KR20140145833A - Apparatus for controlling regenerative energy of vehicle and method thereof - Google Patents

Abstract

A method for controlling generative energy of a vehicle according to an embodiment of the present invention, which is a method of controlling an inverter to drive a motor and controlling power regenerated from the motor to a battery when the vehicle stops, comprises the following steps: receiving a DC link voltage regenerated to the battery if a constant voltage command and a constant current command are inputted, generating a DC link current command based on the constant voltage command and the constant current command; calculating required power with the DC link current command and the DC link voltage; comparing the required power with output power of the motor to generate a torque command; and controlling the inverter based on the torque command.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a regenerative energy control apparatus for a vehicle,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a regenerative energy control apparatus and method for a vehicle , and more particularly , to a regenerative energy control apparatus and method for a vehicle that controls voltage and current regenerated by a battery during braking of the vehicle.

Recently, fossil fuels are depleted and environmental pollution becomes worse due to exhaust gas of automobiles. Therefore, researches on electric vehicles using alternate energy of low pollution are being actively carried out. In particular, research is underway to replace existing internal combustion engines using fossil energy with drive systems based on batteries and motors.

The electric vehicle drives the motor using the energy charged in the battery. Since the energy efficiency is low when the motor is driven by the once charged battery, the battery is charged with the regenerative energy generated by the motor when the electric vehicle is braked .

In order to control the regenerative energy of the electric vehicle, it is common to arrange a DC-DC converter between the battery and the inverter and control voltage and current supplied to the battery using the DC-DC converter.

However, the use of a DC-DC converter increases the volume and weight, reduces energy efficiency, and can not avoid durability degradation of the inductor used in the DC-DC converter.

In order to solve such a problem, a method of controlling the voltage and current of the battery by measuring the DC link voltage and the DC link current regenerated in the battery without using the DC-DC converter has been proposed.

However, the DC link current supplied to the battery through the inverter contains a ripple component and must pass through a low pass filter (LPF). Therefore, there is a problem of reducing the dynamic characteristics of the controller.

In addition, the DC link current includes a harmonic component with respect to the rotation speed of the motor. Such a harmonic component is difficult to remove even with a low-pass filter, thereby deteriorating the control performance.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a regenerative energy control apparatus and method for a vehicle which can control a voltage and a current regenerated in a battery by using only an inverter without using a DC-DC converter.

In addition, the present invention provides a regenerative energy control apparatus and method for a vehicle that can control voltage and current regenerated in a battery while maintaining dynamic characteristics of a controller by not measuring a DC link current.

Further, the present invention provides a regenerative energy control device for a vehicle and a method thereof, which can improve control performance by reflecting a variable DC link voltage environment.

According to an embodiment of the present invention, there is provided a regenerative energy control method of a vehicle that controls an inverter to drive a motor and controls electric power regenerated from the motor to the battery when the vehicle is braked, wherein when a constant voltage command and a constant current command are input Receiving a DC link voltage regenerated by the battery; Generating a DC link current command based on the constant voltage command, the constant current command, and the DC link voltage; Calculating a required power from the DC link current command and the DC link voltage; Comparing the required power with output power of the motor to generate a torque command; And controlling the inverter on the basis of the torque command.

Wherein the step of generating the DC link current command includes the step of generating a DC link current command by performing a proportional integral control so that a difference between the constant voltage command and the DC link voltage is reduced, Lt; / RTI >

The calculating of the required power may calculate the required power with reference to a lookup table according to the DC link current command and the DC link voltage.

The step of generating the torque command may generate the torque command by performing a proportional integral control so that the difference between the required electric power and the output power of the motor is reduced.

The step of generating the torque command includes: calculating a magnetic flux of the motor; calculating an output torque of the motor with reference to a lookup table according to d-axis current and q-axis current; And calculating an output power of the motor based on the magnetic flux and the output torque.

The step of calculating the output power of the motor may calculate an output power of the motor by referring to a lookup table according to the magnetic flux and the output torque.

