KR20120114606A - Electric vehicle and control method thereof - Google Patents

Abstract

The present invention calculates a first torque value and controls a motor in response to the main control unit for generating a torque command to control the running of the vehicle, and controls the motor, and the row for the first torque value and the first torque value. And a motor controller for feeding back data to the main controller, wherein the main controller calculates a second torque value using the low data, compares the torque command, the first torque value, and the second torque value. The present invention relates to an electric vehicle that determines a state of a vehicle and controls driving.

Description

Electric vehicle and control method

The present invention relates to an electric vehicle and a control method thereof. More specifically, when an error occurs in the motor controller that controls the operation of the motor, the main controller detects the error and determines the state of the vehicle and controls the driving. It relates to a control method.

Research is actively being made in the sense that electric vehicles are the most likely alternative to solve future automobile pollution and energy problems.

Electric vehicle (EV) is a vehicle that obtains power mainly by driving AC or DC motor by using battery power. It is classified into battery-only electric vehicle and hybrid electric vehicle. Using a motor to drive, recharging when the power is exhausted, the hybrid electric vehicle can run the engine to generate electricity to charge the battery and drive the electric motor using this electricity to move the car.

In addition, the motor / control technology has also been developed recently, a high power, small size and high efficiency system has been developed. As the DC motor is converted to an AC motor, the output and EV power performance (acceleration performance, top speed) are greatly improved, reaching a level comparable to that of gasoline cars. As the motor rotates with high output, the motor becomes light and compact, and the payload and volume are greatly reduced.

Such electric vehicles generally include a main control unit for controlling the overall function and a motor control unit for controlling the motor by receiving a command from the main control unit. Due to its own error, the torque value of the motor will be abnormal and the vehicle will not operate normally. In particular, when an abnormality occurs while driving, there is a problem that the motor is driven in a direction different from the command generated by the main controller to lead to an accident.

An object of the present invention is to provide an electric vehicle and a method of controlling the same, by additionally monitoring the torque value calculated by the main controller to detect an error of the motor controller itself, thereby determining the state of the vehicle and controlling the driving.

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

In order to achieve the above object, the electric vehicle according to the invention the main control unit for generating a torque command to control the running of the vehicle; And a motor controller for calculating a first torque value and controlling the motor in response to the torque command, and feeding back the first torque value and the low data for the first torque value to the main controller. The second torque value is calculated using the low data, and the torque command, the first torque value, and the second torque value are compared to determine a state of the vehicle and to control driving.

In addition, the control method of the electric vehicle according to the present invention comprises the steps of controlling the motor according to the first torque value calculated by the motor control unit receives a torque command from the main control unit; Feeding back the first torque value and the raw data related to the first torque value to the main controller by the motor controller; Calculating a second torque value in response to the row data input by the main controller; And comparing, by the main controller, the torque command with the first torque value and the torque command with the second torque value to determine a state of the vehicle and control driving.

According to the electric vehicle and the control method thereof according to the present invention, by monitoring the torque value calculated by the main control unit in addition to the torque value calculated by the motor control unit, an unexpected problem such as an operation error inside the motor control unit occurs, resulting in the calculated torque value. The output is properly output, but the error can be recognized until an error occurs in the torque value actually applied to the motor, thereby increasing the reliability of the torque value of the motor and securing the safety of the electric vehicle.

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

1 is a view schematically showing the internal configuration of an electric vehicle according to an embodiment of the present invention.
2 is a diagram illustrating a control flow of a vehicle through monitoring of an electric vehicle according to an embodiment of the present invention.
3 is a flowchart illustrating a control method of an electric vehicle according to an embodiment of the present invention.
4 is a flowchart illustrating a method of controlling driving by determining a state of an electric vehicle according to an exemplary embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Hereinafter, the present invention will be described with reference to the drawings for explaining an electric vehicle and a control method thereof according to embodiments of the present invention.

1 is a view schematically showing the internal configuration of an electric vehicle according to an embodiment of the present invention.

