CN115356624B

CN115356624B - Motor iron loss determination method and device, vehicle, storage medium and chip

Info

Publication number: CN115356624B
Application number: CN202210977556.0A
Authority: CN
Inventors: 毛由正
Original assignee: Xiaomi Automobile Technology Co Ltd
Current assignee: Xiaomi Automobile Technology Co Ltd
Priority date: 2022-08-15
Filing date: 2022-08-15
Publication date: 2023-07-18
Anticipated expiration: 2042-08-15
Also published as: CN115356624A

Abstract

The disclosure relates to the technical field of motors, and in particular relates to a method and a device for determining iron loss of a motor, a vehicle, a storage medium and a chip. The method for determining the iron loss of the motor comprises the following steps: determining a current iron loss coefficient of the motor according to a preset first corresponding relation and a current stator current parameter of the motor, wherein the iron loss coefficient represents the relation between the iron loss of the motor and the stator current parameter, and the first corresponding relation is the corresponding relation between the stator current parameter and the iron loss coefficient; and determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor. According to the technical scheme, the iron loss calculation accuracy requirement of the full-working-condition operation of the actual motor driving system can be met, the influence of the voltage change of the battery of the driving motor is avoided, the first corresponding relation is obtained only through a pre-experiment, the workload and the data volume are small, and the method is suitable for engineering application.

Description

Motor iron loss determination method and device, vehicle, storage medium and chip

Technical Field

The disclosure relates to the technical field of motors, and in particular relates to a method and a device for determining iron loss of a motor, a vehicle, a storage medium and a chip.

Background

In the related art, the method for obtaining the iron loss of the motor mainly comprises the following two steps: the first method is to build a motor loss model by actually measuring loss parameters of the motor core material. The second method is to obtain the iron loss parameters through finite element simulation.

In the first method, the conditions during measurement cannot completely meet the full-working-condition operation state of the motor driving system, so that the iron loss calculation accuracy requirement of the full-working-condition operation of the motor driving system cannot be guaranteed. In the second method, the simulation model cannot be completely consistent with the actual motor driving system, and modeling errors of software exist, so that the iron loss calculation accuracy requirement of the actual motor driving system operation cannot be guaranteed.

Disclosure of Invention

In order to overcome the problems in the related art, the present disclosure provides a method, apparatus, vehicle, storage medium, and chip for determining iron loss of a motor.

According to a first aspect of an embodiment of the present disclosure, there is provided a motor iron loss determination method including:

determining a current iron loss coefficient of the motor according to a preset first corresponding relation and a current stator current parameter of the motor, wherein the iron loss coefficient represents the relation between the iron loss of the motor and the stator current parameter, and the first corresponding relation is the corresponding relation between the stator current parameter and the iron loss coefficient;

And determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor.

Optionally, the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter, and the first correspondence is established by:

controlling the speed parameter of the motor to be equal to a first preset value, and obtaining motor iron loss equivalent resistances of the motor under different stator quadrature axis current parameters and stator direct axis current parameters so as to establish a second corresponding relation, wherein the second corresponding relation is a two-dimensional corresponding relation between the motor iron loss equivalent resistances and the stator quadrature axis current parameters and the stator direct axis current parameters;

establishing a first corresponding relation according to the second corresponding relation, the first preset numerical value and a first formula, wherein the first corresponding relation is a two-dimensional corresponding relation of an iron loss coefficient, a stator quadrature axis current parameter and a stator direct axis current parameter, and the first formula is thatWherein K is _Fe Representing the iron loss coefficient of the motor, R _c Representing the iron loss equivalent resistance, w, of the motor _e Representing the synchronous angular velocity of the motor.

Optionally, the method further comprises:

Determining a current iron loss compensation coefficient of the motor according to a preset fourth corresponding relation and a current speed parameter of the motor, wherein the fourth corresponding relation comprises a corresponding relation between the iron loss compensation coefficient and the speed parameter;

the determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter, the current stator current parameter, the stator inductance and the rotor flux linkage of the motor comprises the following steps: and determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter of the motor, the stator current parameter, the iron loss compensation coefficient, the stator inductance and the rotor flux linkage.

Optionally, the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter, and the fourth correspondence is established by:

obtaining a fifth corresponding relation and a sixth corresponding relation of the bus voltage of the motor under the condition that the bus voltage is equal to a second preset value, wherein the fifth corresponding relation is a corresponding relation between a stator quadrature axis current parameter and a speed parameter of the motor and an electromagnetic torque, and the sixth corresponding relation is a corresponding relation between a stator direct axis current parameter and the speed parameter of the motor and the electromagnetic torque;

Obtaining a seventh corresponding relation according to the fifth corresponding relation, the sixth corresponding relation and the first corresponding relation, wherein the seventh corresponding relation is a corresponding relation of iron loss, a speed parameter and electromagnetic torque;

controlling the bus voltage of the motor to be equal to a second preset value, and obtaining the iron loss of the motor under different rotating speed parameters and electromagnetic torque to establish an eighth corresponding relation, wherein the eighth corresponding relation is the corresponding relation between the iron loss and the speed parameters and the electromagnetic torque;

establishing a ninth corresponding relation according to the eighth corresponding relation and the seventh corresponding relation, wherein the ninth corresponding relation is a corresponding relation between an initial iron loss compensation coefficient, a speed parameter and an electromagnetic torque;

and processing the ninth corresponding relation to establish a tenth corresponding relation, wherein the tenth corresponding relation is the corresponding relation between the iron loss compensation coefficient and the speed parameter.

Optionally, the stator quadrature axis current parameter is a component current of the corresponding electromagnetic torque in the stator quadrature axis current of the motor, the stator direct axis current parameter is a component current of the corresponding electromagnetic torque in the stator direct axis current of the motor, the controlling the speed parameter of the motor to be equal to a first preset value, and obtaining the motor iron loss equivalent resistance of the motor under different stator quadrature axis current parameters and stator direct axis current parameters to establish the second correspondence includes:

Controlling the speed parameter of the motor to be equal to a first preset value, obtaining the iron losses of the motor under different stator quadrature-axis currents and stator direct-axis currents, so as to establish a third corresponding relation, and obtaining the stator quadrature-axis voltage and the stator direct-axis voltage corresponding to each group of stator quadrature-axis currents and stator direct-axis currents in the third corresponding relation, wherein the third corresponding relation is a two-dimensional corresponding relation between the iron losses of the motor and the stator quadrature-axis currents and the stator direct-axis currents;

and establishing a second corresponding relation between the equivalent resistance of the motor iron loss and the component current of the corresponding electromagnetic torque in the motor stator quadrature axis current and the component current of the corresponding electromagnetic torque in the motor stator direct axis current according to the first preset numerical value, the third corresponding relation and the stator quadrature axis voltage and the stator direct axis voltage corresponding to each group of stator quadrature axis current and the stator direct axis current in the third corresponding relation.

Optionally, the controlling the speed parameter of the motor to be equal to a first preset value, and the obtaining the iron loss of the motor under different stator quadrature axis currents and stator direct axis currents to establish the third corresponding relationship includes:

acquiring the stator phase resistance, the stator quadrature axis current and the stator direct axis current of the motor, and acquiring copper loss of the motor according to the stator phase resistance, the stator quadrature axis current and the stator direct axis current;

Acquiring bus voltage and bus current of the motor, and acquiring input power of the motor according to the bus voltage and the bus current;

obtaining the mechanical torque and the rotor rotating speed of the motor, and obtaining the output power of the motor according to the mechanical torque and the rotor rotating speed;

obtaining mechanical friction loss power of the motor;

and obtaining the iron loss of the motor under the stator quadrature axis current and the stator direct axis current according to the input power, the output power, the copper loss and the mechanical friction loss power so as to establish a third corresponding relation.

