CN111969922A - Method and device for determining rotating speed of motor and electronic equipment - Google Patents
Method and device for determining rotating speed of motor and electronic equipment Download PDFInfo
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- CN111969922A CN111969922A CN202010700235.7A CN202010700235A CN111969922A CN 111969922 A CN111969922 A CN 111969922A CN 202010700235 A CN202010700235 A CN 202010700235A CN 111969922 A CN111969922 A CN 111969922A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P23/00—Arrangements or methods for the control of AC motors characterised by a control method other than vector control
- H02P23/14—Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/14—Estimation or adaptation of machine parameters, e.g. flux, current or voltage
- H02P21/18—Estimation of position or speed
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Abstract
The invention provides a method and a device for determining the rotating speed of a motor and electronic equipment, wherein the method comprises the following steps: determining the current under an alpha axis and the current under a beta axis of the motor; determining a voltage in the alpha axis and a voltage in the beta axis of the motor; determining a shaft error of the motor according to the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor; and estimating the rotating speed of the motor according to the shaft error. The invention provides a method and a device for determining the rotating speed of a motor and electronic equipment, which can estimate the rotating speed of the motor more accurately.
Description
Technical Field
The invention relates to the technical field of motors, in particular to a method and a device for determining the rotating speed of a motor and electronic equipment.
Background
The shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor, the rotating speed and the position of the motor can be estimated by adopting the shaft error, and whether the shaft error is accurate or not directly influences the accuracy of the estimated rotating speed and the estimated position of the motor.
In the prior art, patent application No. 201310192101.9 discloses a position sensorless control device and a position detection method, in this scheme, a shaft error is determined based on a voltage under a d-axis, an estimated value of a current under the d-axis, an estimated value of a current under a q-axis, a back electromotive force constant, and the like, the voltage under the d-axis, the estimated value of the current under the d-axis, and the estimated value of the current under the q-axis all have certain errors, and when calculating the shaft error, the errors cause the accuracy of the shaft error to be poor, and the shaft error is also influenced by the back electromotive force constant, which also causes the accuracy of the shaft error to be poor, and further, the accuracy of the rotation speed of a motor estimated based on the shaft error is low.
Disclosure of Invention
The embodiment of the invention provides a method and a device for determining the rotating speed of a motor and electronic equipment, which can estimate the rotating speed of the motor more accurately.
In a first aspect, an embodiment of the present invention provides a method for determining a rotation speed of a motor, where the method includes:
determining the current under an alpha axis and the current under a beta axis of the motor;
determining a voltage in the alpha axis and a voltage in the beta axis of the motor;
determining a shaft error of the motor according to the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor;
and estimating the rotating speed of the motor according to the shaft error.
Alternatively,
the determining of the current in the alpha axis and the current in the beta axis of the motor comprises:
determining a current in a u-axis and a current in a w-axis of the motor;
determining the current under the alpha axis and the current under the beta axis according to a first formula, wherein the first formula is as follows:
wherein, IαIs the current under the alpha axis, IβIs the current under the beta axis, IuIs the current under the u-axis, IwIs the current under the w-axis.
Alternatively,
the determining a voltage in the alpha axis and a voltage in the beta axis of the motor comprises:
determining the direct current bus voltage and the PWM (Pulse Width Modulation) period of the motor;
determining the time occupied by the u phase at a high level in one PWM cycle, the time occupied by the v phase at a high level in one PWM cycle and the time occupied by the w phase at a high level in one PWM cycle;
determining a voltage in the alpha axis and a voltage in the beta axis according to an equation two, wherein the equation two is:
wherein, VαIs the voltage under the alpha axis, VβIs the voltage at the beta axis, TuFor the time occupied by the u-phase at a high level in one of said PWM cycles, TvFor the time occupied by the high level of the v-phase in one of said PWM cycles, TwFor the time occupied by the high level of the w-phase in one of said PWM cycles, TcFor said PWM period, EdcIs the dc bus voltage.
Alternatively,
the determining the shaft error of the motor according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis comprises:
determining back electromotive force under the alpha axis and back electromotive force under the beta axis according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis;
and determining the axis error according to the back electromotive force under the alpha axis and the back electromotive force under the beta axis.
