CN118054706A - Demagnetizing compensation method and device for permanent magnet synchronous motor of vehicle - Google Patents

Demagnetizing compensation method and device for permanent magnet synchronous motor of vehicle Download PDF

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CN118054706A
CN118054706A CN202410115858.6A CN202410115858A CN118054706A CN 118054706 A CN118054706 A CN 118054706A CN 202410115858 A CN202410115858 A CN 202410115858A CN 118054706 A CN118054706 A CN 118054706A
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motor
current
torque
value
flux linkage
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李玮
储琦
刘超
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Beijing Electric Vehicle Co Ltd
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Beijing Electric Vehicle Co Ltd
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Abstract

The application relates to the technical field of electric automobiles, in particular to a demagnetization compensation method and device of a permanent magnet synchronous motor of a vehicle, wherein the method comprises the following steps: obtaining a plurality of output torque estimated values of a target motor, detecting whether the target motor meets preset demagnetizing conditions, determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor under the condition that the target motor meets the preset demagnetizing conditions, and calculating compensation torque of the target motor according to the current motor flux linkage value so as to perform demagnetizing compensation on an actual torque command value of the target motor by using the compensation torque. The embodiment of the application can carry out the demagnetization detection of the motor based on the high-precision estimation of the output torque of the motor of the vehicle, and designs the demagnetization compensation strategy by utilizing the estimated torque and the command torque, thereby avoiding the reduction of the actual output torque of the motor caused by the performance reduction of the permanent magnet, enhancing the accuracy of the demagnetization detection of the permanent magnet motor of the vehicle and improving the driving experience of the vehicle.

Description

Demagnetizing compensation method and device for permanent magnet synchronous motor of vehicle
Technical Field
The application relates to the technical field of electric automobiles, in particular to a demagnetization compensation method and device of a permanent magnet synchronous motor of a vehicle.
Background
Permanent Magnet Synchronous Motor (PMSM) has the advantages of high efficiency, high output torque, high power density, good dynamic performance and the like, and is currently becoming the main stream of a pure electric vehicle driving system. In the related art, the permanent magnet synchronous motor may be influenced by factors such as overhigh temperature, severe vibration and external magnetic field of the motor body, so that permanent magnets of a motor rotor generate permanent demagnetization risks, the driving motor works in a state of high current, high temperature and high voltage for a long time, and as the driving mileage of a vehicle increases, the permanent magnets in the motor can age and the irreversible performance is reduced, and the actual running condition of the permanent magnet motor can be obtained by detecting the demagnetization phenomenon of the motor.
However, after detecting that the permanent magnet synchronous motor of the vehicle has demagnetizing phenomenon, the related technology is difficult to correspondingly adjust the influence of the working state of the motor caused by demagnetization, and a related demagnetizing compensation method is not available for rotor permanent magnet demagnetization caused by long-term running of the electric automobile, so that the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, and the use experience of a user is reduced.
Disclosure of Invention
The application provides a demagnetization compensation method and device for a permanent magnet synchronous motor of a vehicle, which are used for solving the problems that in the prior art, after the occurrence of a demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected, the influence of the working state of the motor caused by the demagnetization is difficult to be correspondingly adjusted, the rotor permanent magnet demagnetization caused by long-term running of an electric automobile is not subjected to the related demagnetization compensation method, the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, the use experience of a user is reduced and the like.
An embodiment of a first aspect of the present application provides a demagnetization compensation method for a permanent magnet synchronous motor of a vehicle, including the steps of: obtaining a plurality of output torque estimated values of a target motor; detecting whether the target motor meets a preset demagnetization condition based on the plurality of output torque estimated values; and under the condition that the target motor meets the preset demagnetizing condition, determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor, and calculating the compensation torque of the target motor by the current motor flux linkage value so as to utilize the compensation torque to demagnetize and compensate the actual torque command value of the target motor.
Optionally, in one embodiment of the present application, the obtaining a plurality of output torque estimations of the target motor includes: confirming the current system driving efficiency and the current torque estimation compensation coefficient of the target motor based on the current rotating speed of the target motor and the actual torque command value; and calculating a current output torque estimated value according to the current system driving efficiency and the current torque estimated compensation coefficient, and recording the current output torque estimated value and the estimated times, so that all recorded output torque estimated values are output as the plurality of output torque estimated values under the condition that the estimated times reach the preset estimated times.
Optionally, in one embodiment of the present application, the detecting whether the target motor meets a preset demagnetization condition based on the plurality of output torque estimation values includes: a plurality of torque offset values according to the plurality of output torque estimation values and the actual torque command value; and calculating negative deviation ratios and average negative deviation values of the torque deviation values to detect whether the target motor meets a preset demagnetization condition according to the negative deviation ratios and the average negative deviation values.
Optionally, in one embodiment of the present application, the preset demagnetizing condition is: the negative deviation ratio is greater than a first preset ratio and the average negative deviation value is greater than a second preset ratio during each power-up of a preset power-up cycle.
Optionally, in one embodiment of the present application, before determining the corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor, the method further includes: checking whether the target motor meets a preset calibration condition or not; under the condition that the target motor is detected to meet the preset calibration condition, calibrating all target motor working conditions by an over-temperature fault threshold value and a q-axis current threshold value of the target motor, and traversing all target motor working conditions to obtain a mapping relation among motor temperature, q-axis current and permanent magnet flux linkage; and correcting the original magnetic linked list of the target motor based on the mapping relation to obtain a corrected magnetic linked list of the target motor under the demagnetizing condition, so as to inquire the current motor flux linkage value based on the corrected flux linkage table.
Optionally, in one embodiment of the present application, the calculating the compensation torque of the target motor from the current motor flux linkage value includes: inquiring an original motor flux linkage value in the original flux linkage table according to the current q-axis current and the current temperature value; and calculating the compensation torque according to the original motor flux linkage value and the current motor flux linkage value based on a preset compensation function.
Optionally, in an embodiment of the present application, a calculation formula of the preset compensation function is:
Tint＝1.5KTp0(ψold-ψnew)iq
Wherein, T int is the compensation torque, K T is a torque compensation coefficient, p 0 is a motor pole pair number, ψ old is the original motor flux linkage value, ψ new is the current motor flux linkage value, and i q is the current q-axis current.
