KR20160148379A - Apparatus and method for aontrolling motor of eco-friendly vehicle - Google Patents

Abstract

The present invention relates to an apparatus and method for controlling a motor of an eco-friendly vehicle. According to the present invention, the apparatus for controlling a motor of an eco-friendly vehicle comprises: a control unit which generates an inverse magnetic flux value based on a voltage of a driving motor, a d-axis voltage command, a q-axis voltage command, and electrical angular speed; a current instruction generator which generates a d-axis current command and a q-axis current command based on a torque requirement instruction and inverse magnetic flux correction value; an inverse magnetic flux correction unit which, when current command sizes corresponding to the d-axis current command and the q-axis current command are less than a preset reference value, determines a correction value based on mechanical angular speed of the driving motor and the d-axis and q-axis current command, and displays the correction value; an adder which outputs the inverse magnetic flux correction value by adding the inverse magnetic flux value to the correction value; a current controller which generates a current control value based on the d-axis and q-axis current commands; a coordinate conversion unit which converts the current control value into axial coordinate values; and a PWM generator which generates a PWM signal based on the axial coordinate values, and operates the driving motor.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor control apparatus and method for an eco-

TECHNICAL FIELD [0001] The present invention relates to an apparatus and method for motor control of an environmentally friendly automobile.

Generally, eco-friendly automobiles include fuel cell cars, electric vehicles, plug-in electric vehicles, hybrid cars and the like. An eco-friendly car is equipped with one or more batteries, and uses the energy stored in the battery as driving force of the automobile.

The environmentally friendly automobile is powered by an engine and a drive motor. The engine and the drive motor are controlled according to the driving situation to provide the optimum output torque. This eco-friendly automobile includes a motor system divided into an inverter and a motor device.

The motor system of the eco-friendly automobile uses a maximum torque per unit current (hereinafter referred to as MTPA) and a flux weakening control method by constructing a current map for each magnetic flux and torque command.

The MTPA control method is used in a region where the supply voltage of the battery is larger than the counter electromotive force of the drive motor when the output torque limit of the drive motor is not caused by the voltage ellipse. Also, the abbreviated speed control method is used in a region where the back electromotive force of the driving motor is larger than the supply voltage of the battery when the output torque limit of the driving motor due to the voltage ellipse occurs. In the abbreviated control method, when the torque command is generated, the inverse magnetic flux in the direction opposite to the induced magnetic flux for generating the back electromotive force is determined, and the current operation point is determined according to the inverse magnetic flux.

However, because eco-friendly cars use limited energy, the best way to get the maximum output with the least energy (minimum loss) is the most effective. However, the MTPA control method is not a minimum loss operation method because it minimizes copper loss, and the abrupt speed control method is not a minimum loss operation method because the current operation point is determined by a predetermined current map.

In order to operate the motor system with minimum loss, the loss value for all current operating points should be obtained. It is possible to construct a modeling or a map through experiments or the like as a method for obtaining this, but it requires a lot of development time and it is difficult to correct the error.

In the embodiment of the present invention, the total loss value is calculated according to the speed of the driving motor by increasing the correction value in each step in the region where the current command magnitude for the driving motor is smaller than the set reference value, A motor control apparatus and method for an environmentally friendly automobile that can drive a drive motor with maximum efficiency by determining a value and correcting the inverse magnetic flux value.

A motor control device for an environmentally friendly automobile according to an embodiment of the present invention includes a controller for generating inverse values according to a voltage of a driving motor, a d-axis voltage command, a q-axis voltage command, and an electric angular velocity; A current command generator for generating a d-axis current command and a q-axis current command according to the torque demand command and the inverse speed correction value; Axis current command, the d-axis current command, and the q-axis current command is smaller than a preset reference value, a correction value is determined according to the mechanical angular velocity of the driving motor, the d-axis and q- government; An adder for adding the inverse value and the correction value to output the inverse speed correction value; A current controller for generating a current control value according to a current command of the d-axis and the q-axis; A coordinate converter for converting the current control value into an axis coordinate value; And a PWM generator for generating a PWM signal according to the axis coordinate value to operate the driving motor.

A correction value generation unit for generating the correction value by increments of step when the current command magnitude is smaller than the reference value; And calculating a total loss value of the drive motor for each of the steps using the mechanical angular velocity of the drive motor, the d-axis and the q-axis current command, and calculating any one of the correction values for each step according to the total loss value And the correction value generation unit sets and outputs the correction value selected by the correction value determination unit.