Optionally, the obtaining the quadrature axis voltage and the direct axis voltage corresponding to each set of quadrature axis current and direct axis current in the third correspondence includes:

acquiring the quadrature axis current, the direct axis current, the power factor angle and the phase voltage of the motor;

calculating the current angle of the motor according to the quadrature axis current and the direct axis current;

and acquiring the quadrature axis voltage and the direct axis voltage of the motor according to the current angle, the power factor angle and the phase voltage.

Optionally, the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter, and determining, according to the determined iron loss coefficient and the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor, the current iron loss of the motor includes:

Acquiring the synchronous angular speed of the motor according to the current speed parameter of the motor;

determining the current iron loss equivalent resistance of the motor according to the determined iron loss coefficient and the synchronous angular speed;

acquiring component currents corresponding to motor iron loss in the current stator direct axis current of the motor and component currents corresponding to motor iron loss in the stator quadrature axis current according to the current stator current parameters of the motor;

and obtaining the current iron loss of the motor according to the iron loss equivalent resistance, the component current corresponding to the iron loss of the motor in the stator direct-axis current, the component current corresponding to the iron loss of the motor in the stator quadrature-axis current, the stator inductance and the rotor flux linkage, wherein the stator inductance comprises a stator direct-axis inductance and a stator quadrature-axis inductance.

According to a second aspect of the embodiments of the present disclosure, there is provided a motor iron loss determination apparatus including:

the iron loss coefficient determining module is configured to determine a current iron loss coefficient of the motor according to a preset first corresponding relation and a current stator current parameter of the motor, wherein the iron loss coefficient represents the relation between the iron loss of the motor and the stator current parameter, and the first corresponding relation is the corresponding relation between the stator current parameter and the iron loss coefficient;

And the iron loss determining module is configured to determine the current iron loss of the motor according to the determined iron loss coefficient and the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor.

According to a third aspect of embodiments of the present disclosure, there is provided a vehicle comprising:

a first processor;

a first memory for storing first processor-executable instructions;

wherein the first processor is configured to:

According to a fourth aspect of embodiments of the present disclosure, there is provided a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the method for determining iron loss of a motor provided in the first aspect of the present disclosure.

According to a fifth aspect of embodiments of the present disclosure, there is provided a chip comprising a second processor and an interface; the second processor is configured to read instructions to perform the steps of the method for determining iron loss of a motor provided in the first aspect of the present disclosure.

The technical scheme provided by the embodiment of the disclosure can comprise the following beneficial effects:

obtaining a corresponding relation (a first corresponding relation) between stator current parameters and iron loss coefficients of a motor driving system through experiments; in the running process of the motor driving system, the actual (current) iron loss coefficient is obtained by checking the first corresponding relation in real time through the actual (current) stator current parameter; and then combining the actual (current) speed parameter of the motor, so as to accurately calculate the actual (current) iron loss of the motor. Therefore, the technical scheme provided by the disclosure can meet the iron loss calculation accuracy requirement of full-working condition operation of an actual motor driving system, is not influenced by the voltage change of the battery of the driving motor, and only needs to obtain the first corresponding relation (the first corresponding relation can be displayed in the form of one table data) through experiments in advance, so that the method is small in workload and data quantity and suitable for engineering application.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the disclosure and together with the description, serve to explain the principles of the disclosure.

Fig. 1 is a first equivalent circuit diagram of an electric machine, shown according to an exemplary embodiment.

Fig. 2 is a second equivalent circuit diagram of the motor shown according to an exemplary embodiment.

Fig. 3 is a flowchart illustrating a method of determining iron loss of a motor according to an exemplary embodiment.

Fig. 4 is a schematic diagram showing a fifth correspondence relationship according to an exemplary embodiment.

Fig. 5 is a schematic diagram showing a sixth correspondence relationship according to an exemplary embodiment.

Fig. 6 is a block diagram illustrating a motor iron loss determination apparatus according to an exemplary embodiment.

Fig. 7 is a block diagram of a vehicle, according to an exemplary embodiment.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples are not representative of all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present disclosure as detailed in the accompanying claims.

It should be noted that, all actions for acquiring signals, information or data in the present application are performed under the condition of conforming to the corresponding data protection rule policy of the country of the location and obtaining the authorization given by the owner of the corresponding device.

In order to solve the problems in the background art, the applicant analyzed the motor to obtain equivalent circuit diagrams as shown in fig. 1 and 2. The motor can be an alternating current motor such as a vehicle-mounted driving motor, an induction motor, a switched reluctance motor, a permanent magnet synchronous motor, an electric excitation motor and the like. From the equivalent circuit diagrams as shown in fig. 1 and 2, it is possible to build up:

1) The motor voltage equation is as follows:

U _d ＝R _s i _d +U _od (equation 1)

U _q ＝R _s i _q +U _oq (equation 2)

U _od ＝-w _e L _q i _oq (equation 3)

U _oq ＝w _e (L _d i _od +ψ _m ) (equation 4)

In the above formula, U _d The voltage is the direct-axis voltage of the motor stator, and the unit is V; r is R _s The motor stator phase resistance is the unit Ohm; i.e _d The direct shaft current of the motor stator is in unit A; u (U) _od The voltage is a component voltage corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator, and the unit is V; u (U) _q The motor stator quadrature voltage is in unit V; i.e _q The direct shaft current of the motor stator is in unit A; u (U) _oq The voltage is a component voltage corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator, and the unit is V; w (w) _e Synchronous angular speed of the motor, unit rad/s; l (L) _q The motor stator quadrature axis inductance is the unit H; i.e _oq The unit A is the component current corresponding to the electromagnetic torque in the motor stator quadrature axis current; l (L) _d The motor stator direct axis inductance is the unit H; i.e _od Component current corresponding to electromagnetic torque in direct-axis current of a motor stator; psi phi type _m Is the motor rotor flux linkage, unit Wb.

2) The motor electromagnetic torque equation is as follows:

in the above formula, T _e Is an electric motorElectromagnetic torque in Nm; p is the pole pair number of the motor.

3) The motor iron loss equation is as follows:

wherein f is the current frequency of the motor phase and the synchronous angular velocity relationship with the motor is as follows:

w _e =2pi_f (equation 7)

Therefore, the iron loss equation is rewritten as follows:

in the above formula, ploss _Fe The unit W is the iron loss of the motor; k (k) _σ The motor iron loss empirical coefficient; f is the current frequency of the motor phase, and the unit is Hz; b (B) _m The unit is T, which is the peak value of the magnetic density of the motor iron core; g _Fe The mass of the motor component producing iron loss is in kg.

4) The equivalent resistance equation of the motor iron loss is as follows:

in the above formula, R _c The motor is the equivalent resistance of the iron loss of the motor and has the unit Ohm.