An embodiment of a second aspect of the present application provides a demagnetization compensating apparatus of a permanent magnet synchronous motor of a vehicle, including: the acquisition module is used for acquiring a plurality of output torque estimated values of the target motor;
The detection module is used for detecting whether the target motor meets a preset demagnetization condition or not based on the plurality of output torque estimated values;
And the compensation module is used for determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor under the condition that the target motor is detected to meet the preset demagnetizing condition, and calculating the compensation torque of the target motor by the current motor flux linkage value so as to utilize the compensation torque to demagnetize and compensate the actual torque command value of the target motor.
Optionally, in one embodiment of the present application, the acquiring module includes:
a confirmation unit configured to confirm a current system driving efficiency and a current torque estimation compensation coefficient of the target motor based on a current rotational speed of the target motor and the actual torque command value;
And the recording unit is used for calculating a current output torque estimated value according to the current system driving efficiency and the current torque estimated compensation coefficient, recording the current output torque estimated value and the estimated times, and outputting all recorded output torque estimated values as a plurality of output torque estimated values under the condition that the estimated times reach the preset estimated times.
Optionally, in one embodiment of the present application, the detection module includes:
An obtaining unit, configured to obtain a plurality of torque deviation values according to the plurality of output torque estimation values and the actual torque command value;
And the detection unit is used for calculating the negative deviation proportion and the average negative deviation value of the plurality of torque deviation values so as to detect whether the target motor meets a preset demagnetization condition according to the negative deviation proportion and the average negative deviation value.
Optionally, in one embodiment of the present application, the preset demagnetizing condition is: the negative deviation ratio is greater than a first preset ratio and the average negative deviation value is greater than a second preset ratio during each power-up of a preset power-up cycle.
Optionally, in one embodiment of the present application, the apparatus further includes:
the checking module is used for checking whether the target motor meets a preset calibration condition before determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor;
The traversing module is used for calibrating all target motor working conditions by the over-temperature fault threshold value and the q-axis current threshold value of the target motor under the condition that the target motor is detected to meet the preset calibration condition, and traversing all target motor working conditions to obtain the mapping relation among motor temperature, q-axis current and permanent magnet flux linkage;
and the correction module is used for correcting the original magnetic chain table of the target motor based on the mapping relation to obtain a corrected magnetic chain table of the target motor under the demagnetizing condition so as to inquire the current motor flux linkage value based on the corrected flux linkage table.
Optionally, in one embodiment of the present application, the compensation module includes:
the inquiring unit is used for inquiring an original motor flux linkage value in the original flux linkage table according to the current q-axis current and the current temperature value;
and the calculating unit is used for calculating the compensation torque according to the original motor flux linkage value and the current motor flux linkage value based on a preset compensation function.
Optionally, in an embodiment of the present application, a calculation formula of the preset compensation function is:
Tint＝1.5KTp0(ψold-ψnew)iq
Wherein, T int is the compensation torque, K T is a torque compensation coefficient, p 0 is a motor pole pair number, ψ old is the original motor flux linkage value, ψ new is the current motor flux linkage value, and i q is the current q-axis current.
An embodiment of a third aspect of the present application provides a vehicle including: the device comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the program to realize the demagnetization compensation method of the vehicle permanent magnet synchronous motor according to the embodiment.
A fourth aspect of the present application provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the method of demagnetization compensation of a vehicle permanent magnet synchronous motor as above.
The embodiment of the application can carry out the demagnetization detection of the motor based on the high-precision estimation of the output torque of the motor of the vehicle, and designs the demagnetization compensation strategy by utilizing the estimated torque and the command torque, thereby avoiding the reduction of the actual output torque of the motor caused by the performance reduction of the permanent magnet, enhancing the accuracy of the demagnetization detection of the permanent magnet motor of the vehicle and improving the driving experience of the vehicle. Therefore, the problems that after the demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected in the related technology, the influence of the working state of the motor caused by the demagnetization is difficult to correspondingly adjust, the related demagnetization compensation method does not exist yet for the demagnetization of the rotor permanent magnet caused by the long-term running of the electric automobile, the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, the use experience of a user is reduced and the like are solved.
Additional aspects and advantages of the application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the application.
Drawings
The foregoing and/or additional aspects and advantages of the application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:
fig. 1 is a flowchart of a demagnetization compensating method of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application;
FIG. 2 is a diagram illustrating a torque estimation compensation factor query according to an embodiment of the present application;
Fig. 3 is a schematic diagram of a process of detecting demagnetization of a permanent magnet synchronous motor according to an embodiment of the present application;
FIG. 4 is a schematic diagram illustrating a process for correcting permanent magnet flux parameters of a permanent magnet synchronous motor according to an embodiment of the present application;
FIG. 5 is a diagram illustrating a modified motor flux linkage query according to one embodiment of the present application;
FIG. 6 is a schematic diagram illustrating a process of detecting and processing demagnetization of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of a demagnetization compensating apparatus of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application;
Fig. 8 is a schematic structural view of a vehicle according to an embodiment of the present application.
Detailed Description
Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present application and should not be construed as limiting the application.
The following describes a demagnetization compensation method and a demagnetization compensation device of a permanent magnet synchronous motor of a vehicle according to an embodiment of the application with reference to the accompanying drawings. Aiming at the problems that the performance of a driving system after the demagnetization of a vehicle motor is reduced, the power output and the energy utilization efficiency of the vehicle are influenced and the use experience of a user is reduced due to the fact that the related demagnetization compensation method is not available for the demagnetization of a rotor permanent magnet caused by the long-term operation of an electric vehicle after the demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected, the application provides the demagnetization compensation method of the vehicle permanent magnet synchronous motor, in which the demagnetization detection of the motor can be carried out based on the high-precision estimation of the output torque of the vehicle motor, and the demagnetization compensation strategy is designed by utilizing the estimated torque and the command torque, so that the reduction of the actual output torque of the motor caused by the reduction of the performance of the permanent magnet is avoided, the accuracy of the demagnetization detection of the vehicle permanent magnet motor is enhanced, and the driving experience of the vehicle is improved. Therefore, the problems that after the demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected in the related technology, the influence of the working state of the motor caused by the demagnetization is difficult to correspondingly adjust, the related demagnetization compensation method does not exist yet for the demagnetization of the rotor permanent magnet caused by the long-term running of the electric automobile, the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, the use experience of a user is reduced and the like are solved.
Specifically, fig. 1 is a schematic flow chart of a demagnetization compensating method of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application.
As shown in fig. 1, the demagnetization compensation method of the permanent magnet synchronous motor of the vehicle comprises the following steps:
In step S101, a plurality of output torque estimation values of the target motor are acquired.
