CN115356624A

CN115356624A - Motor iron loss determination method and device, vehicle, storage medium and chip

Info

Publication number: CN115356624A
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: 2022-11-18
Anticipated expiration: 2042-08-15
Also published as: CN115356624B

Abstract

The disclosure relates to the technical field of motors, in particular to a motor iron loss determination method, a motor iron loss determination device, a motor 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 of the motor, the current parameter of the stator, the stator inductance and the rotor flux linkage. The technical scheme provided by the disclosure can meet the iron loss calculation precision requirement of the actual motor driving system in the full-working-condition operation, is not influenced by the voltage change of the battery of the driving motor, only needs to obtain the first corresponding relation through experiments in advance, is small in workload and data volume, and 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, in particular to a motor iron loss determination method, a motor iron loss determination device, a motor vehicle, a storage medium and a chip.

Background

In the related art, the method for acquiring the iron loss of the motor mainly comprises the following two steps: the first method is to establish a motor loss model by actually measuring the 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 measurement condition cannot completely meet the full-working-condition running state of the motor driving system, so that the iron loss calculation precision requirement of the full-working-condition running of the motor driving system cannot be ensured. In the second method, because the simulation model cannot be completely consistent with the actual motor driving system and a modeling error of software exists, the iron loss calculation precision requirement of the actual motor driving system cannot be met.

Disclosure of Invention

To overcome the problems in the related art, the present disclosure provides a motor iron loss determination method, apparatus, vehicle, storage medium, and chip.

According to a first aspect of an embodiment of the present disclosure, there is provided a method for determining an iron loss of a motor, 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 of the motor, the current parameter of the stator, the stator inductance and the rotor flux linkage.

Optionally, the stator current parameters include a stator quadrature axis current parameter and a stator direct axis current parameter, and the first corresponding relationship is established as follows:

controlling the speed parameter of the motor to be equal to a first preset value, and acquiring the motor iron loss equivalent resistance 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 of the motor iron loss equivalent resistance, 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

In the formula, K _Fe Represents the iron loss coefficient, R, of the motor _c Representing the iron loss equivalent resistance, w, of said machine _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 the current speed parameter of the motor, wherein the fourth corresponding relation comprises the corresponding relation between the iron loss compensation coefficient and the speed parameter;

determining the current iron loss of the motor according to the determined iron loss coefficient, the current speed parameter of the motor, the current stator current parameter, the current stator inductance and the current 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 as follows:

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

acquiring 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 the corresponding relation between the iron loss and the speed parameter as well as the electromagnetic torque;

controlling the bus voltage of the motor to be equal to a second preset value, and acquiring the iron loss of the motor under different rotating speed parameters and electromagnetic torques so as 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 torques;

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

controlling the speed parameter of the motor to be equal to a first preset value, acquiring iron loss of the motor under different stator quadrature-axis currents and stator direct-axis currents to establish a third corresponding relation, and acquiring stator quadrature-axis voltage and 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 of the motor iron loss and the stator quadrature-axis currents and the stator direct-axis currents;

and establishing a second corresponding relation 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 stator direct axis current in the third corresponding relation, wherein the second corresponding relation is the corresponding relation 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 controlling the speed parameter of the motor to be equal to a first preset value, and obtaining the iron loss of the motor under different stator quadrature axis currents and stator direct axis currents to establish a third correspondence includes:

obtaining the motor stator phase resistance, the stator quadrature axis current and the stator direct axis current, 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;

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;

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

acquiring mechanical friction loss power of the motor;

and acquiring 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 the quadrature-axis current and the direct-axis current in the third corresponding relationship includes:

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

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

according to the current stator current parameter of the motor, acquiring a component current corresponding to the motor iron loss in the current stator direct-axis current of the motor and a component current corresponding to the motor iron loss in the stator quadrature-axis current;

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 the stator direct-axis inductance and the stator quadrature-axis inductance.

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

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

an iron loss determination module configured to determine a current iron loss of the electric machine based on the determined iron loss factor and the current speed parameter, the stator current parameter, the stator inductance, and the rotor flux linkage of the electric machine.

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

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 motor iron loss determination method provided by 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 execute the steps of the motor iron loss determination method provided by the first aspect of the present disclosure.

