KR20130110555A - Motor controlling apparatus, electronic vehicle having the apparatus, and motor controlling method of the same - Google Patents

Abstract

PURPOSE: A motor control device, an electric vehicle including the same, and a motor control method thereof generate same torque with a minimum current by estimating a DC link voltage changed in real time with a value similar to an actual value. CONSTITUTION: A motor control device (200) includes a DC link capacitor (210), an inverter (230), and a control unit (250). The DC link capacitor supplies a DC voltage by being connected to a battery (100) in parallel. The inverter includes multiple switching elements, converts the DC voltage into a motor driving voltage according to control signals, and outputs the motor driving voltage to a motor. The control unit includes a DC voltage calculator. The DC voltage calculator calculates an actual DC voltage by using an open circuit voltage of the battery and a voltage drop between the battery and the inverter. The control unit generates a control signal based on a torque command and the actual DC voltage. [Reference numerals] (100) Battery; (230) Inverter; (251) DC voltage calculator; (270) Storage unit

Description

Motor control device, electric vehicle comprising the same, and motor control method thereof The present invention relates to a motor control apparatus, and an electric vehicle including the same, and a motor control method thereof.

The present invention relates to a motor control apparatus for controlling a motor by estimating a battery output voltage, an electric vehicle including the same, and a motor control method thereof.

An electric vehicle (EV) refers to a vehicle using an electric battery and an electric motor without using petroleum fuel and an engine, and an electric vehicle using only an electric battery, and other power sources such as gasoline and electric. It includes a hybrid electric vehicle that uses a battery together. An electric vehicle that drives an automobile by rotating an electric motor that is stored in a battery was manufactured earlier than a gasoline automobile in 1873, but was not put to practical use due to problems such as a heavy weight of the battery and a time required for charging. Recently, due to the lack of energy resources such as fossil fuels and environmental pollution caused by gasoline cars, it was re-developed from the 1990s.

As an electric motor for an electric vehicle, both a DC motor and an AC motor may be used, but recently, a brushless DC motor or an induction motor is used, or a modified one thereof is mainly used.

Electric cars are driven using motors and inverters, unlike cars using conventional engines. In the development of electric vehicles, it is necessary to develop a battery and a motor, as well as to develop a method for controlling a motor and a technology for a device.In a method and a device for controlling a motor of an electric vehicle, acceleration characteristics during acceleration, noise, current control, etc. Should be taken into account.

In general, electric vehicles use a minimum voltage as a DC link voltage output from a battery and generate a current command through map base control. Higher voltages can be used to supply the minimum current, but map-based control cannot provide all the maps according to the DC link voltage, resulting in a significant amount of current supplying the same torque using the minimum voltage. Can be.

In other words, in the prior art, there are too many current maps for various battery output voltages, and the control is limited due to the size of the memory. Thus, when the minimum voltage is used, excessive current may be used to generate the same torque, and loss may occur.

Embodiments of the present invention provide a motor control apparatus capable of controlling a minimum current of a motor of an electric vehicle using a battery output voltage, an electric vehicle including the same, and a motor control method thereof.

Embodiments of the present invention can linearly model the characteristics of the battery of the electric vehicle to reflect this, and accordingly estimate the DC link voltage that changes in real time to a value close to the actual value.

The motor control apparatus according to an embodiment includes a DC link capacitor connected in parallel with a battery and supplying a DC voltage, and a plurality of switching elements, and converting the DC voltage into a motor driving voltage according to a control signal and outputting the same to the motor. And a direct current voltage calculator configured to calculate an actual direct current voltage using an open circuit voltage of the battery and a voltage drop between the battery and the inverter, wherein the control signal is generated based on a torque command and the actual direct current voltage. It is configured to include a control unit to generate.

In the motor control apparatus, the control unit further comprises a speed compensator for compensating the rotational speed of the motor on the basis of the actual DC voltage and outputting a compensating rotational speed.

