first relay for interrupting supply of power from the low-voltage battery to the field current supply unit and the three-phase current supply unit;
A second relay for interrupting the supply of power from the high-voltage battery to the field current supply unit and the three-phase current supply unit;
The motor generator power supply of the mild hybrid vehicle.
3. The inverter according to claim 2,
A boost converter disposed between the field current supply unit and the relay unit;
The motor generator power supply of the mild hybrid vehicle.
A control method of a motor generator power supply device for a mild hybrid vehicle including a high voltage battery, an inverter for converting a direct current power of the high voltage battery and a three phase power source of a field winding motor generator, and a low voltage battery for applying power to the inverter In this case,
Wherein the inverter includes a field current supply unit for applying power to the field of the motor generator and a three-phase current supply unit for applying three-phase power to the windings of the motor generator,
Detecting an abnormality in the power supplied to the inverter from the high voltage battery or the high voltage battery;
Converting the battery connected to the field current supply unit and the three-phase current supply unit from the high-voltage battery to the low-voltage battery when the abnormality is detected;
Activating a boost converter that boosts the power of the low-voltage battery and transfers the boosted power to the field current supply unit;
Determining whether the motor generator needs to be driven;
And a control unit for controlling the motor generator power supply of the mild hybrid vehicle.
The method according to claim 6,
Wherein the step of determining necessity of driving the motor-
Wherein the controller determines the necessity of driving the motor generator based on at least one of a charging rate of the low-voltage battery, a required power generation amount of the vehicle, and an engine rotation speed of the vehicle.
The method according to claim 6,
If it is determined that the motor generator needs to be driven,
Controlling the field current supply unit so that the power of the boosted low voltage battery can be supplied to the field of the motor generator;
Wherein the motor generator power supply of the mild hybrid vehicle further comprises:
9. The method of claim 8,
After the step of controlling the field current supply unit,
Monitoring a charging rate of the low-voltage battery; And
Comparing the generated power of the motor generator with the required power of the vehicle;
Wherein the motor generator power supply of the mild hybrid vehicle further comprises:
10. The method of claim 9,
When the difference between the generated power of the motor generator and the required power of the vehicle is less than a preset value,
Wherein the step of controlling the field current supply unit is performed again.
10. The method of claim 9,
When the difference between the generated power of the motor generator and the required power of the vehicle is equal to or greater than a predetermined value,
Modifying a target output value of the motor generator;
Wherein the motor generator power supply of the mild hybrid vehicle further comprises:

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