Alternatively,
the determining, from the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, a back electromotive force in the α axis and a back electromotive force in the β axis, includes:
determining a phase resistance of the motor;
acquiring the last estimated rotating speed of the motor;
determining the inductance under the d axis and the inductance under the q axis of the motor;
determining the back electromotive force under the alpha axis and the back electromotive force under the beta axis according to a third formula, wherein the third formula is as follows:
wherein e isαIs the back electromotive force under the alpha axis, eβIs the back electromotive force, V, under the beta axisαIs the voltage under the alpha axis, VβIs the voltage under the beta axis, IαIs the current under the alpha axis, IβIs the current under the beta axis, LdIs the inductance under the d-axis, LqAnd the inductance under the q axis, r, the phase resistance of the motor, omega, the rotation speed of the motor estimated last time and p, the differential operation.
Alternatively,
the determining the axis error according to the back electromotive force in the alpha axis and the back electromotive force in the beta axis includes:
determining the position of the rotor of the motor estimated last time according to the rotating speed of the motor estimated last time;
determining the axis error according to equation four, wherein equation four is:
where Δ θ is the axis error, eαIs the back electromotive force under the alpha axis, eβθ is the last estimated position of the rotor of the motor, which is the back electromotive force in the β axis.
In a second aspect, an embodiment of the present invention provides an apparatus for determining a rotational speed of a motor, the apparatus including:
the first determination module is used for determining the current under the alpha axis and the current under the beta axis of the motor;
a second determination module to determine a voltage in the alpha axis and a voltage in the beta axis of the motor;
the third determining module is used for determining a shaft error of the motor according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor;
and the estimation module is used for estimating the rotating speed of the motor according to the shaft error.
Alternatively,
the third determining module is configured to determine a back electromotive force in the α axis and a back electromotive force in the β axis according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, and determine the axis error according to the back electromotive force in the α axis and the back electromotive force in the β axis.
In a third aspect, an embodiment of the present invention provides an electronic device, including: at least one memory and at least one processor;
the at least one memory to store a machine readable program;
the at least one processor is configured to invoke the machine-readable program to perform the method of any of the first aspects.
In a fourth aspect, embodiments of the present invention provide a computer-readable medium having stored thereon computer instructions, which, when executed by a processor, cause the processor to perform the method of any of the first aspects.
In the embodiment of the invention, the shaft error is determined by the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft can be accurately determined without estimation, so that no error exists, the shaft error is not influenced by a counter electromotive force constant, the accuracy of the determined shaft error is higher, and the rotating speed of the motor can be more accurately estimated based on the shaft error.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of the positional relationship between the α, β, d, q, u, v and w axes provided by an embodiment of the present invention;
FIG. 2 is a flow chart of a method of determining a rotational speed of an electric machine according to one embodiment of the present invention;
FIG. 3 is a flow chart of another method of determining a rotational speed of a motor provided by an embodiment of the present invention;
fig. 4 is a schematic diagram of an apparatus for determining a rotational speed of a motor according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the technical solutions in the embodiments of the present invention will be described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention, and based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the scope of the present invention.
It should be noted that: the alpha axis and the beta axis are mutually perpendicular fixed coordinate axes, the d axis and the q axis are mutually perpendicular rotating coordinate axes, and the u axis, the v axis and the w axis are motor three-phase fixed coordinate axes with a 120-degree difference between any two axes. The direction of the u axis is consistent with the direction of the alpha axis, and the direction of the d axis is consistent with the direction of the motor rotor. As shown in fig. 1, fig. 1 shows the positional relationship between the respective axes.
In the prior art, the voltage under the d-axis is obtained by estimating the current under the d-axis, and the estimated value of the current under the d-axis has a certain error, so that the voltage under the d-axis also has a certain error. The current under the q axis has a certain error, and the back electromotive force constant has a certain error, which are accumulated in the calculated axis error, and the accuracy of the rotation speed of the motor estimated based on the axis error is low.
In order to make the estimated accuracy of the rotation speed of the motor higher, as shown in fig. 2, an embodiment of the present invention provides a method of determining the rotation speed of the motor, the method including:
step 201: determining the current under an alpha axis and the current under a beta axis of the motor;
step 202: determining a voltage in the alpha axis and a voltage in the beta axis of the motor;
step 203: determining a shaft error of the motor according to the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor;
step 204: and estimating the rotating speed of the motor according to the shaft error.
In the embodiment of the invention, the shaft error is determined by the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft can be accurately determined without estimation, so that no error exists, the shaft error is not influenced by a counter electromotive force constant, the accuracy of the determined shaft error is higher, and the rotating speed of the motor can be more accurately estimated based on the shaft error.