Substituting 1) a motor voltage equation and 3) a motor iron loss equation into formula 9 to obtain:

5) Iron loss coefficient of motor

The applicant designed an iron loss coefficient K according to equation (10) _Fe The method is used for representing the mathematical analysis relation between the iron loss of the motor and the stator current of the motor, and comprises the following steps:

Observing the above K _Fe The equation shows that the intrinsic parameters of the motor body (L _q 、L _d 、ψ _m 、k _σ 、G _Fe 、B _m ) It is only related to the motor current, i.e. the iron loss coefficient characterizes the essential correspondence of the motor iron loss to the motor stator current. Thus, different i can be calibrated in advance _oq 、i _od Lower iron loss coefficient K _Fe Establishing K _Fe And i _oq 、i _od If the two-dimensional corresponding relation of the table is calibrated in advance to obtain a two-dimensional table, the abscissa of the table is i _oq The ordinate is i _od A value of K _Fe . In practical application, according to actual (current) i _oq 、i _od Looking up the two-dimensional table to obtain i from the actual (current) _oq 、i _od Corresponding K _Fe The method comprises the steps of carrying out a first treatment on the surface of the Based on the actual (current) w _e The actual (current) R can be obtained according to the formula 11 _c . According to actual (current) i _oq 、i _od I can be obtained by using the following equation 12 and equation 13 _cd And i _cq The method comprises the steps of carrying out a first treatment on the surface of the The iron loss Ploss of the motor can be obtained according to the formula 14 _Fe 。

Based on the above technical idea, fig. 3 is a flowchart illustrating a method for determining iron loss of a motor according to an exemplary embodiment. The motor iron loss determination method may be applied to a VCU (Vehicle Control Unit ) of a vehicle. As shown in fig. 3, the motor iron loss determination method includes the following steps.

In step S11, a current iron loss coefficient of the motor is determined according to a preset first corresponding relationship and a current stator current parameter of the motor, wherein the iron loss coefficient represents a relationship between the iron loss of the motor and the stator current parameter, and the first corresponding relationship is a corresponding relationship between the stator current parameter and the iron loss coefficient.

The preset first corresponding relation can be obtained and stored according to experimental calibration. The stator current parameter may be a component current (i) of the motor stator quadrature axis current corresponding to the electromagnetic torque _oq ) And component current (i) corresponding to electromagnetic torque in direct-axis current of motor stator _od ) Stator quadrature current (i _q ) And stator straight axis current (i) _d ) Or component current (i) corresponding to motor iron loss in motor stator quadrature axis current _cq ) And component current (i) corresponding to motor iron loss in motor stator straight shaft current _cd ). It is apparent that although the expression of the iron loss coefficient in the formula 11 is expressed by i _oq 、i _od Represented, but may not use i _oq 、i _od Representation, e.g. according to i _q 、i _d 、i _cq 、i _cd Or other variables indirectly representing i by formula _oq 、i _od . It should be noted that equation 11 is merely an expression showing the iron loss coefficient by way of example, and is not intended to limit the present invention. For example, the replacement of i by another variable is removed _oq 、i _od The intrinsic parameters of the motor body included in the iron loss coefficient can be properly removed completely or partially, for example, the iron loss coefficient can also be K _Fe ＝((L _q i _oq ) ² +(L _d i _od +ψ _m ) ² ) At this time, R is further determined _c When it is needed to multiplyFor example, the iron loss coefficient may also be K _Fe ＝(2π) ^1.3 ((L _q i _oq ) ² +(L _d i _od +ψ _m ) ² ) At this time, R is further determined _c When it is needed to multiplyFor economy of description, no further examples are provided herein.

In step S12, the current iron loss of the motor is determined according to the determined iron loss coefficient and the current speed parameter, stator current parameter, stator inductance and rotor flux linkage of the motor.

Wherein the speed parameter can be the synchronous angular speed w of the motor _e Or the motor rotor speed NEm, or other can indirectly obtain w _e Is used for the speed parameter of the vehicle. Wherein,,

when the stator current parameter is i _oq And i _od When the speed parameter is w _e When the method is used, the iron loss coefficient Ploss can be obtained according to the current speed parameter, the stator current parameter, the stator inductance, the rotor flux linkage and the current iron loss coefficient and formulas 12, 13 and 14 _Fe . It should be noted that when the stator current parameter is not i _oq And i _od When the speed parameter is not w _e When the iron loss coefficient Ploss is obtained by deforming according to the formulas 12, 13 and 14 _Fe 。

According to the technical scheme provided by the disclosure, the corresponding relation (first corresponding relation) between the stator current parameter and the iron loss coefficient of the motor driving system is obtained through experiments; in the running process of the motor driving system, the actual (current) iron loss coefficient is obtained by checking the first corresponding relation in real time through the actual (current) stator current parameter; and then combining the actual (current) speed parameter of the motor, so as to accurately calculate the actual (current) iron loss of the motor. Therefore, the technical scheme provided by the disclosure can meet the iron loss calculation accuracy requirement of full-working condition operation of an actual motor driving system, is not influenced by the voltage change of the battery of the driving motor, and only needs to obtain the first corresponding relation (the first corresponding relation can be displayed in the form of one table data) through experiments in advance, so that the method is small in workload and data quantity and suitable for engineering application.

The method can be applied to vehiclesThe method may be performed by a device provided to the vehicle and having a processing function. When the vehicle executes the method, the current i can be obtained through the torque command calculation of the VCU of the vehicle _oq And i _od Collecting the current rotor rotation speed NEm of the motor in real time through a speed sensor; at the time of acquiring the current i _oq And i _od Then, inputting the first corresponding relation into a device with a processing function, wherein the device is pre-stored with the first corresponding relation according to the current i _oq And i _od The current iron loss coefficient of the motor is obtained according to a pre-stored first corresponding relation; and then the current rotor rotating speed NEm of the motor is combined, namely the current iron loss of the motor is calculated.

Optionally, the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter. Wherein the stator quadrature current parameter may be i _oq 、i _q Or i _cq Etc., the stator straight axis current parameter may be i _od 、i _d Or i _cd Etc. The first corresponding relation is established by the following way:

and controlling the speed parameter of the motor to be equal to a first preset value, and acquiring motor iron loss equivalent resistances of the motor under different stator quadrature axis current parameters and stator direct axis current parameters to establish a second corresponding relation, wherein the second corresponding relation is a two-dimensional corresponding relation between the motor iron loss equivalent resistances and the stator quadrature axis current parameters and the stator direct axis current parameters.

Establishing a first corresponding relation according to the second corresponding relation, the first preset numerical value and a first formula, wherein the first corresponding relation is a two-dimensional corresponding relation between an iron loss coefficient and a stator quadrature axis current parameter and a stator direct axis current parameter, and the first formula is thatWherein K is _Fe Representing the iron loss coefficient of the motor, R _c Representing the iron loss equivalent resistance, w, of the motor _e Representing the synchronous angular velocity of the motor.

Through the technical proposal, the iron loss coefficient is proposedObtaining the equivalent resistance R of the iron loss of the motor _c And obtaining the two-dimensional corresponding relation (first corresponding relation) between the iron loss coefficient and the stator quadrature axis current parameter and the stator direct axis current parameter after the two-dimensional corresponding relation (second corresponding relation) between the iron loss coefficient and the stator quadrature axis current parameter and the stator direct axis current parameter is obtained.

Optionally, the stator cross current parameter is a component current i of the motor stator cross current corresponding to electromagnetic torque _oq The stator direct-axis current parameter is component current i corresponding to electromagnetic torque in the motor stator direct-axis current _od The controlling the speed parameter of the motor to be equal to a first preset value, and the obtaining the motor iron loss equivalent resistance of the motor under different stator quadrature axis current parameters and stator direct axis current parameters so as to establish a second corresponding relation comprises:

And controlling the speed parameter of the motor to be equal to a first preset value, acquiring the iron losses of the motor under different stator quadrature axis currents and stator direct axis currents to establish a third corresponding relation, and acquiring the stator quadrature axis voltage and the stator direct axis voltage corresponding to each group of stator quadrature axis currents and stator direct axis currents in the third corresponding relation, wherein the third corresponding relation is a two-dimensional corresponding relation between the iron losses of the motor and the stator quadrature axis currents and the stator direct axis currents.