It is understood that in the embodiment of the present application, a plurality of output torque estimated values of the target motor to be demagnetized and detected, that is, output torque estimated values of the permanent magnet synchronous motor that performs actual operation based on the command torque may be first obtained.
Optionally, in one embodiment of the present application, obtaining a plurality of output torque estimates of the target motor includes: based on the current rotating speed and the actual torque command value of the target motor, confirming the current system driving efficiency and the current torque estimation compensation coefficient of the target motor; and calculating a current output torque estimated value according to the current system driving efficiency and the current torque estimated compensation coefficient, and recording the current output torque estimated value and the estimated times, so that all recorded output torque estimated values are output as a plurality of output torque estimated values under the condition that the estimated times reach the preset estimated times.
It should be noted that the preset number of estimations may be set by those skilled in the art according to the actual situation, and is not specifically limited herein.
It can be understood that, in the embodiment of the present application, since the vector control of the permanent magnet synchronous motor of the pure electric vehicle in the prior art may use a rotational coordinate system d-q axis current table lookup method to obtain a current command, that is, a set of d-q axis current commands are queried according to a torque command of the whole vehicle and a current rotation speed of the motor, and then the actual d-q axis current of the motor is kept consistent with the command current through the current loop control in the vector control, so as to ensure that the motor outputs an expected torque according to the torque command of the whole vehicle, thereby realizing a running function of the vehicle, and the torque formula of the insert permanent magnet synchronous motor is as follows:
Te＝1.5·p0·[(Ld-Lq)·id·iq+ψf·iq]，
Wherein T e represents motor output torque, p 0 represents motor pole pair number, i d and i q respectively represent actual d-q axis current of the motor, and L d and L q represent d-q axis equivalent inductance of the motor; and ψ f denotes the permanent magnet flux linkage. Based on the formula, the output torque of the motor is closely related to the flux linkage of the permanent magnet, and the output torque of the motor is reduced after the permanent magnet is demagnetized.
However, in practical application, the flux linkage value of the motor permanent magnet needs to be obtained in real time when the torque formula is used for estimating the motor output torque, but the flux linkage value originally stored in the motor controller after the motor permanent magnet is demagnetized is inaccurate, so that if the torque formula is continuously used for estimating the motor output torque, larger error can be generated, the power method can be used for estimating the motor output torque, and the torque estimation formula of the power method is as follows:
Wherein T estimate is the estimated current output torque of the motor, U DC is the DC bus voltage value of the motor controller, I DC is the DC bus current value of the motor controller, eta represents the total efficiency of the driving system (motor controller+driving motor), n represents the current rotating speed of the motor, and K c represents the torque estimation compensation coefficient. The direct current bus voltage U DC, the direct current bus current I DC and the current rotating speed n of the motor in the formula are all accurately detected by the motor controller through the sensor.
The efficiency eta of the driving system is not a fixed value, is related to the working state of the motor, namely, is in a two-dimensional monotonous mapping relation with the output torque of the motor and the rotating speed of the motor, the driving system of the electric automobile can perform efficiency map test before delivery, the system efficiency under different output torque and rotating speed conditions is tested, and the total efficiency eta of the current driving system can be obtained by inquiring the efficiency map table according to the rotating speed and the torque command of the motor.
K c is a torque estimation compensation coefficient, which acts to improve the accuracy of the torque estimation. When K c =1, the above formula is a conventional power method torque estimation formula, specifically:
Wherein, T con is the motor output torque estimated by the traditional power method, and is influenced by the perturbation factor of the motor system parameters, the estimation error is larger by simply adopting the traditional power method to estimate the torque, and is insufficient to support the subsequent demagnetization detection of the permanent magnet, so that the compensation coefficient K c is introduced, is not a fixed value, and is changed in a small range in the left and right neighborhood of 1 according to the different working states of the motor, and a two-dimensional map table of the motor output torque, the motor rotating speed and the compensation coefficient K c is established by a bench test method before the drive system leaves the factory.
Specifically, it is possible to design to increase the motor rotation speed in steps of 100rpm from the motor rotation speed n=1000 rpm until the motor rotation speed reaches the base speed point; traversing the torque command T cmd from 0.2T Max in 10Nm steps at each motor speed point to cause the motor to output torque in accordance with the torque command until the motor outputs a maximum torque T Max; table 1, motor status and K c parameter map table, is obtained, and a limited number of operating states are obtained according to the combination of motor speed n and torque command T cmd. In Table 1, a permanent magnet synchronous motor with a maximum output torque of 300Nm and a base speed of 4000rpm is used as an example to describe the motor state and K c parameter map table.
TABLE 1
In each working state, the actual output torque of the motor is measured by utilizing the motor to-drag test bench, the torque is defined as T q, meanwhile, the estimated torque T con is calculated according to the traditional power method torque estimation formula, and then the compensation coefficient K c in the current working state is calculated, wherein the formula is as follows:
The calculation of the compensation coefficient K c of all the torque estimation in the table 1 is completed, and the compensation coefficient K c is stored in a motor controller in a table form, and the compensation coefficient K c value can be uniquely obtained through the motor rotating speed n and the torque command T cmd in the actual torque estimation, so that the accurate estimation of the motor output torque is realized. By adopting the method, the motor torque estimation precision can be improved to +/-2%.
In particular, the selected value ranges of the motor rotation speed and the motor output torque command in table 1 are respectively specified in the calibration process of K c, wherein the range of the rotation speed n is specified as [1000, the motor base speed ], the range of the output torque command is specified as [0.2T Max,TMax ], so as to consider the applicability problem of the power method estimated torque, and under the low rotation speed and small torque output working condition, the estimated motor output torque mostly adopts a current method instead of a power method in view of the estimation precision; in addition, the permanent magnet synchronous motor adopts Maximum Torque current ratio Control (MTPA) in the industry when the base speed is below the base speed point, field weakening Control is not interposed, torque estimation accuracy is high at the moment, and the motor state and the motor rotating speed and Torque command value ranges in the K c parameter map table are determined based on the reasons.
Further, fig. 2 is a schematic diagram of torque estimation compensation coefficient query, according to fig. 2, a parameter K c is obtained by a table look-up method according to the rotation speed and the torque command of the motor in the actual operation process of the driving system, so as to realize real-time estimation of the output torque of the motor by using a torque estimation formula of a power method. And further, based on a certain time interval, the motor output torque estimated value is acquired for a plurality of times in the power-on process of the same vehicle, and the output torque estimated value obtained by the plurality of times of power-on is recorded.
