WO2023000366A1

WO2023000366A1 - Temperature control method and module for heat dissipation system of new energy commercial vehicle

Info

Publication number: WO2023000366A1
Application number: PCT/CN2021/109037
Authority: WO
Inventors: 胥军; 左家鹏; 李刚炎; 胡剑
Original assignee: 武汉理工大学
Priority date: 2021-07-19
Filing date: 2021-07-28
Publication date: 2023-01-26
Also published as: CN113568395A

Abstract

A temperature control method and module for a heat dissipation system of a new energy commercial vehicle. The method comprises: determining an operating state of a driving motor according to the temperature of the driving motor, the torque of the driving motor, the rotational speed of the driving motor, the temperature of a cooling liquid, the temperature of ambient air, an output voltage of a motor controller, and an output current of the motor controller; and calculating an optimal target temperature of the driving motor according to a control function associated with a target temperature steady-state control function by an energy optimization control function and outputting a corresponding PWM fan control signal. The temperature control method and module for a heat dissipation system of a new energy commercial vehicle achieve optimal balance between heat loss of a driving motor and power consumption of a heat dissipation system by optimizing the output of the heat dissipation system, thereby reducing the sum of the heat loss of the driving motor and the power consumption of a cooling system while the driving motor operates in a safe temperature interval, facilitating the improvement of the energy utilization efficiency of a new energy commercial vehicle, and implementing energy conservation and emission reduction.

Description

A new energy commercial vehicle cooling system temperature control method and module

technical field

The invention belongs to the field of automotive electronics, and in particular relates to a temperature control method and module for a heat dissipation system of a new energy commercial vehicle.

Background technique

With the advantages of advanced technology, energy saving and environmental protection, and low operating costs, new energy commercial vehicles have entered a period of rapid development with the acceleration of urbanization.

New energy commercial vehicles adopt the electric drive mode. During the driving process, the stator core and stator winding of the drive motor will generate energy loss. The energy loss is mainly dissipated in the form of heat. If the heat generated is not discharged from the body in time, it will seriously affect The performance and service life of important components such as drive motors. At present, there are few studies on the heat dissipation system of the drive motor of new energy commercial vehicles, and its control method is relatively simple. There is a lack of a control method and system that comprehensively considers the heat loss of the drive motor and the power consumption of the heat dissipation system.

Contents of the invention

The technical problem to be solved by the present invention is to provide a new energy commercial vehicle heat dissipation system temperature control method and system, which solves the above-mentioned technical defects from the control method and hardware module, so as to realize the balance between the heat loss of the drive motor and the power consumption of the heat dissipation system. optimal balance.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A method for temperature control of a heat dissipation system of a new energy commercial vehicle, characterized in that: according to the temperature of the driving motor, the torque of the driving motor, the rotational speed of the driving motor, the temperature of the coolant, the temperature of the outside air, the output voltage of the motor controller, and the output current of the motor controller, Determine the working state of the drive motor, and calculate the optimal target temperature of the drive motor according to the control function associated with the energy optimization control function and the target temperature steady-state control function, and output the corresponding PWM fan control signal.

In the above technical solution, the energy optimization control function calculates the heat loss and cooling system power of the driving motor at various temperatures according to the operating state quantity of the driving motor, and obtains the temperature of the driving motor that reduces the total power; the operating state of the driving motor Quantities include: drive motor temperature, drive motor torque, drive motor speed, coolant temperature, outside air temperature, motor controller output voltage, motor controller output current; the target temperature steady-state control function is output as an energy optimization control function The temperature of the driving motor is taken as the target value, and the current temperature of the driving motor is taken as the state value to ensure that the temperature of the driving motor is stable at the target temperature.

In the above technical scheme, if the key signal is lost for a long time within the specified time limit, the heat dissipation system will operate with the maximum heat dissipation to ensure that the drive motor is at a safe temperature.