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

acquiring a corresponding relation (a first corresponding relation) between a stator current parameter and an iron loss coefficient of a motor driving system through experiments; in the running process of the motor driving system, real-time checking a first corresponding relation through an actual (current) stator current parameter to obtain an actual (current) iron loss coefficient; and the actual (current) iron loss of the motor can be accurately calculated by combining the actual (current) speed parameter of the motor. Therefore, the technical scheme provided by the disclosure can meet the iron loss calculation precision requirement of the actual motor driving system in all-working-condition operation, is not influenced by the voltage change of the battery of the driving motor, 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, is small in workload and data volume, and is 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 present 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 according to an exemplary embodiment.

Fig. 2 is a second equivalent circuit diagram of the motor shown in accordance with an exemplary embodiment.

FIG. 3 is a flow chart illustrating a method of determining iron loss of a motor in accordance with an exemplary embodiment.

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

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

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

FIG. 7 is a block diagram of a vehicle shown in accordance with an exemplary embodiment.

Detailed Description

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

It should be noted that all actions of acquiring signals, information or data in the present application are performed under the premise of complying with the corresponding data protection regulation 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 an equivalent circuit diagram 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. According to the equivalent circuit diagrams as shown in fig. 1 and 2, it is possible to establish:

1) The motor voltage equation is as follows:

U _d ＝R _s i _d +U _od (formula 1)

U _q ＝R _s i _q +U _oq (formula 2)

U _od ＝-w _e L _q i _oq (formula 3)

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

In the above formula, U _d Is the motor stator direct axis voltage, unit V; r _s Is the phase resistance of the motor stator, and the unit is Ohm; i.e. i _d Electric machineStator direct axis current, unit a; u shape _od The unit is a component voltage corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator; u shape _q The motor stator quadrature axis voltage is in unit V; i.e. i _q The motor stator direct axis current is in unit A; u shape _oq The unit V is the component voltage corresponding to the iron loss of the motor in the direct axis voltage of the motor stator; w is a _e Is the synchronous angular velocity of the motor, unit rad/s; l is _q The motor stator quadrature axis inductance is expressed by unit H; i all right angle _oq The unit is component current corresponding to electromagnetic torque in motor stator quadrature axis current; l is _d The unit is the direct axis inductance of the motor stator, and the unit is H; i.e. i _od The component current corresponding to the electromagnetic torque in the direct axis current of the motor stator is obtained; psi _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 the electromagnetic torque of the motor in Nm; p is the number of pole pairs of the motor.

3) The iron loss equation of the motor is as follows:

in the formula, f is the motor phase current frequency, and has the following relation with the synchronous angular velocity of the motor:

w _e =2 pi f (equation 7)

Thus, the iron loss equation is rewritten as follows:

in the above formula, ploss _Fe Is the iron loss of the motor, unit W; k is a radical of formula _σ Is the motor iron loss empirical coefficient; f is the motor phase current frequency in Hz; b is _m The magnetic density peak value of the motor iron core is in unit T; g _Fe Motor part generating iron lossPiece mass in kg.

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

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

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

5) Iron loss coefficient of motor

The applicant designs an iron loss coefficient K according to a formula (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:

observation of the above K _Fe As can be seen from the equation, the intrinsic parameter (L) of the motor body is removed _q 、L _d 、ψ _m 、k _σ 、G _Fe 、B _m ) The iron loss coefficient represents the essential corresponding relation between the iron loss of the motor and the stator current of the motor. Thus, the difference i can be pre-calibrated _oq 、i _od Iron loss coefficient K _Fe Establishing K _Fe And i _oq 、i _od For example, a two-dimensional table is obtained by pre-calibration, the abscissa of the table is i _oq Ordinate is i _od Value of K _Fe . In actual application, according to the actual (current) i _oq 、i _od Looking up the two-dimensional table to obtain i (current) with the actual _oq 、i _od Corresponding K _Fe (ii) a Again according to the actual (current) w _e The actual (current) R can be obtained according to the formula 11 _c . According to the reality (at present)I of (a) _oq 、i _od By using the following formula 12 and formula 13, i can be obtained _cd And i _cq (ii) a The iron loss Ploss of the motor can be obtained according to the formula 14 _Fe 。

