KR101284334B1 - System and method for motor control of electric vehicle - Google Patents

Abstract

Disclosed are a motor control system of an electric vehicle and a method thereof.
In the system for controlling a motor of an electric vehicle according to an embodiment of the present invention, a vehicle speed calculation unit for calculating the speed of the electric vehicle from the number of revolutions of the motor and a pedal detection unit for detecting a brake pedal operation signal input from the driver And a motor controller for applying an excitation current to the motor to secure torque response while driving the electric vehicle, and a speed and a brake pedal operating signal of the electric vehicle, respectively, when compared with a preset corresponding stop condition. And a vehicle controller for transmitting a motor excitation current off command (MOT PWM OFF) for interrupting the excitation current to the motor controller.

Description

Motor control system of electric vehicle and its method {SYSTEM AND METHOD FOR MOTOR CONTROL OF ELECTRIC VEHICLE}

The present invention relates to a motor control system and method thereof for an electric vehicle.

In general, a hybrid electric vehicle (HEV) refers to a vehicle driven by efficiently combining two or more different power sources in a broad sense.

Hybrid cars use the optimum operating area of the engine and electric motor to improve the fuel economy of the entire drive system and to recover energy from the electric motor to charge high voltage batteries, thus enabling efficient use of energy.

In addition, a fuel cell vehicle, which is a hybrid vehicle of another type, generates electricity by supplying hydrogen to a fuel cell, and refers to a vehicle driven by driving a motor with electricity generated by the fuel cell.

In addition, an electric vehicle (EV) refers to a vehicle that drives an electric motor to operate a motor with energy accumulated in a high voltage battery.

Hereinafter, since the hybrid vehicle, the fuel cell vehicle, and the electric vehicle all have a common point for driving a motor by using electric energy, they are called an electric vehicle.

On the other hand, Figure 1 is a view for explaining the problem according to the prior art, a graph showing a state in which the motor current is applied when the stop in order to ensure the response in the electric vehicle according to the prior art.

Referring to FIG. 1, a motor control unit of an electric vehicle widely uses MTPA (Max Torque Per Ampere) control for the purpose of reducing the stir of a stator when controlling a vector of an induction motor.

As shown in FIG. 1, the loss is generated at low load by applying the d-axis current in advance to secure the response and control stability. have.

In other words, the vehicle controller (VCU) of the electric vehicle to reduce the response through the gentle torque control to prevent the vehicle shock (MCU) is a contradictory situation to increase the response caused the energy consumption There is a problem.

Patent Document 1: Korean Patent Publication No. 2009-0055070 (2009.06.02.published)

Accordingly, an object of the present invention is to provide a motor control system and method for preventing unnecessary energy loss of an electric vehicle.

In order to solve the above technical problem, according to an embodiment of the present invention, a system for controlling a motor of an electric vehicle,

A vehicle speed calculator configured to calculate a speed of the electric vehicle from the rotation speed of the motor; A pedal detecting unit detecting a brake pedal operation signal input from a driver; A motor controller configured to apply an exciting current to the motor to secure torque response while driving the electric vehicle; And when it is determined that the vehicle is stopped by comparing the speed and brake pedal operation signals of the electric vehicle with a corresponding stop condition set in advance, a motor excitation current off command (MOT PWM OFF) for interrupting the excitation current is transmitted to the motor controller. And a vehicle controller.

A vehicle speed calculator configured to calculate a vehicle speed from a rotation speed of the motor; A pedal detecting unit detecting a brake pedal operation signal input from a driver; A motor controller configured to apply an exciting current to the motor to secure torque response while driving the electric vehicle; And a motor excitation current off command (MOT PWM OFF) for blocking the excitation current applied to the motor to the motor controller when it is determined that the vehicle speed and the brake pedal operation signal are stopped by comparing with each preset stop condition. A vehicle controller for transmitting.

The motor controller may stop the motor by turning off the Insulated Gate Bipolar Transistor (IGBT) when the motor excitation current off command is received from the vehicle controller.