Here, the correction value generator calculates the current command magnitude according to Equation (1) below.

[Equation 1]

(Where Isref is the current command magnitude, Idref is the d-axis current command, and Iqref is the q-axis current command).

The correction value determiner may include an iron loss torque extractor for extracting iron loss torque values from a lookup table previously stored according to the d-axis current command, the q-axis current command, and the mechanical angular speed of the drive motor; An iron loss calculator for calculating an iron loss of the drive motor according to the mechanical angular speed of the drive motor and the iron loss torque value; A coarse loss computing unit for computing a coarse loss of the drive motor according to the d-axis current command and the q-axis current command; A loss calculation unit for calculating the total loss amount in accordance with iron loss and copper loss of the drive motor; And a determination unit that compares the total loss value of the current step with the total loss value of the previous step and selects the correction value of the current step if the total loss value of the current step is less than the total loss value of the immediately preceding step .

Here, the look-up table stores the iron loss torque value corresponding to the current command magnitude and the mechanical angular speed of the drive motor. Then, the iron loss calculation unit calculates iron loss of the drive motor according to the following equation (2).

&Quot; (2) "

(Where PIronloss is the iron loss of the drive motor, and Wm is the mechanical angular velocity of the drive motor).

Further, the copper loss calculation section calculates the copper loss of the drive motor according to the following equation (3).

&Quot; (3) "

(Where Pcupperloss is the copper loss of the drive motor, Rs is the phase resistance value, and Isref is the current command magnitude).

The loss amount calculation unit adds the iron loss and the copper loss of the drive motor to calculate the total loss amount.

According to another aspect of the present invention, there is provided a motor control method for an environmentally friendly automobile, the method comprising: generating an inverse value according to a voltage of a drive motor, a d-axis voltage command, a q-axis voltage command, and an electric angular velocity; Generating a d-axis current command and a q-axis current command in accordance with the torque demand command and the inverse speed correction value; Determining whether a current command magnitude corresponding to the d-axis current command and the q-axis current command is smaller than a preset reference value; Determining a correction value according to the mechanical angular velocity of the driving motor, the d-axis, and the q-axis current command when the current command magnitude is smaller than the reference value; And generating the inverse fast correction value by adding the correction value to the inverse fast axis value.

Wherein the step of determining the correction value comprises: calculating the current command magnitude; Comparing the current command magnitude with the reference value; If the current command magnitude is smaller than the reference value, generating the correction value step by step; Calculating a total loss value of the drive motor for each of the steps using the mechanical angular velocity of the drive motor, the d-axis, and the q-axis current command; Determining whether a total loss value of a current step among the plurality of steps is less than a total loss value of a previous step; And fixing the correction value of the current step if the total loss value of the current step is less than or equal to the total loss value of the immediately preceding step.

Here, the current command magnitude is calculated according to the following expression (1).

[Equation 1]

(Where Isref is the current command magnitude, Idref is the d-axis current command, and Iqref is the q-axis current command).

The calculating of the total loss value of the driving motor may include extracting an iron loss torque value from a lookup table stored in advance according to the d-axis current command, the q-axis current command, and the mechanical angular velocity of the driving motor. Calculating an iron loss of the driving motor according to the mechanical angular speed of the driving motor and the iron loss torque value; Calculating a copper loss of the drive motor in accordance with the d-axis current command and the q-axis current command; And adding iron loss and copper loss of the drive motor.

Here, the iron loss of the drive motor is calculated according to the following equation (2).

 &Quot; (2) "

(Where PIronloss is the iron loss of the drive motor, and Wm is the mechanical angular velocity of the drive motor).

Then, the power loss of the drive motor is calculated according to the following equation (3).

&Quot; (3) "

(Where Pcupperloss is the copper loss of the drive motor, Rs is the phase resistance value, and Isref is the current command magnitude).

