KR102579442B1 - Apparatus and method for corporated control of motors in electric vehicle - Google Patents

Abstract

Existing electric vehicle MCUs (Motor Control Units) control only the vehicle drive motor. However, according to the system/method proposed in the present invention, the MCU serves to drive the EWP (Electric Water Pump), the electric compressor motor, and the drive motor. Accordingly, the speed of the EWP can be varied, thereby increasing noise and efficiency, and the existing electric compressor control board and power unit are integrated into the MCU, which has the effect of reducing design costs and labor costs by eliminating the existing Local CAN communication line. . According to the present invention, a motor control unit (MCU) of an electric vehicle includes a drive motor control unit that controls the drive motor according to a torque command signal, an EWP motor control unit that controls the EWP motor according to a speed command signal, and a speed command signal. It includes a compressor motor control unit that controls the compressor motor accordingly. Here, the EWP motor control unit and the compressor motor control unit control the control target EWP motor and compressor motor using a sensorless speed estimation method.

Description

Integrated motor control system and method for electric vehicle {Apparatus and method for corporated control of motors in electric vehicle}

The present invention relates to an integrated control system for a drive motor, radiator fan (EWP), and electric compressor that can be used in an electric vehicle, which is one of the environmentally friendly vehicles.

In engine cars, the refrigerant is compressed using a belt-driven compressor using engine power, and in hybrid cars, the refrigerant is compressed using an electric compressor using high voltage. Here, because the electric compressor uses high voltage, it is a module type consisting of a motor, inverter, and compression unit. Accordingly, the size and location of the electric compressor are restricted, and a separate control board, software, and cooperative control technology are required.

Meanwhile, unlike engine cars, electric cars do not have an engine or transmission. Instead of these, electric vehicles are equipped with an inverter and motor device and can be driven solely by electricity. The MCU (motor control unit) in an electric vehicle is a control system that can control the drive motor and includes logic to operate the EWP (electric water pump) and electric compressor.

The purpose of the present invention is to reduce costs and reduce the volume of the EWP and electric compressor by integrating the control of the EWP and electric compressor by a controller within the MCU, and, unlike the existing method, to omit the local CAN communication line for compressor control.

Existing electric vehicle MCUs (Motor Control Units) control only the vehicle drive motor. However, according to the system/method proposed in the present invention, the MCU serves to drive the EWP (Electric Water Pump), the electric compressor motor, and the drive motor. Accordingly, the speed of the EWP can be varied, thereby increasing noise and efficiency, and the existing electric compressor control board and power unit are integrated into the MCU, which has the effect of reducing design costs and labor costs by eliminating the existing Local CAN communication line. .

The present invention includes control logic that can control the BLDC (Brushless DC) motor of the EWP, and proposes to create an EWP speed change value according to the situation of the vehicle and surrounding devices, and a sensorless (sensor) control logic that controls the electric compressor motor. -less) control algorithm and driving sequence are proposed.

The structure and operation of the present invention introduced above will become clearer through specific embodiments described later with drawings.

In addition to the driving motor of an electric vehicle, the control of the EWP and electric compressor can be integrated into the control logic within the MCU to reduce costs and reduce the volume of the EWP and electric compressor. Also, unlike before, there is no local can communication line for compressor control, so design labor costs can be reduced.

More specifically, the following effects can be achieved.

-Existing EWP control is an on/off control that is controlled only at a constant speed, but it changes the rotation speed according to temperature and performs speed control based on the changing speed command, thereby increasing noise and efficiency. By inserting the initial entry sequence of the electric compressor, stable electric compressor operation is possible.

-As the device that can drive the EWP and electric compressor is integrated into the MCU, the existing housing disappears, enabling cost reduction. Additionally, since it uses a sensorless algorithm, there is no need for a position sensor.

-Because the control ECU related to motor control is integrated, space in the vehicle's engine room can be secured.

1 is a diagram introducing components included in an embodiment of the present invention.
Figure 2 is a detailed flowchart of calculating and operating (speed control) the speed of the BLDC motor 14 of the EWP.
3 is a flowchart of the control operation process of the compressor motor 17.
Figure 4 shows the motor control logic configuration of the MCU.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms. However, the present embodiments are intended to ensure that the disclosure of the present invention is complete and that common knowledge in the technical field to which the present invention pertains is not limited to the present invention. It is provided to fully inform those who have the scope of the invention. The technical scope of the present invention is defined by the claims.

Meanwhile, the terms used in this specification are for describing embodiments and are not intended to limit the present invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, “comprises” or “comprising” means the presence or presence of one or more other components, steps, operations and/or elements other than the mentioned elements, steps, operations and/or elements. Addition is not ruled out.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to components in each drawing, the same numerals are assigned to the same components as much as possible even if they are shown in different drawings, and when explaining the present invention, a detailed description of the related known configuration or function is provided. In cases where it may obscure the gist of the present invention, detailed description will be omitted.