The vehicle controller may further include a signal collection module configured to collect the vehicle speed and the brake pedal operating signal; A stop condition determining module that determines that the first stop condition is satisfied when the vehicle speed is equal to or lower than a set reference speed, and that the second stop condition is satisfied when the brake pedal operation signal exceeds a set braking reference value; A stop condition maintaining counter for counting a time at which both the first stop condition and the second stop condition are satisfied and generating a stop event signal when the counted time exceeds a set stop condition holding time; A communication unit which transmits a command for controlling the motor to the motor controller through CAN communication; And a control module configured to generate the motor excitation current off command and transmit the command through the communication unit when the stop event signal is received.

The control module may generate a motor excitation current command (MOT PWM ON) to the motor controller when one of the vehicle speed and the brake pedal operation signal does not satisfy the stop condition after the motor is stopped. Can transmit

The brake pedal operation signal may be any one of the brake pedal angle, the brake pedal shaft, and a push rod movement signal.

Further, the signal collection module further collects a position signal of the shift lever input by the driver, and the stop condition determination module is configured to select the shift lever position signal at either the N stage (neutral) or the P stage (parking). In this case, it may be determined that the third stop condition is satisfied.

The stop condition maintenance counter stops the electric vehicle when the first stop condition, the second stop condition, and the third stop condition are cross checked to satisfy two or more stop conditions. You can judge that it is in progress.

On the other hand, the vehicle controller of the motor control system of the electric vehicle according to an embodiment of the present invention to control the motor,

a) collecting vehicle speed and brake pedal actuation signals of the electric vehicle; b) comparing the vehicle speed and the brake pedal operation signal with each preset stop condition and determining that the vehicle is stopped; And c) stopping the motor by transmitting a motor excitation current off command (MOT PWM OFF) for blocking the excitation current applied to the motor to the motor controller for controlling the motor torque.

Also, the step b) may include b-1) collecting the vehicle speed and determining that the first stop condition is satisfied when the vehicle is less than or equal to a set reference speed; b-2) the vehicle controller determining that the second stop condition is satisfied when the brake pedal operation signal exceeds a set braking reference value; And b-3) counting a time when both the first stop condition and the second stop condition are satisfied and determining that the vehicle is stopped when the set stop condition holding time is exceeded.

In addition, after step c), if any one of the vehicle speed and the brake pedal operation signal does not satisfy a corresponding stop condition, a motor excitation current ON command (MOT PWM ON) is transmitted to the motor controller to drive the motor. It may further comprise the step.

Further, between the step b-2) and the step b-3), when the position signal of the shift lever is collected and the shift lever position signal is at either the N stage (neutral) or the P stage (parking), a third The method may further include determining that the stop condition is satisfied.

Also, in the step b-3), when the time for satisfying two or more stop conditions by cross checking the first stop condition, the second stop condition, and the third stop condition exceeds the stop condition holding time, it is determined that the vehicle is stopped. can do.

According to the embodiment of the present invention by the above-described configuration, by controlling the exciting current of the motor in accordance with the stop condition of the electric vehicle has the effect of preventing unnecessary energy loss issued during the stop.

By cross-checking various stop conditions of the electric vehicle to determine the driver's willingness to stop (zero required torque), it is possible to secure responsiveness for torque control while driving.

In addition, when the stop time is increased in an extreme urban congestion section such as a large city, it is expected to increase the driving distance higher than the existing.

1 is a graph illustrating a state in which a motor current is applied when stopping to secure responsiveness in an electric vehicle according to the related art.
2 is a block diagram schematically illustrating a configuration of a motor control system of an electric vehicle according to an exemplary embodiment of the present invention.
3 is a block diagram showing a detailed configuration of a motor controller according to an embodiment of the present invention.
4 is a flowchart illustrating a motor control method according to a stop condition of an electric vehicle according to a first embodiment of the present invention.
5 is a flowchart illustrating a motor control method according to a stop condition of an electric vehicle according to a second exemplary embodiment of the present invention.
6 is a graph showing a result of running a driving experiment using the motor control of the electric vehicle according to an embodiment of the present invention.

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. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

Throughout the specification, the stop refers to a state in which the vehicle is stopped due to traffic congestion or signal waiting, and the stop condition refers to various conditions in which the vehicle is stopped and the driver's stop will, such as zero torque. .

Now, a motor control system and method thereof for an electric vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram schematically illustrating a configuration of a motor control system of an electric vehicle according to an exemplary embodiment of the present invention.

Referring to FIG. 2, a motor control system according to an exemplary embodiment of the present invention includes a vehicle speed calculator 110, a pedal detector 120, a shift detector 130, and a vehicle control unit (VCU) ( 140, a motor controller 150, and a motor 160.

