CN-121984410-A - Method and system for constructing thermal network model of integrated motor

CN121984410ACN 121984410 ACN121984410 ACN 121984410ACN-121984410-A

Abstract

The invention relates to a method and a system for constructing a thermal network model of an integrated motor, wherein the method comprises the steps of inputting different currents into a first controller, acquiring first heating data and second heating data corresponding to each current, calculating thermal network model parameters of the first controller according to the first heating data corresponding to each current to obtain controller model parameters, calculating thermal network model parameters of the second motor according to the second heating data corresponding to each current to obtain motor model parameters, constructing a thermal network model state equation of the integrated motor according to the controller model parameters and the motor model parameters, utilizing a controller of one integrated motor to supply power to a motor of the other integrated motor, respectively acquiring heating data of the two integrated motors, and respectively utilizing the acquired heating data of the two integrated motors to calculate model parameters of the two controllers and the motor, thereby obtaining more accurate model parameters.

Inventors

ZHANG YUXI
WU CHENGQIU
Zou Renfang
HAO XIN
BAI YANG
HU WEIJIE
CHENG XIAOTAO
HE YONG
Zhi Chuanyin
GUI BIN

Assignees

辰致科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251205

Claims (10)

1. The method for constructing the thermal network model of the integrated motor is characterized by comprising the following steps of: inputting different currents to a first controller, and acquiring first heating data and second heating data corresponding to each current, wherein the first heating data are heating data of the first controller, the second heating data are heating data of a second motor, the first motor and the first controller share one shell, the first motor is disconnected from the first controller, the second motor and the second controller share one shell, and the first controller and the second motor are electrically connected through wires so as to drive the second motor by using the first controller; calculating a thermal network model parameter of the first controller according to the first heating data corresponding to each current to obtain a controller model parameter; Calculating a thermal network model parameter of the second motor according to the second heating data corresponding to each current to obtain a motor model parameter; and constructing a thermal network model state equation of the integrated motor according to the controller model parameters and the motor model parameters.
2. The method for constructing a thermal network model of an integrated motor according to claim 1, wherein different currents are input to a first controller, and first temperature rise data and second temperature rise data corresponding to each of the currents are acquired, comprising the steps of: Inputting different currents to the first controller; when the second motor rotates after inputting the current, step current alternating current signals with different preset amplitudes are input on the d-axis of the phase current at intervals of preset time until the temperature of a stator winding of the second motor exceeds a preset temperature, the input of the step current alternating current signals is stopped, and the next current is input for the first controller after the ambient temperature is reduced to the room temperature; Recording temperature rise data of a circuit board of the first controller measured by a thermistor during the period from the current input of the first controller until the ambient temperature is reduced to the room temperature, and obtaining the first temperature rise data; And recording temperature rise data of a circuit board of the second controller measured by the thermistor during the period from the current input of the first controller until the ambient temperature is reduced to the room temperature, and obtaining the second temperature rise data.
3. The method for constructing a thermal network model of an integrated motor according to claim 2, wherein the calculation of the thermal network model parameters of the first controller according to the first temperature rise data corresponding to each current to obtain controller model parameters includes the steps of: acquiring the relation between the thermal resistance parameters of each preset part of the first controller and each preset thermal resistance coefficient through a thermal network model according to the first heating data corresponding to each current; Solving the relation between the thermal resistance parameters of all preset parts and all preset thermal resistance coefficients through a second-order thermal network model, and determining the thermal resistance parameters of all preset parts of the first controller, wherein the controller model parameters comprise the thermal resistance parameters of all preset parts of the first controller.
4. The method for constructing a thermal network model of an integrated motor according to claim 3, wherein calculating the thermal network model parameters of the second motor according to the second temperature rise data corresponding to each current to obtain the motor model parameters comprises the following steps: Acquiring the relation between the thermal resistance parameters of each preset part of the second motor and each preset thermal resistance coefficient through a thermal network model according to the second heating data corresponding to each current; Solving the relation between the thermal resistance parameters of all preset parts and the thermal resistance coefficients of all preset parts through a second-order thermal network model, and determining the thermal resistance parameters of all preset parts of the second motor, wherein the motor model parameters comprise the thermal resistance parameters of all preset parts of the second motor.
5. The method for constructing a thermal network model of an integrated motor according to claim 4, wherein the relationship between the thermal resistance parameter of each preset part and each preset thermal resistance coefficient is solved by a second-order thermal network model, and the thermal resistance parameter of each preset part of the first controller is determined, and the calculation formula is as follows: ; Wherein, the The controller PCB heat capacity of the first controller is represented; Representing an end cap heat capacity in contact with a controller PCB board of the first controller; representing a thermal resistance between a controller PCB board of the first controller and the housing; representing thermal resistance between the controller PCB of the first controller and the end cover; 、、、、 The thermal resistance parameters of each preset component of the first controller comprise the heat capacity of the controller PCB, the heat capacity of the end cover contacted with the controller PCB, the thermal resistance between the controller PCB and the shell and the thermal resistance between the controller PCB and the end cover.
6. The method for constructing a thermal network model of an integrated motor according to claim 5, wherein the relationship between the thermal resistance parameter of each preset part and each preset thermal resistance coefficient is solved by a second-order thermal network model, and the thermal resistance parameter of each preset part of the second motor is determined, and the calculation formula is as follows: ; Wherein, the Representing the stator winding heat capacity of the second electric machine, Representing the stator core heat capacity of the second motor, Representing a thermal resistance between a stator winding and a stator core of the second electric machine; The thermal resistance parameters of all preset parts of the second motor comprise heat capacity of a stator winding, heat capacity of the stator core, thermal resistance between the stator winding and the stator core and thermal resistance between the stator core and the external environment.
7. The method of claim 6, wherein the expression of the state equation of the thermal network model is as follows: ; Wherein, the A temperature matrix representing the various components of the integrated motor, Representing a heat consumption matrix of the various components of the integrated motor, 、、、 Representing the coefficients of the state equation of the thermal network model, respectively.
8. The method of constructing a thermal network model of an integrated motor of claim 7, wherein the temperature matrix of each component of the integrated motor is represented as follows: ; Wherein, the Indicating the temperature of the stator windings, The temperature of the stator core is indicated, The temperature of the PCB of the controller is indicated, Indicating the temperature of the end cap in contact with the controller PCB board, Indicating the temperature of the external environment, superscript Representing a matrix transposition operation.
9. The method for constructing a thermal network model of an integrated motor according to claim 7, wherein the heat consumption matrix of each component of the integrated motor is represented as follows: ; Wherein, the Indicating the copper loss of the stator winding; Indicating the controller heat consumption.
10. A thermal network model building system for an integrated motor, comprising: The system comprises a data acquisition module, a first controller, a second controller, a first motor, a second motor, a wire, a first controller and a second controller, wherein the data acquisition module is used for inputting different currents to the first controller and acquiring first heating data and second heating data corresponding to each current, the first heating data is heating data of the first controller, the second heating data is heating data of the second motor, the first motor and the first controller share one shell, the first motor is disconnected with the first controller, the second motor and the second controller share one shell, and the first controller and the second motor are electrically connected through the wire so as to drive the second motor by using the first controller; the parameter calculation module is used for calculating the thermal network model parameters of the first controller according to the first temperature rise data corresponding to each current to obtain controller model parameters; and the model construction module is used for constructing a thermal network model state equation of the integrated motor according to the controller model parameters and the motor model parameters.