According to one embodiment of the present invention, the motor-related configuration of an electric vehicle is configured as shown in FIG. 1. Components of an embodiment of the present invention will be described with reference to FIG. 1 as follows.

Block 11 is the top controller in an electric vehicle, VCU (Vehicle Control Unit), and block 12 is an MCU that controls the drive motor, BLDC motor, and electric compressor motor. Block 13 is the drive motor, and block 14 is the motor for EWP's radiator fan. This EWP motor can be used as a BLDC motor, but is not limited to this. Block 15 is FATC (Full Automatic Temperature Control), which controls the air conditioning inside the vehicle, and block 16 is a direct current converter (LDC) (Low Voltage DC-DC Converter), which generally outputs 12V. Block 17 is an electric compressor motor that compresses refrigerant to control the temperature inside the car. The electric compressor consists of a compression unit (compressor) and a motor (17).

The MCU (12) calculates and operates the speed of the BLDC motor (14) of the EWP using the compression state of the electric compressor, vehicle speed, air conditioner ON/OFF, and temperature information of various controllers. In addition, the electric compressor operation enable signal and the electric compressor command rotation speed are received from the FATC (15) and used as control commands, and the current signal of the compressor motor (17) is measured to calculate the rotation speed of the electric compressor and operate it. The MCU 12 transmits a high-voltage PWM control signal to the BLDC motor 14 and the compressor motor 17, which are examples of EWP motors, to drive them in a sensorless manner. Status and information are transmitted and received between the controllers 11, 12, 15, and 16 through CAN communication using a pre-arranged protocol.

The MCU 12 of the present invention naturally includes the driving motor control logic, which is an original function, and in addition, the control logic of the BLDC motor 14 for the EWP radiator fan and the control logic of the compressor motor 17 are added. Details related to these added control logics are described below. Below, the functions of the MCU of the present invention are described using a process flow chart, but this also explains the hardware or software configuration of the control logic of the MCU of the present invention. Those skilled in the art can design an MCU assembly, which is a collection of physical components, through the following description.

First, a detailed flowchart for calculating the speed and operating (speed control) of the BLDC motor 14 of the EWP is shown in Figure 2.

The operation of the present invention begins when the vehicle is started, and the BLDC motor 14 of the EWP is measured using the vehicle speed from the VCU 11, the temperature from the converter 16, and the temperature of the MCU and motor measured by the MCU 12. Determine the rotation speed. The rotation speed is determined so that it can be increased according to the temperature of each component.

Explain in detail.

101: When the vehicle starts, the process begins, and the MCU 12 acquires the temperature of the drive motor, MCU, and LDC.

103: Check whether the acquired MCU temperature, driving motor temperature, or LDC temperature is higher than or equal to the preset condition minimum temperature for each. That is, check whether (MCU Temp (temperature) ≥ MCU_T2) or (Motor Temp ≥ Motor_T2) or (LDC Temp ≥ LDC_T2).

105: As a result of comparison with the condition minimum temperature in step 103, if the MCU temperature, drive motor temperature, or LDC temperature is lower than the preset condition minimum temperature, the MCU 12 operates the BLDC motor 14 of the EWP. Turn off. This is because there is no need to operate the water pump associated with the radiator fan.

107: As a result of comparison with the condition minimum temperature in step 103, if the MCU temperature, drive motor temperature, or LDC temperature is higher than the preset condition minimum temperature, this time the MCU temperature, drive motor temperature, or LDC temperature is Check whether the temperature is lower than the maximum temperature preset for each condition. In other words, check whether (MCU Temp (temperature) < MCU_T1) or (Motor Temp < Motor_T1) or (LDC Temp < LDC_T1).

109: As a result of comparison with the condition maximum temperature in step 107, if the MCU temperature, drive motor temperature, or LDC temperature is higher than the preset condition maximum temperature, the MCU (12) operates the BLDC motor (14) of the EWP at the maximum temperature. drive with This is because the MCU temperature, drive motor temperature, or LDC temperature is higher than the temperature set as the maximum condition, so the water pump associated with the radiator fan must be operated to cool it.

111: As a result of comparison with the condition maximum temperature in steps 107 above, if the MCU temperature, drive motor temperature, or LDC temperature is lower than the preset condition maximum temperature, the MCU 12 sets the condition in steps 103 and 107. The highest temperature among the temperatures of the MCU, drive motor, or LDC that meets the above is set as the 'current temperature', one of the variables for calculating the EWP operation speed.

113: Set the conditional minimum temperature of the component selected as the highest temperature in step 111 as variable 'T2', and set the conditional maximum temperature of this component as variable 'T1'.