I.e. establish iron loss Ploss by experiment _Fe With stator straight axis current i _d And stator quadrature axis current i _q And record each group i in the third corresponding relation _d 、i _q And Ploss _Fe Corresponding stator quadrature axis voltage U _q And stator direct axis voltage U _d 。

From equations 1 and 2, equations 15 and 16 can be deduced, and i in the third correspondence relationship _d 、i _q Corresponding U _d 、U _q Motor intrinsic parameter motor stator phase resistance R _s With the formulas 15 and 16, the component voltage U corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator can be obtained _od And component voltage U corresponding to motor iron loss in motor stator direct axis voltage _oq The method comprises the steps of carrying out a first treatment on the surface of the If the speed parameter equal to the first preset value is NEm, NEm can be converted to w according to equation 17 _e The method comprises the steps of carrying out a first treatment on the surface of the The root will determine U _od And U _oq And motor intrinsic parameter motor stator quadrature axis inductance L _q Direct-axis inductance L of motor stator _d Magnetic chain psi of motor rotor _m Taking into equations 18 and 19, component current i corresponding to electromagnetic torque in motor stator quadrature axis current is obtained _oq And component current i corresponding to electromagnetic torque in direct-axis current of motor stator _od The method comprises the steps of carrying out a first treatment on the surface of the U determined by equation 15 and equation 16 _od And U _oq And Ploss in the third correspondence _Fe R can be obtained by taking into the formula 20 _c . Thus realizing the establishment of R _c And i _oq And i _od Is a second correspondence of (a).

U _od ＝U _d -R _s i _d (equation 15)

U _oq ＝U _q -R _s i _q (equation 16)

By the technical scheme, the Ploss is firstly established _Fe And i _d And i _q The third corresponding relation is converted into R _c And i _oq And i _od Is a second correspondence of (a). The foregoing steps can prove that after the second corresponding relationship is obtained, the first corresponding relationship can be obtained according to the second corresponding relationship and the first preset value.

and obtaining the stator phase resistance, the stator quadrature axis current and the stator direct axis current of the motor, and obtaining the copper loss of the motor according to the stator phase resistance, the stator quadrature axis current and the stator direct axis current.

Stator phase resistance R of each measuring point can be acquired in real time through a bench power analyzer and a current sensor _s Stator quadrature axis current i _q And stator straight axis current i _d The copper loss P of the motor can be obtained by bringing the formula 21 into _cu 。

And obtaining the bus voltage and the bus current of the motor, and obtaining the input power of the motor according to the bus voltage and the bus current.

Bus voltage U of each measuring point can be acquired in real time through a rack power analyzer _dc And bus current i _dc The input power P of the motor can be obtained by taking in the formula 22 _in 。

P _in ＝U _dc i _dc (equation 22)

And obtaining the mechanical torque and the rotor rotating speed of the motor, and obtaining the output power of the motor according to the mechanical torque and the rotor rotating speed.

The mechanical torque T of each measuring point can be acquired in real time through a torque sensor _m And rotor speed NEm, and carrying into formula 23 to obtain output power P of motor _out 。

And obtaining the mechanical friction loss power of the motor.

In general, the mechanical friction loss power Ploss of an electric machine _mech As the rotor speed NEm changes, the motor design and manufacture is completed and then the complete mechanical friction loss and rotor speed NEm one-dimensional table data are tested. Thus, the one-dimensional table data may be queried based on the current rotor speed NEm to obtain the current mechanical friction loss power.

The input power P to be obtained _in Output power P _out Copper loss P _cu Power of mechanical friction loss Ploss _mech By taking the formula 24, the iron loss Ploss can be obtained _Fe Thereby realizing the establishment of Ploss _Fe And i _d And i _q Is a third correspondence of (a).

Ploss _Fe ＝P _in -P _out -P _cu -Ploss _mech (equation 24)

and acquiring the quadrature axis current, the direct axis current, the power factor angle and the phase voltage of the motor.

For example, the quadrature current i of each measuring point can be detected by a current sensor _q And a direct axis current i _d The motor phase voltage of each measuring point can be acquired in real time through a power analyzer of the experiment benchU _s Power factor angle alpha.

And calculating the current angle of the motor according to the quadrature axis current and the direct axis current.

And (5) bringing the acquired quadrature axis current and direct axis current into a formula 25 to calculate the current angle theta of the motor.

The obtained current angle theta, the power factor angle alpha and the phase voltage U _s By respectively carrying out the formulas 26 and 27, the direct-axis voltage U can be obtained _d And quadrature axis voltage U _q 。

U _d ＝U _s cos (alpha + theta) (equation 26)

U _q ＝U _s sin (alpha + theta) (equation 27)

Optionally, step S12 includes:

and acquiring the synchronous angular speed of the motor according to the current speed parameter of the motor.

If the speed parameter is synchronous angular speed w _e The synchronous angular velocity w can be directly obtained _e . If the speed parameter is the motor rotor speed NEm, the synchronous angular velocity w can be obtained according to equation 17 _e . The current speed parameter of the motor can be acquired by a speed sensor.

And determining the current iron loss equivalent resistance of the motor according to the determined iron loss coefficient and the synchronous angular speed.

And determining the current iron loss equivalent resistance of the motor by adopting a formula 11 (or a formula 10) according to the iron loss coefficient and the synchronous angular velocity obtained by the first corresponding relation.

And acquiring component currents corresponding to the motor iron loss in the current stator direct axis current of the motor and component currents corresponding to the motor iron loss in the stator quadrature axis current according to the current stator current parameters of the motor.

Since the stator current parameter may be i _oq And i _od Or i _q And i _d Or i _cq And i _cd Therefore, according to the difference of the stator current parameters, i is obtained according to the stator current parameters _oq 、i _od The manner of acquisition is known to those skilled in the art and will not be described in detail herein.

According to the R obtained _c 、i _cd And i _cq The iron loss Ploss of the motor can be obtained according to the formula 14 _Fe 。

When the first correspondence relationship is established under the condition that the speed parameter of the motor is equal to a first preset value, the influence of the rotor rotation speed on the iron loss is considered, and the iron loss coefficient can be compensated. Optionally, the method further comprises:

and determining a current iron loss compensation coefficient of the motor according to a preset fourth corresponding relation and the current speed parameter of the motor, wherein the fourth corresponding relation comprises a corresponding relation between the iron loss compensation coefficient and the speed parameter.

Through the technical scheme, the fourth corresponding relation of the iron loss compensation coefficient corresponding to the speed parameter is established in advance, and when in actual use, the actual (current) iron loss compensation coefficient is obtained according to the actual (current) speed parameter and the fourth corresponding relation, and the obtained actual (current) iron loss compensation coefficient is added into iron loss calculation, so that iron loss is compensated, and the compensated iron loss is more consistent with the actual iron loss. Therefore, according to the technical scheme provided by the disclosure, the first corresponding relation and the fourth corresponding relation (the first corresponding relation and the fourth corresponding relation can be displayed in the form of one table data) need to be obtained through experiments in advance, so that the workload and the data volume are small, and the method is suitable for engineering application.

and obtaining a fifth corresponding relation and a sixth corresponding relation of the bus voltage of the motor under the condition that the bus voltage is equal to a second preset value, wherein the fifth corresponding relation is the corresponding relation of the stator quadrature axis current parameter, the speed parameter and the electromagnetic torque of the motor, and the sixth corresponding relation is the corresponding relation of the stator direct axis current parameter, the speed parameter and the electromagnetic torque of the motor.

