A method for estimating temperature of cooling liquid of motor controller for vehicle, motor controller and vehicle

Abstract

The application discloses a kind of estimating the temperature of motor controller cooling fluid of vehicle, estimating the temperature of motor controller cooling fluid of vehicle method includes: the maximum sampling temperature is detected by the temperature sensor inside IGBT power module;According to the current working state information of motor controller, the loss of the IGBT power module is calculated;According to the maximum sampling temperature, the loss of the IGBT power module and the thermal resistance parameter of the temperature sensor inside the IGBT power module, determine cooling fluid temperature.The application can obtain the temperature of cooling fluid by simple calculation, and the calculation is small, and simple to realize.

Description

Technical Field

[0001] This invention relates to the field of vehicle control technology, and in particular to a method for estimating the coolant temperature of an automotive motor controller, the motor controller, and the vehicle. Background Technology

[0002] The electric drive three-in-one system (motor controller, reducer, and motor) is the core equipment of electric vehicles. Although it can efficiently convert the DC power from the battery into the three-phase AC power required for electric operation, it still generates a lot of heat during its operation, including losses in the controller and various copper and iron losses in the motor. Therefore, additional coolant is needed to dissipate heat from the components.

[0003] However, existing technologies calculate coolant temperature based on the power module's losses and thermal resistance. Therefore, the calculation of coolant temperature depends on accurate junction temperature calculation, module heat loss calculation, and thermal resistance information from the power module junction to the coolant. This requires a lot of information and involves a large amount of calculation. Summary of the Invention

[0004] The purpose of this invention is to provide a method for estimating the coolant temperature of an automotive motor controller, the motor controller itself, and the vehicle. The coolant temperature can be obtained through simple calculations, requiring minimal computation and being easy to implement.

[0005] This invention provides a method for estimating the coolant temperature of an automotive motor controller, comprising: detecting the maximum sampling temperature using a temperature sensor inside the IGBT power module; calculating the losses of the IGBT power module based on the current operating status information of the motor controller; and determining the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameter of the temperature sensor inside the IGBT power module.

[0006] In one embodiment, the method for determining the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameter of the temperature sensor inside the IGBT power module includes: determining the temperature rise of the internal temperature sensor of the IGBT power module caused by the losses of the IGBT power module based on the product of the losses of the IGBT power module and the thermal resistance parameter of the internal temperature sensor of the IGBT power module; and determining the coolant temperature based on the difference between the maximum sampling temperature and the temperature rise of the internal temperature sensor of the IGBT power module.

[0007] In one embodiment, the method for obtaining the maximum sampling temperature by detecting the temperature sensor inside the IGBT power module includes: acquiring the sampling temperatures detected by the temperature sensors inside the IGBT power modules of the three branches located in the upper phase arm of the six branches connected to the motor; and taking the maximum sampling temperature among the three sampling temperatures detected by the temperature sensors inside the IGBT power modules of the three branches located in the upper phase arm as the maximum sampling temperature obtained by detecting the temperature sensor inside the IGBT power module.

[0008] In one embodiment, the method for calculating the losses of the IGBT power module based on the current operating status information of the motor controller includes: acquiring the operating status information, which includes output current, output frequency, output modulation ratio, junction temperature, switching frequency, and bus voltage; and determining the losses of the IGBT power module based on the output current, output frequency, output modulation ratio, junction temperature, switching frequency, and bus voltage.

[0009] In one embodiment, the method for determining the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameters of the temperature sensor inside the IGBT power module includes: performing a step load thermal test; and obtaining the thermal resistance parameters of the temperature sensor inside the IGBT power module.

[0010] In one embodiment, the over-temperature protection method includes: reducing the switching frequency or current output value of the motor.

[0011] The present invention also discloses a motor controller, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the steps of the method for estimating the coolant temperature of an automotive motor controller as described in any of the preceding claims.

[0012] In one embodiment, the motor controller includes a register, which includes an output current and power module loss table.

[0013] The present invention also discloses a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, it implements the steps of the method for estimating the coolant temperature of a vehicle motor controller as described in any of the preceding claims.