An electric vehicle according to an embodiment may include a motor control device including a battery supplying a DC voltage, a DC link capacitor connected in parallel to the battery, and an inverter converting the DC voltage into a motor driving voltage according to a control signal. And a motor configured to receive the motor driving voltage and to be driven by the motor control device to generate a rotational force, wherein the motor control device calculates an actual DC voltage actually input to the inverter by using the characteristic information of the battery. And a control unit generating a current command for the motor by using the actual DC voltage and torque command and the rotational speed of the motor.

In the electric vehicle, the control unit includes a DC voltage calculator for calculating the actual DC voltage using the open circuit voltage of the battery and the voltage drop between the battery and the inverter, and the rotation based on the actual DC voltage. A speed compensator for compensating the speed and outputting a compensating rotational speed, and a current command generator for receiving the torque command and the compensating rotational speed and generating the current command using the relationship between the torque command, the rotational speed, and the current command. It is configured to include.

Motor control method of an electric vehicle according to an embodiment of the present invention, a motor of an electric vehicle including a DC link capacitor connected in parallel to the battery to supply a DC voltage, and an inverter converting the DC voltage into a motor driving voltage and output to the motor The control method includes receiving a torque command, calculating an actual DC voltage using an open circuit voltage of the battery, and a voltage drop between the battery and the inverter, and based on the calculated actual DC voltage. Compensating for the rotational speed of the motor, generating a current command using the torque command and the compensating rotational speed, generating a voltage command based on the current command, and based on the voltage command. Generating a control signal for and outputting the control signal to the inverter.

Embodiments of the present invention linearly model the characteristics of a battery of an electric vehicle to reflect this, and accordingly estimate the DC link voltage that changes in real time to a value close to the actual value to estimate the estimated voltage, not the minimum voltage, when a current command is generated. Can be used and the minimum current to determine the same torque can be determined.

Embodiments of the present invention can minimize losses such as switching loss by using the minimum current to generate the same torque when performing map-based control in controlling the motor of the electric vehicle, Improve system stability

1 is a schematic view of an electric vehicle according to embodiments of the present invention;
2 is a block diagram schematically showing the configuration of a motor control apparatus according to embodiments of the present invention;
FIG. 3 schematically shows a motor control device with means for detecting the speed of the rotor in FIG. 2; FIG.
4 schematically shows a motor control device with means for detecting the position of the rotor in FIG. 2;
FIG. 5 is a schematic view of a sensorless motor control device in FIG. 2; FIG.
6 is a graph for explaining an operation of estimating a battery output voltage according to a characteristic of a battery;
7 illustrates a configuration of a current command generator in accordance with embodiments of the present invention;
8 is a graph illustrating a changed driving point according to embodiments of the present invention;
9 shows schematically a motor control apparatus with means for detecting a battery output voltage; And
10 is a flowchart schematically illustrating a method of controlling a motor of an electric vehicle according to an exemplary embodiment.

Referring to FIG. 1, an electric vehicle according to an embodiment of the present invention may include a battery module 100 that supplies DC power and a power module that converts DC power supplied by the battery 100 into AC power to generate rotational force. 150, a front wheel 510 and a rear wheel 520 rotated by the power module 150, and a front wheel suspension 610 and a rear wheel suspension 620 that block vibration of the road surface from being transmitted to the vehicle body. In addition, the electric vehicle may further include a drive gear (not shown) for converting the rotational speed of the motor 300 according to the gear ratio.

The power module 150 includes a motor control device 200 that receives a DC power from the battery 100, and a motor 300 that is driven by the motor control device 200 to generate rotational force.

The battery 100 supplies DC power to the power module 150. The battery 100 generally forms a set in which a plurality of unit cells are connected in series and / or in parallel. The plurality of unit cells are managed to maintain a constant voltage by a battery management system (BMS). That is, the battery management system causes the battery 100 to emit a constant voltage. The battery 100 is preferably configured as a secondary battery capable of charging and discharging, but is not limited thereto. As the battery 100, a nickel metal hydride (Ni-MH) battery or a lithium ion (Li-ion) battery is generally used.