Based on the above technical concept, 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 can be applied to a Vehicle Control Unit (VCU) of a Vehicle. As shown in fig. 3, the motor iron loss determining 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, where the iron loss coefficient represents a relationship between an iron loss of the motor and a 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 relationship may be obtained and stored according to an experimental calibration. The stator current parameter may be a component current (i) of motor stator quadrature axis current corresponding to electromagnetic torque _oq ) And component current (i) corresponding to electromagnetic torque in motor stator direct axis current _od ) Or stator quadrature axis current (i) _q ) And stator direct axis current (i) _d ) Or component current (i) corresponding to motor iron loss in motor stator quadrature axis current _cq ) And the component current (i) corresponding to the iron loss of the motor in the direct-axis current of the motor stator _cd ). It is obvious that although the iron loss coefficient is expressed by i in equation 11 _oq 、i _od As a result of the presentation of the data,but may not use i _oq 、i _od Is expressed, e.g. according to i _q 、i _d 、i _cq 、i _cd Or other variables indirectly representing i by formulas _oq 、i _od . It should be noted that equation 11 is only an exemplary expression for illustrating the iron loss coefficient, and is not meant to limit the present invention. For example, removing the replacement of i by other variables _oq 、i _od The inherent 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 ) Then, R is obtained again _c When it is needed to be multiplied by

The iron loss coefficient can also be K _Fe ＝(2π) ^1.3 ((L _q i _oq ) ² +(L _d i _od +ψ _m ) ² ) Then, R is obtained again _c When it is needed to multiply

For economy of space, this is not illustrated here.

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

Wherein the speed parameter may be a synchronous angular speed w of the motor _e Or motor rotor speed NEm, or other methods for indirectly obtaining w _e The speed parameter of (2). Wherein, the first and the second end of the pipe are connected with each other,

when the stator current parameter is i _oq And i _od When the velocity parameter is w _e Then, according to the current speed parameter, the stator current parameter, the stator inductance, the rotor flux linkage and the current iron loss coefficient, the iron loss coefficient Ploss can be obtained according to the formulas 12, 13 and 14 _Fe . To say thatIt is clear that when the stator current parameter is not i _oq And i _od When the velocity parameter is not w _e Then, the iron loss coefficient Ploss can be obtained according to the deformation of 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, real-time checking a first corresponding relation through an actual (current) stator current parameter to obtain an actual (current) iron loss coefficient; and the actual (current) iron loss of the motor can be accurately calculated by combining the actual (current) speed parameter of the motor. Therefore, the technical scheme provided by the disclosure can meet the iron loss calculation precision requirement of the actual motor driving system in all-working-condition operation, is not influenced by the voltage change of the battery of the driving motor, 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, is small in workload and data volume, and is suitable for engineering application.

The method may be applied to a vehicle, and the 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 Acquiring the current rotor rotating speed NEm of the motor in real time through a speed sensor; in acquiring current i _oq And i _od Then, the first correspondence relation is prestored in a device with a processing function, and the device is input according to the current i _oq And i _od Obtaining the current iron loss coefficient of the motor according to a pre-stored first corresponding relation; and then the current rotor rotation 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 axis current parameter may be i _oq 、i _q Or i _cq Etc., the stator direct axis current parameter may be i _od 、i _d Or i _cd And so on. The first correspondence is established by:

and controlling the speed parameter of the motor to be equal to a first preset value, and acquiring the motor iron loss equivalent resistance 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 of the motor iron loss equivalent resistance, the stator quadrature axis current parameters and the stator direct axis current parameters.

In the formula, K _Fe Representing the iron loss coefficient, R, of said machine _c Representing the iron loss equivalent resistance, w, of said machine _e Representing the synchronous angular velocity of the motor.

By the technical scheme, the iron loss coefficient is provided

Then obtaining the equivalent resistance R of the iron loss of the motor _c And obtaining a two-dimensional corresponding relation (a 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 (a second corresponding relation) between the stator quadrature axis current parameter and the stator direct axis current parameter.

Optionally, the stator quadrature axis current parameter is a component current i of the motor stator quadrature axis current corresponding to the electromagnetic torque _oq The stator direct axis current parameter is a component current i of the corresponding electromagnetic torque in the motor stator direct axis current _od Controlling the speed parameter of the motor to be equal to a first preset value, and acquiring the motor iron loss equivalent resistance of the motor under different stator quadrature axis current parameters and stator direct axis current parameters to establish a second corresponding relationship, wherein the step of controlling the speed parameter of the motor to be equal to the first preset value comprises the following steps:

and controlling the speed parameter of the motor to be equal to a first preset value, acquiring the iron loss 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 of the motor iron loss and the stator quadrature-axis currents and the stator direct-axis currents.