The step of controlling the inverter includes generating a d-axis current command and a q-axis current command from the torque command; Generating d-axis voltage command and q-axis voltage command by performing proportional integral control so that the d-axis current command and q-axis current command are compared with d-axis current and q-axis current to reduce the difference; Converting the coordinates of the d-axis voltage command and the q-axis voltage command to generate a three-phase voltage command; And modulating the 3-phase voltage command by a space vector voltage modulation (SVPWM) method and outputting the 3-phase voltage command to the inverter.

According to another embodiment of the present invention, there is provided an inverter comprising: an inverter for driving a motor; A voltage detector for measuring a DC link voltage regenerated from the motor to the battery through the inverter; And calculating a torque command by comparing the required electric power with the output power of the motor when the constant voltage command and the constant electric current command are input from the upper control unit and receiving the DC link voltage and calculating a DC link current command and required electric power, And a control unit for controlling the inverter based on the torque command.

The required power is calculated with reference to a lookup table according to the DC link voltage and the DC link current command, and the output power of the motor can be calculated with reference to a lookup table according to the output torque of the motor and the magnetic flux of the motor have.

According to the embodiment of the present invention, the voltage and current regenerated in the battery can be controlled by only the inverter without using the DC-DC converter, so that the energy efficiency can be increased and the volume and weight can be reduced.

In addition, according to the embodiment of the present invention, since the look-up table prepared in advance is used in place of the measured value of the DC link current, the voltage and current of the battery can be controlled while maintaining the dynamic characteristics of the controller.

Further, according to the embodiment of the present invention, since the variable DC link voltage environment can be reflected, the control performance can be improved.

1 is a block diagram showing a configuration of a regenerative energy control device for a vehicle according to an embodiment of the present invention.
2 is a block diagram showing a detailed configuration of a control unit in a regenerative energy control apparatus for a vehicle according to an embodiment of the present invention.
3 is a control block diagram for explaining the operation of the voltage current control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.
4 is a graph showing changes in current and voltage of a battery with time according to an apparatus for controlling regenerative energy of a vehicle according to an embodiment of the present invention.
5 is a control block diagram for explaining the operation of the power control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.
6 is a control block diagram for explaining the operation of the torque calculation module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.
7 is a control block diagram for explaining the operation of the torque control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.
8 is a control block diagram for explaining the operation of the vector control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.
9 is a flowchart showing an operation of a regenerative energy control method of a vehicle according to an embodiment of the present invention.
FIGS. 10 and 11 are graphs showing simulation results of a regenerative energy control method of a vehicle according to an embodiment of the present invention.

The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated and described in the drawings. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms including ordinal, such as second, first, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as a first component, and similarly, the first component may also be referred to as a second component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings, wherein like or corresponding elements are denoted by the same reference numerals, and redundant description thereof will be omitted.

FIG. 1 is a block diagram showing a configuration of a regenerative energy control device for a vehicle according to an embodiment of the present invention. FIG. 2 is a block diagram showing a detailed configuration of a control part in a regenerative energy control device for a vehicle according to an embodiment of the present invention. It is a block diagram.

1, a regenerative energy control apparatus for a vehicle according to an embodiment of the present invention includes an upper controller 10, a battery 20, an inverter 30, a voltage detector 40, a motor 50, A position sensor 70, a memory unit 80, and a control unit 100. As shown in FIG.

The upper control unit 10 determines a running state and a braking state of the vehicle based on the running condition of the vehicle and the state information of the battery 20, and generates a command signal corresponding to the running state and the braking state to output to the control unit 100.

The upper control unit 10 determines the running state of the vehicle based on the accelerator pedal signal input from the accelerator pedal sensor (not shown), calculates a drive torque required for acceleration of the vehicle, and outputs a drive torque command to the control unit 100 Output.

The upper control unit 10 determines the braking state of the vehicle based on the brake pedal signal input from the brake pedal sensor (not shown) and determines the braking state of the vehicle based on the battery current input from the battery sensor (not shown) (SOC) of the battery 20 to selectively perform the braking torque control or the voltage and current control of the battery 20.

When performing the braking torque control, the high-level control section 10 calculates a braking torque necessary for braking the vehicle and outputs a braking torque command to the control section 100. [

On the other hand, when voltage and current control of the battery 20 is performed, the upper controller 10 calculates the constant voltage and the constant current necessary for charging the battery 20, and outputs the constant voltage command Vdc_ref and the constant current command Idc_ref, (100).