The motor control apparatus 200 receives DC power from the battery 100. The motor control apparatus 200 converts the DC power received from the battery 100 into AC power and supplies the same to the motor 300. In general, the motor control device 200 supplies a three-phase AC power to the motor.

The motor 300 is composed of a stator (not shown) that is fixed without rotation, and a rotating rotor (not shown), and generates a rotational force by receiving AC power supplied from the motor control apparatus 200. When AC power is applied to the motor 300, the stator of the motor 300 receives AC power to generate a magnetic field. In the case of a motor having a permanent magnet, the rotor rotates due to the repulsion of the magnetic field generated by the stator and the magnetic field of the permanent magnet provided in the rotor. The rotational force is generated by the rotation of the rotor.

One side of the motor 300 may be provided with a drive gear (not shown). The drive gear converts the rotational force of the motor 300 according to the gear ratio. The rotational force output from the drive gear is transmitted to the front wheel 510 and / or the rear wheel 520 to allow the vehicle to move.

The front wheel suspension 610 and the rear wheel suspension 620 support the front wheel 510 and the rear wheel 520 with respect to the vehicle body, respectively. The front wheel suspension 610 and the rear wheel suspension 620 prevent the vibration of the road surface from touching the vehicle body by a spring or a damping mechanism.

The front wheel 510 may be further provided with a steering device (not shown). The steering device is a device for adjusting the direction of the front wheel 510 to drive the vehicle in the direction intended by the driver.

Referring to FIG. 2, the motor control apparatus according to the present invention includes a DC link capacitor 210 for smoothing and storing an output voltage of the battery 100 and a plurality of switching elements. The inverter 230 converts the DC voltage output from the link capacitor into the motor driving voltage and outputs the motor driving voltage to the motor, and the current according to the torque command and the magnetic flux command using the proportional gain and the integral gain determined based on the rotor speed of the motor. And a control unit 250 for converting the command into a voltage command and generating the control signal based on the converted voltage command and outputting the control signal to the inverter.

The DC link capacitor 210 is provided between the battery 100 and the inverter 230 or between the converter and the inverter when a converter to be described later is provided. The DC link capacitor smoothes and stores the output voltage of the battery 100. The DC link capacitor 210 may also smooth the DC voltage boosted through the converter.

The inverter 230 includes a plurality of switching elements, and applies a motor driving current according to a voltage command to the motor using a control signal generated from the control unit 250, for example, a PWM driving signal.

The motor control apparatus may further include a converter for boosting or stepping down the DC voltage supplied from the battery 100. The converter is provided with a switching element, for example an Insulated Gate Bipolar Transistor (IGBT) (IGBT), and further includes a reactor if necessary. The converter is connected to the battery 100 and is a boost converter for boosting a voltage between a ground line and a power line, that is, a DC voltage generated by the battery 100, or configured to be stepped down as necessary.

Referring to FIG. 2, the control unit 250 calculates an actual DC voltage using an open circuit voltage of the battery 100 and a voltage drop between the battery 100 and the inverter 230. And 251.

The DC voltage calculator 251 may use the graph of FIG. 6. In other words, the DC voltage calculator linearly models the characteristics of the battery that powers the electric vehicle. The DC voltage calculator uses the open circuit voltage (OCV) of the battery and the voltage drop between the battery and the inverter, i.e., I * R _BAT, to determine the actual battery output voltage (the voltage across the DC link capacitor, V _BAT can be calculated. At this time, the open circuit voltage of the battery, the resistance R _BAT , the voltage drop according to the resistance, and the actual DC voltage are different depending on the state of charge (SOC) of the battery, as shown in FIG. 6.

3 to 5, the control unit 250 further includes a speed compensator 252 for compensating the rotational speed of the motor based on the actual DC voltage and outputting a compensating rotational speed.

The speed compensator 252 may calculate the compensation rotation speed ω ₂ by, for example, the following equation.