According to the present invention, a total loss value according to the speed of the drive motor is increased by increasing the correction value in each step in a region where the current command magnitude for the drive motor is smaller than a set reference value, and a correction value So that the driving motor can be driven with maximum efficiency by correcting the inverse value.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a motor control apparatus for an environmentally friendly automobile according to an embodiment of the present invention; FIG.
Fig. 2 is a diagram showing a current command map for inverse speed and torque command. Fig.
3 is a detailed block diagram of the inverse fast axis correcting unit 120 shown in FIG.
4 is a graph showing the efficiency of the drive motor with respect to the torque command.
5 is a detailed block diagram showing the correction value determination unit 124 shown in FIG.
6 is a graph showing the iron loss torque value with respect to the current command magnitude according to the mechanical angular velocity of the drive motor.
7 is a flowchart showing a motor control method of an environmentally friendly automobile according to an embodiment of the present invention.
8 is a graph showing a current operating point for a torque command.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, parts not related to the description are omitted. Like numbers refer to like parts throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between. Also, when a part is referred to as "including " an element, it does not exclude other elements unless specifically stated otherwise.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing a motor control device of an environmentally friendly automobile according to an embodiment of the present invention.

1, an apparatus 100 for driving an eco-friendly automobile according to an exemplary embodiment of the present invention includes a control unit 110, a inverse matching unit 120, a current command generator 130, a current controller 140, A first coordinate transformation unit 150, a PWM generator 160, and a second coordinate transformation unit 170.

The control unit 110 generates the inverse magnetic flux value 1 /? Max according to the voltage Vdc, the voltage command VdqRef for the d-axis and the q-axis, and the electric angular velocity Wr of the drive motor 200.

The inverse fast correction unit 120 generates the correction value x when the current command magnitude corresponding to the current command Idref for the d axis and the current command magnitude Iqref for the q axis is smaller than a preset reference value, The correction value (x) is incremented stepwise by a unit size and output.

The inverse fast axis correcting unit 120 corrects the total of the driving motors 200 according to the mechanical angular velocity Wm of the driving motor 200, the current command Idref for the d axis, and the current command Iqref for the q axis. And when the total loss value of the drive motor 200 is the minimum value, the correction value (x) of the step is fixed and output.

The adder 122 adds the inverse value (1 /? Max) and the correction value (x) and outputs the inverse speed correction value (1 /? Max ').

The current command generator 130 generates a current command Idref for the d axis and a current command Iqref for the q axis according to the torque command Tref * and the inverse magnetic correction value 1 /? Max 'of the driver And provides it to the current controller 140.

2, the current command generator 130 includes a current command map for each inverse speed and torque command, and generates a torque command Tref * and a reverse inverse correction value 1 /? Max 'from the current command map, Axis current command Idref and the q-axis current command Iqref corresponding to the d-axis and the q-axis.

The current controller 140 generates a current control value for operating the drive motor 200 according to the current command Idref for the d axis and the current command Iqref for the q axis and outputs the current control value to the first coordinate converter 150 to provide. The current controller 140 receives the actual current IdAct applied to the d axis and the actual current IqAct applied to the q axis from the second coordinate converter 170 and corrects the current control value to remove the torque error .

The first coordinate transformation unit 150 converts the current control value generated by the current controller 140 into an axis coordinate value and applies the coordinate value to the PWM generator 160.

The PWM generator 160 generates a PWM signal according to the axis coordinate value applied from the first coordinate converter 150 to operate the driving motor 200.

The second coordinate converter 170 detects the actual current IdAct applied to the d axis of the driving motor 200 and the actual current IqAct applied to the q axis and provides the detected current IqAct to the current controller 140 as feedback information .

3 is a detailed block diagram of the inverse fast correction unit 120 shown in FIG.

3, the inverse fast correction unit 120 according to the embodiment of the present invention includes a correction value generation unit 122 and a correction value determination unit 124. [ The correction value generation section 122 calculates the current command magnitude Isref corresponding to the current command Idref for the d axis and the current command Iqref for the q axis. Here, the correction value generation unit 122 can calculate the current command magnitude Isref according to the following equation (1).

The correction value generation unit 122 generates the correction value x when the current command magnitude Isref is smaller than the preset reference value Isrefr and increases the correction value x step by step. The correction value generating unit 122 fixes and outputs the correction value (x) of the step when the step with the minimum total loss amount of the drive motor 200 is determined through the correction value determining unit 124. [

Here, the reference value Isrefr is calculated according to the current operation point extracted by applying the inverse fast axis correction unit 120 according to the embodiment of the present invention and the current operation point extracted through the current command map for each inverse speed and torque command The efficiency of the drive motor 200 to be driven can be calculated experimentally and set to the maximum current command magnitude Isref in the region where the efficiency of the drive motor 200 is higher than the current command map.