A new energy commercial vehicle heat dissipation system temperature control module, characterized in that it includes: a main control chip, a CAN signal conditioning circuit, a power supply chip integrated with CAN transceiver functions, a power supply circuit, a fan drive circuit, a fan current sampling circuit, and a temperature signal sampling circuit and a serial port debugging circuit; the power supply circuit and the CAN signal conditioning circuit are respectively connected to the power supply chip of the integrated CAN transceiver function; the power supply chip of the integrated CAN transceiver function is connected to the CAN communication of the main control chip port and SPI communication port; the fan drive circuit is connected to the PWM channel of the main control chip; the fan current sampling circuit is connected to the first A/D conversion channel of the main control chip; the water tank temperature signal sampling The circuit is connected to the second A\D conversion channel of the main control chip; the external temperature signal sampling circuit is connected to the third A\D conversion channel of the main control chip; the serial port debugging circuit is connected to the main control chip The RS232 communication channel of the control chip.

In the above technical solution, the control flow of the heat dissipation system is as follows: when the power is turned on, if the main control chip is working normally, the main control chip completes the initialization, receives the CAN message containing the motor running state, the temperature analog signal and the fan current signal; the main control chip The control chip calls the energy optimization function. The main tasks of the energy optimization control function include: acquisition of key input signals, calculation of corresponding points in the MAP map of the drive motor, calculation of heat loss at each temperature of the drive motor, calculation of the corresponding speed of the electronic fan at each temperature of the drive motor, and calculation of the corresponding speed of the drive motor. Cooling system power consumption calculation at each temperature, drive motor target temperature calculation, electronic fan speed calculation at the drive motor target temperature, electronic fan speed output, and key input signal loss fault detection; after the main control chip obtains the target temperature and the current temperature of the drive motor, The main control chip calls the temperature steady-state control function. The temperature steady-state control function determines whether the drive motor is at the steady-state target temperature according to the target temperature of the drive motor, the current temperature of the drive motor, and the current speed of the electronic fan, and adjusts the speed of the electronic fan through PI feedback to ensure Steady-state control of the target temperature of the driving motor; after the fan speed is calculated, the main control chip outputs a PWM control signal to drive the fan to work.

In the above technical solution, the main control chip is an embedded control chip, which is set to receive the temperature signal from the engine ECU through CAN communication, and the temperature signal from the water tank temperature and the external air temperature sensor obtained through A/D sampling and the temperature signal from the fan. The current signal of the drive circuit sends a PWM signal to the fan drive circuit to make the fan drive circuit work.

In the above technical solution, the driving object of the fan driving circuit is a DC brushed motor, the PWM signal from the main control chip is connected to the base of the triode Q3 through the resistor R24, and grounded through the resistor R25, and the emitter of the triode Q3 is directly connected to the ground. Grounded, while the emitter and collector of the triode Q3 are connected through the resistor R29, the 12V voltage BATIN obtained through the power circuit processing is connected to the collector of the triode Q3, the bidirectional TVS diode FD1, and the gate of the MOS transistor Q4 through the resistor R23 The substrate of the MOS transistor Q4 is directly connected to the other end of the bidirectional transient suppression diode FD1 and then grounded through the resistor R31. The source and drain of the MOS transistor Q4 are connected through a diode, and the drain of Q4 is connected to the negative electrode of the fan P1. MOTOR1- is connected, and the positive pole MOTOR1+ of the fan is connected to the power supply VBAT to drive the fan to run. When the control chip fails, there is no PWM signal input, and the fan runs at the highest speed.

In the above technical solution, the fan current sampling circuit includes a comparator U1, and the source current signal SENSE1 of the MOS tube Q4 is connected to the same input terminal (+) of the comparator U1 through the resistor R26, and the current signal SENSE1 is grounded through the resistor R31 , the inverting input terminal (-) of the comparator U1 is grounded through the resistor R28, the signal at the output terminal of the comparator U1 is input into the inverting input terminal of the comparator U1 through R30 as a negative feedback signal, and at the same time, the output terminal of the comparator U1 outputs current through the resistor R27 The sampling signal AD_SENSE1 is grounded through the capacitor C17, the +5V working power VCC of the comparator U1 is grounded through the capacitor C19, and the negative voltage working power is grounded.