In the embodiment of the invention, the accuracy of the estimated rotating speed of the motor is higher, and the accuracy of determining the position of the motor rotor based on the rotating speed is also higher, so that smooth transition is facilitated when the motor is dragged from open loop to closed loop control, particularly under the condition that the motor is started with back pressure, the current waveform is improved, and the capacity of starting with the back pressure is improved.
In an embodiment of the present invention, the determining the current in the α axis and the current in the β axis of the motor includes:
determining a current in a u-axis and a current in a w-axis of the motor;
determining the current under the alpha axis and the current under the beta axis according to a first formula, wherein the first formula is as follows:
wherein, IαIs the current under the alpha axis, IβIs the current under the beta axis, IuIs the current under the u-axis, IwIs the current under the w-axis.
In the embodiment of the present invention, the current under the u-axis and the current under the w-axis can be obtained through measurement, and the accuracy of the current under the u-axis and the current under the w-axis obtained through measurement is higher, so that the accuracy of the current under the α -axis and the current under the β -axis obtained based on the formula one is also higher.
In an embodiment of the present invention, the determining the voltage in the α axis and the voltage in the β axis of the motor includes:
determining the direct current bus voltage and the PWM period of the motor;
determining the time occupied by the u phase at a high level in one PWM cycle, the time occupied by the v phase at a high level in one PWM cycle and the time occupied by the w phase at a high level in one PWM cycle;
determining a voltage in the alpha axis and a voltage in the beta axis according to an equation two, wherein the equation two is:
wherein, VαIs the voltage under the alpha axis, VβIs the voltage at the beta axis, TuFor the time occupied by the u-phase at a high level in one of said PWM cycles, TvFor the time occupied by the high level of the v-phase in one of said PWM cycles, TwFor the time occupied by the high level of the w-phase in one of said PWM cycles, TcFor said PWM period, EdcIs the dc bus voltage.
In the embodiment of the invention, the DC bus voltage EdcCan be obtained by measurement and has higher accuracy. PWM period Tc、Tu、TvAnd TwCan also be determined accurately. That is, the parameters for calculating the voltage on the α axis and the voltage on the β axis can be accurately determined, and the accuracy of the voltage on the α axis and the voltage on the β axis is high.
In an embodiment of the present invention, the determining a shaft error of the motor according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis includes:
determining back electromotive force under the alpha axis and back electromotive force under the beta axis according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis;
and determining the axis error according to the back electromotive force under the alpha axis and the back electromotive force under the beta axis.
In the embodiment of the present invention, the back electromotive force in the α axis and the back electromotive force in the β axis are determined, and then the axis error is determined based on the back electromotive force in the α axis and the back electromotive force in the β axis.
Specifically, the counter electromotive force in the α axis and the counter electromotive force in the β axis can be determined by:
the determining, from the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, a back electromotive force in the α axis and a back electromotive force in the β axis, includes:
determining a phase resistance of the motor;
determining the last estimated rotating speed of the motor;
determining the inductance under the d axis and the inductance under the q axis of the motor;
determining the back electromotive force under the alpha axis and the back electromotive force under the beta axis according to a third formula, wherein the third formula is as follows:
wherein e isαIs the back electromotive force under the alpha axis, eβIs the back electromotive force, V, under the beta axisαIs the voltage under the alpha axis, VβIs the voltage under the beta axis, IαIs the current under the alpha axis, IβIs the current under the beta axis, LdIs the inductance under the d-axis, LqAnd the inductance under the q axis, r, the phase resistance of the motor, omega, the rotation speed of the motor estimated last time and p, the differential operation.
In the embodiment of the present invention, the parameters for calculating the back electromotive force in the α axis and the back electromotive force in the β axis can be accurately determined, and therefore, the accuracy of the back electromotive force in the α axis and the back electromotive force in the β axis is also high. The process of estimating the rotating speed of the motor is a cyclic process, and after the rotating speed of the motor is estimated for the last time, the process of estimating the rotating speed of the motor is carried out, and so on. Wherein, ω is the last estimated rotation speed of the motor before the process of this time of estimating the rotation speed of the motor, and the process of this time of estimating the rotation speed of the motor needs to use the last estimated rotation speed of the motor, which is an iterative process.