4, the MTPA control method (a) using the current command map and the MTPA control method (b) using the inverse fast correction unit 120 according to the embodiment of the present invention are similar to the MTPA control method The efficiency of the driving motor 200 is changed on the basis of the driving efficiency of the driving motor 200.

That is, in the region where the current command magnitude Isref is smaller than the reference value Isref, the efficiency of the driving motor 200 according to the embodiment of the present invention is higher than that in the case of applying the current command map, To correct the inverse value (1 /? Max). In a region where the current command magnitude Isref is larger than the reference value Isrefs, it is the same as in the case where the current command map is applied, so the current operating point is calculated by the current command map.

This is because the larger the current command magnitude Isref is, the greater the specific gravity of the loss of the drive motor 200 is compared to the iron loss. That is, in the case of the MTPA control method, the current operation point is calculated by applying the current command map in the region where the current command magnitude Isref is large because of the minimum copper loss operation technique, and in the region where the current command magnitude Isref is small, The maximum efficiency of the drive motor 200 can be obtained with respect to the entire current operating point by calculating the current operating point by applying the inverse fast correction unit 120 according to FIG.

The correction value determination unit 124 determines the total loss amount of the drive motor 200 using the mechanical angular velocity Wm of the drive motor 200, the current command Idref for the d-axis, and the current command Iqref for the q- In accordance with the stepwise correction value (x), and determines the correction step when the total loss amount of the drive motor 200 is the minimum value.

5 is a detailed block diagram showing the correction value determination unit 124 shown in FIG.

5, a correction value determination unit 124 according to an embodiment of the present invention includes an iron loss torque extraction unit 1241, an iron loss calculation unit 1243, a copper loss calculation unit 1245, a loss calculation unit 1247, 1249).

The iron loss torque extracting unit 1241 extracts the iron loss torque value from the lookup table stored in advance according to the current command Idref for the d axis, the current command Iqref for the q axis, and the mechanical angular speed Wm of the drive motor 200 .

Here, the look-up table includes an iron loss torque value corresponding to the current command magnitude Isref and the mechanical angular velocity Wm, as shown in Table 1. The lookup table can be extracted from a graph showing the iron loss torque value with respect to the current command magnitude Isref for each of the mechanical angular velocities Wm of the drive motor 200 as shown in FIG.

Wm1 Wm2 Wm3 Isref1 The iron loss torque value (A) The iron loss torque value (B) The iron loss torque value (C) Isref2 The iron loss torque value (D) The iron loss torque value (E) The iron loss torque value (F) Isref3 The iron loss torque value (G) The iron loss torque value (H) The iron loss torque value (I)

The iron loss calculator 1243 calculates the iron loss PIronloss of the drive motor 200 in accordance with the mechanical angular speed Wm of the drive motor 200 and the extracted iron loss torque value. Here, the iron loss calculation unit 1243 can calculate the iron loss PIronloss of the drive motor 200 according to the following equation (2).

The coarse loss computing unit 1245 computes PCupperloss of the drive motor 200 in accordance with the current command Idref for the d-axis and the current command Iqref for the q-axis. Here, the coarse loss computing unit 1245 computes the PCupperloss of the drive motor 200 according to the following equation (3).

Here, Rs is the phase resistance value. The loss calculation unit 1247 calculates the total loss amount of the drive motor 200 in accordance with the iron loss PIronloss and the PC damage loss. Here, the loss calculation unit 1247 can calculate the total loss amount of the drive motor 200 by the sum of iron loss (PIronloss) and copper loss (PCupperloss).

The determination unit 1249 compares the total loss amount of the drive motor 200 in the present stage with the total loss amount of the drive motor 200 in the immediately preceding stage, (X) of the current stage is determined as the final correction value when the total correction value is equal to or less than the total loss amount of the correction value (200).

7 is a flowchart illustrating a motor control method of an environmentally friendly automobile according to an embodiment of the present invention.

Referring to FIG. 7, first, the correction value generator 122 calculates the current command magnitude Isref according to the current command Idref for the d-axis and the current command Iqref for the q-axis (step S1). The correction value generation unit 122 determines whether the current command magnitude Isref is smaller than the reference value Isrefr (step S2).