Here, ω ₁ is the actual rotation speed, V _BAT is the actual DC voltage, V _{BAT , MAP} is the reference map data voltage. The reference map data voltage means, for example, a voltage set to a direct current voltage when the SOC is 50%. K is a proportionality constant.

The control unit 250 further includes a current command generator 253 that receives the torque command and the compensation rotation speed and generates a current command using the relationship between the torque command, the rotation speed, and the current command.

The current command generator 253 generates and outputs a current command using map data based on the torque command T ^* _e and the rotation speed. In this case, as the rotation speed, a compensation rotation speed that has passed through the speed compensator 252 is used. The current command generator 253 may include a comparator and a proportional integral controller. In this case, as illustrated in FIG. 2, the motor control apparatus 200 may further include a storage unit 270 that stores the relationship between the torque command, the rotation speed, and the current command as map data. The storage unit 270 stores the relationship between the torque command, rotational speed and current command as map data.

Referring to FIG. 8, the current command generator 253 generates a current command in consideration of the variation of the battery output voltage of the electric vehicle, that is, the actual DC voltage. As shown in FIG. 8, when the minimum voltage limit value V ₁ is used, the operating point is at C ₁ or C ₂ , but the actual DC voltage calculated by the DC voltage calculator 251. Based on this, the operating point is either B ₁ or B ₂ . In FIG. 8, the voltage limit value V ₂ is greater than V ₁ . That is, the motor control apparatus 200 moves the voltage limit value for the motor driving voltage to a value V ₂ greater than the minimum voltage limit value V ₁ for the same torque command using the actual DC voltage. Let's do it. Accordingly, since the vector distance from the operating point, the size of the current command with respect to the same torque curve (Equivalent Torque Curve), is shorter that the distance away from above the operating point B ₁ to the operating point C ₁ from the origin (O) at least Current can be used.

The control unit 250 further includes a current controller 254 that receives the current command and generates a voltage command based on the current command. The current controller 254 receives the q-axis current command i ^* _q and the d-axis current command i ^* _d to generate and output a voltage command.

The current controller generates the q-axis voltage command (V ^* _q ) through the proportional integral controller and the filter. The current controller compares the q-axis current command and the q-axis detection current (i _q ) obtained by axially converting the motor drive current, and compares the difference, that is, the current error, through the proportional integral controller and the filter with the q-axis voltage command (V ^* _q ). Create and print

On the other hand, the current controller generates the d-axis current command V ^* _d through the proportional integral controller and the filter. That is, the current controller compares the d-axis current command and the d-axis detection current i _{d obtained} by axially converting the motor drive current, and compares the difference, that is, the current error, through the proportional integral controller and the filter with the d-axis voltage command (V ^*). Create and print _d ).

The control unit 250 further includes a control signal generator 255 that receives the voltage command, generates the control signal, and outputs the control signal to the inverter.

The control signal generator 255 generally converts the voltage command of the synchronous coordinate system into the voltage command of the still coordinate system (α, β). That is, the control signal generator converts (V ^* _d , V ^* _q ) into (V ^* _α , V ^* _β ). In addition, the control signal generator converts and outputs the voltage command of the stationary coordinate system according to the type of the motor to be driven. If an electric vehicle uses a three-phase motor, such as a three-phase induction motor, a three-phase BLDC, for example, the control signal generator uses the three-phase voltage reference (V ^* _a , V ^* _b , V ^* _c) for the stationary coordinate system. ) Is output to the inverter 230.

Referring to FIG. 3, the motor control apparatus further includes a speed detecting unit 710 provided or connected to the motor to detect a rotational speed of the motor.

Referring to FIG. 4, the motor control apparatus further includes a position detecting unit 720 provided or connected to the motor to detect a position of the rotor. In this case, the control unit 250 may further include a speed calculator 256 that calculates the rotor speed from the detected position of the rotor.