Specifically, the axis error may be determined by:
the determining the axis error according to the back electromotive force in the alpha axis and the back electromotive force in the beta axis includes:
determining the position of the rotor of the motor estimated last time according to the rotating speed of the motor estimated last time;
determining the axis error according to equation four, wherein equation four is:
where Δ θ is the axis error, eαIs the back electromotive force under the alpha axis, eβθ is the last estimated position of the rotor of the motor, which is the back electromotive force in the β axis.
In the embodiment of the present invention, the position of the rotor of the motor estimated last time is determined according to the rotation speed of the motor estimated last time, and in the case that the rotation speed of the motor estimated last time is accurate, the position of the rotor of the motor estimated last time is also accurate, so that each parameter for calculating the shaft error has higher accuracy, and then the accuracy of the shaft error is also higher.
In addition, it should be noted that: the fourth expression is based on the premise that Δ θ ═ θ - θ ' ≈ sin (θ - θ ') when θ - θ ' is small, and generally, Δ θ ═ θ ' ≈ sin (θ - θ ') is small. Where θ' is the true position of the rotor of the motor.
After the shaft error is determined, the rotation speed of the motor may be estimated by phase-locking the shaft error to 0 by a phase-locked loop, that is, by performing a proportional-integral operation on (0- Δ θ), and specifically, may be estimated by the following equation:
ω1＝Kp(0-Δθ)+∫KI(0-Δθ)dt；
wherein, ω is1For estimated rotational speed of the motor, KpIs a proportionality coefficient, KIIs an integral coefficient.
After estimating the rotation speed of the motor, the estimated rotation speed of the motor may be integrated to estimate the position of the rotor of the motor, that is, θ1＝∫ω1dt, wherein theta1For the estimated position of the rotor of the motor, ω1Is the estimated rotational speed of the motor.
A method for determining a rotation speed of a motor according to an embodiment of the present invention is described in detail below with reference to a specific embodiment, and as shown in fig. 3, the method may include the following steps:
step 301: the current in the u-axis and the current in the w-axis of the motor are determined.
Step 302: determining the current under the alpha axis and the current under the beta axis according to a first expression, wherein the first expression is as follows:
wherein, IαIs the current under the alpha axis, IβIs the current under the beta axis, IuIs the current under the u-axis, IwIs the current under the w-axis.
Step 303: the method comprises the steps of determining the direct-current bus voltage and the PWM period of a motor, and determining the time occupied by a u phase with a high level in one PWM period, the time occupied by a v phase with a high level in one PWM period and the time occupied by a w phase with a high level in one PWM period.
Step 304: and determining the voltage under the alpha axis and the voltage under the beta axis according to the formula two, wherein the formula two is as follows:
wherein, VαIs the voltage under the alpha axis, VβIs the voltage at the beta axis, TuFor the time occupied by the u-phase at a high level in one of said PWM cycles, TvFor the time occupied by the high level of the v-phase in one of said PWM cycles, TwFor the time occupied by the high level of the w-phase in one of said PWM cycles, TcFor said PWM period, EdcIs the dc bus voltage.
Step 305: and determining the phase resistance of the motor, acquiring the rotating speed of the motor estimated last time, and determining the inductance under the d axis and the inductance under the q axis of the motor.
Step 306: and determining the back electromotive force under the alpha axis and the back electromotive force under the beta axis according to a third formula, wherein the third formula is as follows:
wherein e isαIs the back electromotive force under the alpha axis, eβIs the back electromotive force, V, under the beta axisαIs the voltage under the alpha axis, VβIs the voltage under the beta axis, IαIs the current under the alpha axis, IβIs the current under the beta axis, LdIs the inductance under the d-axis, LqAnd the inductance under the q axis, r, the phase resistance of the motor, omega, the rotation speed of the motor estimated last time and p, the differential operation.
Step 307: and determining the position of the rotor of the motor estimated last time according to the rotating speed of the motor estimated last time.
Step 308: determining the axis error according to the fourth formula, wherein the fourth formula is as follows:
wherein, Delta theta is the axis error,eαis the back electromotive force under the alpha axis, eβθ is the last estimated position of the rotor of the motor, which is the back electromotive force in the β axis.
Step 309: the rotational speed of the motor is estimated by phase-locking the shaft error to 0 by means of a phase-locked loop.