As a result of the determination, if the current command magnitude Isref is smaller than the reference value Isrefr, the correction value generator 122 increments the correction value x by step S3. For example, the first stage generates the correction value x at 0.1, the second stage generates the correction value x at 0.2, and the third stage generates the correction value x at 0.3.

Then, the iron loss torque extracting section 1241 extracts iron loss from the look-up table stored in advance according to the current command Idref for the d-axis, the current command Iqref for the q-axis, and the mechanical angular speed Wm of the drive motor 200 The torque value is extracted.

Next, the iron loss calculation section 1243 calculates the iron loss PIron_Loss of the drive motor 200 using the above-described expression (2) according to the mechanical angular speed Wm of the drive motor 200 and the extracted iron loss torque value (Step S4).

The copper loss calculator 1245 computes the copper loss (PCupperloss) of the drive motor 200 using the above-described expression (3) according to the current command Idref for the axis and the current command Iqref for the q axis (Step S5).

Then, the loss calculating section 1247 calculates the total loss amount of the driving motor 200 by the sum of the iron loss (PIronloss) and the copper loss (PCupperloss) (Step S6). Next, the determination unit 1249 determines whether the total amount of loss calculated in the current step (i) is equal to or less than the total amount of loss calculated in the previous step (i-1) (step S7).

As a result of the determination, if the total loss amount calculated in the current step (i) is equal to or less than the total loss amount calculated in the previous step (i-1), the correction value x corresponding to the current step (i) is fixed (step S8).

Then, the correction value x fixed through the adder 122 is added to the inverse component value 1 /? Max to generate the inverse component correction value 1 /? Max ', and the current command generator 130 generates the torque command Axis current command Idref and the q-axis current command Iqref in accordance with the in-phase compensation value Tref * and inverse-flux correction value 1 /? Max '.

On the other hand, if it is determined in step S2 that the current command magnitude Isref is greater than the reference value Isrefr, the correction value generator 122 does not generate the correction value x. That is, the current command generator 130 generates the current command Idref for the d-axis from the current command map according to the torque command Tref * and the inverse magnetic flux value 1 /? Max of the driver without correcting the in-line value 1 /? Max, And the q-axis current command Iqref.

8 is a graph showing the current operating point for the torque command.

Referring to FIG. 8, when the MTPA control method is applied only to the current command map according to inverse speed and torque command without correcting the inverse value (1 /? Max) as in the embodiment of the present invention, the same torque command Tref * The current operation point 1 is the same regardless of the mechanical angular velocity Wm of the drive motor 200. [

In contrast, if the correction value x of the inverse magnetic flux value 1 /? Max, which is the minimum total loss value of the drive motor 200, is determined according to the embodiment of the present invention, the mechanical angular velocity Wm of the drive motor 200, (2, 3, 4, 5) per 500 rpm, 1000 rpm, 1500 rpm and 2000 rpm can be calculated.

Therefore, the development time for finding the maximum efficiency operating point for all the current operating points can be shortened by the mechanical angular speed (Wm) of the driving motor 200, and without a separate modeling for obtaining the loss value for all the current operating points It can be applied to all the speed regions of the drive motor 200 by using the already-modeled current command map.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

110:
120:
130: Current command generator
140: current controller
150: first coordinate transformation unit
160: PWM generator
170: a second coordinate transformation unit

Claims (14)

A control unit for generating inverse values according to a voltage of the drive motor, a d-axis voltage command, a q-axis voltage command, and an electric angular velocity;
A current command generator for generating a d-axis current command and a q-axis current command according to the torque demand command and the inverse speed correction value;
Axis current command, the d-axis current command, and the q-axis current command is smaller than a preset reference value, and determines and outputs a correction value according to the mechanical angular velocity of the driving motor, the d- government;
An adder for adding the inverse value and the correction value to output the inverse speed correction value;
A current controller for generating a current control value according to a current command of the d-axis and the q-axis;
A coordinate converter for converting the current control value into an axis coordinate value; And
A PWM generator for generating a PWM signal according to the axis coordinate value to operate the driving motor,
And a control unit for controlling the motor of the environmentally friendly automobile. The method according to claim 1,
A correction value generation unit for increasing the correction value step by step when the current command size is smaller than the reference value; And
Calculating a total loss value of the drive motor for each step by using the mechanical angular velocity of the drive motor, the d-axis and the q-axis current command, and selecting any one of the correction values for each step according to the total loss value And a correction value determination unit for determining,
The correction value generator
And fixes and outputs the correction value selected by the correction value determination unit. 3. The method of claim 2,
Wherein the correction value generator calculates the current command magnitude according to Equation (1) below.
[Equation 1]