1, an electric vehicle according to an embodiment of the present invention includes a main controller (VCM) 110, a motor controller (MCU) 120, a motor 130, a sensor 140, and a PRA 150. , Battery 160, and BMS 170.

The electric vehicle includes a battery 160 as described above, and operates using power charged in the battery as an operating power source, and the battery 160 is provided with power from a predetermined charging station or vehicle charging facility or from outside of the home. To charge.

The battery 160 is composed of a plurality of battery cells, and stores electrical energy of high voltage. At this time, the electric vehicle controls the charging of the battery 160, determines the remaining capacity of the battery 160, the need for charging, and performs management for supplying the charging current stored in the battery 160 to each part of the electric vehicle. A battery management system (BMS) 170 is further included.

When the BMS 170 charges and uses the battery 160, the BMS 170 maintains the voltage difference between cells in the battery evenly, thereby extending the life of the battery 160 by controlling the battery 160 from being overcharged or overdischarged.

The power relay assembly (PRA) 150 includes a plurality of relays for switching a high voltage and a sensor, and applies or blocks a high voltage operating power applied from the battery 160 to the motor controller 120. At this time, the PRA 150 operates a relay by a control command of the main controller 110.

The PRA 150 is stored in the battery 160 in each part of the vehicle by switching a plurality of relays provided in a predetermined order according to a control command of the main controller 110 when the vehicle is started or when the vehicle is turned off. Ensure that high voltage operating power is applied.

The PRA 150 may cut off the power applied from the battery 160 to the motor control unit 120. Since the power supplied to the motor 130 is cut off, the vehicle also stops as the motor 130 stops.

The motor controller 120 generates a control signal for driving at least one motor 130 connected to the motor controller 120, and generates and applies a predetermined signal for motor control. In this case, the motor controller 120 may control the driving of the motor 130 by controlling the inverter or the converter including an inverter (not shown) and a converter (not shown).

The motor controller 120 calculates a torque value according to the torque command applied from the main controller 110 and drives the motor 130 according to the torque command using the power of the battery 160 supplied through the PRA 150. Control as possible.

The sensor unit 140 may include a plurality of sensors and measure the input current of the motor 130 and the rotor angle of the motor 130 to transmit the measured value to the motor controller 120.

The main controller 110 issues a torque command to drive the motor 130 to the motor controller 120 and monitors whether there is an operation error inside the motor controller 120.

2 is a diagram illustrating a control flow of a vehicle through monitoring of an electric vehicle according to an embodiment of the present invention.

Referring to FIG. 2, the main controller 110 issues a torque command to drive the motor 130 to the motor controller 120. The motor controller 130 feeds back the first torque value calculated in response to the torque command and the raw data regarding the first torque value to the main controller 110.

The low data may include a U phase current value, a V phase current value, and a W phase current value input to the motor 130, and include a torque ID, a rotor angle of the motor 130, a rated torque of the motor 130, and a motor. The current at rated torque of 130 may also be included.

The main controller 110 uses the raw data input from the motor controller 120 to monitor whether the torque value actually applied to the motor 130 is correct in response to the torque command from the motor controller 120. Calculate the torque value.

The main controller 110 compares the torque command applied to the motor controller 120 with the second torque value calculated using the first torque value and the low data input from the motor controller 120 to determine the state of the vehicle. Control the ride.

3 is a flowchart illustrating a control method of an electric vehicle according to the present invention.

Referring to FIG. 3, the main controller 110 generates a torque command to control the driving of the vehicle based on the input signal, and transmits the torque command to the motor controller 120. At this time, the motor controller 120 calculates a first torque value in response to the torque command received from the main controller 110 and controls the motor 130 (S310).

The motor controller 120 feeds back the first torque value calculated by itself and the raw data related to the first torque value to the main controller 110 (S320).

The main controller 110 calculates a second torque value in response to the low data input from the motor controller 120 (S330).

The second torque value can be calculated using the following equation.