115: Calculate the operating speed of EWP using the formula below.

EWP speed = (-maximum operation speed/(T2-T1))*current temperature + (maximum operation speed*T2/(T2-T1))

117: The MCU 12 generates a control amount that limits the maximum operation speed of the EWP to the EWP speed calculated in this way.

119: And the speed of the EWP is controlled and driven using this speed control amount.

Next, the operation process flowchart of the compressor motor 17 by the MCU 12 is shown in FIG. 3. Figure 3 is a flowchart showing, in particular, the initial sequence of operation of the compressor motor 17.

201: The operation of the compressor motor 17 starts according to the allowed signal from the FATC 15 and the compressor 17, and the MCU 12 receives the allowed signal and speed control command from the FATC 15. Take control.

Specifically, control of the compressor motor 17 is performed when the command speed of the compressor motor 17 is higher than the minimum command speed (V1) (≥V1) and (&&) when an allow signal is generated (allow operation == TRUE).

203~209: However, since the control of the compressor motor 17 is sensorless, a separate initial sequence is required. In other words, since it is sensorless control, a total of 4 initialization operations (forced alignment, forced drive acceleration, forced drive maintenance, and sensorless algorithm switching) are required to stabilize the angle (or speed) estimation and estimation algorithm. During the initialization sequence operation, the estimated speed is not used but proceeds through open loop control.

To explain each step, first, in the forced alignment step, the current of I1 (current for forced alignment of the compressor) is forcibly applied during the forced alignment time (T1) (203). .

Next, in the forced drive acceleration step, the compressor motor is forcibly accelerated to V1 speed during T2 time (forced drive acceleration time) (205).

Next, in the forced drive maintenance step, the compressor motor is forcibly maintained at V1 during the T3 time (forced drive maintenance time) (207).

Then, it switches to the sensorless algorithm (209).

211: Determine whether switching to the sensorless algorithm has failed. If the sensorless algorithm switching has not failed, return to step 201.

213: If sensorless algorithm switching fails (switching failure == TRUE), speed control of the compressor motor 17 is performed.

215: Also determine whether the speed control of the compressor motor 17 has failed. If the speed control of the compressor motor 17 does not fail, the process returns to step 201.

217: If the speed control of the compressor motor 17 fails (speed control failure == TRUE), the speed of the compressor motor 17 is controlled according to the speed control command of the FATC (15).

In this way, the operation of the compressor motor 17 by the MCU 12 is performed.

The control logic for the motors of the MCU is explained in FIG. 4. Figure 4 is a control block diagram for torque control of the vehicle drive motor and speed control of the BLDC motor and compressor motor.

The MCU 12 according to the present invention includes a drive motor control unit 30, an EWP BLDC motor control unit 40, and a compressor motor control unit 50.

The driving motor control unit 30 contains basic control blocks for 3-phase PWM control, a 3-phase to 2-phase converter (3/2 converter), and a 2-phase to 3-phase converter (2/3 converter). The torque (command torque) received from the VCU 11 is converted into a current command and this current is controlled to control the drive motor 13 using the PWM method.

The BLDC motor control unit 40, which controls the BLDC motor 14 of the EWP impeller, is a sensorless speed estimation algorithm that estimates the speed using the induced voltage measured using the back electromotive force detector 42 from the voltage delivered to the BLDC motor 14. (44) is applied. That is, in the drive motor control unit 30, the drive motor 13 has a position sensor 18 and performs PWM control using the position signal, but the BLDC motor control unit 40 operates the BLDC motor (BLDC motor) in a sensorless manner. 14) is controlled. In a typical MCU, there are no circuits or switch devices that can control the BLDC motor of the EWP. However, in the present invention, the circuit and switch device that controls the BLDC motor 14 of the EWP are all located in the MCU 12, and the EWP consists only of the BLDC motor 14 and the impeller 19. This is because EWP is a system that must be well sealed, so a position sensor cannot be installed.

Likewise, the compressor motor control unit 50, which controls the compressor motor 17, also performs sensorless speed control. For this purpose, there is a sensorless position and speed estimator (52). For this purpose, in the present invention, all circuits and switch devices for controlling the electric compressor are located in the MCU 12, and only the compression unit 20 and the motor 17 are included in the electric compressor. This is because an electric compressor is a system that must be well sealed, so a position sensor cannot be installed. Therefore, the angle and speed of the compressor motor 17 are estimated using the sensorless position and speed estimator 52 using the three-phase current output to the compressor motor 17 as feedback.

In the above, the configuration of the present invention has been described in detail through preferred embodiments of the present invention, but those skilled in the art will understand that the present invention is disclosed herein without changing its technical idea or essential features. You will be able to understand that it can be implemented in a specific form that is different from the content. The embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of protection of the present invention is determined by the claims described below rather than the detailed description above, and all changes or modified forms derived from the scope of the claims and their equivalent concepts should be construed as being included in the technical scope of the present invention. .