In step S102, it is detected whether the target motor satisfies a preset demagnetization condition based on a plurality of output torque estimation values.
It should be noted that the preset demagnetizing conditions may be set by those skilled in the art according to the actual situation, and are not specifically limited herein.
It is understood that in the embodiment of the present application, whether the target motor satisfies the preset demagnetization condition at this time may be detected based on the output torque estimation values of the plurality of target motors obtained in the above steps.
Optionally, in one embodiment of the present application, detecting whether the target motor satisfies a preset demagnetization condition based on a plurality of output torque estimation values includes: a plurality of torque deviation values are obtained according to the plurality of output torque estimated values and the actual torque command value; and calculating the negative deviation ratio and the average negative deviation value of the plurality of torque deviation values to detect whether the target motor meets the preset demagnetization condition according to the negative deviation ratio and the average negative deviation value.
In the actual implementation process, as shown in fig. 3, a schematic diagram of a process of detecting demagnetization of a permanent magnet synchronous motor according to an embodiment of the present application is shown, and specifically:
step S301: starting.
And starting demagnetization detection of the permanent magnet synchronous motor.
Step S302: and judging the conformity of the motor rotating speed and the torque command condition, wherein n is E [1000, the base speed ] and T cmd∈[0.2Tmax,Tmax].
And judging the consistency of the motor rotating speed and the torque command condition, wherein the consistency is n epsilon [1000, the base speed ] and T cmd∈[0.2Tmax,Tmax].
Step S303: and judging whether the two types of the liquid crystal display meet the requirement.
If yes, step S304 is performed, and if not, step S302 is performed to ensure accuracy of output torque estimation.
Step S304: current output torque estimation of the motor: t estimate.
And calculating a current output torque estimated value by adopting a power method torque estimated formula.
Step S305: calculating the deviation between the estimated torque and the torque command: Δt=t estimate-Tcmd (torque command value).
Wherein, the deviation between the estimated torque and the torque command, deltaT represents the deviation torque. According to the torque estimation formula of the power method, when the permanent magnet of the motor rotor is demagnetized, the output torque capacity of the motor is reduced, and the estimated output torque of the motor in the state is lower than the actual torque command, namely the deviation torque delta T is a continuous negative deviation (corresponding to delta T < 0).
Step S306: and comprehensively judging the demagnetization condition of the permanent magnet of the motor rotor.
And comprehensively judging the demagnetization conditions of the permanent magnet to detect whether permanent demagnetization of the permanent magnet occurs.
Step S307: and (5) ending.
And finishing the demagnetization judgment of the permanent magnet to obtain a demagnetization detection result.
Optionally, in one embodiment of the present application, the preset demagnetization condition is: the negative deviation ratio is greater than a first preset ratio and the average negative deviation value is greater than a second preset ratio during each power-up of the preset power-up period.
It should be noted that the preset power-up period, the first preset ratio and the second preset ratio may be set by those skilled in the art according to actual situations, and are not specifically limited herein.
Specifically, the judgment that the motor permanent magnet is demagnetized needs to be satisfied: first, the proportion of negative deviation in the motor estimated torque is higher than 90% in a single power-on period of the vehicle, and N s times of motor output torque estimation are defined in the single power-on period of the vehicle, wherein the number of times of negative deviation DeltaT <0 of the torque is N neg, the number of times of positive deviation DeltaT is more than or equal to 0 of the torque is N pos,Ns＝Nneg+Npos, and the proportion of negative deviation in the motor estimated torque is considered to be higher than 90% when the following inequality is established:
Secondly, the estimated torque average negative deviation exceeds 10% in a single vehicle power-on period, defining that N s motor output torque estimations are performed in the single power-on period of the vehicle, and prescribing that the motor estimated torque average negative deviation exceeds 10% when the following inequality is established:
Wherein, T estimate (N) is the nth output torque estimated value, T cmd (N) is the nth actual torque command value, and N s is the motor output torque estimated number. When the conditions are satisfied in 30 continuous vehicle power-on periods, namely, permanent demagnetization of the motor is considered, the demagnetization condition of the permanent magnet of the motor rotor can be effectively detected through the method, and the power-on period conditions can avoid misjudgment of the demagnetization of the permanent magnet caused by the influence of external environmental factors.
In step S103, in the case that the target motor is detected to meet the preset demagnetization condition, a corresponding current motor flux linkage value is determined according to the current q-axis current and the current temperature value of the target motor, and a compensation torque of the target motor is calculated according to the current motor flux linkage value, so that demagnetization compensation is performed on an actual torque command value of the target motor by using the compensation torque.
It may be appreciated that in the embodiment of the present application, in case that the target motor is detected to satisfy the preset demagnetization condition according to the detection result in the above step, a corresponding current motor flux linkage value may be determined according to the current q-axis current and the current temperature value of the target motor, and the compensation torque of the target motor may be calculated according to the current motor flux linkage value, so as to perform demagnetization compensation on the actual torque command value of the target motor by using the compensation torque.
Specifically, a compensation torque may be superimposed on the torque command to compensate for the effect on the power output of the de-cranking system due to motor permanent magnet demagnetization by artificially increasing the torque output of the drive motor.
TFC＝Tcmd+Tcomp，
Wherein T FC is a compensated torque command, T cmd is an original torque command, and T comp is a compensation torque. By performing torque compensation, the influence of motor permanent magnet demagnetization on the power output of the vehicle is improved, so that the driving feeling of the vehicle during demagnetization is improved.
Optionally, in one embodiment of the present application, before determining the corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor, the method further includes: checking whether the target motor meets a preset calibration condition; under the condition that the target motor is checked to meet the preset calibration condition, calibrating all target motor working conditions by an over-temperature fault threshold value and a q-axis current threshold value of the target motor, and traversing all target motor working conditions to obtain a mapping relation among motor temperature, q-axis current and permanent magnet flux linkage; and correcting the original magnetic linked list of the target motor based on the mapping relation to obtain a corrected magnetic linked list of the target motor under the demagnetizing condition so as to inquire the current motor flux linkage value based on the corrected magnetic linked list.
It should be noted that the preset calibration conditions may be set by those skilled in the art according to actual situations, and are not specifically limited herein.