Since the present embodiment relates to the voltage and current control of the battery 20, focusing on the case where the upper level control section 10 outputs the constant voltage command Vdc_ref and the constant current command Idc_ref to the control section 10, do.

Referring to FIG. 1, a counter electromotive force is generated in the motor 50 when the vehicle is braked, and a regenerative electric power due to the counter electromotive force is supplied to the battery 20 through the inverter 30. At this time, the motor 50 may be an Interior Permanent Magnet Synchronous Motor (IPMSM).

The voltage detector 40 measures the DC link voltage Vdc regenerated from the motor 50 to the battery 20 through the inverter 30 and outputs the DC link voltage Vdc to the controller 100.

The current sensor 60 measures the three-phase currents ia, ib and ic outputted from the inverter 30 to the motor 50 and outputs the three-phase currents to the control unit 100. The position sensor 70 detects the three- And outputs it to the control unit 100. The control unit 100 detects the rotor position?

When the constant voltage command Vdc_ref and the constant current command Idc_ref are inputted from the upper controller 10, the controller 100 receives the DC link voltage Vdc from the voltage detector 40 and outputs the DC link current command Idc * And calculates the required power P *.

The control unit 100 compares the required power P * with the output power P ^ of the motor 50 to calculate the torque command Te * and outputs the torque command Te * to the inverter 30 according to the torque command Te * And controls the DC link voltage Vdc and the DC link current Idc regenerated from the motor 50 to the battery 20. [

In other words, the control unit 100 according to the embodiment of the present invention generates the DC link current command Idc * from the measured value of the DC link voltage Vdc and outputs the DC link voltage Vdc and the DC link current Idc Can be controlled.

The control unit 100 according to the embodiment of the present invention calculates the required power P * from the DC link voltage Vdc and the DC link current instruction Idc * and compares the required power P * with the output power P ^ Thereby generating the torque command Te *.

2, the control unit 100 includes a voltage current control module 110, a power control module 120, a torque calculation module 130, a torque control module 140, and a vector control module 150 do. Hereinafter, detailed operation of the control unit 100 will be described in detail with reference to FIG. 2 to FIG.

3 is a control block diagram for explaining the operation of the voltage current control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention. 4 is a graph showing changes in current and voltage of a battery with time according to an apparatus for controlling regenerative energy of a vehicle according to an embodiment of the present invention.

3, the voltage current control module 110 inputs the DC link voltage Vdc from the voltage detector 40 when the constant voltage instruction Vdc_ref and the constant current instruction Idc_ref are inputted from the upper controller 10 Generates a DC link current command Idc *, and transmits it to the power control module 120.

Specifically, the voltage / current control module 110 performs proportional integral (PI) control so as to reduce the difference between the constant voltage command Vdc_ref and the DC link voltage Vdc to generate a DC link current command Idc * do.

4, the voltage current control module 110 controls the voltage current control module 110 such that the DC link current command Idc * is saturated by the proportional integral control during the initial operation in which the difference between the constant voltage command Vdc_ref and the DC link voltage Vdc is large, , And the DC link current instruction Idc * is limited to a value equal to or less than the constant current instruction Idc_ref (t1 section).

Thereafter, when the power regenerated to the battery 20 increases and the difference between the constant voltage command Vdc_ref and the DC link voltage Vdc becomes small, the voltage current control module 110 performs the constant voltage control. Therefore, the DC link current instruction Idc * gradually decreases (t2 section).

5 is a control block diagram for explaining the operation of the power control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.

5, first, the power control module 120 receives the DC link current command Idc * input from the voltage current control module 110 and the DC link voltage Vdc input from the voltage detector 40 And calculates the required power P * on the basis of the required power P *.

At this time, the power control module 120 can calculate the required power P * by referring to the memory section 80 from the first lookup table according to the DC link current command Idc * and the DC link voltage Vdc .

Here, the first look-up table is obtained by experimentally measuring the optimum required power P * according to the DC link current command Idc * and the DC link voltage Vdc in advance and storing it in the memory unit 80 do.