[0014] The above-described method for estimating the coolant temperature of a vehicle motor controller, along with the motor controller and the vehicle, allows for simple calculations to determine the coolant temperature. The calculations are minimal and the implementation is straightforward. Attached Figure Description

[0015] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0016] Figure 1 This is a schematic diagram of a method for estimating the coolant temperature of an automotive motor controller according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the structure of an IGBT power module according to an embodiment of the present invention.

[0018] Figure 3 The coolant temperature curve is obtained according to a method for estimating the coolant temperature of an automotive motor controller, as described in an embodiment of the present invention.

[0019] Figure 4 This is a thermal network parameter curve of the internal temperature sensor of an IGBT power module according to an embodiment of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Figure 1 This is a schematic diagram illustrating a method for estimating the coolant temperature of an automotive motor controller according to a first embodiment of the present invention. Figure 1 As shown, the method for estimating the coolant temperature of an automotive motor controller includes:

[0022] Step S1: The maximum sampling temperature is obtained by detecting the temperature sensor inside the IGBT power module.

[0023] Specifically, each of the six branches connected to the motor is equipped with an IGBT power module to control switching elements and obtain the required current. By installing temperature sensors inside the IGBT power modules, the temperature of the IGBT power modules can be monitored in real time, preventing motor damage if the IGBT power module temperature exceeds a preset temperature. Therefore, multiple temperature sensors can be installed inside the IGBT power modules on the six branches to detect multiple temperatures. The maximum sampling temperature can then be determined by the temperature sensor inside each IGBT power module to prevent motor damage if any IGBT power module temperature exceeds the preset temperature. The temperature sensors installed inside the IGBT power modules can be NTC temperature sensors.

[0024] In one embodiment, Figure 2 This is a schematic diagram of the structure of an IGBT power module according to an embodiment of the present invention, as shown below. Figure 2As shown, the method for obtaining the maximum sampling temperature by detecting the temperature sensor inside the IGBT power module includes: acquiring the sampling temperatures detected by the internal temperature sensors of the IGBT power modules in the three branches of the upper phase bridge arm among the six branches connected to the motor; and taking the maximum sampling temperature among the three sampling temperatures detected by the internal temperature sensors of the IGBT power modules in the three branches of the upper phase bridge arm as the maximum sampling temperature obtained by the temperature sensor inside the IGBT power module. In one embodiment, as... Figure 2 As shown, each branch connected to the motor can be equipped with multiple IGBT power modules. Thus, the sampled temperature detected by the temperature sensor inside an IGBT power module in the upper arm of a phase can be used as the temperature of multiple IGBT power modules in the upper and lower arms of that phase. For example, a temperature sensor is installed inside the IGBT power module in the upper arm of phase U, and the sampled temperature detected by this temperature sensor can be used as the temperature of multiple IGBT power modules in the upper and lower arms of phase U.

[0025] Of course, this embodiment does not limit the installation of temperature sensors inside the IGBT power modules of the three branches in the upper phase bridge arm. For example, temperature sensors can be installed inside the IGBT power modules of the three branches in the lower phase bridge arm. Correspondingly, this embodiment does not limit the use of the maximum sampling temperature among the three sampling temperatures detected by the temperature sensors inside the IGBT power modules of the three branches in the upper phase bridge arm as the maximum sampling temperature obtained by the temperature sensors inside the IGBT power modules. For example, the maximum sampling temperature among the three sampling temperatures detected by the temperature sensors inside the IGBT power modules of the three branches in the lower phase bridge arm can be used as the maximum sampling temperature obtained by the temperature sensors inside the IGBT power modules.

[0026] Step S2: Calculate the losses of the IGBT power module based on the current operating status information of the motor controller.

[0027] In one embodiment, a method for calculating the losses of an IGBT power module based on the current operating state information of the motor controller includes: acquiring operating state information, including output current, output frequency, output modulation ratio, junction temperature, switching frequency, and bus voltage; and determining the losses of the IGBT power module based on the output current, output frequency, output modulation ratio, junction temperature, switching frequency, and bus voltage. In another embodiment, the loss P of the IGBT power module is... lass IGB7 The calculation formula can be:

[0028] P loss-IOBT =P table [T]·K f_P (f)·KM_P (M)·K Tj_F (T j )·K fsw_P (f sw )·K vde_P (Vdc)

[0029] in:

[0030] P table [I] is a table storing the output current and power module losses; Kf_p(f) is the function relating output frequency and losses; KM_p(M) is the function relating output modulation ratio and losses; KTmp_p(Tj) is the function relating junction temperature and losses; Kfsw_p(fsw) is the function relating switching frequency and losses; KVdc_p(Vdc) is the function relating bus voltage and losses.