Namely, the iron loss Ploss is established through experiments _Fe Current i in direct axial relation to the stator _d And stator quadrature axis current i _q And recording 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 。

According to the

formulas

1 and 2, the formulas 15 and 16 can be derived, and the i in the third corresponding relation is determined _d 、i _q And corresponding U _d 、U _q And motor stator phase resistance R _s Substituting into the formula 15 and the formula 16 to obtain the component voltage U corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator _od The component voltage U corresponding to the iron loss of the motor in the direct-axis voltage of the motor stator _oq (ii) a If the speed parameter equal to the first predetermined value is NEm, NEm may be converted to w according to equation 17 _e (ii) a Then root the determined U _od And U _oq And motor stator quadrature axis inductance L of motor intrinsic parameter _q Stator straight-axis inductor L of motor _d Magnetic linkage psi of motor rotor _m Substituting into equations 18 and 19, obtaining component current i corresponding to electromagnetic torque in motor stator quadrature axis current _oq And component current i corresponding to electromagnetic torque in motor stator direct axis current _od (ii) a U determined by equation 15 and equation 16 _od And U _oq And Ploss in the third correspondence _Fe Substituting into equation 20, R can be obtained _c . Thus achieving the establishment of R _c And i _oq And i _od The second correspondence relationship of (1).

U _od ＝U _d -R _s i _d (formula 15)

U _oq ＝U _q -R _s i _q (formula 16)

Through the technical scheme, firstly, ploss is established _Fe And i _d And i _q And then converting the third corresponding relationship into R _c And i _oq And i _od The second correspondence of (2). As can be seen from the foregoing steps, 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 acquiring the stator phase resistance, the stator quadrature axis current and the stator direct axis current of the motor, and acquiring the copper loss of the motor according to the stator phase resistance, the stator quadrature axis current and the stator direct axis current.

Can be realized by a bench power analyzer and a current sensorThe stator phase resistance R of each measuring point is acquired _s Stator quadrature axis current i _q And stator direct axis current i _d Substituting the formula 21, the copper loss P of the motor can be obtained _cu 。

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

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

P _in ＝U _dc i _dc (formula 22)

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

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

And acquiring mechanical friction loss power of the motor.

In general, the mechanical friction loss power Ploss of an electric machine _mech With the change of the rotor rotation speed NEm, complete one-dimensional table data of mechanical friction loss and the rotor rotation speed NEm can be tested after the motor is designed and manufactured. Therefore, the one-dimensional table data can be queried according to the current rotor rotation speed NEm to obtain the current mechanical friction loss power.

And acquiring 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.

The input power P to be obtained _in Output power P _out Copper loss P _cu Mechanical friction loss power Ploss _mech Substituting into the formula 24, the iron loss Ploss can be obtained _Fe Thereby achieving the establishment of Ploss _Fe And i _d And i _q The third correspondence relationship of (1).

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

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

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

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

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

Substituting the acquired quadrature axis current and the acquired direct axis current into a formula 25, and calculating the current angle theta of the motor.

The obtained current angle theta, power factor angle alpha and phase voltage U _s The direct axis voltage U is obtained by substituting the equation 26 and the equation 27 into the equation _d And quadrature axis voltage U _q 。

U _d ＝U _s cos (. Alpha. + Theta) (equation 26)

U _q ＝U _s sin (α + θ) (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 Then the synchronous angular velocity w can be directly obtained _e . If the speed parameter is the motor rotor rotation speed NEm, the synchronous angular speed w can be obtained according to the formula 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.

According to the iron loss coefficient and the synchronous angular velocity obtained by the first corresponding relation, the current iron loss equivalent resistance of the motor can be determined by adopting a formula 11 (or a formula 10).

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

Since the stator current parameter may be i _oq And i _od Or is i _q And i _d Or is i _cq And i _cd Therefore, i is obtained from the stator current parameter according to the difference of the stator current parameter _oq 、i _od Since the obtaining method is known to those skilled in the art, it is not described herein.

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

When the first correspondence is established in the case where the speed parameter of the motor is equal to the first preset value, the iron loss coefficient may be compensated in consideration of the influence of the rotor speed on the iron loss. Optionally, the method further comprises:

and determining 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 the corresponding relation between the iron loss compensation coefficient and the speed parameter.