That is, this embodiment does not directly measure the DC link current Idc but controls the DC link current Idc using the measured data in advance, so that the voltage and current of the battery 20 Can be controlled.

Meanwhile, the power control module 120 may calculate the required power P * by multiplying the DC link current command Idc * and the DC link voltage Vdc. However, it is preferable to calculate the required power P * using a first lookup table created experimentally in order to reflect variations in the internal impedance of the battery 20 due to the DC link voltage Vdc.

Next, the power control module 120 calculates the output torque Te ^ of the motor 50 input from the torque calculation module 130 and the magnetic flux? R of the motor 50 input from the torque control module 140 To calculate the output power (P ^) of the motor (50).

At this time, the power control module 120 refers to the second lookup table corresponding to the output torque Te ^ of the motor 50 and the magnetic flux lambda r of the motor 50 from the memory unit 80, The output power (P ^) can be calculated.

The second lookup table is a table that is obtained by experimentally measuring the output power Te of the motor 50 and the output power P of the motor 50 according to the magnetic flux r of the motor 50 And is stored in the memory unit 80.

On the other hand, the output power P ^ of the motor 50 can be expressed by the product of the output torque Te ^ of the motor 50 and the rotation speed rho of the motor 50. [ However, in order to reflect the output error of the motor 50 due to the fluctuation of the DC link voltage Vdc and the fluctuation in the back electromotive force magnitude due to the parameter variation of the motor 50, the output torque Te ^ It is preferable to calculate the output power P ^ of the motor 50 using the second lookup table according to the magnetic flux lambda r of the motor 50. [

Thereafter, the power control module 120 performs proportional integral control so as to reduce the difference between the required power P * and the output power P ^ of the motor 50 to generate the torque command Te * To the control module (140).

6 is a control block diagram for explaining the operation of the torque calculation module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.

6, the torque calculating module 130 calculates an output torque Te ^ of the motor 50 from the d-axis currents irds and q-axis currents irqs input from the vector control module 150 do.

At this time, the torque calculation module 130 calculates the output torque Te ^ of the motor 50 by referring to the memory section 80 from the third lookup table according to the d-axis currents irds and q-axis currents irqs can do.

Here, the third lookup table is a table prepared by experimentally measuring the output torque Te ^ of the motor 50 according to the d-axis currents (irds) and the q-axis currents (irqs) .

The output torque Te ^ of the motor 50 calculated by referring to the third lookup table is output to the power control module 120 and used to calculate the output power P ^ of the motor 50 .

7 is a control block diagram for explaining the operation of the torque control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.

Referring to FIG. 7, the torque control module 140 calculates the magnetic flux? R (? R) of the motor 50 using the voltage command Vrdqs * input from the vector control module 150 and the rotational speed? R of the motor 50 ) And the total magnetic flux ([lambda] max).

)을 모터(50)의 회전속도(ωr)로 나누어 전체자속(λmax)을 연산한다. Here, the torque control module 140 calculates the maximum linear modulation voltage (SV) of the space vector PWM (SVPWM)

Is divided by the rotation speed? R of the motor 50 to calculate the total magnetic flux? Max.

)과 비교하여 그 차이가 감소하도록 비례적분제어를 수행하고, 이를 모터(50)의 회전속도(ωr)로 나누어 모터(50)의 자속(λr)을 연산한다. The torque control module 140 also adjusts the magnitude of the voltage command Vrdqs * to the maximum linear modulation voltage of the space vector voltage modulation

And calculates the magnetic flux lambda r of the motor 50 by dividing the result by the rotational speed? R of the motor 50. The proportional integral control is performed so that the difference is reduced.

On the other hand, the torque control module 140 generates the d-axis current command (irds *) and the q-axis current command (irds *) based on the magnetic flux lambda r of the motor 50 and the torque command Te * input from the power control module 120 (irqs *) to the vector control module 150. At this time, the torque command Te * input from the power control module 120 is limited by the torque limit value Tlimit calculated from the total magnetic flux? Max.

Here, the torque limit value Tlimit represents the maximum output of the motor 50 with respect to the rotational speed? R of the motor 50 and the DC link voltage Vdc.