Here, iu is the U-phase current value input to the motor 130, iv is the V-phase current value input to the motor 130, iw is the W-phase current value input to the motor 130, θ is the rotor angle .

The values calculated using Equation 1 are d-axis rotational coordinate system currents and q-axis rotational coordinate system currents iqse.

Here, iqse is the q-axis rotational coordinate current calculated in Equation 1, Trate is the rated torque of the motor 130, irate is the current at the rated torque.

Tvcm-cal is a second torque value calculated by the main controller 110.

 The main controller 110 compares and analyzes the torque command and the first torque value received from the motor controller 120 and the second torque value calculated using the low data in the main controller 110 (S340).

Here, when the main control unit 110 compares the torque command transmitted by the main controller 110 with the second torque value calculated using the low data, there is a delay time between the transmitting time and the receiving time. In order to solve this problem, the main controller 110 assigns and transmits a torque ID to the torque command, and when the motor controller 110 feeds back low data to the main controller, the main controller 110 transmits the same torque ID as the torque ID given to the torque command. Give feedback to the data. The main controller 110 compares the second torque value calculated using the low data assigned with the same torque ID and the torque command, thereby accurately comparing the delay time without delay.

 It is determined whether the motor control unit 120 is operating within the normal range (S350).

When the motor control unit 120 is normal, the motor controller 120 operates normally without limiting the output and torque (S360). If the motor control unit 120 is not normal, the motor control unit 120 does not stop the vehicle and sets the limit value of the output of the motor 130 and the torque. Control to operate in (S370). At this time, the limit value is preferably set in the range of 35kW ~ 45kW for the output, it is preferable to set in the range of 110Nm ~ 120Nm for the torque.

3 is a flowchart illustrating a method of controlling driving by determining a state of an electric vehicle according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the main controller 110 calculates a difference between the torque command and the first torque value and a difference between the torque command and the second torque value (S410).

The main controller 110 determines whether a difference value between the torque command and the first torque value and a difference value between the torque command and the second torque value is larger than the preset first reference value (S420).

Here, it is preferable to set a 1st reference value in the range of 55Nm-65Nm.

If at least one of the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is not greater than the first reference value, the main controller 110 determines that the motor controller 120 is normal and the motor. It is allowed to operate normally without placing a limit value in the output and torque of the (S430).

If the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is greater than the first reference value, the main controller 110 next determines the difference between the torque command and the first torque value and the torque command. It is determined whether at least one of the difference between the second torque value and the second reference value is greater than the second reference value set larger than the first reference value (S440).

The second reference value is preferably set in the range of 110 Nm to 120 Nm.

 If the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is not greater than the second reference value, the main controller 110 does not stop the vehicle and does not stop the output and torque of the motor 130. The limit value is set and controlled to operate within the limit value range (S450).

As described above, the limit value is preferably set in the range of 35 kW to 45 kW in the case of the output, and preferably in the range of 110 Nm to 120 Nm in the case of torque.

If at least one of the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is greater than the second reference value, the main controller 110 next determines the difference between the torque command and the first torque value. It is determined whether the difference between the value and the torque command and the second torque value is greater than the second reference value (S460).

If any one of the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is not greater than the second reference value, the main controller 110 determines that the output current of the battery 160 is a preset limit value. It is determined whether it is larger (S470). At this time, if the output current of the battery 160 is not greater than the limit value, the main controller 110 controls to operate within the limit value by setting the limit value for the output and torque of the motor 130 without stopping the vehicle. (S350). At this time, if the output current of the battery 160 is greater than the limit value, the main controller 110 issues a stop command to the motor controller 120 and cut off the power applied from the battery 160 to the motor controller 120. Control (S480).

Here, the threshold value for the output current of the battery 160 is preferably set in the range of 125A to 135A, and when the output and torque of the motor 130 are limited, it is common that the output current of the battery 160 decreases. In spite of limiting the output and torque of the motor 130, if the output current of the battery 160 increases and becomes larger than the limit value, the motor controller 120 determines that there is an error and stops the vehicle.