The second preset value may be set according to practical situations, for example 760V. For bus voltage with fixed value, stator cross current parameter (such as component current i corresponding to electromagnetic torque in stator cross current _oq ) With speed parameters, such as rotor speed NEm, and electromagnetic torque (T _e ) (fifth correspondence), stator direct-axis current parameters (e.g., component current i corresponding to electromagnetic torque in stator direct-axis current) _od ) With speed parameters, such as rotor speed NEm, and electromagnetic torque (T _e ) The two-dimensional data relationship (sixth corresponding relationship) of the motor can be obtained through motor performance calibration, and belongs to the standard technical development process of motor calibration. As shown in FIG. 4, the fifth correspondence is shown in the form of a table, in FIG. 4, the abscissa represents the rotor rotation speed NEM, and the ordinate represents the electromagnetic torque T _e The value is the component current i of the corresponding electromagnetic torque in the stator quadrature axis current _oq . As shown in fig. 5, a sixth correspondence is shown in the form of a table, in fig. 5, the abscissa represents the rotor rotation speed NEM, and the ordinate represents the electromagnetic torque T _e The value is the component current i of the stator straight shaft current corresponding to the electromagnetic torque _od 。

And obtaining a seventh corresponding relation according to the fifth corresponding relation, the sixth corresponding relation and the first corresponding relation, wherein the seventh corresponding relation is a corresponding relation of the iron loss coefficient, the speed parameter and the electromagnetic torque.

According to the fifth corresponding relation and the sixth corresponding relation, the abscissa stator quadrature axis current parameter and the ordinate stator direct axis current parameter in the first corresponding relation can be converted into the speed parameter and the electromagnetic torque, namely, the first corresponding relation is converted into the corresponding relation of the iron loss coefficient, the speed parameter and the electromagnetic torque. According to the corresponding relation between the iron loss coefficient and the speed parameter and the electromagnetic torque, the corresponding relation between the iron loss and the speed parameter and the corresponding relation between the iron loss and the electromagnetic torque (seventh corresponding relation) can be obtained through the fifth corresponding relation, the sixth corresponding relation, the motor inherent parameter and the formula 28.

And controlling the bus voltage of the motor to be equal to a second preset value, and obtaining the iron loss of the motor under different rotating speed parameters and electromagnetic torque to establish an eighth corresponding relation, wherein the eighth corresponding relation is the corresponding relation of the iron loss, the speed parameters and the electromagnetic torque.

And controlling the bus voltage of the motor to be equal to a second preset value, obtaining the electromagnetic torque of each measuring point through a torque sensor, obtaining the rotating speed parameter of each measuring point through a speed sensor, and obtaining the iron loss of each measuring point through input power, output power, copper loss and mechanical friction loss power, thereby establishing an eighth corresponding relation.

And establishing a ninth corresponding relation according to the eighth corresponding relation and the seventh corresponding relation, wherein the ninth corresponding relation is the corresponding relation between the initial iron loss compensation coefficient and the speed parameter and between the initial iron loss compensation coefficient and the electromagnetic torque.

From the above, the eighth correspondence relationship is iron loss under different speed parameters and electromagnetic torque actually tested. And the seventh corresponding relation is iron loss under different speed parameters and electromagnetic torque calculated by adopting the iron loss coefficient in the first corresponding relation which is established in advance. Therefore, the iron loss in the eighth correspondence relationship may be taken as the actual iron loss, and the iron loss in the seventh correspondence relationship is the iron loss calculated using the iron loss coefficient in the first correspondence relationship, and therefore the ratio of the iron loss in the eighth correspondence relationship to the iron loss in the seventh correspondence relationship under the same speed parameter and electromagnetic torque is taken as the initial iron loss compensation coefficient to compensate the iron loss calculated using the iron loss coefficient in the seventh correspondence relationship. And establishing a ninth corresponding relation according to the corresponding relation between the initial iron loss compensation coefficient and the speed parameter and the electromagnetic torque.

The initial iron loss compensation coefficient of the plurality of measurement points having the same speed parameter but different electromagnetic torques may be processed as one compensation coefficient by a least square method or other mathematical method, without limitation. For example, when the ninth correspondence is a data table in which the abscissa is a speed parameter, the ordinate is an electromagnetic torque, and the value is an initial iron loss compensation coefficient, the initial iron loss compensation coefficient of each column may be processed into a compensation coefficient by a least square method or other mathematical methods. For another example, when the ninth correspondence is a data table in which the ordinate is a speed parameter, the abscissa is an electromagnetic torque, and the value is an initial iron loss compensation coefficient, the initial iron loss compensation coefficient of each line may be processed into one compensation coefficient by a least square method or other mathematical methods.

Through the technical scheme, the corresponding relation between the iron loss compensation coefficient and the speed parameter is established, the influence of the rotor rotating speed on the iron loss is considered, and the iron loss coefficient can be compensated; and a plurality of initial iron loss compensation coefficients under the same speed parameter (different electromagnetic torques) are processed into one compensation coefficient, so that the workload of calculating by applying the initial iron loss compensation coefficients is saved.

In practical use, the influence of the rotor rotation speed on the iron loss and the compensation of the iron loss coefficient may be considered, and the influence of the battery voltage on the iron loss and the compensation of the iron loss coefficient may be considered.

The above method may be applied to a vehicle, and the above method may be performed by a device having a processing function provided to the vehicle. When the vehicle executes the method, the current i can be obtained through the torque command calculation of the VCU of the vehicle _oq And i _od Collecting the current rotor rotation speed NEm of the motor in real time through a speed sensor; at the time of acquiring the current i _oq And i _od Then, inputting the first corresponding relation into a device with a processing function, wherein the device is pre-stored with the first corresponding relation according to the current i _oq And i _od The current iron loss coefficient of the motor is obtained according to a pre-stored first corresponding relation; determining a compensation coefficient by combining the current rotor rotating speed NEm of the motor, and compensating the iron loss coefficient by multiplying the compensation coefficient by the iron loss coefficient; and calculating the current iron loss of the motor by combining the current rotor rotating speed NEm of the motor and the compensated iron loss coefficient.

Based on the technical conception, the embodiment of the disclosure also provides a motor iron loss determining device. Fig. 6 is a block diagram illustrating a motor iron loss determination apparatus according to an exemplary embodiment. Referring to fig. 6, the apparatus includes:

The iron loss coefficient determining module 11 is configured to determine a current iron loss coefficient of the motor according to a preset first corresponding relation and a current stator current parameter of the motor, wherein the iron loss coefficient represents a relation between iron loss of the motor and the stator current parameter, and the first corresponding relation is a corresponding relation between the stator current parameter and the iron loss coefficient;

a core loss determination module 12 configured to determine a current core loss of the motor based on the determined core loss coefficient and current speed parameters, stator current parameters, stator inductances, and rotor flux linkages of the motor.

Optionally, the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter. Wherein the stator quadrature current parameter may be i _oq 、i _q Or i _cq Etc., the stator straight axis current parameter may be i _od 、i _d Or i _cd Etc. The apparatus further comprises:

the second corresponding relation establishing module is configured to control the speed parameter of the motor to be equal to a first preset value, and obtain motor iron loss equivalent resistances of the motor under different stator quadrature axis current parameters and stator direct axis current parameters so as to establish a second corresponding relation, wherein the second corresponding relation is a two-dimensional corresponding relation between the motor iron loss equivalent resistances and the stator quadrature axis current parameters and the stator direct axis current parameters.