As shown in fig. 4, an embodiment of the present invention provides an apparatus for determining a rotational speed of a motor, the apparatus including:
a first determination module 401 for determining a current in an α axis and a current in a β axis of the motor;
a second determination module 402 for determining a voltage in the alpha axis and a voltage in the beta axis of the motor;
a third determining module 403, configured to determine a shaft error of the motor according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, where the shaft error is a difference between an estimated value of a position of a rotor of the motor and an actual value of the position of the rotor of the motor;
an estimation module 404 for estimating a rotational speed of the motor based on the shaft error.
In an embodiment of the present invention, the first determining module is configured to perform:
determining a current in a u-axis and a current in a w-axis of the motor;
determining the current under the alpha axis and the current under the beta axis according to a first formula, wherein the first formula is as follows:
wherein, IαIs the current under the alpha axis, IβIs the current under the beta axis, IuIs the current under the u-axis, IwIs the current under the w-axis.
In an embodiment of the present invention, the second determining module is configured to perform:
determining the direct current bus voltage and the PWM period of the motor;
determining the time occupied by the u phase at a high level in one PWM cycle, the time occupied by the v phase at a high level in one PWM cycle and the time occupied by the w phase at a high level in one PWM cycle;
determining a voltage in the alpha axis and a voltage in the beta axis according to an equation two, wherein the equation two is:
wherein, VαIs the voltage under the alpha axis, VβIs the voltage at the beta axis, TuFor the time occupied by the u-phase at a high level in one of said PWM cycles, TvFor the time occupied by the high level of the v-phase in one of said PWM cycles, TwFor the time occupied by the high level of the w-phase in one of said PWM cycles, TcFor said PWM period, EdcIs the dc bus voltage.
In an embodiment of the present invention, the third determining module is configured to determine a back electromotive force in the α axis and a back electromotive force in the β axis according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, and determine the axis error according to the back electromotive force in the α axis and the back electromotive force in the β axis.
In an embodiment of the present invention, when the determining the back electromotive force in the α axis and the back electromotive force in the β axis according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis is performed, the third determining module is specifically configured to perform:
determining a phase resistance of the motor;
acquiring the last estimated rotating speed of the motor;
determining the inductance under the d axis and the inductance under the q axis of the motor;
determining the back electromotive force under the alpha axis and the back electromotive force under the beta axis according to a third formula, wherein the third formula is as follows:
wherein e isαIs the back electromotive force under the alpha axis, eβIs the back electromotive force, V, under the beta axisαIs the voltage under the alpha axis, VβIs the voltage under the beta axis, IαIs the current under the alpha axis, IβIs the current under the beta axis, LdIs the inductance under the d-axis, LqAnd the inductance under the q axis, r, the phase resistance of the motor, omega, the rotation speed of the motor estimated last time and p, the differential operation.
In an embodiment of the present invention, when the determining the axis error according to the back electromotive force in the α axis and the back electromotive force in the β axis is performed, the third determining module is specifically configured to perform:
determining the position of the rotor of the motor estimated last time according to the rotating speed of the motor estimated last time;
determining the axis error according to equation four, wherein equation four is:
where Δ θ is the axis error, eαIs the back electromotive force under the alpha axis, eβθ is the last estimated position of the rotor of the motor, which is the back electromotive force in the β axis.
An embodiment of the present invention provides an electronic device, including: at least one memory and at least one processor;
the at least one memory to store a machine readable program;
the at least one processor is configured to invoke the machine readable program to perform any of the methods for determining a rotational speed of a motor according to embodiments of the present invention.
Embodiments of the present invention provide a computer readable medium having stored thereon computer instructions, which, when executed by a processor, cause the processor to execute the method of determining the rotational speed of an electric motor according to any of the embodiments of the present invention.
The method and the device for determining the rotating speed of the motor are suitable for variable frequency motors, in particular permanent magnet brushless direct current motors. The motor in the embodiment of the invention can be a motor applied to a refrigerator.
In the embodiment of the invention, the axis error is determined based on the transformation of the alpha and beta coordinates of the fixed coordinate axis, the axis error is not influenced by the back electromotive force constant, the rotating speed and the position estimation precision of the motor rotor can be improved, the robustness is good, the method is particularly suitable for starting the motor with back pressure, the control is stable, the starting capability of the motor with back pressure can be improved, and the probability of starting failure with back pressure is reduced.