The vehicle speed calculator 110 calculates the speed of the vehicle from the rotation speed of the motor 160 and transmits the speed of the vehicle to the vehicle controller 140.

The pedal detector 120 detects a brake pedal operation signal input from the driver and transmits the brake pedal operation signal to the vehicle controller 140. Here, the brake operation signal may be a brake pedal angle or a movement signal of the shaft or push rod of the brake pedal.

The shift detecting unit 130 detects that the position of the transmission gear shift lever is located at any one of the R stage, the N stage, the D stage, and the P stage, and transmits it to the vehicle controller 140.

The vehicle controller 140 is responsible for the overall control of the electric vehicle.

The vehicle controller 140 determines a stop condition of the electric vehicle and transmits a command to cut off the supply of the excitation current to the motor 160 when the vehicle is stopped.

3 is a block diagram showing a detailed configuration of a motor controller according to an embodiment of the present invention.

Referring to FIG. 3, the vehicle controller 140 according to an embodiment of the present invention may include a signal collection module 141, a stop condition determination module 142, a stop condition maintenance counter 143, a communication module 144, and the like. Control module 145.

The signal collection module 141 collects a vehicle speed, a brake pedal operation signal, and a shift lever position signal from the vehicle speed calculator 110, the pedal detector 120, and the shift detector 130.

The stop condition determination module 142 determines that the stop condition (hereinafter, referred to as a first stop condition) is satisfied when the vehicle speed collected from the vehicle speed calculator 110 is equal to or less than a predetermined reference speed.

In addition, the stop condition determination module 142 determines that the stop condition (hereinafter, referred to as a second stop condition) is satisfied when the brake pedal operation signal collected from the pedal detector 120 exceeds a preset braking reference value. do. Here, when the brake pedal operation signal exceeds the braking reference value means that the required torque of the driver is zero.

The stop condition maintaining counter 143 counts a time from a state in which both the first stop condition and the second stop condition are satisfied by the vehicle speed and the brake pedal operation signal, so that the counted time exceeds the preset stop condition hold time. Then, the vehicle transmits a stop event signal indicating that the vehicle is stopped to the control module 145.

The communication module 144 transmits a command for controlling the motor to the motor controller 150 through CAN communication.

When the control module 145 receives the stop event signal from the stop condition maintenance counter 143, the control module 145 generates a motor excitation current OFF command (MOT PWM OFF) and transmits the generated motor to the motor controller 150. After the motor 160 is stopped, the control module 145 generates a motor excitation current on command (MOT PWM ON) if one of the vehicle speed and the brake pedal operation signal does not satisfy the stop condition. 150).

The motor controller 150 applies an excitation current to the motor 160 in order to ensure responsiveness while the electric vehicle is driven according to the command of the vehicle controller 140. For example, in the case where the electric vehicle slows down or stops standing on a congested road, an excitation current may be applied to secure an anti-Jerk control and acceleration response.

On the other hand, when the motor controller 150 receives the excitation current off command (MOT PWM OFF) according to the stop of the electric vehicle from the vehicle controller 140, all of the IGBTs (OFF) are turned off (OFF) to the motor 160. To stop.

The motor 160 may be configured as a three-phase induction motor, and driven under the control of the motor controller 150 to adjust the output torque and perform regenerative braking with a regenerative braking amount determined at deceleration.

General control operation in the motor control system 100 of the electric vehicle according to an embodiment of the present invention including the function as described above is made the same or similar to the hybrid vehicle and the electric vehicle, so the description of the operation thereof will be omitted. Only the configuration necessary for motor control according to the determination of the stop condition is described.

Meanwhile, a motor control method of an electric vehicle according to an embodiment of the present invention will be described with reference to FIGS. 4 and 5.

4 is a flowchart illustrating a motor control method according to a stop condition of an electric vehicle according to a first embodiment of the present invention.

Referring to FIG. 4, the vehicle controller 140 of the motor control system 100 according to the first embodiment of the present invention operates the vehicle speed and the brake pedal from the vehicle speed calculator 110 and the pedal detector 120. Collect the signal (S101).

The vehicle controller 140 determines that the first stop condition is satisfied when the vehicle speed collected from the vehicle speed calculator 110 is less than or equal to a predetermined reference speed (S102; YES).