According to the technical scheme, a fourth corresponding relation of the iron loss compensation coefficient corresponding to the speed parameter is established in advance, the actual (current) iron loss compensation coefficient is obtained according to the actual (current) speed parameter and the fourth corresponding relation when the device is actually used, the obtained actual (current) iron loss compensation coefficient is added into the iron loss calculation, so that the 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 (which can be displayed in the form of one table data) need to be obtained through experiments in advance, the workload and the data volume are small, and the method is suitable for engineering application.

Optionally, the stator current parameters include a stator quadrature axis current parameter and a stator direct axis current parameter, and the fourth correspondence relationship is established as follows:

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

Wherein the second preset value can be set according to actual conditions, such as 760And V. For a fixed value of bus voltage, the stator quadrature axis current parameter (e.g. component current i corresponding to electromagnetic torque in stator quadrature axis current) _oq ) With speed parameters (e.g., rotor speed NEm) and electromagnetic torque (T) _e ) The stator direct axis current parameter (e.g., the component current i corresponding to the electromagnetic torque in the stator direct axis current) _od ) With speed parameters (e.g., rotor speed NEm) and electromagnetic torque (T) _e ) The two-dimensional data relationship (the sixth corresponding relationship) of (a) may be obtained by motor performance calibration, which belongs to a standard technology 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 is the rotor speed NEM, and the ordinate is the electromagnetic torque T _e The value is the component current i of the stator quadrature axis current corresponding to the electromagnetic torque _oq . As shown in fig. 5, the sixth correspondence is shown in the form of a table, in fig. 5, the abscissa is the rotor speed NEM, and the ordinate is the electromagnetic torque T _e The value is the component current i of the stator direct axis current corresponding to the electromagnetic torque _od 。

And acquiring 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 the corresponding relation between the iron loss coefficient and the speed parameter as well as the electromagnetic torque.

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

And controlling the bus voltage of the motor to be equal to a second preset value, and acquiring the iron loss of the motor under different rotating speed parameters and electromagnetic torques so as 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 torques.

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 so as to establish 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 as well as the electromagnetic torque.

From the above, the eighth corresponding relationship is the iron loss under different speed parameters and electromagnetic torques actually tested. And the seventh corresponding relation is the iron loss under different speed parameters and electromagnetic torques calculated by adopting the iron loss coefficients in the first corresponding relation established in advance. Therefore, the iron loss in the eighth correspondence may be taken as the actual iron loss, and the iron loss in the seventh correspondence is the iron loss calculated using the iron loss coefficient in the first correspondence, so that the ratio of the iron loss in the eighth correspondence to the iron loss in the seventh correspondence 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. 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 a plurality of measurement points with the same speed parameter but different electromagnetic torques can be processed into one compensation coefficient, and the processing method can be a least square method or other mathematical methods, which are not limited herein. For example, when the ninth correspondence relationship is a data table having an abscissa as a speed parameter, an ordinate as an electromagnetic torque, and an initial iron loss compensation coefficient, the initial iron loss compensation coefficient of each column may be processed as one compensation coefficient by a least square method, or other mathematical methods. For another example, when the ninth correspondence relationship 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 row may be processed as 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, not only the influence of the rotor speed on the iron loss and the compensation of the iron loss coefficient can be considered, but also the influence of the battery voltage on the iron loss and the compensation of the iron loss coefficient can be considered.

The method may be applied to a vehicle, and the 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 Acquiring the current rotor rotation speed NEm of the motor in real time through a speed sensor; at the moment of obtaining current i _oq And i _od Then, the first correspondence relation is prestored in a device with a processing function, and the device is input according to the current i _oq And i _od Obtaining the current iron loss coefficient of the motor according to a pre-stored first corresponding relation; determining a compensation coefficient by combining the current rotor rotation 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 rotation speed NEm of the motor and the compensated iron loss coefficient.

Based on the technical concept, the embodiment of the disclosure further provides a motor iron loss determination device. Fig. 6 is a block diagram illustrating a motor iron loss determining 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 relationship and a current stator current parameter of the motor, where the iron loss coefficient represents a relationship between an 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;

an iron loss determination module 12 configured to determine a current iron loss of the electric machine based on the determined iron loss factor and the current speed parameter, the stator current parameter, the stator inductance and the rotor flux linkage of the electric machine.