[0031] Step S3: Determine the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameters of the temperature sensor inside the IGBT power module.

[0032] In one embodiment, a method for determining the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameter of the temperature sensor inside the IGBT power module includes: determining the coolant temperature based on the product of the losses of the IGBT power module and the thermal resistance parameter of the temperature sensor inside the IGBT power module, i.e., P. loss_FGBT *Z th_j_nte The temperature rise of the internal temperature sensor of the IGBT power module caused by IGBT power module losses is determined; based on the difference between the maximum sampling temperature and the temperature rise of the internal temperature sensor of the IGBT power module, the coolant temperature, i.e., coolant temperature T, is determined. the-Est The calculation formula is: T tha-Est =T NTC -P loss_JOBT *Z th_i_nte .

[0033] Figure 3 This is a coolant temperature curve obtained according to a method for estimating the coolant temperature of an automotive motor controller, as described in an embodiment of the present invention. Figure 3 As shown, the method for estimating the coolant temperature of an automotive motor controller according to this embodiment can yield an estimated coolant temperature under the following conditions: 30°C, 340V bus voltage, motor operation at 6000rpm, and three-phase current increased from 0A to 400A. Even during dynamic load changes, the accuracy of the coolant temperature estimation can be guaranteed within ±4°C, which meets the requirements of system applications.

[0034] The method for estimating the coolant temperature of an automotive motor controller according to embodiments of the present invention can obtain the coolant temperature through simple calculation, with minimal computational load and simple implementation.

[0035] In one embodiment, the method for determining the coolant temperature based on the maximum sampling temperature, the losses of the IGBT power module, and the thermal resistance parameter of the temperature sensor inside the IGBT power module includes: performing a step load thermal test; and obtaining the thermal resistance parameter of the temperature sensor inside the IGBT power module. Specifically, obtaining the thermal resistance parameter of the temperature sensor inside the IGBT power module through calculation would be quite complex, while the thermal resistance parameter of the temperature sensor inside the IGBT power module can be obtained more easily through a step load thermal test, saving calculation time and improving the response speed of over-temperature protection.

[0036] In one embodiment, a thermal network model of the coolant temperature is established based on the thermal network parameters of the temperature sensor inside the IGBT power module. Therefore, the coolant temperature can be determined relatively quickly using this thermal network model. Furthermore, the coolant temperature can be used to calculate parameters of other components, such as the temperature of the motor rotor, thus preventing dangerous accidents caused by overheating. Figure 4 This is a thermal network parameter curve of the internal temperature sensor of an IGBT power module according to an embodiment of the present invention. In one embodiment, the parameter curve is obtained as follows: Figure 2 The thermal network parameters of the three temperature sensors shown can be obtained offline using dedicated testing equipment and are generally expressed using 2nd-4th order thermal resistance parameters. The calculation expression for the thermal network parameters of the temperature sensor inside the IGBT power module is as follows:

[0037]

[0038] Among them, F i =H thi C tht R thi For the thermal resistance of the IGBT power module, C thi This refers to the heat capacity of the IGBT power module.

[0039] In one embodiment, the method for estimating the coolant temperature of the vehicle motor controller further includes: determining the temperature of the motor rotor or the junction temperature of the IGBT power module based on the coolant temperature; determining whether the temperature of the motor rotor exceeds a preset temperature; and if so, performing over-temperature protection.

[0040] In one embodiment, the over-temperature protection method includes reducing the switching frequency or current output value of the motor. This embodiment does not specifically limit the over-temperature protection; over-temperature protection may include reducing the switching frequency or current output value of the motor, and may also include using other methods to limit the torque of the motor, stop the motor, etc.

[0041] Based on the same inventive concept, embodiments of the present invention also provide a motor controller, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for estimating the coolant temperature of the vehicle motor controller according to any of the above embodiments.

[0042] In one embodiment, the motor controller includes a register that includes an output current and a power module loss table for calculating the IGBT power module loss P. loss IGB7 .