In addition, the vehicle controller 140 determines that the second stop condition is satisfied when the brake pedal operation signal collected from the pedal sensing unit 120 exceeds a preset braking reference value (S103; YES).

The vehicle controller 140 counts a time at which both the first and second stop conditions satisfy AND, and determines whether the counted time satisfies the set stop condition holding time (S104).

At this time, when the counted time exceeds the set stop condition holding time, the vehicle controller 140 determines that the stop condition holding time is satisfied (S104; YES), and generates a motor exciting current off command (MOT PWM OFF). It generates and transmits to the motor controller 150 (S105).

When the motor controller 150 receives the motor excitation current off command (MOT PWM OFF) from the vehicle controller 140, all of the IGBTs are turned off to stop the motor 160 (S106). That is, the motor 160 is stopped while the vehicle is stopped without applying an exciting current.

On the other hand, if it is determined that the stop condition is not satisfied in any one of the steps S102, S103, and S104 (S102, S103, S104; No), the vehicle controller 140 generates a motor excitation current on command (MOT PWM ON). ) Is generated and transmitted to the motor controller 150 (S107).

Then, the motor controller 150 applies a current according to the motor excitation current on command (MOT PWM ON) received from the vehicle controller 140 to operate the motor (S108).

5 is a flowchart illustrating a motor control method according to a stop condition of an electric vehicle according to a second exemplary embodiment of the present invention.

Referring to FIG. 5, the motor control method according to the stopping condition of the electric vehicle according to the second embodiment of the present invention is similar to the first embodiment, and the shift detection unit 130 shifts to determine the stopping condition. The difference in determining the stop condition is further considered by lever position signals.

That is, the vehicle controller 140 of the motor control system 100 further collects the shift lever position signal from the shift detection unit 130 as well as the vehicle speed and brake pedal operation signal (S201).

The vehicle controller 140 determines whether the collected vehicle speed or the brake pedal operation signal satisfies any one of the first and second stop conditions (S202).

At this time, if any one of the first and second stop condition is satisfied (S202; Yes), the stop condition determination module 142 of the vehicle controller 140 is collected from the shift detection unit 130 When the shift lever position signal is in either the N stage or the P stage, it is determined that the stopping condition (hereinafter referred to as the third stopping condition) is satisfied (S203; YES). Here, the shift lever positions located at the N stage and the P stage mean that the required torque according to the driver's will is zero.

The vehicle controller 140 determines whether the set stop condition holding time is satisfied by counting a time when at least one of the first stop condition and the second stop condition satisfies the third stop condition (S204).

That is, according to the second embodiment of the present disclosure, when the vehicle controller 140 cross-checks the first stop condition, the second stop condition, and the third stop condition to satisfy a plurality of stop conditions for a predetermined time, the driver stops the vehicle. You can judge the will.

Subsequently, the steps S205 to S208 of the vehicle controller 140 generating the motor excitation current off command (MOT PWM OFF) and transmitting it to the motor controller 150 are the same as the steps S105 to S108 of the first embodiment. Omit.

Thus, according to the embodiment of the present invention, by controlling the excitation current of the motor in accordance with the stop condition of the electric vehicle has the effect of preventing unnecessary energy loss issued during the stop.

In addition, by cross-checking various stop conditions of the electric vehicle to determine the driver's willingness (zero required torque), there is an effect of ensuring the responsiveness for torque control while driving.

On the other hand, Figure 6 is a graph showing the results of the driving experiment using the motor control of the electric vehicle according to an embodiment of the present invention.

Referring to FIG. 6, a driving experiment was performed in an electric vehicle mileage authentication mode (UDD) using an electric vehicle (EV), and the total driving time was 258 seconds among the total driving time of 1369 seconds. It shows that 19% of stops are stops.

As a result, it was confirmed that the driving distance of the light electric vehicle was increased by 2% in the UDDS mode, and the battery power consumption was reduced from the existing 500W to 300W.

Therefore, when driving in a severe urban congestion section such as a large city, it is possible to expect a higher driving distance increase effect than before.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention, a recording medium on which the program is recorded And such an embodiment can be easily implemented by those skilled in the art from the description of the embodiments described above.

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.