In the embodiment of the invention, a motor fixed coordinate axis control model is constructed, the motor phase current is detected by detecting the DC bus voltage of a controller, so that the shaft error of the motor rotor is obtained, the rotating speed of the motor rotor is obtained by controlling a phase-locked loop which enables the shaft error to be phase-locked to 0, and finally the position of the motor rotor is obtained by integral calculation.
It is to be understood that the illustrated structure of the embodiment of the present invention does not constitute a specific limitation to the means for determining the rotation speed of the motor. In other embodiments of the invention, the means for determining the rotational speed of the motor may comprise more or fewer components than shown, or some components may be combined, some components may be split, or a different arrangement of components. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.
Because the information interaction, execution process, and other contents between the units in the device are based on the same concept as the method embodiment of the present invention, specific contents may refer to the description in the method embodiment of the present invention, and are not described herein again.
The present invention also provides a computer readable medium storing instructions for causing a computer to perform a method of determining a rotational speed of an electric machine as described herein. Specifically, a system or an apparatus equipped with a storage medium on which software program codes that realize the functions of any of the above-described embodiments are stored may be provided, and a computer (or a CPU or MPU) of the system or the apparatus is caused to read out and execute the program codes stored in the storage medium.
In this case, the program code itself read from the storage medium can realize the functions of any of the above-described embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.
Examples of the storage medium for supplying the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (e.g., CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD + RW), a magnetic tape, a nonvolatile memory card, and a ROM. Alternatively, the program code may be downloaded from a server computer via a communications network.
Further, it should be clear that the functions of any one of the above-described embodiments may be implemented not only by executing the program code read out by the computer, but also by causing an operating system or the like operating on the computer to perform a part or all of the actual operations based on instructions of the program code.
Further, it is to be understood that the program code read out from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion unit connected to the computer, and then causes a CPU or the like mounted on the expansion board or the expansion unit to perform part or all of the actual operations based on instructions of the program code, thereby realizing the functions of any of the above-described embodiments.
The method and the device for determining the rotating speed of the motor provided by the embodiment of the invention at least have the following beneficial effects:
1. in the embodiment of the invention, the shaft error is determined by the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft can be accurately determined without estimation, so that no error exists, the shaft error is not influenced by a counter electromotive force constant, the accuracy of the determined shaft error is higher, and the rotating speed of the motor can be more accurately estimated based on the shaft error.
2. In the embodiment of the invention, the accuracy of the estimated rotating speed of the motor is higher, and the accuracy of determining the position of the motor rotor based on the rotating speed is also higher, so that smooth transition is facilitated when the motor is dragged from open loop to closed loop control, particularly under the condition that the motor is started with back pressure, the current waveform is improved, and the capacity of starting with the back pressure is improved.
3. In the embodiment of the present invention, the current under the u-axis and the current under the w-axis can be obtained through measurement, and the accuracy of the current under the u-axis and the current under the w-axis obtained through measurement is higher, so that the accuracy of the current under the α -axis and the current under the β -axis obtained based on the formula one is also higher.
4. In the embodiment of the invention, the DC bus voltage EdcCan be obtained by measurement and has higher accuracy. PWM period Tc、Tu、TvAnd TwCan also be determined accurately. That is, the parameters for calculating the voltage on the α axis and the voltage on the β axis can be accurately determined, and the accuracy of the voltage on the α axis and the voltage on the β axis is high.
5. In the embodiment of the present invention, the parameters for calculating the back electromotive force in the α axis and the back electromotive force in the β axis can be accurately determined, and therefore, the accuracy of the back electromotive force in the α axis and the back electromotive force in the β axis is also high.
6. In the embodiment of the present invention, the position of the rotor of the motor estimated last time is determined according to the rotation speed of the motor estimated last time, and in the case that the rotation speed of the motor estimated last time is accurate, the position of the rotor of the motor estimated last time is also accurate, so that each parameter for calculating the shaft error has higher accuracy, and then the accuracy of the shaft error is also higher.
7. In the embodiment of the invention, the axis error is determined based on the transformation of the alpha and beta coordinates of the fixed coordinate axis, the axis error is not influenced by the back electromotive force constant, the rotating speed and the position estimation precision of the motor rotor can be improved, the robustness is good, the method is particularly suitable for starting the motor with back pressure, the control is stable, the starting capability of the motor with back pressure can be improved, and the probability of starting failure with back pressure is reduced.