The torque control module 140 also refers to the fifth lookup table according to the magnetic flux lambda r and the torque command Te * of the motor 50 from the memory unit 80 and outputs the d axis current command The constant current command (irqs *) can be calculated.

Here, the fifth lookup table experimentally measures the d-axis current command (irds *) and the q-axis current command (irqs *) according to the magnetic flux lambda r and the torque command Te * of the motor 50, Dimensional table, and is stored in the memory unit 80. [

8 is a control block diagram for explaining the operation of the vector control module in relation to the regenerative energy control device of the vehicle according to the embodiment of the present invention.

8, first, the vector control module 150 uses the rotor position (?) Of the motor 50 input from the position sensor 70 to calculate the three-phase currents ia, ib , ic) into d-axis currents (irds) and q-axis currents (iqds).

Thereafter, the vector control module 150 compares the difference between the d-axis current command (irds *) and the d-axis current (irds) input from the torque control module 140 and the q-axis current command (irqs *) and the q- ) Is reduced to generate the d-axis voltage command Vrds * and the q-axis voltage command Vrqs *, respectively.

Next, the vector control module 150 calculates the d-axis voltage command Vrds * and the q-axis voltage command Vrqs * using the rotor position [theta] of the motor 50 input from the position sensor 70 Phase voltage command (Vas *, Vbs *, Vcs *).

Then, the vector control module 150 modulates the three-phase voltage commands Vas *, Vbs *, and Vcs * by the space vector voltage modulation (SVPWM) method and outputs the modulated signals to the inverter 30. [

The vector control module 150 calculates the rotational speed? R of the motor 50 by differentiating the rotor position? Of the motor 50 input from the position sensor 70, .

9 is a flowchart showing an operation of a regenerative energy control method of a vehicle according to an embodiment of the present invention.

9, first, the control unit 100 checks whether the constant voltage command Vdc_ref and the constant current command Idc_ref are inputted from the host controller 10 (S11).

If the constant voltage instruction Vdc_ref and the constant current instruction Idc_ref are inputted from the upper control unit 10, the control unit 100 receives the DC link voltage Vdc from the voltage detection unit 40 (S12).

The control unit 100 then generates a DC link current instruction Idc * based on the constant voltage command Vdc_ref, the constant current command Idc_ref, and the DC link voltage Vdc (S13).

Next, the control unit 100 calculates the required power P * based on the DC link current command Idc * and the DC link voltage Vdc (S14). At this time, the control unit 100 can calculate the required power P * by referring to the memory unit 80 from the first lookup table corresponding to the DC link current command Idc * and the DC link voltage Vdc.

Next, the control section 100 estimates the magnetic flux lambda r of the motor 50 using the voltage command Vrdqs * and the rotational speed rr of the motor 50 (S15)

)과 비교하여 그 차이가 감소하도록 비례적분제어를 수행하고, 이를 모터(50)의 회전속도(ωr)로 나누어 모터(50)의 자속(λr)을 연산할 수 있다. At this time, the controller 100 sets the magnitude of the voltage command Vrdqs * as the maximum linear modulation voltage of the spatial vector voltage modulation

, The proportional integral control is performed so that the difference is reduced and is divided by the rotational speed? R of the motor 50 to calculate the magnetic flux? R of the motor 50. [

Then, the control unit 100 calculates the output torque Te ^ of the motor 50 by referring to the memory unit 80 from the third lookup table according to the d-axis currents irds and q-axis currents irqs (S16).

The control unit 100 calculates the output power P ^ of the motor 50 based on the output torque Te ^ of the motor 50 and the magnetic flux r of the motor 50 (S17).

At this time, the control unit 100 refers to the second lookup table corresponding to the output torque Te ^ of the motor 50 and the magnetic flux lambda r of the motor 50 from the memory unit 80, (P ^).

After calculating the required power P * and the output power P ^ of the motor 50 as described above, the controller 100 calculates the required power P * and the output power P ^ of the motor 50 The proportional integral control is performed to reduce the difference to generate the torque command Te * (S18)

Then, the control unit 100 drives the inverter 30 based on the torque command Te * (S19).

FIGS. 10 and 11 are graphs showing simulation results of a regenerative energy control method of a vehicle according to an embodiment of the present invention.