In the actual implementation, the voltage equation in the vector control of the permanent magnet synchronous motor has the following form in the steady state:
Wherein u d and u q are d-q axis voltages of the permanent magnet synchronous motor respectively; r s is the resistance of a motor stator winding; i d and i q are d-q axis currents of the motor; l d and L q are d-q axis currents of the motor; omega e is the electrical angular velocity of the motor; and ψ f denotes the permanent magnet flux linkage. Controlling i d to 0, the q-axis voltage equation represented by u q in the above can be reduced to:
Most of the motor controllers of the electric automobiles have the detection capability of U, V, W three-phase currents and three-phase voltages, and the voltages and currents based on a d-q axis rotation coordinate system of the permanent magnet synchronous motor, namely the d-q axis currents and the voltages u d、uq of the permanent magnet synchronous motor can be obtained by performing Clark and Park conversion on the three-phase currents and the three-phase voltages; the motor stator winding resistor R s is used for decoupling a current loop in vector control of the permanent magnet synchronous motor, and the resistance value is measured in advance; the electric angular velocity omega e of the motor is key information necessary for implementing motor control, and the value of the key information is acquired in real time. In summary, other parameters except the flux linkage psi f of the motor permanent magnet in the q-axis voltage reduction equation can be directly obtained, and the flux linkage value of the motor permanent magnet can be calculated based on the formula.
It should be noted that in the field of electric vehicles, miniaturization, high power density and high torque output of a driving system are current technological development trends, and under the promotion of the trend, a driving motor in the electric vehicle can have higher electromagnetic load in a working state, at the moment, serious magnetic circuit saturation occurs in the motor, and under the condition of high magnetic circuit saturation, a permanent magnet flux linkage can be subjected to nonlinear change along with the change of current; in addition, the temperature of the rotor has a large influence on the flux linkage of the permanent magnet, so that the influence factor needs to be considered in the process of measuring the flux linkage of the rotor of the motor. The mapping relation of the motor temperature, the q-axis current and the permanent magnet flux can be established by establishing a flux linkage map table, the mapping is established by calculating the flux linkage value of the motor in each divided working state, the mapping relation is stored in a table form after the establishment is completed, the correction of the permanent magnet flux linkage parameters of the motor is completed, then the current motor flux linkage can be inquired according to the motor temperature and the q-axis current in the working state of a driving system, and the flux linkage value is used for completing a corresponding control strategy. As shown in fig. 4, a process diagram of permanent magnet flux parameter correction of a permanent magnet synchronous motor according to an embodiment of the present application is shown, specifically:
Step S401: starting.
Wherein, the permanent magnet flux linkage parameter correction of the motor is started.
Step S402: and establishing a motor temperature, q-axis current and motor flux linkage map table, and dividing the motor state.
The map table is established to establish the mapping relation of the motor temperature, the q-axis current and the permanent magnet flux linkage, and the mapping establishment is carried out by calculating the flux linkage value of the motor in each divided working state.
Step S403: the permanent magnet flux linkage allows for calibration condition judgment.
And judging whether the working state of the motor meets the permanent magnet flux linkage allowable calibration condition.
Step S404: and traversing the working state of the motor, and determining the current instruction of the d-q axis of the motor.
Under the condition that the motor working state meets the permanent magnet flux linkage allowable calibration condition, traversing the motor working state, and determining the d-q axis current instruction of the motor under different working states.
Step S405: and calculating a permanent magnet flux linkage value and updating a motor flux linkage map table.
The permanent magnet flux linkage value calculated value is stored in a table form, and the motor flux linkage map table is updated.
Step S406: and finishing judgment of the motor working state traversal.
And detecting whether the motor working state traversal is finished or not.
Step S407: it is determined whether the traversal is complete.
If the traversal is completed, the process proceeds to step S408, otherwise, the process proceeds to step S403.
Step S408: and (5) ending.
And obtaining a corrected magnetic chain table, and ending the process.
In the actual execution process, the establishment of the mapping relation can prescribe that the temperature of the motor increases from 20 ℃ according to the interval of 10 ℃ and ends when the over-temperature fault threshold value of the permanent magnet synchronous motor is reached; the q-axis current starts at 20A and increases at intervals of 20A to a maximum q-axis current value. As shown in table 2, the motor state and flux linkage parameter map table, T mot-max represents an over-temperature fault threshold value of the permanent magnet synchronous motor, and i q-max represents a maximum q-axis current value.
TABLE 2
Judging the permanent magnet flux linkage calibration working condition on the basis of finishing the motor working state division, wherein the preset calibration condition is required to be met before the motor permanent magnet flux linkage calibration is regulated: firstly, the rotating speed of the motor is more than 200rpm but not more than the base speed, the d-axis current is 0 at the moment by calculating the flux linkage value, for the inserted permanent magnet synchronous motor, the weak magnetic control cannot be implemented when the d-axis current is 0, the limiting condition of the base speed point is regulated, and for the current common rotating transformer motor rotor position detection scheme, the error of the rotating transformer is larger at low rotating speed, and the minimum rotating speed limitation of 200rpm is provided for ensuring the flux linkage calculation precision; secondly, the torque command of the motor does not exceed T q-max, the correction calculation of the motor flux linkage can be carried out, the d-axis current is required to be 0 at the moment, and i d =0 is brought into the torque formula (1) of the permanent magnet synchronous motor, so that the motor flux linkage is obtained
Te＝1.5·p0·ψf·iq，
The expression that the maximum output torque of the motor does not exceed T q-max,Tq-max at this time is:
Tq-max＝1.5p0ψfiq-max，
according to the above two equations, the torque command of the motor is specified not to exceed T q-max. If the current working condition meets the permanent magnet flux linkage calibration condition, traversing the working state of the motor according to the states divided in the table 2, and calculating a d-q axis current instruction of the motor in the traversing process. For example, if the current motor temperature is 100 ℃, the output torque command of the motor is T cmd, the d-q current command of the motor is i d-cmd and i q-cmd according to the calculated q-axis current command:
Under the action of the d-q axis current command in the above formula, the driving motor can output torque according to expectancy, but the motor efficiency is lower at the moment, and the current flux linkage can be calculated in the running process of the vehicle in a mode that the motor output torque is unchanged and the system efficiency is temporarily sacrificed. The actual q-axis current of the motor is obtained through coordinate transformation calculation according to the three-phase current of the motor obtained through actual collection, and when the q-axis current is a specified point in the abscissa in the table 2, the flux linkage value of the motor permanent magnet in the current state is obtained through calculation, and is recorded in the table 2.