The motor control apparatus detects and feeds back the position and speed of the motor 300 using the speed detecting unit 710 or the position detecting unit 720 to control the motor 300. As a method of measuring the position and speed of the motor 300, there are a method using an analog sensor and a method using a digital sensor. The analog measuring apparatus is a synchro, a resolver, a taco-generator, or the like, and measures a position and a speed from a displacement amount of the rotor converted into an analog amount. The digital measuring device is a rotary encoder or the like, and measures the position and velocity from the displacement amount converted into a digital form. In an induction motor, for example, the position of the rotor is detected using a digital encoder. In this case, the motor control apparatus should further include an algorithm for determining an initial position. The encoder is a device for outputting a change in the rotation angle of the rotor in a pulse train (Pulse Train). The pulse train has a frequency that varies in proportion to the rotational speed of the rotor. Types of the encoder include an absolute encoder and an incremental encoder, the absolute encoder can detect the absolute position information of the rotor, the incremental encoder can detect only the change of the rotor. On the other hand, in a BLDC (Blush-Less DC) motor, the position of the rotor must be known in order to implement the functions of the commutator and the brush as a power semiconductor switch. Since the rotor is a permanent magnet, the rotor is located using a magnetic flux detection sensor such as a Hall element.

Referring to FIG. 5, the motor control device further includes a current detection unit 260 that detects a motor driving current applied to the motor. At this time, the control unit 250 estimates the position of the rotor based on the motor drive current, and calculates the rotational speed of the motor from the estimated position of the rotor. The current detection unit 260 is connected between the inverter 230 and the motor 300 to detect the motor driving current of each phase. The current detection unit 260 generally uses a current transducer that continuously detects the motor driving current. The current transducer detects the motor driving current, converts it into a voltage signal, and outputs the converted voltage signal to the control unit 250. For example, in the case of a three-phase motor, the current detection unit 260 detects all of the currents (ia, ib, ic) applied in three phases, or detects only two phases (ia, ib) of the ic. After calculation, it is output to the control unit 250. The control unit 250 generates an interrupt signal to sample a voltage signal according to the detected motor driving current. In this case, the motor control apparatus includes a sensorless algorithm, and the control unit 250 further includes a speed calculator 257 for estimating the rotor position and the rotation speed to use the estimated position or speed of the rotor. To drive the motor. This is useful in the case of not including the position detecting unit or the speed detecting unit due to the difficulty in mounting.

9 is a block diagram schematically illustrating a configuration of an electric vehicle according to another embodiment. Referring to FIG. 9, the electric vehicle according to another embodiment generates a rotational force by converting the battery 100 supplying the DC power and the DC power supplied by the battery 100 to the AC power as in the embodiment. Power module 150, the front wheel 510 and the rear wheel 520 rotated by the power module 150, the front wheel suspension 610 and rear wheel suspension 620 to block the vibration of the road surface to the vehicle body It includes. The power module 150 includes a motor control device 200 that receives a DC power from the battery 100, and a motor 300 that is driven by the motor control device 200 to generate rotational force. Here, the motor control apparatus includes a DC voltage detection unit 800 provided in the DC link capacitor 210 to detect the battery output voltage, that is, the actual DC voltage.

That is, in the case of FIG. 9, unlike the case of FIGS. 1 to 8, the actual DC voltage is detected without estimating the actual DC voltage, and speed compensation and current command generation are performed using the detected DC voltage.

Referring to FIG. 10, a method for controlling a motor of an electric vehicle according to an embodiment includes a DC link capacitor connected in parallel with a battery to supply a DC voltage, and an inverter converting the DC voltage into a motor driving voltage and outputting the motor to a motor. The motor control method of an electric vehicle includes a step of receiving a torque command (S10), and calculating an actual DC voltage by using an open circuit voltage of the battery and a voltage drop between the battery and the inverter (S20). Compensating for the rotational speed of the motor based on the calculated actual DC voltage (S30), generating a current command using the torque command and the compensating rotational speed (S40), and performing the current command. Generating a voltage command on the basis of the step S50, generating a control signal for the inverter based on the voltage command, and outputting the control signal to the inverter; It is configured to include a system (S60). Hereinafter, the configuration of the apparatus will be described with reference to FIGS. 1 to 8.