[0043] The implementation of this motor controller can be found in the above-described embodiment of the method for estimating the coolant temperature of an automotive motor controller; details that are repeated will not be repeated here.

[0044] Based on the same inventive concept, this invention also provides a vehicle, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the method for estimating the coolant temperature of the vehicle motor controller according to any of the above embodiments. The implementation of this vehicle can refer to the embodiments of the method for estimating the coolant temperature of the vehicle motor controller described above, and the repeated parts will not be described again.

[0045] The method for estimating the coolant temperature of a vehicle motor controller, the motor controller, and the vehicle according to embodiments of the present invention can obtain the coolant temperature through simple calculation, with minimal computational load and simple implementation.

[0046] This document uses specific examples to illustrate the principle and implementation of the method for estimating the coolant temperature of an automotive motor controller according to the present invention. The above description of the implementation is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention, and the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A method of estimating a temperature of a cooling liquid of a motor controller for a vehicle, characterized by, The method comprises the following steps: detecting a maximum sampling temperature by a temperature sensor inside an IGBT power module; calculating a loss of the IGBT power module according to current working state information of a motor controller; determining a coolant temperature according to the maximum sampling temperature, the loss of the IGBT power module and a thermal resistance parameter of the temperature sensor inside the IGBT power module. The method of determining the coolant temperature according to the maximum sampling temperature, the loss of the IGBT power module and the thermal resistance parameter of the temperature sensor inside the IGBT power module comprises: determining a temperature rise of the temperature sensor inside the IGBT power module caused by the loss of the IGBT power module according to a product value of the loss of the IGBT power module and the thermal resistance parameter of the temperature sensor inside the IGBT power module; determining the coolant temperature according to a difference between the maximum sampling temperature and the temperature rise of the temperature sensor inside the IGBT power module.

2. The method of estimating temperature of cooling liquid of motor controller for vehicle according to claim 1, wherein, The method of detecting the maximum sampling temperature by the temperature sensor inside the IGBT power module comprises: obtaining sampling temperatures detected by temperature sensors inside IGBT power modules of three branches of a phase upper bridge arm from six branches connected with a motor; taking a maximum sampling temperature from the three sampling temperatures detected by the temperature sensors inside the IGBT power modules of the three branches of the phase upper bridge arm as the maximum sampling temperature detected by the temperature sensor inside the IGBT power module.

3. The method of estimating temperature of coolant of motor controller for vehicle according to claim 1, wherein, The method of calculating the loss of the IGBT power module according to the current working state information of the motor controller comprises: obtaining the working state information, wherein the working state information comprises an output current, an output frequency, an output modulation ratio, a junction temperature, a switching frequency and a bus voltage; determining the loss of the IGBT power module according to the output current, the output frequency, the output modulation ratio, the junction temperature, the switching frequency and the bus voltage.

4. The method of estimating temperature of coolant of motor controller for vehicle according to claim 1, wherein, The method of determining the coolant temperature according to the maximum sampling temperature, the loss of the IGBT power module and the thermal resistance parameter of the temperature sensor inside the IGBT power module comprises: performing a step load thermal test; obtaining the thermal resistance parameter of the temperature sensor inside the IGBT power module.

5. The method of estimating temperature of coolant of motor controller for vehicle according to claim 1, wherein, The method further comprises: determining a temperature of a motor rotor or a junction temperature of the IGBT power module according to the coolant temperature; judging whether the temperature of the motor rotor exceeds a preset temperature, and performing an over-temperature protection if the temperature exceeds the preset temperature.

6. The method of estimating temperature of cooling liquid of motor controller for vehicle according to claim 5, wherein The method of the over-temperature protection comprises: reducing a switching frequency or a current output value of the motor.

7. An electric machine controller characterized by The method comprises: a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method of estimating a coolant temperature of a motor controller according to any one of claims 1 to 6.

8. The motor controller of claim 7, wherein, The motor controller comprises a register, and the register comprises an output current and a power module loss table.

9. A vehicle characterized by comprising: The method comprises: The memory, the processor and the computer program stored in the memory and executable on the processor, when the processor executes the computer program, implement the method for estimating the temperature of the cooling liquid of the motor controller for vehicle according to any one of claims 1 to 6.

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