And traversing all states in the table 2 according to the above process, calculating corresponding flux linkage values, and finishing after finishing traversing all working states in the table 2, and establishing a new flux linkage map table. In the subsequent control process, for example, the vector control current loop is decoupled, according to the corrected flux linkage map table, the current flux linkage value of the permanent magnet of the motor can be obtained by using the q-axis current of the motor and the temperature value of the motor in a table look-up mode, and the current flux linkage value is used for completing corresponding control logic, specifically, as shown in fig. 5, according to the current q-axis current and the current temperature value of the target motor, the corresponding current motor flux linkage value is determined by the corrected flux linkage map table of the motor.
The embodiment of the application can carry out online correction of the permanent magnet flux linkage of the permanent magnet synchronous motor after the demagnetization of the permanent magnet is detected, and under the premise of not changing the power output of a driving system, the parameters for calculating the permanent magnet flux linkage are obtained by controlling the driving motor to enter a non-efficient working point in a maximum torque current ratio control area of the motor, wherein the parameters comprise q-axis voltage and q-axis current of the motor, the rotating speed of the motor, the motor temperature and the like, the flux linkage of the permanent magnet under the current working condition is calculated by utilizing the obtained parameter values, and the mapping relation between the permanent magnet flux linkage of the motor and the motor temperature and the motor q-axis current is finally established through repeated iteration of the processes, so that the correction of a permanent magnet flux linkage parameter table of the motor is realized. The flux linkage correction method can be finished on line, normal running of the vehicle is not affected, nonlinear influence of motor current and temperature on flux linkage value is considered, the corrected flux linkage can meet the requirement that the driving motor accurately obtains the flux linkage value under high magnetic circuit saturation, control performance of a system is improved, intermediate variables used for calculating the flux linkage do not contain parameters, such as inductance of the motor, greatly affected by working states, and the like, the intermediate variables can be obtained accurately in real time, and therefore the flux linkage correction method has good practical engineering value.
Optionally, in one embodiment of the present application, calculating the compensation torque of the target motor from the current motor flux linkage value includes: inquiring an original motor flux linkage value in an original flux linkage table according to the current q-axis current and the current temperature value; and calculating the compensation torque according to the original motor flux linkage value and the current motor flux linkage value based on a preset compensation function.
It should be noted that the preset compensation function may be set by those skilled in the art according to the actual situation, and is not specifically limited herein.
In the actual execution process, for an electric automobile, the driving system has two working modes of electric power and power generation, the driving system consumes electric energy and outputs power in the electric mode, the forward and backward functions of the automobile are realized, the power generation mode is generally used for the braking energy recovery or sliding energy recovery process of the automobile, at the moment, the driving system generates braking torque, and part of braking energy is converted into electric energy to charge a battery. The driving feeling of the driver is more easily affected by the demagnetization of the motor in the electric mode than in the power generation mode, that is, a decrease in the power performance of the vehicle due to the demagnetization of the permanent magnet is felt, for example, if the power output of the vehicle does not reach the psychological expectation during the acceleration operation by the driver, the driving feeling of the vehicle is reduced. In the power generation mode, the permanent magnet demagnetizes to reduce the braking torque in the vehicle energy recovery process, the driving experience of a driver can be improved by reducing the braking torque, and the driving experience of the vehicle is prevented from being damaged by demagnetization. After the calibration of the correction magnetic chain table is finished, two magnetic chain lookup tables are actually stored in the motor controller, the original magnetic chain table and the correction magnetic chain table are searched in the original magnetic chain table according to the current q-axis current and the current temperature value, and the compensation torque is calculated according to the original magnetic chain value and the current magnetic chain value.
The embodiment of the application can carry out motor output torque compensation control based on the corrected permanent magnet flux linkage so as to avoid the reduction of the actual output torque of the motor due to the performance reduction of the permanent magnet, thereby improving the driving feeling of the vehicle.
Optionally, in an embodiment of the present application, a calculation formula of the preset compensation function is:
Tint＝1.5KTp0(ψold-ψnew)iq，
Wherein, T int is the compensation torque, K T is the torque compensation coefficient, p 0 is the pole pair number of the motor, ψ old is the original motor flux linkage value, ψ new is the current motor flux linkage value, and i q is the current q-axis current.
Specifically, the flux linkage value queried through the original flux linkage table is phi old, the flux linkage value queried through the corrected flux linkage table is phi new, and the compensation torque command is calculated by a preset compensation function through the two flux linkage values, so that compensation control of the motor output torque is realized.
Wherein the torque compensation coefficient K T,KT is E [0,1]. When K T =1, T int is the motor output torque deviation caused by the motor permanent magnet flux linkage difference, and the value of the torque compensation coefficient K T,KT can be introduced to be recommended to be in the range of 0.6-0.8 in consideration of the influence of factors such as flux linkage parameter perturbation on the compensation torque, and the compensation torque is prevented from exceeding the expectations of a driver (overcompensation) by artificially reducing the magnitude of the compensation torque, so that the safety of the driving process is ensured.
In addition, the discrimination is needed after the compensation torque is obtained:
Wherein T comp is the final compensation torque. The influence of the demagnetization of the permanent magnet on the power performance output of the system is reduced through flux linkage correction and torque compensation, then T int calculated in the demagnetizing state should be a positive value, if T int is less than 0, the flux linkage of the motor in the working state is normal, and the torque compensation is not needed.
The working of the embodiment of the present application will be described in detail with reference to fig. 6.
Step S601: starting.
Wherein, the demagnetization detection and processing of the permanent magnet synchronous motor are started.
Step S602: and (5) demagnetizing and detecting the permanent magnet of the motor rotor.
And carrying out demagnetization detection on the permanent magnet of the motor rotor.
Step S603: judging whether demagnetization occurs.
If yes, step S604 is performed, and if not, step S602 is performed.
Step S604: and (5) correcting the flux linkage parameters of the permanent magnet of the motor.
The flux linkage value of the permanent magnet is corrected according to parameters in the running process of the motor, and the process is not completed in a single vehicle power-on period and can be completed in multiple times.
Step S605: and judging whether the correction is finished.
If yes, step S606 is performed, and if not, step S604 is performed.
Step S606: and (5) motor output torque compensation control.
Wherein compensation control is performed on the motor output torque according to the new flux linkage value.
Step S607: and (5) ending.
Wherein, the demagnetizing detection and processing process is ended.