A first correspondence establishing module configured to establish a first correspondence according to the second correspondence, the first preset value, and a first formula, where the first correspondence is a two-dimensional correspondence between an iron loss coefficient and a stator quadrature axis current parameter and a stator direct axis current parameter, and the first formula is thatWherein K is _Fe Representing the iron loss coefficient of the motor, R _c Representing the iron loss equivalent resistance, w, of the motor _e Representing the synchronous angular velocity of the motor.

Through the technical proposal, the iron loss coefficient is proposed Obtaining the equivalent resistance R of the iron loss of the motor _c Two-dimensional correspondence with stator quadrature axis current parameter and stator direct axis current parameter (second correspondenceRelationship), a two-dimensional corresponding relationship (first corresponding relationship) between the iron loss coefficient and the stator quadrature axis current parameter and the stator direct axis current parameter can be obtained.

Optionally, the stator cross current parameter is a component current i of the motor stator cross current corresponding to electromagnetic torque _oq The stator direct-axis current parameter is component current i corresponding to electromagnetic torque in the motor stator direct-axis current _od The second correspondence establishing module includes:

the third corresponding relation establishing sub-module is configured to control the speed parameter of the motor to be equal to a first preset value, obtain the iron losses of the motor under different stator quadrature axis currents and stator direct axis currents, establish the third corresponding relation, and obtain the stator quadrature axis voltage and the stator direct axis voltage corresponding to each group of stator quadrature axis currents and stator direct axis currents in the third corresponding relation, wherein the third corresponding relation is a two-dimensional corresponding relation between the iron losses of the motor and the stator quadrature axis currents and the stator direct axis currents.

The second correspondence establishing sub-module is configured to establish a second correspondence according to the first preset value, the third correspondence and the stator quadrature axis voltage and the stator direct axis voltage corresponding to each group of stator quadrature axis current and stator direct axis current in the third correspondence, wherein the second correspondence is a correspondence between the motor iron loss equivalent resistance and the component current of the corresponding electromagnetic torque in the motor stator quadrature axis current and the component current of the corresponding electromagnetic torque in the motor stator direct axis current.

Optionally, the third correspondence sub-module includes:

and the copper loss acquisition submodule is configured to acquire the stator phase resistance, the stator quadrature axis current and the stator direct axis current of the motor and acquire the copper loss of the motor according to the stator phase resistance, the stator quadrature axis current and the stator direct axis current.

And the input power acquisition sub-module is configured to acquire bus voltage and bus current of the motor and acquire the input power of the motor according to the bus voltage and the bus current.

An output power acquisition sub-module configured to acquire a mechanical torque and a rotor rotational speed of the motor, and to acquire an output power of the motor based on the mechanical torque and the rotor rotational speed.

A mechanical friction loss power acquisition sub-module configured to acquire mechanical friction loss power of the motor.

The first iron loss acquisition submodule is configured to acquire the iron loss of the motor under the stator cross-axis current and the stator direct-axis current according to the input power, the output power, the copper loss and the mechanical friction loss power so as to establish a third corresponding relation.

Optionally, the third correspondence sub-module further includes:

and the acquisition sub-module is configured to acquire the quadrature axis current, the direct axis current, the power factor angle and the phase voltage of the motor.

And the current angle acquisition sub-module is configured to calculate the current angle of the motor according to the quadrature axis current and the direct axis current.

And the alternating-direct axis voltage acquisition sub-module is configured to acquire the alternating-axis voltage and the direct-axis voltage of the motor according to the current angle, the power factor angle and the phase voltage.

Optionally, the iron loss determination module 12 includes:

and the synchronous angular velocity determining submodule is configured to acquire the synchronous angular velocity of the motor according to the current velocity parameter of the motor.

And the iron loss equivalent resistance determining submodule is configured to determine the current iron loss equivalent resistance of the motor according to the determined iron loss coefficient and the synchronous angular speed.

And the motor iron loss component current determining sub-module is configured to acquire component currents corresponding to motor iron loss in the current stator direct-axis current and component currents corresponding to motor iron loss in the stator quadrature-axis current of the motor according to the current stator current parameters of the motor.

And the iron loss determination submodule is configured to acquire the current iron loss of the motor according to the iron loss equivalent resistance, the component current corresponding to the iron loss of the motor in the stator direct-axis current, the component current corresponding to the iron loss of the motor in the stator quadrature-axis current, the stator inductance and the rotor flux linkage, wherein the stator inductance comprises the stator direct-axis inductance and the stator quadrature-axis inductance.

Optionally, the apparatus further comprises: and the iron loss compensation coefficient determining module.

The iron loss compensation coefficient determining module is configured to determine the current iron loss compensation coefficient of the motor according to a preset fourth corresponding relation and the current speed parameter of the motor, wherein the fourth corresponding relation comprises a corresponding relation between the iron loss compensation coefficient and the speed parameter.

In compensation, the iron loss determination module 12 is configured to determine the current iron loss of the motor based on the determined iron loss coefficient, the current speed parameter of the motor, the stator current parameter, the iron loss compensation coefficient, the stator inductance, and the rotor flux linkage.

Optionally, the iron loss compensation coefficient determining module includes:

a fifth corresponding relation determining sub-module configured to obtain a fifth corresponding relation and a sixth corresponding relation of the bus voltage of the motor under a second preset value, wherein the fifth corresponding relation is a corresponding relation of a stator quadrature axis current parameter, a speed parameter and an electromagnetic torque of the motor, and the sixth corresponding relation is a corresponding relation of a stator direct axis current parameter, the speed parameter and the electromagnetic torque of the motor.

The seventh corresponding relation determining sub-module is configured to obtain a seventh corresponding relation according to the fifth corresponding relation, the sixth corresponding relation and the first corresponding relation, wherein the seventh corresponding relation is a corresponding relation of an iron loss coefficient, a speed parameter and an electromagnetic torque.

And the eighth corresponding relation determining submodule is configured to control the bus voltage of the motor to be equal to a second preset value, and acquire the iron loss of the motor under different rotation speed parameters and electromagnetic torque so as to establish the eighth corresponding relation, wherein the eighth corresponding relation is the corresponding relation of the iron loss, the speed parameters and the electromagnetic torque.

And a ninth corresponding relation determining sub-module configured to establish a ninth corresponding relation according to the eighth corresponding relation and the seventh corresponding relation, wherein the ninth corresponding relation is a corresponding relation between the initial iron loss compensation coefficient and the speed parameter and between the initial iron loss compensation coefficient and the electromagnetic torque.

And a tenth corresponding relation determining sub-module configured to process the ninth corresponding relation and establish a tenth corresponding relation, wherein the tenth corresponding relation is a corresponding relation between the iron loss compensation coefficient and the speed parameter.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

The present disclosure also provides a computer readable storage medium having stored thereon computer program instructions which, when executed by a processor, implement the steps of the motor iron loss determination method provided by the present disclosure.