In the above technical solution, the linearity of the comparator U1 is 1pA.

Therefore, a new energy commercial vehicle heat dissipation system temperature control method and module proposed by the present invention, the temperature control method comprehensively considers the drive motor temperature, drive motor torque, drive motor speed, coolant temperature, motor controller output voltage, The motor controller outputs the current to determine the working state of the driving motor and decides the output of the PWM (Pulse width modulation) fan control signal to ensure that the driving motor runs in a safe operating temperature range and reduce the sum of the heat loss of the driving motor and the power consumption of the cooling system . Based on the method used, the corresponding hardware module is designed, which includes the main control chip, CAN (Controller Area Network) signal conditioning circuit, power chip integrated with CAN transceiver function, power supply circuit, fan drive circuit, fan current sampling circuit, temperature signal sampling circuit And serial debugging circuit.

Compared with the prior art, the present invention is beneficial to improving the energy utilization efficiency of the new energy commercial vehicle and realizing energy saving and emission reduction. By optimizing the output of the heat dissipation system, the best balance between the heat loss of the drive motor and the power consumption of the heat dissipation system is achieved. While making the driving motor run in a safe temperature range, it also reduces the sum of the heat loss of the driving motor and the power consumption of the cooling system, so as to realize energy saving and emission reduction.

Description of drawings

Fig. 1 is a schematic diagram of the hardware structure of the temperature control module of the new energy commercial vehicle cooling system of the present invention.

FIG. 2 is a schematic diagram of the cooling system control method of the present invention.

Fig. 3 is a control flow chart of the energy optimization control function.

Figure 4 is a flow chart of the energy optimization control function.

Figure 5 is the power supply in Figure 1.

Figure 6 is the water tank temperature sampling circuit in Figure 1.

FIG. 7 is the fan driving circuit in FIG. 1 .

Fig. 8 is the fan current sampling circuit in Fig. 1 .

detailed description

The temperature control module of the new energy commercial vehicle heat dissipation system implemented according to the present invention is composed of a main control chip, a power chip integrated with CAN transceiver function, a power supply circuit, a CAN signal conditioning circuit, a fan drive circuit, a fan current sampling circuit, a temperature signal sampling circuit and a serial port. Debugging circuit composition, as shown in Figure 1.

According to the temperature control method of the heat dissipation system of the new energy commercial vehicle implemented in the present invention, according to the temperature of the driving motor, the torque of the driving motor, the speed of the driving motor, the temperature of the coolant, the temperature of the outside air, the output voltage of the motor controller, and the output current of the motor controller, the driving temperature is determined. According to the working state of the motor, according to the energy optimization control function and the target temperature steady-state control function, the temperature target value of the drive motor is calculated and the PWM fan control signal is output to ensure that the drive motor runs within the safe operating temperature range and reduce the overall cost of the drive motor and cooling system. Power, if the key signal is lost for a long time within the specified time limit or the main control chip cannot work normally, the heat dissipation system will operate with the maximum heat dissipation to ensure that the drive motor is at a safe temperature.

Preferably, the main control chip adopts an 8-bit single-chip microcomputer, has 10 A/D channels with 10-bit precision and 6 PWM channels, and the power chip is integrated with a CAN transceiver function. The power circuit and the CAN signal conditioning circuit are connected to the corresponding interface of the power chip integrated with the CAN transceiver function, and the power chip and other four circuits are connected to the corresponding interface of the main control chip. The new energy commercial vehicle power supply is input to the power chip through the power circuit, and the power chip then supplies power to the main control chip.