Referring to FIG. 10, it can be seen that the DC link current Idc of the battery is also stably controlled with respect to the gain for the control dynamic characteristic of 0.01 second.

Also, referring to FIG. 11, it is confirmed that constant voltage and constant current control is stably performed even at the maximum speed of 1500 rpm.

As described above, according to the embodiment of the present invention, since the voltage and current regenerated in the battery can be controlled by only the inverter without using the DC-DC converter, the energy efficiency can be increased, and the volume and weight can be reduced.

In addition, since the previously prepared look-up table is used instead of using the measured DC link current, the voltage and current of the battery can be controlled while maintaining the dynamic characteristics of the controller.

In addition, since the variable DC link voltage environment is reflected, the control performance can be improved.

As used in this embodiment, the term " portion " refers to a hardware component such as software or an FPGA (field-programmable gate array) or ASIC, and 'part' performs certain roles. However, 'part' is not meant to be limited to software or hardware. &Quot; to " may be configured to reside on an addressable storage medium and may be configured to play one or more processors. Thus, by way of example, 'parts' may refer to components such as software components, object-oriented software components, class components and task components, and processes, functions, , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and components may be further combined with a smaller number of components and components or further components and components. In addition, the components and components may be implemented to play back one or more CPUs in a device or a secure multimedia card.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

10: upper control section 20: battery
30: inverter 40: voltage detector
50: motor 60: current sensor
70: Position sensor 80: Memory part
100: control unit 110: voltage current control module
120: power control module 130: torque calculation module
140: torque control module 150: vector control module

Claims (9)

A regenerative energy control method for a vehicle that controls an inverter to drive a motor and controls electric power regenerated from the motor to the battery upon braking of the vehicle,
Receiving a DC link voltage regenerated by the battery when a constant voltage command and a constant current command are input;
Generating a DC link current command based on the constant voltage command, the constant current command, and the DC link voltage;
Calculating a required power from the DC link current command and the DC link voltage;
Comparing the required power with output power of the motor to generate a torque command; And
And controlling the inverter based on the torque command.
The method according to claim 1,
Wherein the step of generating the DC link current command comprises:
A proportional integral control is performed to reduce a difference between the constant voltage command and the DC link voltage to generate the DC link current command,
Wherein the DC link current command is limited to the constant current command or less.
The method according to claim 1,
The step of calculating the required power includes:
And calculating the required power with reference to a lookup table according to the DC link current command and the DC link voltage.
The method according to claim 1,
Wherein the generating the torque command comprises:
And the torque command is generated by performing a proportional integral control so that the difference between the required electric power and the output power of the motor is reduced.
2. The method of claim 1, wherein generating the torque command comprises:
Calculating a magnetic flux of the motor;
calculating an output torque of the motor with reference to a lookup table according to d-axis current and q-axis current; And
And calculating the output power of the motor based on the magnetic flux and the output torque.
6. The method of claim 5,
Wherein the step of calculating the output power of the motor comprises:
And calculating an output power of the motor with reference to a lookup table according to the magnetic flux and the output torque.
The method according to claim 1,
The step of controlling the inverter includes:
Generating a d-axis current command and a q-axis current command from the torque command;
Generating d-axis voltage command and q-axis voltage command by performing proportional integral control so that the d-axis current command and q-axis current command are compared with d-axis current and q-axis current to reduce the difference;
Converting the coordinates of the d-axis voltage command and the q-axis voltage command to generate a three-phase voltage command; And
Modulating the three-phase voltage command by a space vector voltage modulation (SVPWM) method and outputting the modulated three-phase voltage command to the inverter.
An inverter for driving the motor;
A voltage detector for measuring a DC link voltage regenerated from the motor to the battery through the inverter; And
A torque command is calculated by comparing the required power with the output power of the motor to calculate a DC link current command and required power when the constant voltage command and the constant current command are input from the upper control section, And a controller for controlling the inverter based on the command.
9. The method of claim 8,
The required power is calculated with reference to a look-up table according to the DC link voltage and the DC link current command,
Wherein the output power of the motor is calculated by referring to a lookup table according to an output torque of the motor and a magnetic flux of the motor.

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