The motor control method may further include storing, as map data, a relationship between a torque command, a rotation speed, and a current command. In this case, in the generating of the current command (S40), the current command is generated using the map data.

The motor control apparatus may estimate the actual DC voltage using the graph of FIG. 6. That is, the motor control device linearly models the characteristics of the battery that powers the electric vehicle. For example, the motor control device is open circuit voltage of a battery; applied to the voltage drop, that is, the actual battery output voltage (the DC link capacitor using the I * R _BAT occurring between the (Open Circuit Voltage OCV), the battery and the inverter Voltage, hereinafter referred to as 'actual DC voltage') V _BAT can be calculated (S20). At this time, the open circuit voltage of the battery, the resistance R _BAT , the voltage drop according to the resistance, and the actual DC voltage are different depending on the state of charge (SOC) of the battery, as shown in FIG. 6. Moreover, the motor control apparatus calculates the compensation rotation speed using the actual DC voltage and the detected or calculated rotation speed (S30).

The motor control apparatus receives the torque command and the compensation rotation speed, and generates a current command using the relationship between the torque command, the rotation speed, and the current command (S40). The motor controller generates and outputs a current command based on the torque command T ^* _e and the rotational speed, and using map data. At this time, as the rotation speed, the compensation rotation speed calculated in the step S30 is used. In this case, the motor control apparatus may generate the current command using the relationship between the torque command, the rotation speed, and the current command stored as map data. As shown in FIG. 8, when the minimum voltage limit value V ₁ is used, the operating point is at C ₁ or C ₂ , but the operating point is B ₁ based on the actual DC voltage. Or B ₂ . In FIG. 8, the voltage limit value V ₂ is greater than V ₁ . That is, the motor control device moves the voltage limit value for the motor drive voltage to a value V ₂ greater than the minimum voltage limit value V ₁ for the same torque command using the actual DC voltage. Accordingly, since the vector distance from the operating point, the size of the current command with respect to the same torque curve (Equivalent Torque Curve), is shorter that the distance away from above the operating point B ₁ to the operating point C ₁ from the origin (O) at least Current can be used.

The motor control apparatus receives the q-axis current command (i ^* _q ) and the d-axis current command (i ^* _d ) to generate and output a voltage command (S50). The motor control device generates the q-axis voltage command (V ^* _q ) through the q-axis current command through a proportional integral controller and a filter. The motor controller compares the q-axis detected current, converts the q-axis current command and the motor drive current axis (i _q), and, the q-axis voltage command through its car, that a proportional integral controller and filters a current error (V ^* _q ). In addition, the motor control device generates the d-axis current command V ^* _d through the proportional integration controller and the filter. That is, the motor controller compares the d-axis current command and the d-axis detection current i _{d obtained} by axially converting the motor drive current, and compares the difference, that is, the current error, through the proportional integration controller and the filter to the d-axis voltage command ( V ^* _d ) is generated (S50).

Then, the motor control device converts the voltage command of the synchronous coordinate system into the voltage command of the still coordinate systems α and β, and converts and outputs the voltage command of the stationary coordinate system according to the type of the motor to be driven. If an electric vehicle uses a three-phase motor, such as a three-phase induction motor, a three-phase BLDC, for example, the control signal generator uses the three-phase voltage reference (V ^* _a , V ^* _b , V ^* _c) for the stationary coordinate system. ) And output to the inverter. The switching elements in the inverter are driven according to the control signal (S60).

As described above, the motor control apparatus according to the embodiments of the present invention, an electric vehicle including the same, and a motor control method thereof include linearly modeling characteristics of a battery of the electric vehicle, reflecting them, and changing them in real time. By estimating the DC link voltage to a value close to the actual value, it is possible to use the estimated voltage rather than the minimum voltage when generating the current command, and determine the minimum current to generate the same torque. Embodiments of the present invention can minimize losses such as switching loss by using a minimum current to generate the same torque when performing the map-based control in controlling the motor of the electric vehicle.