100: motor control system 110: vehicle speed calculating unit
120: pedal detection unit 130: shift detection unit
140: vehicle controller 141: signal acquisition module
142: stop condition determination module 143: stop condition maintenance counter
144: communication module 145: control module
150: motor controller 160: motor

Claims (12)

In a system for controlling a motor of an electric vehicle,
A vehicle speed calculator configured to calculate a vehicle speed of the electric vehicle from the rotation speed of the motor;
A pedal detecting unit detecting a brake pedal operation signal input from a driver;
A motor controller configured to apply an exciting current to the motor to secure torque response while driving the electric vehicle; And
A vehicle controller which transmits a motor excitation current off command (MOT PWM OFF) to cut off the excitation current to the motor controller when it is determined that the vehicle speed and the brake pedal operating signal are respectively stopped compared to a corresponding stop condition set in advance; Including,
The vehicle controller generates and transmits a motor excitation current on command (MOT PWM ON) to the motor controller when one of the vehicle speed and the brake pedal operation signal does not satisfy the stop condition after the motor is stopped. Motor control system of an electric vehicle, characterized in that. The method of claim 1,
The motor controller,
And receiving the motor excitation current off command from the vehicle controller to turn off the motor by turning off the Insulated Gate Bipolar Transistor (IGBT). 3. The method according to claim 1 or 2,
Wherein the vehicle controller comprises:
A signal collection module for collecting the vehicle speed and brake pedal activation signal;
A stop condition determining module that determines that the first stop condition is satisfied when the vehicle speed is equal to or lower than a set reference speed, and that the second stop condition is satisfied when the brake pedal operation signal exceeds a set braking reference value;
A stop condition maintaining counter for counting a time at which both the first stop condition and the second stop condition are satisfied and generating a stop event signal when the counted time exceeds a set stop condition holding time;
A communication unit which transmits a command for controlling the motor to the motor controller through CAN communication; And
A control module for generating the motor excitation current off command and transmitting it through the communication unit upon receiving the stop event signal.
Motor control system of the electric vehicle comprising a. delete The method of claim 1,
The brake pedal operation signal,
A motor control system for an electric vehicle, characterized in that either the brake pedal angle or the brake pedal shaft or a push rod movement signal. The method of claim 3, wherein
The signal collection module further collects the position signal of the shift lever input by the driver,
And the stop condition determination module determines that the third stop condition is satisfied when the shift lever position signal is at either the N stage (neutral) or the P stage (parking). The method according to claim 6,
The stop condition maintenance counter,
Characterized in that the electric vehicle is stopped when the time when the first stop condition, the second stop condition, and the third stop condition is cross checked to satisfy two or more stop conditions exceeds the stop condition holding time. Motor control system of the car. In a method in which a vehicle controller of a motor control system of an electric vehicle controls a motor,
a) collecting vehicle speed and brake pedal actuation signals of the electric vehicle;
b) comparing the vehicle speed and the brake pedal operation signal with each preset stop condition and determining that the vehicle is stopped; And
c) stopping the motor by the vehicle controller transmitting a motor excitation current off command (MOT PWM OFF) to cut off the excitation current applied to the motor to the motor controller controlling the motor torque.
After the step c), if any one of the vehicle speed and the brake pedal operation signal does not satisfy the stop condition, transmitting a motor excitation current command (MOT PWM ON) to the motor controller to drive the motor. Motor control method of an electric vehicle characterized in that it further comprises. The method of claim 8,
The step b)
b-1) collecting the vehicle speed and determining that the first stop condition is satisfied when the vehicle speed is lower than or equal to a set reference speed;
b-2) the vehicle controller determining that the second stop condition is satisfied when the brake pedal operation signal exceeds a set braking reference value; And
b-3) counting a time when both the first and second stop conditions are satisfied and determining that the vehicle is stopped when the set stop condition holding time is exceeded.
Motor control method of an electric vehicle comprising a. delete The method of claim 9,
Between step b-2) and step b-3),
And collecting the position signal of the shift lever and determining that the third stop condition is satisfied when the shift lever position signal is at either the N stage (neutral) or the P stage (parking). How to control the motor of an electric car. The method of claim 11,
Step b-3),
The motor control of the electric vehicle, characterized in that the first stop condition, the second stop condition and the third stop condition is cross-checked to determine that the vehicle is stopped when the time for satisfying at least two stop conditions exceeds the stop condition holding time. Way.

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