According to the demagnetization compensation method for the vehicle permanent magnet synchronous motor, disclosed by the embodiment of the application, the demagnetization detection of the motor can be performed based on the high-precision estimation of the output torque of the vehicle motor, and the demagnetization compensation strategy is designed by utilizing the estimated torque and the command torque, so that the actual output torque of the motor is prevented from being reduced due to the performance reduction of the permanent magnet, the accuracy of the demagnetization detection of the vehicle permanent magnet motor is enhanced, and the driving experience of the vehicle is improved. Therefore, the problems that after the demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected in the related technology, the influence of the working state of the motor caused by the demagnetization is difficult to correspondingly adjust, the related demagnetization compensation method does not exist yet for the demagnetization of the rotor permanent magnet caused by the long-term running of the electric automobile, the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, the use experience of a user is reduced and the like are solved.
Next, a demagnetization compensating apparatus of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application will be described with reference to the accompanying drawings.
Fig. 7 is a schematic structural diagram of a demagnetization compensating apparatus of a permanent magnet synchronous motor of a vehicle according to an embodiment of the present application.
As shown in fig. 7, the demagnetization compensating apparatus 10 of the permanent magnet synchronous motor of a vehicle includes: an acquisition module 100, a detection module 200 and a compensation module 300.
Wherein, the acquisition module 100 is configured to acquire a plurality of output torque estimated values of the target motor.
The detection module 200 is configured to detect whether the target motor satisfies a preset demagnetization condition based on a plurality of output torque estimation values.
And the compensation module 300 is used for determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor under the condition that the target motor is detected to meet the preset demagnetizing condition, and calculating the compensation torque of the target motor according to the current motor flux linkage value so as to utilize the compensation torque to demagnetize and compensate the actual torque command value of the target motor.
Optionally, in one embodiment of the present application, the acquiring module 100 includes: a confirmation unit and a recording unit.
And the confirmation unit is used for confirming the current system driving efficiency and the current torque estimation compensation coefficient of the target motor based on the current rotating speed and the actual torque command value of the target motor.
And the recording unit is used for calculating a current output torque estimated value according to the current system driving efficiency and the current torque estimated compensation coefficient, recording the current output torque estimated value and the estimated times, and outputting all recorded output torque estimated values as a plurality of output torque estimated values under the condition that the estimated times reach the preset estimated times.
Optionally, in one embodiment of the present application, the detection module 200 includes: an acquisition unit and a detection unit.
The acquisition unit is used for acquiring a plurality of torque deviation values according to the plurality of output torque estimated values and the actual torque command value.
And the detection unit is used for calculating the negative deviation proportion and the average negative deviation value of the plurality of torque deviation values so as to detect whether the target motor meets the preset demagnetizing condition according to the negative deviation proportion and the average negative deviation value.
Optionally, in one embodiment of the present application, the preset demagnetization condition is: the negative deviation ratio is greater than a first preset ratio and the average negative deviation value is greater than a second preset ratio during each power-up of the preset power-up period.
Optionally, in one embodiment of the present application, the apparatus 10 further comprises: the system comprises an inspection module, a traversing module and a correction module.
The checking module is used for checking whether the target motor meets preset calibration conditions before determining the corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor.
And the traversing module is used for calibrating all target motor working conditions by the over-temperature fault threshold value and the q-axis current threshold value of the target motor under the condition that the target motor is detected to meet the preset calibration condition, and traversing all target motor working conditions to obtain the mapping relation among the motor temperature, the q-axis current and the permanent magnet flux linkage.
And the correction module is used for correcting the original magnetic linked list of the target motor based on the mapping relation to obtain a corrected magnetic linked list of the target motor under the demagnetizing condition so as to inquire the current motor flux linkage value based on the corrected magnetic linked list.
Optionally, in one embodiment of the present application, the compensation module 300 includes: a query unit and a calculation unit.
The query unit is used for querying an original motor flux linkage value in the original flux linkage table according to the current q-axis current and the current temperature value.
And the calculating unit is used for calculating the compensation torque according to the original motor flux linkage value and the current motor flux linkage value based on a preset compensation function.
Optionally, in an embodiment of the present application, a calculation formula of the preset compensation function is:
Tint＝1.5KTp0(ψold-ψnew)iq
Wherein, T int is the compensation torque, K T is the torque compensation coefficient, p 0 is the pole pair number of the motor, ψ old is the original motor flux linkage value, ψ new is the current motor flux linkage value, and i q is the current q-axis current.
It should be noted that the foregoing explanation of the embodiment of the demagnetization compensating method of the permanent magnet synchronous motor of the vehicle is also applicable to the demagnetization compensating device of the permanent magnet synchronous motor of the vehicle in this embodiment, and will not be repeated here.
According to the demagnetization compensating device of the vehicle permanent magnet synchronous motor, disclosed by the embodiment of the application, the demagnetization detection of the motor can be performed based on the high-precision estimation of the output torque of the vehicle motor, and the demagnetization compensating strategy is designed by utilizing the estimated torque and the command torque, so that the actual output torque of the motor is prevented from being reduced due to the performance reduction of the permanent magnet, the accuracy of the demagnetization detection of the vehicle permanent magnet motor is enhanced, and the driving experience of the vehicle is improved. Therefore, the problems that after the demagnetization phenomenon of the permanent magnet synchronous motor of the vehicle is detected in the related technology, the influence of the working state of the motor caused by the demagnetization is difficult to correspondingly adjust, the related demagnetization compensation method does not exist yet for the demagnetization of the rotor permanent magnet caused by the long-term running of the electric automobile, the performance of a driving system after the demagnetization of the motor of the vehicle is reduced, the power output and the energy utilization efficiency of the vehicle are influenced, the use experience of a user is reduced and the like are solved.
Fig. 8 is a schematic structural diagram of a vehicle according to an embodiment of the present application. The vehicle may include:
A memory 801, a processor 802, and a computer program stored on the memory 801 and executable on the processor 802.
The processor 802 implements the demagnetization compensation method of the permanent magnet synchronous motor of the vehicle provided in the above embodiment when executing the program.
Further, the vehicle further includes:
a communication interface 803 for communication between the memory 801 and the processor 802.
A memory 801 for storing a computer program executable on the processor 802.
The memory 801 may include high-speed RAM memory or may further include non-volatile memory (non-volatile memory), such as at least one magnetic disk memory.
If the memory 801, the processor 802, and the communication interface 803 are implemented independently, the communication interface 803, the memory 801, and the processor 802 may be connected to each other through a bus and perform communication with each other. The bus may be an industry standard architecture (Industry Standard Architecture, abbreviated ISA) bus, an external device interconnect (PERIPHERAL COMPONENT INTERCONNECT, abbreviated PCI) bus, or an extended industry standard architecture (Extended Industry Standard Architecture, abbreviated EISA) bus, among others. The buses may be divided into address buses, data buses, control buses, etc. For ease of illustration, only one thick line is shown in fig. 8, but not only one bus or one type of bus.