Claims (10)

In the electric vehicle including a vehicle control unit (VCU), motor control unit (MCU), FATC (Full Automatic Temperature Control), LDC (Low Voltage DC-DC Converter), drive motor, EWP motor, and compressor motor, The motor control unit (MCU) is
A drive motor control unit that controls the drive motor according to a torque command signal,
An EWP motor control unit that controls the EWP motor according to a speed command signal,
It includes a compressor motor control unit that controls the compressor motor according to a speed command signal,
An integrated motor control system for an electric vehicle, wherein the EWP motor control unit and the compressor motor control unit control the EWP motor and compressor motor, which are control targets, using a sensorless speed estimation method. In claim 1, the EWP motor control unit applies a sensorless speed estimation algorithm that estimates the speed using the induced voltage measured using a back electromotive force detector from the voltage delivered to the EWP motor for the sensorless speed estimation. An integrated motor control system for electric vehicles. In claim 1 or 2, the EWP motor control unit determines the rotation speed of the EWP motor using vehicle speed information received from the VCU, temperature information received from the LDC, and temperature information of the MCU and the EWP motor measured by the MCU. A motor integrated control system for an electric vehicle, characterized in that determining. In claim 1, the compressor motor control unit estimates the angle and speed of the compressor motor as a sensorless position and speed estimator by using the three-phase current transmitted to the compressor motor as feedback for the sensorless speed estimation. An integrated motor control system for electric vehicles. The integrated motor control system for an electric vehicle according to claim 1 or 2, wherein the compressor motor control unit receives a drive permit signal and a speed control command from the FATC and performs speed control of the compressor motor. As a method of integrated control of the drive motor, EWP motor, and compressor motor of an electric vehicle,
1) Acquiring the temperatures of the driving motor, MCU, and LDC;
2) Control the turn-off of the EWP motor by checking whether the acquired MCU temperature, driving motor temperature, or LDC temperature is higher than or equal to the preset temperature T2 for each of the MCU, driving motor, and LDC, that is, MCU_T2, Motor_T2, or LDC_T2. step; and
3) Check whether the MCU temperature, driving motor temperature, or LDC temperature is lower than the preset temperature T1 for each of the MCU, driving motor, and LDC, i.e., MCU_T1, Motor_T1, or LDC_T1 (where T1 < T2), and determine whether the EWP motor A motor integrated control method for an electric vehicle including the step of controlling the speed of. In claim 6, step 2) turns off the EWP motor if the MCU temperature, driving motor temperature, or LDC temperature is lower than the MCU_T2, Motor_T2, or LDC_T2; If the MCU temperature, driving motor temperature, or LDC temperature is higher than MCU_T2, Motor_T2, or LDC_T2, checking whether the MCU temperature, driving motor temperature, or LDC temperature of step 3) is lower than MCU_T1, Motor_T1, or LDC_T1. A motor integrated control method for an electric vehicle including. In clause 6, step 3) is
As a result of comparison with the MCU_T1, Motor_T1, or LDC_T1, if the MCU temperature, driving motor temperature, or LDC temperature is greater than or equal to the MCU_T1, Motor_T1, or LDC_T1, the EWP motor is operated at the maximum; If the MCU temperature, driving motor temperature, or LDC temperature is lower than the MCU_T1, Motor_T1, or LDC_T1, determining the highest temperature among the MCU, driving motor, or LDC temperature;
Calculating the operating speed of the EWP motor using the MCU_T2, Motor_T2, or LDC_T2 of the MCU, driving motor, or LDC selected with the highest temperature, and MCU_T1, Motor_T1, or LDC_T1 as variables;
A method for integrated motor control of an electric vehicle, further comprising generating a control amount that limits the maximum operating speed of the EWP motor using the calculated EWP motor speed, and controlling the speed of the EWP motor using this speed control amount. As a method of integrated control of the drive motor, EWP motor, and compressor motor of an electric vehicle,
performing an initialization algorithm including forced alignment, forced drive acceleration, and forced drive maintenance;
A motor integrated control method for an electric vehicle, comprising the step of switching to a sensorless algorithm to control the compressor motor using a sensorless speed estimation algorithm after the initialization algorithm. In claim 9, the step of switching to the sensorless algorithm is
Determine whether the conversion to the sensorless algorithm has failed, and if the conversion fails, control the speed of the compressor motor.
Motor integration of an electric vehicle, characterized in that it determines whether the speed control of the compressor motor has failed and, in case of speed control failure, additionally controls the speed of the compressor motor according to the speed control command of FATC (Full Automatic Temperature Control). Control method.