Description

Method and system for constructing thermal network model of integrated motor Technical Field The invention relates to the technical field of motor temperature estimation, in particular to a method and a system for constructing a thermal network model of an integrated motor. Background Since the electric power steering system (integrated motor) is of a short-time operation system, but occasionally, the heating caused by the continuous high-torque operation condition is serious, a temperature protection function is required, and since the integrated motor is usually not provided with a stator winding temperature sensor, the temperature of the motor winding is estimated. The temperature rise model of the equivalent thermal path method is often adopted to estimate the temperature of the integrated motor, so that the calculated amount is small, and the error is within an acceptable range. The motor part and the controller part of the integrated motor can generate heat, and the controller can conduct heat to the motor when the integrated motor operates, so that the temperature is increased, and the calculation error is larger when the temperature rise model of the equivalent thermal path method is adopted for temperature estimation of the integrated motor. Disclosure of Invention The invention provides a method and a system for constructing a thermal network model of an integrated motor, aiming at solving the technical problems that in the prior art, when an integrated motor is operated, the heat of a controller is transmitted to the motor to cause the temperature increase, so that when the temperature rise model of an equivalent thermal path method is adopted to carry out temperature estimation of the integrated motor, the calculation error is large and the like. The technical scheme for solving the technical problems is as follows: A method for constructing a thermal network model of an integrated motor comprises the following steps: inputting different currents to a first controller, and acquiring first heating data and second heating data corresponding to each current, wherein the first heating data are heating data of the first controller, the second heating data are heating data of a second motor, the first motor and the first controller share one shell, the first motor is disconnected from the first controller, the second motor and the second controller share one shell, and the first controller and the second motor are electrically connected through wires so as to drive the second motor by using the first controller; calculating a thermal network model parameter of the first controller according to the first heating data corresponding to each current to obtain a controller model parameter; Calculating a thermal network model parameter of the second motor according to the second heating data corresponding to each current to obtain a motor model parameter; and constructing a thermal network model state equation of the integrated motor according to the controller model parameters and the motor model parameters. The method has the advantages that when the thermal network model of the integrated motor is built, the two integrated motors are adopted, the controller of one of the integrated motors is used for supplying power to the motor of the other integrated motor, the heating data of the two integrated motors are respectively collected, heating data which are not affected by the controller and the motor are obtained, the model parameters of the two controllers and the motor are respectively calculated by the collected heating data of the two integrated motors, and therefore more accurate model parameters are obtained, and therefore, the method can improve the precision of a thermal network model state equation of the integrated motor, and reduce the temperature calculation error of the integrated motor. On the basis of the technical scheme, the invention can be improved as follows. Further, inputting different currents to the first controller, and acquiring first temperature rise data and second temperature rise data corresponding to each current, including the following steps: Inputting different currents to the first controller; when the second motor rotates after inputting the current, step current alternating current signals with different preset amplitudes are input on the d-axis of the phase current at intervals of preset time until the temperature of a stator winding of the second motor exceeds a preset temperature, the input of the step current alternating current signals is stopped, and the next current is input for the first controller after the ambient temperature is reduced to the room temperature; Recording temperature rise data of a circuit board of the first controller measured by a thermistor during the period from the current input of the first controller until the ambient temperature is reduced to the room temperature, and obtaining the first temperature rise data; And recording temperature