The apparatus may be a stand-alone electronic device or may be part of a stand-alone electronic device, for example, in one embodiment, the apparatus may be an integrated circuit (Integrated Circuit, IC) or a chip, where the integrated circuit may be an IC or may be a collection of ICs; the chip may include, but is not limited to, the following: GPU (Graphics Processing Unit, graphics processor), CPU (Central Processing Unit ), FPGA (Field Programmable Gate Array, programmable logic array), DSP (Digital Signal Processor ), ASIC (Application Specific Integrated Circuit, application specific integrated circuit), SOC (System on Chip, SOC, system on Chip or System on Chip), etc. The integrated circuit or chip may be configured to execute executable instructions (or code) to implement the method for determining iron loss of the motor. The executable instructions may be stored on the integrated circuit or chip or may be retrieved from another device or apparatus, such as the integrated circuit or chip including a second processor, a second memory, and an interface for communicating with the other device. The executable instructions may be stored in the second memory, which when executed by the second processor implements the above-described method of determining motor iron loss; or the integrated circuit or the chip can receive the executable instruction through the interface and transmit the executable instruction to the second processor for execution so as to realize the motor iron loss determination method.

Referring to fig. 7, fig. 7 is a functional block diagram of a vehicle 600 according to an exemplary embodiment. The vehicle 600 may be configured in a fully or partially autonomous mode. For example, the vehicle 600 may obtain environmental information of its surroundings through the perception system 620 and derive an automatic driving strategy based on analysis of the surrounding environmental information to achieve full automatic driving, or present the analysis results to the user to achieve partial automatic driving.

The vehicle 600 may include various subsystems, such as an infotainment system 610, a perception system 620, a decision control system 630, a drive system 640, and a computing platform 650. Alternatively, vehicle 600 may include more or fewer subsystems, and each subsystem may include multiple components. In addition, each of the subsystems and components of vehicle 600 may be interconnected via wires or wirelessly.

In some embodiments, the infotainment system 610 may include a communication system 611, an entertainment system 612, and a navigation system 613.

The communication system 611 may comprise a wireless communication system, which may communicate wirelessly with one or more devices, either directly or via a communication network. For example, the wireless communication system may use 3G cellular communication, such as CDMA, EVD0, GSM/GPRS, or 4G cellular communication, such as LTE. Or 5G cellular communication. The wireless communication system may communicate with a wireless local area network (wireless local area network, WLAN) using WiFi. In some embodiments, the wireless communication system may communicate directly with the device using an infrared link, bluetooth, or ZigBee. Other wireless protocols, such as various vehicle communication systems, for example, wireless communication systems may include one or more dedicated short-range communication (dedicated short range communications, DSRC) devices, which may include public and/or private data communications between vehicles and/or roadside stations.

Entertainment system 612 may include a display device, a microphone, and an audio, and a user may listen to the broadcast in the vehicle based on the entertainment system, playing music; or the mobile phone is communicated with the vehicle, the screen of the mobile phone is realized on the display equipment, the display equipment can be in a touch control type, and a user can operate through touching the screen.

In some cases, the user's voice signal may be acquired through a microphone and certain controls of the vehicle 600 by the user may be implemented based on analysis of the user's voice signal, such as adjusting the temperature within the vehicle, etc. In other cases, music may be played to the user through sound.

The navigation system 613 may include a map service provided by a map provider to provide navigation of a travel route for the vehicle 600, and the navigation system 613 may be used with the global positioning system 621 and the inertial measurement unit 622 of the vehicle. The map service provided by the map provider may be a two-dimensional map or a high-precision map.

The perception system 620 may include several types of sensors that sense information about the environment surrounding the vehicle 600. For example, sensing system 620 may include a global positioning system 621 (which may be a GPS system, or may be a beidou system, or other positioning system), an inertial measurement unit (inertial measurement unit, IMU) 622, a lidar 623, a millimeter wave radar 624, an ultrasonic radar 625, and a camera 626. The sensing system 620 may also include sensors (e.g., in-vehicle air quality monitors, fuel gauges, oil temperature gauges, etc.) of the internal systems of the monitored vehicle 600. Sensor data from one or more of these sensors may be used to detect objects and their corresponding characteristics (location, shape, direction, speed, etc.). Such detection and identification is a critical function of the safe operation of the vehicle 600.

The global positioning system 621 is used to estimate the geographic location of the vehicle 600.

The inertial measurement unit 622 is configured to sense a change in the pose of the vehicle 600 based on inertial acceleration. In some embodiments, inertial measurement unit 622 may be a combination of an accelerometer and a gyroscope.

The lidar 623 uses a laser to sense objects in the environment in which the vehicle 600 is located. In some embodiments, lidar 623 may include one or more laser sources, a laser scanner, and one or more detectors, among other system components.

The millimeter-wave radar 624 utilizes radio signals to sense objects within the surrounding environment of the vehicle 600. In some embodiments, millimeter-wave radar 624 may be used to sense the speed and/or heading of an object in addition to sensing the object.

The ultrasonic radar 625 may utilize ultrasonic signals to sense objects around the vehicle 600.

The image pickup device 626 is used to capture image information of the surrounding environment of the vehicle 600. The image capturing device 626 may include a monocular camera, a binocular camera, a structured light camera, a panoramic camera, etc., and the image information acquired by the image capturing device 626 may include still images or video stream information.

The decision control system 630 includes a computing system 631 that makes analysis decisions based on information acquired by the perception system 620, and the decision control system 630 also includes a vehicle controller 632 that controls the powertrain of the vehicle 600, as well as a steering system 633, throttle 634, and braking system 635 for controlling the vehicle 600.

The computing system 631 may be operable to process and analyze the various information acquired by the perception system 620 in order to identify targets, objects, and/or features in the environment surrounding the vehicle 600. The targets may include pedestrians or animals and the objects and/or features may include traffic signals, road boundaries, and obstacles. The computing system 631 may use object recognition algorithms, in-motion restoration structure (Structure from Motion, SFM) algorithms, video tracking, and the like. In some embodiments, the computing system 631 may be used to map the environment, track objects, estimate the speed of objects, and so forth. The computing system 631 may analyze the acquired various information and derive control strategies for the vehicle.

The vehicle controller 632 may be configured to coordinate control of the power battery and the engine 641 of the vehicle to enhance the power performance of the vehicle 600.

Steering system 633 is operable to adjust the direction of travel of vehicle 600. For example, in one embodiment may be a steering wheel system.

Throttle 634 is used to control the operating speed of engine 641 and thereby the speed of vehicle 600.

The braking system 635 is used to control deceleration of the vehicle 600. The braking system 635 may use friction to slow the wheels 644. In some embodiments, the braking system 635 may convert kinetic energy of the wheels 644 into electrical current. The braking system 635 may take other forms to slow the rotational speed of the wheels 644 to control the speed of the vehicle 600.

The drive system 640 may include components that provide powered movement of the vehicle 600. In one embodiment, the drive system 640 may include an engine 641, an energy source 642, a transmission 643, and wheels 644. The engine 641 may be an internal combustion engine, an electric motor, an air compression engine, or other types of engine combinations, such as a hybrid engine of a gasoline engine and an electric motor, or a hybrid engine of an internal combustion engine and an air compression engine. The engine 641 converts the energy source 642 into mechanical energy.

Examples of energy sources 642 include gasoline, diesel, other petroleum-based fuels, propane, other compressed gas-based fuels, ethanol, solar panels, batteries, and other sources of electricity. The energy source 642 may also provide energy to other systems of the vehicle 600.

The transmission 643 may transfer mechanical power from the engine 641 to wheels 644. The transmission 643 may include a gearbox, a differential, and a driveshaft. In one embodiment, the transmission 643 may also include other devices, such as a clutch. Wherein the drive shaft may include one or more axles that may be coupled to one or more wheels 644.