The control system structure of the heat dissipation system is shown in Figure 2. When the power is turned on, if the main control chip is working normally, the main control chip will complete initialization and receive CAN messages containing motor operating status, temperature analog signal and fan current signal. The main control chip calls the energy optimization function. The main tasks of the energy optimization control function include: acquisition of key input signals, calculation of corresponding points in the MAP map of the driving motor, calculation of heat loss at each temperature of the driving motor, calculation of the corresponding speed of the electronic fan at each temperature of the driving motor, and driving Calculation of power consumption of the cooling system at each temperature of the motor, calculation of the target temperature of the drive motor, calculation of the speed of the electronic fan at the target temperature of the drive motor, output of the speed of the electronic fan, and detection of key input signal loss faults, as shown in Figure 3. After the main control chip obtains the target temperature and the current temperature of the driving motor, the main control chip calls the temperature steady-state control function, which determines whether the driving motor is at the steady-state target temperature according to the target temperature of the driving motor, the current temperature of the driving motor and the current speed of the electronic fan. And the electronic fan speed is adjusted through PI feedback to ensure the steady-state control of the target temperature of the drive motor, as shown in Figure 4. After the fan speed is calculated, the main control chip outputs a PWM control signal to drive the fan to work.

Preferably, the running state quantity of the drive motor from the ECU of the new energy commercial vehicle passes through the CAN signal conditioning circuit, is received by the power chip integrated with the CAN transceiver function, and then sent to the CAN communication port of the main control chip, and the main control chip passes through the SPI communication port Interact with the power chip to ensure the stable operation of the system. The power chip selects Freescale's second-generation system basis chip MC33903 as the power management of the ECU. The chip can stabilize the 5V power supply output, and integrates the serial peripheral interface SPI and CAN transceiver.

Preferably, the power supply circuit is shown in Figure 5, and its function is to convert the 24V power supply VBAT of the new energy commercial vehicle into a 12V voltage BATIN that can be input to the power supply chip. Wherein, the power supply VBAT is grounded through resistors R3 and R7, and the TVS diode D4 is connected in parallel with R7. Connect both ends of R7 to pin 1 and pin 4 of MOS tube Q1 respectively, pin 4 of MOS tube Q1 is connected to the power supply VBAT, pin 3 of Q1 is connected to the power supply pin of the power chip integrated with CAN transceiver function.

The cooling water tank temperature signal (analog signal) is input to the A/D channel of the main control chip through the water tank temperature signal sampling circuit, and the external air temperature signal (analog signal) is input to the A/D channel of the main control chip through the temperature signal sampling circuit. The current signal (analog signal) is input to the A/D channel of the main control chip through the fan current sampling circuit.

Preferably, the temperature sampling circuit takes a water tank temperature sampling circuit as an example, and the outside air temperature sampling circuit is similar to the water tank temperature sampling circuit. Referring to Fig. 6, the function of the temperature signal sampling circuit is to collect the voltage at both ends of the resistive temperature sensor as a temperature signal and input it into the second A/D channel of the main control chip. Among them, P2 is the temperature sensor interface, the 5V voltage VCC is grounded through the resistor R6 and the temperature sensor, the capacitor C11 is connected in parallel with the temperature sensor, the temperature signal AD_temp is connected to the 3 pin of the transient suppression diode D1, and then input to the A/D channel of the main control chip , Pin 2 of D1 is connected to 5V voltage VCC, and pin 1 is grounded.

The present invention will be further described below, but the present invention is not limited.

Combined with Figure 7, the function of the fan circuit is: the PWM control signal PWM1 is input to pin 1 of the triode Q3 to control the on-off of pin 3 and pin 2 of the triode, thereby controlling the voltage change of the gate of the MOS tube and controlling the source of the MOS tube The on-off of the pole and the drain, thus controlling the speed of the fan. If the main control chip does not work normally, the PWM control signal cannot be output, that is, there is no PWM1 signal input in Figure 7, and the transistor Q3 does not work. After the BATIN voltage generated by the power chip is divided by the resistor R23, the gate of the MOS transistor Q4 is maintained. The source voltage is stable, making its drain output voltage the highest, driving the fan to rotate at the highest speed.