100: battery 110: converter
200: motor control device 210: DC link capacitor
230: inverter 250: control unit
260: current detection unit 270: storage unit
300: motor 710: speed detection unit
720: position detection unit 800: DC voltage detection unit

Claims (14)

A DC link capacitor connected in parallel to the battery and supplying a DC voltage;
An inverter having a plurality of switching elements and converting the DC voltage into a motor driving voltage according to a control signal and outputting the same to a motor; And
A control unit having a direct current voltage of the battery and a direct current voltage calculator for calculating an actual direct current voltage using the voltage drop between the battery and the inverter, the control unit generating the control signal based on the torque command and the actual direct current voltage; Motor control device comprising a. The method of claim 1, wherein the control unit,
And a speed compensator for compensating the rotational speed of the motor based on the actual DC voltage and outputting a compensating rotational speed. 3. The apparatus according to claim 2,
A current command generator which receives the torque command and the compensation rotation speed and generates a current command using a relationship between the torque command, the rotation speed, and the current command;
A current controller which receives the current command and generates a voltage command based on the current command; And
And a control signal generator for receiving the voltage command and generating the control signal and outputting the control signal to the inverter. The method of claim 3,
And a storage unit that stores the relationship between the torque command, rotational speed, and current command as map data. 5. The method according to any one of claims 1 to 4,
And the voltage limit value for the motor drive voltage is moved to a value greater than the minimum voltage limit value for the same torque command using the actual DC voltage. 5. The method according to any one of claims 1 to 4,
And a speed detecting unit detecting the rotation speed. The method of claim 6,
And a current detection unit detecting a motor driving current applied to the motor.
And the control unit calculates the rotational speed based on the motor drive current. A battery for supplying a DC voltage;
A motor control device including a DC link capacitor connected in parallel to the battery and an inverter converting the DC voltage into a motor driving voltage according to a control signal; And
And a motor that receives the motor driving voltage and is driven by the motor control device to generate a rotational force.
The motor control device includes:
A control unit for calculating an actual DC voltage actually input to the inverter by using the characteristic information of the battery, and generating a current command for the motor using the actual DC voltage and torque command and the rotational speed of the motor; An electric vehicle further comprising a. The method of claim 8, wherein the control unit,
A direct current voltage calculator configured to calculate the actual direct current voltage using an open circuit voltage of the battery and a voltage drop between the battery and the inverter;
A speed compensator for compensating the rotation speed based on the actual DC voltage and outputting a compensation rotation speed; And
And a current command generator which receives the torque command and the compensation rotation speed and generates the current command using a relationship between the torque command, the rotation speed, and the current command. The method of claim 9, wherein the control unit,
A current controller which receives the current command and generates a voltage command based on the current command; And
And a control signal generator for receiving the voltage command and generating the control signal and outputting the control signal to the inverter. The method of claim 10, wherein the motor control device,
And a storage unit that stores the relationship between the torque command, rotational speed, and current command as map data. The motor control device according to any one of claims 8 to 11, wherein
And the voltage limit value for the motor drive voltage is moved to a value greater than the minimum voltage limit value for the same torque command using the actual DC voltage. In a motor control method of an electric vehicle comprising a DC link capacitor connected in parallel to a battery to supply a DC voltage, and an inverter converting the DC voltage into a motor driving voltage and outputting the same to a motor.
Receiving a torque command;
Calculating an actual direct current voltage using the open circuit voltage of the battery and the voltage drop between the battery and the inverter;
Compensating for the rotational speed of the motor based on the calculated actual DC voltage;
Generating a current command using the torque command and a compensation rotation speed;
Generating a voltage command based on the current command; And
Generating a control signal for the inverter based on the voltage command, and outputting the control signal to the inverter. The method of claim 13,
And storing the relationship between the torque command, rotational speed, and current command as map data.
The generating of the current command may include generating the current command using the map data.

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