If the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is greater than the second reference value, the main controller 110 issues a stop command to the motor controller 120 and the battery 160 from the battery 160. Control to cut off the power applied to the motor control unit 120 (S480).

Therefore, the electric vehicle and the control method according to the present invention have an unexpected problem such as an operation error inside the motor control unit, and the first torque value is correctly output, but is actually applied to the motor when an error occurs in the torque value applied to the motor. By comparing the second torque value computed by the main controller with the low data, the abnormality of the motor controller can be determined and the driving of the vehicle can be controlled accordingly. In electric vehicles, the torque value of the motor is a very necessary factor, so it is possible to control the electric vehicle by increasing the reliability of this value.

Although the above has been illustrated and described with respect to preferred embodiments of the present invention, the present invention is not limited to the specific embodiments described above, but in the art to which the invention pertains without departing from the spirit of the invention as claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

110: main control unit 120: motor control unit
130: motor 140: sensor
150: PRA 160: battery
170: BMS

Claims (11)

A main controller for generating a torque command to control the running of the vehicle; And
A motor control unit configured to calculate a first torque value and control a motor in response to the torque command, and to feed back the first torque value and the low data for the first torque value to the main controller;
And the main controller calculates a second torque value using the low data, compares the torque command, the first torque value and the second torque value, and determines a state of the vehicle and controls driving. The method of claim 1,
The main controller sets a limit value for the output and torque of the motor when the difference between the torque command and the first torque value and the difference between the torque command and the second torque value are greater than a first reference value. To control the vehicle to operate within the limit value without stopping the vehicle. The method of claim 2,
The main control unit outputs current of the battery when one of a difference between the torque command and the first torque value and a difference between the torque command and the second torque value is greater than a second reference value greater than the first reference value. Is greater than a preset limit value, the motor control unit issues a stop command to control the vehicle to stop, and if the output current of the battery is less than the limit value, the electric vehicle is controlled to operate within the limit value range without stopping. car. The method of claim 2,
The main controller stops the command to the motor controller when the difference value between the torque command and the first torque value and the difference value between the torque command and the second torque value are greater than a second reference value that is set larger than the first reference value. An electric vehicle that lowers and controls the vehicle to stop. The method of claim 1,
And the motor controller feeds back low data including at least one of an input current of the motor, a rotor angle of the motor, and a rated torque of the motor. 6. The method of claim 5,
An electric vehicle comprising a plurality of sensors, the sensor unit for measuring the input current of the motor and the rotor angle of the motor. The method of claim 1,
And a PRA for switching a power supply from a battery to the motor controller according to a control command of the main controller.
The main controller controls the PRA to stop the power applied to the motor control unit from the battery when the vehicle is stopped. Controlling the motor according to the first torque value calculated by receiving a torque command from the motor controller;
Feeding back the first torque value and the raw data related to the first torque value to the main controller by the motor controller;
Calculating a second torque value in response to the row data input by the main controller; And
And controlling, by the main controller, the state of the vehicle and controlling driving by comparing the torque command with the first torque value and the torque command with the second torque value. The method of claim 8,
As a result of the comparison, when the difference value between the torque command and the first torque value and the difference value between the torque command and the second torque value is larger than a preset first reference value, the main control unit limits the output of the motor and the torque. The control method of the electric vehicle to control the vehicle to operate within the limit value range without stopping. The method of claim 9,
The battery output current and the preset limit when any one of the difference between the torque command and the first torque value and the difference between the torque command and the second torque value is greater than a second reference value greater than the first reference value. Further comparing the values,
When the battery output current is greater than the threshold as a result of comparing the battery output current with the threshold value, the main controller controls the motor controller to stop the power and cut off the power applied from the battery to the motor controller. Control method of electric vehicle. The method of claim 9,
When the difference value between the torque command and the first torque value and the difference value between the torque command and the second torque value is greater than a second reference value set larger than the first reference value, the main control unit issues a stop command to the motor controller. The control method of the electric vehicle for controlling to lower the power supplied from the battery to the motor control unit.

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