According to the technical scheme, 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, real-time checking a first corresponding relation through an actual (current) stator current parameter to obtain an actual (current) iron loss coefficient; and the actual (current) iron loss of the motor can be accurately calculated by combining the actual (current) speed parameter of the motor. Therefore, the technical scheme provided by the disclosure can meet the iron loss calculation precision requirement of the actual motor driving system in all-working-condition operation, is not influenced by the voltage change of the battery of the driving motor, 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, is small in workload and data volume, and is suitable for engineering application.

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

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

A first corresponding relation establishing module configured to establish a first corresponding relation according to the second corresponding relation, the first preset 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 a two-dimensional corresponding relation of a stator quadrature axis current parameter and a stator direct axis current parameter

By the technical scheme, the iron loss coefficient is provided

Then obtaining the equivalent resistance R of the iron loss of the motor _c And obtaining a two-dimensional corresponding relation (a first corresponding relation) of the iron loss coefficient, the stator quadrature axis current parameter and the stator direct axis current parameter after the two-dimensional corresponding relation (a second corresponding relation) of the stator quadrature axis current parameter and the stator direct axis current parameter.

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

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

And the second corresponding relation establishing submodule is configured to establish a second corresponding relation according to 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 first preset numerical value, the third corresponding relation and the third corresponding relation, wherein the second corresponding relation is the corresponding relation between the component current of the corresponding electromagnetic torque in the motor iron loss equivalent resistance and the motor stator quadrature axis current and the component current of the corresponding electromagnetic torque in the motor stator direct axis current.

Through the technical scheme, firstly, ploss is established _Fe And i _d And i _q And then converting the third correspondence into R _c And i _oq And i _od The second correspondence relationship of (1). As can be seen from the foregoing steps, 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.

Optionally, the third correspondence relation 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.

The input power acquisition submodule is configured to acquire bus voltage and bus current of the motor and obtain input power of the motor according to the bus voltage and the bus current.

The output power acquisition submodule is configured to acquire the mechanical torque and the rotor speed of the motor and obtain the output power of the motor according to the mechanical torque and the rotor speed.

A mechanical friction loss power acquisition submodule configured to acquire mechanical friction loss power of the electric machine.

And the first iron loss acquisition submodule is configured to acquire 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 third correspondence relation sub-module further includes:

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

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

Optionally, the iron loss determining module 12 comprises:

a synchronous angular velocity determination submodule configured to acquire a synchronous angular velocity of the motor according to a current speed parameter of the motor.

And the iron loss equivalent resistance determination 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 determination submodule is configured to obtain a component current corresponding to motor iron loss in the current stator direct-axis current of the motor and a component current corresponding to motor iron loss in the stator quadrature-axis current according to the current stator current parameter of the motor.

And the iron loss determining submodule is configured to obtain 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 an iron loss compensation coefficient determining module.

And the iron loss compensation coefficient determining module is configured to determine 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 the corresponding relation between the iron loss compensation coefficient and the speed parameter.

In compensating, the iron loss determining module 12 is configured to determine 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 iron loss compensation coefficient determining module includes:

the fifth and sixth correspondence determining submodule is configured to obtain a fifth correspondence and a sixth correspondence when the bus voltage of the motor is equal to a second preset value, the fifth correspondence is a correspondence between a stator quadrature axis current parameter of the motor and a speed parameter and an electromagnetic torque, and the sixth correspondence is a correspondence between a stator direct axis current parameter of the motor and a speed parameter and an electromagnetic torque.

And the seventh corresponding relation determining submodule 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 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 rotating speed parameters and electromagnetic torques so as 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 torques.

And the ninth corresponding relation determining submodule is 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 of the initial iron loss compensation coefficient, the speed parameter and the electromagnetic torque.