The linearity of the comparator U1 is preferably 1pA. The source current signal SENSE1 of the collected MOS transistor Q4 is connected to the same input terminal (+) of the comparator U1 through the resistor R26. At the same time, the current signal SENSE1 is grounded through the resistor R31, and the comparator U1 The inverting input terminal (-) is grounded through the resistor R28, and the output signal of the comparator U1 is input into the inverting input terminal of the comparator U1 through R30 as a negative feedback signal. At the same time, the output terminal of the comparator U1 outputs the current sampling signal AD_SENSE1 through the resistor R27, and at the same time The capacitor C17 is grounded, the +5V working power VCC of the comparator U1 is grounded through the capacitor C19, and the negative voltage working power is grounded.

Referring to Fig. 8, the function of the fan current sampling circuit is to collect the current signal of the source of the MOS transistor Q4, amplify it and input it to the first A/D channel of the main control chip. Among them, the core component is the comparator U1, the source current signal SENSE1 of the collected MOS transistor Q4 is input to the 3 pin of the comparator U1 through the resistor R26, the 2 pin of U1 is connected to the ground of the resistor R31 through the resistor R28, and the ground of the U1 Pin 1 outputs the amplified signal, and outputs signal AD_SENSE1 through resistor 27; pin 8 of U1 is connected to 5V VCC, pin 4 is grounded, and R30 is connected in parallel between

pins

1 and 2 of U1. In the hardware circuit, the electronic fan selects the DC 24V brushed axial flow fan of COMEX Company, and the rated current is 16A. IRFB3307Z enhanced N-channel MOS tube can be selected. The MOS tube has an operating voltage of ±20V and a maximum continuous drain current of 120A, which can withstand the peak starting current of the electronic fan.

The content not described in detail in this specification is the prior art known to those skilled in the art. The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and its purpose is to allow those familiar with this technology to understand the content of the present invention and According to implementation, the protection scope of the present invention cannot be limited by this. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