It should be noted that not all steps and modules in the above flows and system structure diagrams are necessary, and some steps or modules may be omitted according to actual needs. The execution order of the steps is not fixed and can be adjusted as required. The system structure described in the above embodiments may be a physical structure or a logical structure, that is, some modules may be implemented by the same physical entity, or some modules may be implemented by a plurality of physical entities, or some components in a plurality of independent devices may be implemented together.
In the above embodiments, the hardware unit may be implemented mechanically or electrically. For example, a hardware element may comprise permanently dedicated circuitry or logic (such as a dedicated processor, FPGA or ASIC) to perform the corresponding operations. The hardware elements may also comprise programmable logic or circuitry, such as a general purpose processor or other programmable processor, that may be temporarily configured by software to perform the corresponding operations. The specific implementation (mechanical, or dedicated permanent, or temporarily set) may be determined based on cost and time considerations.
While the invention has been shown and described in detail in the drawings and in the preferred embodiments, it is not intended to limit the invention to the embodiments disclosed, and it will be apparent to those skilled in the art that various combinations of the code auditing means in the various embodiments described above may be used to obtain further embodiments of the invention, which are also within the scope of the invention.
Claims (10)
1. A method of determining the rotational speed of an electric machine, the method comprising:
determining the current under an alpha axis and the current under a beta axis of the motor;
determining a voltage in the alpha axis and a voltage in the beta axis of the motor;
determining a shaft error of the motor according to the current under the alpha shaft, the current under the beta shaft, the voltage under the alpha shaft and the voltage under the beta shaft, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor;
and estimating the rotating speed of the motor according to the shaft error.
2. The method of claim 1,
the determining of the current in the alpha axis and the current in the beta axis of the motor comprises:
determining a current in a u-axis and a current in a w-axis of the motor;
determining the current under the alpha axis and the current under the beta axis according to a first formula, wherein the first formula is as follows:
wherein, IαIs the current under the alpha axis, IβIs the current under the beta axis, IuIs the current under the u-axis, IwIs the current under the w-axis.
3. The method of claim 1,
the determining a voltage in the alpha axis and a voltage in the beta axis of the motor comprises:
determining a direct current bus voltage and a Pulse Width Modulation (PWM) period of the motor;
determining the time occupied by the u phase at a high level in one PWM cycle, the time occupied by the v phase at a high level in one PWM cycle and the time occupied by the w phase at a high level in one PWM cycle;
determining a voltage in the alpha axis and a voltage in the beta axis according to an equation two, wherein the equation two is:
wherein, VαIs the voltage under the alpha axis, VβIs the voltage at the beta axis, TuFor the time occupied by the u-phase at a high level in one of said PWM cycles, TvFor the time occupied by the high level of the v-phase in one of said PWM cycles, TwFor the time occupied by the high level of the w-phase in one of said PWM cycles, TcFor said PWM period, EdcIs the dc bus voltage.
4. The method of claim 1,
the determining the shaft error of the motor according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis comprises:
determining back electromotive force under the alpha axis and back electromotive force under the beta axis according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis;
and determining the axis error according to the back electromotive force under the alpha axis and the back electromotive force under the beta axis.
5. The method of claim 4,
the determining, from the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, a back electromotive force in the α axis and a back electromotive force in the β axis, includes:
determining a phase resistance of the motor;
acquiring the last estimated rotating speed of the motor;
determining the inductance under the d axis and the inductance under the q axis of the motor;
determining the back electromotive force under the alpha axis and the back electromotive force under the beta axis according to a third formula, wherein the third formula is as follows:
wherein e isαIs the back electromotive force under the alpha axis, eβIs the back electromotive force, V, under the beta axisαIs the voltage under the alpha axis, VβIs the voltage under the beta axis, IαIs the current under the alpha axis, IβIs the current under the beta axis, LdIs the inductance under the d-axis, LqAnd the inductance under the q axis, r, the phase resistance of the motor, omega, the rotation speed of the motor estimated last time and p, the differential operation.
6. The method of claim 4,
the determining the axis error according to the back electromotive force in the alpha axis and the back electromotive force in the beta axis includes:
determining the position of the rotor of the motor estimated last time according to the rotating speed of the motor estimated last time;
determining the axis error according to equation four, wherein equation four is:
where Δ θ is the axis error, eαIs the back electromotive force under the alpha axis, eβθ is the last estimated position of the rotor of the motor, which is the back electromotive force in the β axis.