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

With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

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 part of a stand-alone electronic device, for example, in an embodiment, the apparatus may be an Integrated Circuit (IC) or a chip, where the IC may be one IC or a set of multiple ICs; the chip may include, but is not limited to, the following categories: a GPU (Graphics Processing Unit), a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an SOC (System on Chip, SOC, system on Chip, or System on Chip), and the like. The integrated circuit or chip may be configured to execute executable instructions (or code) to implement the motor iron loss determination method. Where the executable instructions may be stored in the integrated circuit or chip or may be retrieved from another apparatus or device, for example where the integrated circuit or chip includes a second processor, a second memory, and an interface for communicating with the other apparatus. The executable instructions may be stored in the second memory, and when executed by the second processor, implement the motor iron loss determination method described above; alternatively, the integrated circuit or chip may receive the executable instructions through the interface and transmit the executable instructions to the second processor for execution, so as to implement 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 driving mode. For example, the vehicle 600 may acquire environmental information of its surroundings through the sensing system 620 and derive an automatic driving strategy based on an analysis of the surrounding environmental information to implement full automatic driving, or present the analysis result to the user to implement 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 sub-systems and components of the vehicle 600 may be interconnected by wire 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 that 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 (WLAN) using WiFi. In some embodiments, the wireless communication system may utilize an infrared link, bluetooth, or ZigBee to communicate directly with the device. Other wireless protocols, such as various vehicular communication systems, for example, a wireless communication system may include one or more Dedicated Short Range Communications (DSRC) devices that may include public and/or private data communications between vehicles and/or roadside stations.

The entertainment system 612 may include a display device, a microphone, and a sound box, and a user may listen to a broadcast in the car based on the entertainment system, playing music; or the mobile phone is communicated with the vehicle, screen projection 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 the display equipment by touching the screen.

In some cases, the voice signal of the user may be acquired through a microphone, and certain control of the vehicle 600 by the user, such as adjusting the temperature in the vehicle, etc., may be implemented according to the analysis of the voice signal of the user. In other cases, music may be played to the user through a sound.

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

The sensing system 620 may include several types of sensors that sense information about the environment surrounding the vehicle 600. For example, the sensing system 620 may include a global positioning system 621 (the global positioning system may be a GPS system, a beidou system or other positioning system), an Inertial Measurement Unit (IMU) 622, a laser radar 623, a millimeter wave radar 624, an ultrasonic radar 625, and a camera 626. The sensing system 620 may also include sensors of internal systems of the monitored vehicle 600 (e.g., an in-vehicle air quality monitor, a fuel gauge, an oil temperature gauge, etc.). Sensor data from one or more of these sensors may be used to detect the object and its corresponding characteristics (position, shape, orientation, velocity, etc.). Such detection and identification is a critical function of the safe operation of the vehicle 600.

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

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

Lidar 623 utilizes laser light to sense objects in the environment in which vehicle 600 is located. In some embodiments, lidar 623 may include one or more laser sources, laser scanners, 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, in addition to sensing objects, the millimeter-wave radar 624 may also be used to sense the speed and/or heading of objects.

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

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

Decision control system 630 includes a computing system 631 that makes analytical decisions based on information acquired by sensing system 620, decision control system 630 further includes a vehicle control unit 632 that controls the powertrain of vehicle 600, and a steering system 633, throttle 634, and brake system 635 for controlling vehicle 600.

The computing system 631 may operate to process and analyze the various information acquired by the perception system 620 to identify 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, motion from Motion (SFM) algorithms, video tracking, and the like. In some embodiments, the computing system 631 may be used to map an environment, track objects, estimate the speed of objects, and so forth. The computing system 631 may analyze the various information obtained and derive a control strategy for the vehicle.

The vehicle controller 632 may be used to perform coordinated control on the power battery and the engine 641 of the vehicle to improve the power performance of the vehicle 600.

The steering system 633 is operable to adjust the heading of the vehicle 600. For example, in one embodiment, a steering wheel system.

The throttle 634 is used to control the operating speed of the engine 641 and thus the speed of the vehicle 600.

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

The drive system 640 may include components that provide powered motion to 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 consisting of a gasoline engine and an electric motor, a hybrid engine consisting of an internal combustion engine and an air compression engine. The engine 641 converts the energy source 642 into mechanical energy.

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

The transmission 643 may transmit mechanical power from the engine 641 to the wheels 644. The transmission 643 may include a gearbox, a differential, and a drive shaft. In one embodiment, the transmission 643 may also include other components, such as clutches. 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 functionality of the vehicle 600 is controlled by the computing platform 650. The computing platform 650 can include at least one first processor 651, which first processor 651 can execute instructions 653 stored in a non-transitory computer-readable medium, such as 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 a processor such as a Graphics Processor Unit (GPU), a Field Programmable Gate Array (FPGA), a System On Chip (SOC), an 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, those skilled in the art will appreciate that the processor, computer, or memory may actually 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 drive or other storage medium located in a different enclosure than the computer. Thus, references to a processor or computer are to be understood as including references to a collection of processors or computers or memories which may or may not operate in parallel. Rather than using a single processor to perform the steps described herein, some of the components, such as the steering and deceleration components, may each have their own processor that performs only computations related to the component-specific functions.