Alternatively, in a specific implementation, if the memory 801, the processor 802, and the communication interface 803 are integrated on a chip, the memory 801, the processor 802, and the communication interface 803 may communicate with each other through internal interfaces.
The processor 802 may be a central processing unit (Central Processing Unit, abbreviated as CPU), or an Application SPECIFIC INTEGRATED Circuit, abbreviated as ASIC, or one or more integrated circuits configured to implement embodiments of the present application.
The present embodiment also provides a computer-readable storage medium having stored thereon a computer program which, when executed by a processor, implements the demagnetization compensation method of the vehicle permanent magnet synchronous motor as above.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or N embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, "N" means at least two, for example, two, three, etc., unless specifically defined otherwise.
Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and additional implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order from that shown or discussed, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the embodiments of the present application.
Logic and/or steps represented in the flowcharts or otherwise described herein, e.g., a ordered listing of executable instructions for implementing logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or N wires, a portable computer cartridge (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer readable medium may even be paper or other suitable medium on which the program is printed, as the program may be electronically captured, via optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.
It is to be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above-described embodiments, the N steps or methods may be implemented in software or firmware stored in a memory and executed by a suitable instruction execution system. As with the other embodiments, if implemented in hardware, may be implemented using any one or combination of the following techniques, as is well known in the art: discrete logic circuits having logic gates for implementing logic functions on data signals, application specific integrated circuits having suitable combinational logic gates, programmable Gate Arrays (PGAs), field Programmable Gate Arrays (FPGAs), and the like.
Those of ordinary skill in the art will appreciate that all or a portion of the steps carried out in the method of the above-described embodiments may be implemented by a program to instruct related hardware, where the program may be stored in a computer readable storage medium, and where the program, when executed, includes one or a combination of the steps of the method embodiments.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing module, or each unit may exist alone physically, or two or more units may be integrated in one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules may also be stored in a computer readable storage medium if implemented in the form of software functional modules and sold or used as a stand-alone product.
The above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, or the like. While embodiments of the present application have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the application.

Claims (10)

1. The demagnetizing compensation method of the permanent magnet synchronous motor of the vehicle is characterized by comprising the following steps of:
Obtaining a plurality of output torque estimated values of a target motor;
detecting whether the target motor meets a preset demagnetization condition based on the plurality of output torque estimated values;
and under the condition that the target motor meets the preset demagnetizing condition, determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor, and calculating the compensation torque of the target motor by the current motor flux linkage value so as to utilize the compensation torque to demagnetize and compensate the actual torque command value of the target motor.
2. The method of claim 1, wherein the obtaining a plurality of output torque estimates for the target motor comprises:
Confirming the current system driving efficiency and the current torque estimation compensation coefficient of the target motor based on the current rotating speed of the target motor and the actual torque command value;
and calculating a current output torque estimated value according to the current system driving efficiency and the current torque estimated compensation coefficient, and recording the current output torque estimated value and the estimated times, so that all recorded output torque estimated values are output as the plurality of output torque estimated values under the condition that the estimated times reach the preset estimated times.
3. The method of claim 1, wherein detecting whether the target motor satisfies a preset demagnetization condition based on the plurality of output torque estimates comprises:
A plurality of torque offset values according to the plurality of output torque estimation values and the actual torque command value;
and calculating negative deviation ratios and average negative deviation values of the torque deviation values to detect whether the target motor meets a preset demagnetization condition according to the negative deviation ratios and the average negative deviation values.
4. A method according to claim 3, wherein the predetermined demagnetization conditions are: the negative deviation ratio is greater than a first preset ratio and the average negative deviation value is greater than a second preset ratio during each power-up of a preset power-up cycle.
5. The method of claim 1, further comprising, prior to determining the corresponding current motor flux linkage value from the current q-axis current and the current temperature value of the target motor:
checking whether the target motor meets a preset calibration condition or not;
Under the condition that the target motor is detected to meet the preset calibration condition, calibrating all target motor working conditions by an over-temperature fault threshold value and a q-axis current threshold value of the target motor, and traversing all target motor working conditions to obtain a mapping relation among motor temperature, q-axis current and permanent magnet flux linkage;
And correcting the original magnetic linked list of the target motor based on the mapping relation to obtain a corrected magnetic linked list of the target motor under the demagnetizing condition, so as to inquire the current motor flux linkage value based on the corrected flux linkage table.
6. The method of claim 5, wherein said calculating the compensation torque of the target motor from the current motor flux linkage value comprises:
inquiring an original motor flux linkage value in the original flux linkage table according to the current q-axis current and the current temperature value;
And calculating the compensation torque according to the original motor flux linkage value and the current motor flux linkage value based on a preset compensation function.
7. The method of claim 6, wherein the predetermined compensation function is calculated by the formula:
Tint＝1.5KTp0(ψold-ψnew)iq
Wherein, T int is the compensation torque, K T is a torque compensation coefficient, p 0 is a motor pole pair number, ψ old is the original motor flux linkage value, ψ new is the current motor flux linkage value, and i q is the current q-axis current.
8. A demagnetization compensating apparatus of a permanent magnet synchronous motor of a vehicle, characterized by comprising:
The acquisition module is used for acquiring a plurality of output torque estimated values of the target motor;
The detection module is used for detecting whether the target motor meets a preset demagnetization condition or not based on the plurality of output torque estimated values;
And the compensation module is used for determining a corresponding current motor flux linkage value according to the current q-axis current and the current temperature value of the target motor under the condition that the target motor is detected to meet the preset demagnetizing condition, and calculating the compensation torque of the target motor by the current motor flux linkage value so as to utilize the compensation torque to demagnetize and compensate the actual torque command value of the target motor.
9. A vehicle, characterized by comprising: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor executing the program to implement the method of demagnetizing a vehicle permanent magnet synchronous motor according to any one of claims 1-7.
10. A computer-readable storage medium having stored thereon a computer program, characterized in that the program is executed by a processor for realizing the demagnetization compensation method of the vehicle permanent magnet synchronous motor according to any of claims 1 to 7.
CN202410115858.6A 2024-01-26 2024-01-26 Demagnetizing compensation method and device for permanent magnet synchronous motor of vehicle Pending CN118054706A (en)

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