7. Apparatus for determining the speed of a motor, the apparatus comprising:
the first determination module is used for determining the current under the alpha axis and the current under the beta axis of the motor;
a second determination module to determine a voltage in the alpha axis and a voltage in the beta axis of the motor;
the third determining module is used for determining a shaft error of the motor according to the current under the alpha axis, the current under the beta axis, the voltage under the alpha axis and the voltage under the beta axis, wherein the shaft error is a difference value between an estimated value of the position of the motor rotor and an actual value of the position of the motor rotor;
and the estimation module is used for estimating the rotating speed of the motor according to the shaft error.
8. The apparatus of claim 7,
the third determining module is configured to determine a back electromotive force in the α axis and a back electromotive force in the β axis according to the current in the α axis, the current in the β axis, the voltage in the α axis, and the voltage in the β axis, and determine the axis error according to the back electromotive force in the α axis and the back electromotive force in the β axis.
9. An electronic device, comprising: at least one memory and at least one processor;
the at least one memory to store a machine readable program;
the at least one processor, configured to invoke the machine readable program, to perform the method of any of claims 1 to 6.
10. Computer readable medium, characterized in that it has stored thereon computer instructions which, when executed by a processor, cause the processor to carry out the method of any one of claims 1 to 6.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103199779A (en) * | 2013-04-22 | 2013-07-10 | 哈尔滨工业大学 | Position observation device and method for rotor of built-in permanent magnetic synchronous motor based on adaptive filtering |
| CN106026801A (en) * | 2016-07-04 | 2016-10-12 | 珠海格力节能环保制冷技术研究中心有限公司 | Method and apparatus for detecting rotor position of permanent magnet synchronous motor |
| CN108347207A (en) * | 2018-03-14 | 2018-07-31 | 包头长安永磁电机有限公司 | Permanent magnet synchronous motor position and speed evaluation method based on plural PI controllers |
| US10291160B1 (en) * | 2018-03-09 | 2019-05-14 | Haier Us Appliance Solutions, Inc. | Method for operating a synchronous motor |
| CN110350835A (en) * | 2019-07-29 | 2019-10-18 | 南通大学 | A kind of permanent magnet synchronous motor method for controlling position-less sensor |
| CN110768590A (en) * | 2018-07-25 | 2020-02-07 | 哈尔滨工业大学 | Permanent magnet synchronous motor rotor position and speed estimation system and method adopting improved sliding-mode observer |
| CN111342727A (en) * | 2020-03-15 | 2020-06-26 | 华中科技大学 | Permanent magnet synchronous motor position sensorless control method and device |
-
2020
- 2020-07-20 CN CN202010700235.7A patent/CN111969922A/en not_active Withdrawn
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103199779A (en) * | 2013-04-22 | 2013-07-10 | 哈尔滨工业大学 | Position observation device and method for rotor of built-in permanent magnetic synchronous motor based on adaptive filtering |
| CN106026801A (en) * | 2016-07-04 | 2016-10-12 | 珠海格力节能环保制冷技术研究中心有限公司 | Method and apparatus for detecting rotor position of permanent magnet synchronous motor |
| US10291160B1 (en) * | 2018-03-09 | 2019-05-14 | Haier Us Appliance Solutions, Inc. | Method for operating a synchronous motor |
| CN108347207A (en) * | 2018-03-14 | 2018-07-31 | 包头长安永磁电机有限公司 | Permanent magnet synchronous motor position and speed evaluation method based on plural PI controllers |
| CN110768590A (en) * | 2018-07-25 | 2020-02-07 | 哈尔滨工业大学 | Permanent magnet synchronous motor rotor position and speed estimation system and method adopting improved sliding-mode observer |
| CN110350835A (en) * | 2019-07-29 | 2019-10-18 | 南通大学 | A kind of permanent magnet synchronous motor method for controlling position-less sensor |
| CN111342727A (en) * | 2020-03-15 | 2020-06-26 | 华中科技大学 | Permanent magnet synchronous motor position sensorless control method and device |
Non-Patent Citations (2)
| Title |
|---|
| 朱嘉骏: "电动汽车用永磁同步电机直接转矩控制的研究", 《中国优秀博硕士学位论文全文数据库(硕士)-工程科技Ⅱ辑》 * |
| 蒋亚杰: "电动汽车用永磁同步电机驱动***抗干扰控制策略研究", 《中国优秀博硕士学位论文全文数据库(硕士)-工程科技Ⅱ辑》 * |
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