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

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

In some embodiments, the first memory 652 can contain instructions 653 (e.g., program logic), which instructions 653 can be executed 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, first memory 652 may also store data such as road maps, route information, the location, direction, speed, and other such vehicle data of the vehicle, 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.

Computing platform 650 may control functions of vehicle 600 based on inputs received from various subsystems (e.g., drive system 640, perception system 620, and 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, the computing platform 650 is operable to provide control over many aspects of the vehicle 600 and its subsystems.

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

Optionally, the above components are only an example, in an actual application, components in the above modules may be added or deleted according to an actual need, and fig. 7 should not be construed as limiting the embodiment of the present disclosure.

An autonomous automobile traveling on a roadway, such as vehicle 600 above, may identify objects within its surrounding environment to determine an adjustment 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 the respective characteristics of the object, such as its current speed, acceleration, separation from the vehicle, etc., may be used to determine the speed at which the autonomous vehicle is to be adjusted.

Optionally, the vehicle 600 or a sensory and computing device associated with the vehicle 600 (e.g., computing system 631, computing platform 650) may predict behavior of the identified object based on characteristics of the identified object and the state of the surrounding environment (e.g., traffic, rain, ice on the road, etc.). Optionally, each identified object depends on the behavior of each other, so it is also possible to predict the behavior of a single identified object taking all identified objects together into account. The vehicle 600 is able to adjust its speed based on the predicted behavior of the identified object. In other words, the autonomous vehicle 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 being traveled, 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 to cause the autonomous vehicle to follow a given trajectory and/or maintain a safe lateral and longitudinal distance from objects in the vicinity of the autonomous vehicle (e.g., vehicles in adjacent lanes on the road).

The vehicle 600 may be any type of vehicle, such as a car, a truck, a motorcycle, a bus, a boat, an airplane, a helicopter, a recreational vehicle, a train, etc., and the disclosed embodiment is 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 motor iron loss determination method when 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 variations, 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 in 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 will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made 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 of an electric machine, comprising:

2. The method of determining iron loss of an electric machine according to claim 1, wherein the stator current parameters include a stator quadrature axis current parameter and a stator direct axis current parameter, and the first correspondence is established by:

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 iron loss coefficient and stator quadrature axis currentThe two-dimensional corresponding relation between the parameters and the stator direct axis current parameters, and the first formula is

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

4. The method according to claim 3, wherein the stator current parameters include a stator quadrature axis current parameter and a stator direct axis current parameter, and the fourth correspondence is established by:

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

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 of the initial iron loss compensation coefficient, the speed parameter and the electromagnetic torque;

5. The method for determining the iron loss of the motor according to claim 2, 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 the equivalent iron loss resistance of the motor under different stator quadrature axis current parameters and stator direct axis current parameters to establish the second corresponding relationship comprises:

6. The method for determining the iron loss of the motor according to claim 5, wherein the controlling the speed parameter of the motor to be equal to a first preset value, and obtaining the iron loss of the motor under different stator quadrature axis currents and stator direct axis currents to establish a third corresponding relationship comprises:

obtaining the stator phase resistance, stator quadrature axis current and 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;

acquiring mechanical friction loss power of the motor;

7. The method of determining iron loss of an electric machine according to claim 5, wherein the obtaining quadrature-axis voltage and direct-axis voltage corresponding to each set of quadrature-axis current and direct-axis current in the third correspondence comprises:

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

8. The method of claim 1, wherein the stator current parameters comprise 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 factor and the current speed parameter, the stator current parameter, the stator inductance, and the rotor flux linkage of the motor comprises:

9. An electric machine iron loss determining apparatus, comprising:

10. A vehicle, characterized by comprising:

a first processor;

a first memory for storing first processor-executable instructions;

wherein the first processor is configured to:

11. A computer-readable storage medium, on which computer program instructions are stored, which program instructions, when executed by a processor, carry out the steps of the method according to any one of claims 1 to 8.

12. A chip comprising a second processor and an interface; the second processor is to read instructions to perform the method of any one of claims 1-8.