(Where Isref is the current command magnitude, Idref is the d-axis current command, and Iqref is the q-axis current command). 3. The method of claim 2,
The correction value determination unit
An iron loss torque extracting unit for extracting an iron loss torque value from a lookup table previously stored according to the d-axis current command, the q-axis current command, and the mechanical angular speed of the drive motor;
An iron loss calculator for calculating an iron loss of the drive motor according to the mechanical angular speed of the drive motor and the iron loss torque value;
A coarse loss computing unit for computing a coarse loss of the drive motor according to the d-axis current command and the q-axis current command;
A loss calculation unit for calculating the total loss amount in accordance with iron loss and copper loss of the drive motor; And
A determination unit for comparing the total loss value of the current step with the total loss value of the immediately preceding step and selecting the correction value of the current step if the total loss value of the current step is less than the total loss value of the immediately preceding step;
And a control unit for controlling the motor of the environmentally friendly automobile. 5. The method of claim 4,
The look-
Wherein the current command magnitude and the iron loss torque value corresponding to the mechanical angular velocity of the drive motor are stored. 5. The method of claim 4,
Wherein the iron loss calculation unit calculates an iron loss of the drive motor according to the following formula (2).
&Quot; (2) "

(Where PIronloss is the iron loss of the drive motor, and Wm is the mechanical angular velocity of the drive motor). 5. The method of claim 4,
Wherein the copper loss calculation unit calculates a copper loss of the drive motor according to the following equation (3).
&Quot; (3) "

(Where Pcupperloss is the copper loss of the drive motor, Rs is the phase resistance value, and Isref is the current command magnitude). 5. The method of claim 4,
The loss-
Wherein the total loss amount is calculated by adding iron loss and copper loss of the drive motor. Generating a inverse value according to a voltage of the driving motor, a d-axis voltage command, a q-axis voltage command, and an electrical angular velocity;
Generating a d-axis current command and a q-axis current command in accordance with the torque demand command and the inverse speed correction value;
Determining whether a current command magnitude corresponding to the d-axis current command and the q-axis current command is smaller than a preset reference value;
Determining a correction value according to the mechanical angular velocity of the driving motor, the d-axis, and the q-axis current command when the current command magnitude is smaller than the reference value; And
Adding the correction value to the inverse speed value to generate the inverse speed correction value
And a control unit for controlling the motor. 10. The method of claim 9,
The step of determining the correction value
Calculating the current command magnitude;
Comparing the current command magnitude with the reference value;
If the current command magnitude is smaller than the reference value, generating the correction value step by step;
Calculating a total loss value of the drive motor for each of the steps using the mechanical angular velocity of the drive motor, the d-axis, and the q-axis current command;
Determining whether a total loss value of a current step among the plurality of steps is less than a total loss value of a previous step; And
Fixing the correction value of the current step if the total loss value of the current step is less than or equal to the total loss value of the immediately preceding step
And a control unit for controlling the motor. 11. The method of claim 10,
Wherein the current command magnitude is calculated according to the following equation (1): " (1) "
[Equation 1]

(Where Isref is the current command magnitude, Idref is the d-axis current command, and Iqref is the q-axis current command). 11. The method of claim 10,
The step of calculating the total loss value of the drive motor
Extracting an iron loss torque value from a lookup table previously stored according to the d-axis current command, the q-axis current command, and the mechanical angular velocity of the drive motor;
Calculating an iron loss of the driving motor according to the mechanical angular speed of the driving motor and the iron loss torque value;
Calculating a copper loss of the drive motor in accordance with the d-axis current command and the q-axis current command; And
Adding iron loss and copper loss of the drive motor
And a control unit for controlling the motor. 13. The method of claim 12,
Wherein the iron loss of the drive motor is calculated according to the following equation (2).
&Quot; (2) "

(Where PIronloss is the iron loss of the drive motor, and Wm is the mechanical angular velocity of the drive motor). 13. The method of claim 12,
Wherein the power loss of the drive motor is calculated according to the following equation (3).
&Quot; (3) "

(Where Pcupperloss is the copper loss of the drive motor, Rs is the phase resistance value, and Isref is the current command magnitude).

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