Some or all of the functions of the vehicle 600 are controlled by the computing platform 650. The computing platform 650 may include at least one first processor 651, which first processor 651 may execute instructions 653 stored in a non-transitory computer-readable medium, such as a first memory 652. In some embodiments, computing platform 650 may also be a plurality of computing devices that control individual components or subsystems of vehicle 600 in a distributed manner.

The first processor 651 may be any conventional processor, such as a commercially available CPU. Alternatively, the first processor 651 may also include, for example, an image processor (Graphic Process Unit, GPU), a field programmable gate array (Field Programmable Gate Array, FPGA), a System On Chip (SOC), an application specific integrated Chip (Application Specific Integrated Circuit, ASIC), or a combination thereof. Although FIG. 7 functionally illustrates a processor, memory, and other elements of a computer in the same block, it will be understood by those of ordinary skill in the art that the processor, computer, or memory may in fact comprise multiple processors, computers, or memories that may or may not be stored within the same physical housing. For example, the memory may be a hard disk drive or other storage medium located in a different housing than the computer. Thus, references to a processor or computer will be understood to include references to a collection of processors or computers or memories that may or may not operate in parallel. Rather than using a single processor to perform the steps described herein, some components, such as the steering component and the retarding component, may each have their own processor that performs only calculations related to the component-specific functions.

In the presently disclosed embodiment, the first processor 651 may perform the above-described motor iron loss determination method.

In various aspects described herein, the first processor 651 can be located remotely from and in wireless communication with the vehicle. In other aspects, some of the processes described herein are performed on a processor disposed within the vehicle and others are performed by a remote processor, including taking the necessary steps to perform a single maneuver.

In some embodiments, the first memory 652 may contain instructions 653 (e.g., program logic), the instructions 653 being executable by the first processor 651 to perform various functions of the vehicle 600. The first memory 652 may also contain additional instructions, including instructions to send data to, receive data from, interact with, and/or control one or more of the infotainment system 610, the perception system 620, the decision control system 630, the drive system 640.

In addition to instructions 653, the first memory 652 may also store data such as road maps, route information, vehicle location, direction, speed, and other such vehicle data, as well as other information. Such information may be used by the vehicle 600 and the computing platform 650 during operation of the vehicle 600 in autonomous, semi-autonomous, and/or manual modes.

The computing platform 650 may control the functions of the vehicle 600 based on inputs received from various subsystems (e.g., the drive system 640, the perception system 620, and the decision control system 630). For example, computing platform 650 may utilize input from decision control system 630 in order to control steering system 633 to avoid obstacles detected by perception system 620. In some embodiments, computing platform 650 is operable to provide control over many aspects of vehicle 600 and its subsystems.

Alternatively, one or more of these components may be mounted separately from or associated with vehicle 600. For example, the first memory 652 may exist partially or completely separate from the vehicle 600. The above components may be communicatively coupled together in a wired and/or wireless manner.

Alternatively, the above components are only an example, and in practical applications, components in the above modules may be added or deleted according to actual needs, and fig. 7 should not be construed as limiting the embodiments of the present disclosure.

An autonomous car traveling on a road, such as the vehicle 600 above, may identify objects within its surrounding environment to determine adjustments to the current speed. The object may be another vehicle, a traffic control device, or another type of object. In some examples, each identified object may be considered independently and based on its respective characteristics, such as its current speed, acceleration, spacing from the vehicle, etc., may be used to determine the speed at which the autonomous car is to adjust.

Alternatively, the vehicle 600 or a sensing and computing device associated with the vehicle 600 (e.g., computing system 631, computing platform 650) may predict the behavior of the identified object based on the characteristics of the identified object and the state of the surrounding environment (e.g., traffic, rain, ice on a road, etc.). Alternatively, each identified object depends on each other's behavior, so all of the identified objects can also be considered together to predict the behavior of a single identified object. The vehicle 600 is able to adjust its speed based on the predicted behavior of the identified object. In other words, the autonomous car is able to determine what steady state the vehicle will need to adjust to (e.g., accelerate, decelerate, or stop) based on the predicted behavior of the object. In this process, other factors may also be considered to determine the speed of the vehicle 600, such as the lateral position of the vehicle 600 in the road on which it is traveling, the curvature of the road, the proximity of static and dynamic objects, and so forth.

In addition to providing instructions to adjust the speed of the autonomous vehicle, the computing device may also provide instructions to modify the steering angle of the vehicle 600 so that the autonomous vehicle follows a given trajectory and/or maintains safe lateral and longitudinal distances from objects in the vicinity of the autonomous vehicle (e.g., vehicles in adjacent lanes on a roadway).

The vehicle 600 may be various types of traveling tools, such as a car, a truck, a motorcycle, a bus, a ship, an airplane, a helicopter, a recreational vehicle, a train, etc., and embodiments of the present disclosure are not particularly limited.

In another exemplary embodiment, a computer program product is also provided, which comprises a computer program executable by a programmable apparatus, the computer program having code portions for performing the above-mentioned method of determining the iron loss of a motor when being executed by the programmable apparatus.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method of determining iron loss in an electric motor, comprising:

determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor;

the stator current parameters comprise stator quadrature axis current parameters and stator direct axis current parameters, and the first corresponding relation is established by the following modes:

establishing a first corresponding relation according to the second corresponding relation, the first preset numerical value and a first formula, wherein the first corresponding relation is a two-dimensional corresponding relation of an iron loss coefficient, a stator quadrature axis current parameter and a stator direct axis current parameter, and the first formula is that Wherein K is _Fe Representing the iron loss coefficient of the motor, R _c Representing the iron loss equivalent resistance, w, of the motor _e Representing the synchronous angular velocity of the motor.

2. The method of determining iron loss of an electric machine of claim 1, further comprising:

3. The method of determining iron loss of a motor according to claim 2, wherein the stator current parameter includes a stator quadrature axis current parameter and a stator direct axis current parameter, and the fourth correspondence is established by:

4. The method of claim 1, wherein the stator quadrature axis current parameter is a component current of the motor stator quadrature axis current corresponding to the electromagnetic torque, the stator direct axis current parameter is a component current of the motor stator direct axis current corresponding to the electromagnetic torque, the controlling the speed parameter of the motor to be equal to a first preset value, and obtaining motor iron loss equivalent resistances of the motor under different stator quadrature axis current parameters and stator direct axis current parameters to establish a second correspondence comprises:

5. The method of claim 4, wherein controlling the speed parameter of the motor to be equal to a first preset value, obtaining the iron losses of the motor at different stator quadrature axis currents and stator direct axis currents to establish a third correspondence comprises:

obtaining mechanical friction loss power of the motor;

6. The method of determining iron loss of a motor according to claim 4, wherein the obtaining the quadrature axis voltage and the direct axis voltage corresponding to each set of the quadrature axis current and the direct axis current in the third correspondence relation includes:

7. The method of claim 1, wherein the stator current parameters include a stator quadrature axis current parameter and a stator direct axis current parameter, and wherein determining the current iron loss of the motor based on the determined iron loss coefficient and the current speed parameter, stator current parameter, stator inductance, and rotor flux linkage of the motor comprises:

8. An electric motor iron loss determining apparatus, comprising:

the iron loss determining module is configured to determine the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the motor;

9. A vehicle, characterized by comprising:

a first processor;

a first memory for storing first processor-executable instructions;

wherein the first processor is configured to:

10. A computer readable storage medium having stored thereon computer program instructions, which when executed by a processor, implement the steps of the method of any of claims 1-7.

11. A chip comprising a second processor and an interface; the second processor is configured to read instructions to perform the method of any of claims 1-7.