A method for temperature control of a heat dissipation system of a new energy commercial vehicle, characterized in that: according to the temperature of the driving motor, the torque of the driving motor, the rotational speed of the driving motor, the temperature of the coolant, the temperature of the outside air, the output voltage of the motor controller, and the output current of the motor controller, Determine the working state of the drive motor, and calculate the optimal target temperature of the drive motor according to the control function associated with the energy optimization control function and the target temperature steady-state control function, and output the corresponding PWM fan control signal.
The temperature control method of the heat dissipation system of a new energy commercial vehicle according to claim 1, wherein the energy optimization control function calculates the heat loss of the drive motor at various temperatures and the power of the cooling system according to the operating state quantity of the drive motor, and calculates The temperature of the driving motor that makes the total power reduce; the running state quantity of the driving motor includes: the temperature of the driving motor, the torque of the driving motor, the speed of the driving motor, the temperature of the coolant, the temperature of the outside air, the output voltage of the motor controller, the output of the motor controller Current; the target temperature steady-state control function takes the drive motor temperature output by the energy optimization control function as the target value, and takes the current temperature of the drive motor as the state value to ensure that the temperature of the drive motor is stable at the target temperature.
The temperature control method of the heat dissipation system of a new energy commercial vehicle according to claim 1, characterized in that: if a key signal is lost for a long time within a specified time limit, the heat dissipation system operates at the maximum heat dissipation to ensure that the driving motor is at a safe temperature.
A new energy commercial vehicle heat dissipation system temperature control module, characterized in that it includes: a main control chip, a CAN signal conditioning circuit, a power supply chip integrated with CAN transceiver functions, a power supply circuit, a fan drive circuit, a fan current sampling circuit, and a temperature signal sampling circuit and a serial port debugging circuit; the power supply circuit and the CAN signal conditioning circuit are respectively connected to the power supply chip of the integrated CAN transceiver function; the power supply chip of the integrated CAN transceiver function is connected to the CAN communication of the main control chip port and SPI communication port; the fan drive circuit is connected to the PWM channel of the main control chip; the fan current sampling circuit is connected to the first A/D conversion channel of the main control chip; the water tank temperature signal sampling The circuit is connected to the second A\D conversion channel of the main control chip; the external temperature signal sampling circuit is connected to the third A\D conversion channel of the main control chip; the serial port debugging circuit is connected to the main control chip The RS232 communication channel of the control chip.
The temperature control module of the heat dissipation system of a new energy commercial vehicle according to claim 4, which is characterized in that it is applied to the heat dissipation system of a new energy commercial vehicle, and is set to work in the following manner: when the power is turned on, if the main control chip is working normally, The main control chip completes the initialization, and receives the CAN message containing the motor running state, the temperature analog signal and the fan current signal; the main control chip calls the energy optimization function, and the main tasks of the energy optimization control function include: key input signal acquisition, drive motor MAP Calculation of corresponding points in the figure, calculation of heat loss at each temperature of the drive motor, calculation of the corresponding speed of the electronic fan at each temperature of the drive motor, calculation of power consumption of the cooling system at each temperature of the drive motor, calculation of the target temperature of the drive motor, and the speed of the electronic fan at the target temperature of the drive motor Calculation, electronic fan speed output, and key input signal loss fault detection; after the main control chip obtains the target temperature and the current temperature of the drive motor, the main control chip calls the temperature steady-state control function, and the temperature steady-state control function is based on the target temperature of the drive motor, the drive motor The current temperature and the current speed of the electronic fan determine whether the drive motor is at the steady-state target temperature, and adjust the speed of the electronic fan through PI feedback to ensure the steady-state control of the target temperature of the drive motor; after the fan speed is calculated, it is controlled by the main control chip output PWM The signal drives the fan to work.
The temperature control module of the heat dissipation system of a new energy commercial vehicle according to claim 4, wherein the main control chip is an embedded control chip, which is configured to receive a temperature signal from the engine ECU through CAN communication, and obtain it through A/D sampling The temperature signals from the water tank temperature and the outside air temperature sensor and the current signal from the fan drive circuit send PWM signals to the fan drive circuit to make the fan drive circuit work.
The temperature control module of the new energy commercial vehicle heat dissipation system according to claim 4, wherein the driving object of the fan drive circuit is a DC brushed motor, and the PWM signal from the main control chip is connected to the transistor Q3 through a resistor R24 The base of the triode Q3 is grounded through the resistor R25, the emitter of the triode Q3 is directly grounded, and the emitter of the triode Q3 is connected to the collector through the resistor R29, and the 12V voltage BATIN obtained through the processing of the power supply circuit is connected to the triode through the resistor R23 The collector of Q3, the bidirectional TVS diode FD1, the gate of MOS transistor Q4, the substrate of MOS transistor Q4 is directly connected to the other end of bidirectional transient suppression diode FD1 and grounded through resistor R31, the source and drain of MOS transistor Q4 The drain of Q4 is connected to the negative pole MOTOR1- of the fan P1, and the positive pole MOTOR1+ of the fan is connected to the power supply VBAT to drive the fan to run. When the control chip fails, there is no PWM signal input, and the fan operates at the highest speed running.
The temperature control module of the new energy commercial vehicle heat dissipation system according to claim 4, wherein the fan current sampling circuit includes a comparator U1, and the source current signal SENSE1 of the MOS transistor Q4 is connected to the comparator U1 through a resistor R26. At the same time, the current signal SENSE1 is grounded through the resistor R31, the inverting input terminal (-) of the comparator U1 is grounded through the resistor R28, and the output signal of the comparator U1 is input as a negative feedback signal through R30 to the reverse of the comparator U1. At the same time, the output terminal of the comparator U1 outputs the current sampling signal AD_SENSE1 through the resistor R27, and at the same time it is grounded through the capacitor C17, the +5V working power VCC of the comparator U1 is grounded through the capacitor C19, and the negative voltage working power is grounded.
The temperature control module of the heat dissipation system of a new energy commercial vehicle according to claim 4, wherein the linearity of the comparator U1 is 1pA.