阅读说明：本技术 电机的控制方法、装置、压缩机和制冷设备 (Motor control method and device, compressor and refrigeration equipment ) 是由 李太龙 任新杰 于 2020-12-28 设计创作，主要内容包括：本发明提出了一种电机的控制方法、装置、压缩机和制冷设备,其中,包括：获取电机的电流值和电压值；根据电流值和电压值,提取电机的基波反电动势和谐波反电动势；根据基波反电动势和谐波反电动势,对电机进行补偿。本发明提出的电机的控制方法,获取电机的电流值和电压值,并根据电流值和电压值分离提出电机的基波反电动势和谐波反电动势,进而根据基波反电动势和谐波反电动势,对电机进行补偿,而电机的转矩谐波是转子振动的根本原因,进而利用基波反电动势和谐波反电动势对电机进行补偿,进而对电机的转矩谐波进行抑制,进而有效的改善电机系统的振动和噪音问题。(The invention provides a control method and a control device of a motor, a compressor and refrigeration equipment, wherein the control method comprises the following steps: acquiring a current value and a voltage value of the motor; extracting fundamental wave back electromotive force and harmonic wave back electromotive force of the motor according to the current value and the voltage value; and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force. The control method of the motor obtains the current value and the voltage value of the motor, and provides fundamental wave back electromotive force and harmonic wave back electromotive force of the motor according to the current value and the voltage value in a separation mode, so that the motor is compensated according to the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is the root cause of rotor vibration, the motor is compensated by the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is restrained, and the vibration and noise problems of a motor system are effectively improved.)

1. A method of controlling a motor, comprising:

acquiring a current value and a voltage value of the motor;

extracting fundamental wave back electromotive force and harmonic back electromotive force of the motor according to the current value and the voltage value;

and compensating the motor according to the fundamental wave back electromotive force and the harmonic wave back electromotive force.

2. The method according to claim 1, wherein the step of extracting a fundamental back electromotive force and a harmonic back electromotive force of the motor according to the current value and the voltage value specifically includes:

and obtaining the fundamental wave back electromotive force and the harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value.

3. The method of controlling a motor according to claim 2, further comprising, before the step of obtaining the current value and the voltage value of the motor:

sampling the current value and the voltage value of the motor;

and establishing the counter electromotive force observation model of the motor according to the current value and the voltage value obtained by sampling.

4. The method according to claim 2, wherein the step of obtaining the fundamental back electromotive force and the harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value specifically includes:

substituting the current value and the voltage value into the counter electromotive force observation model;

and extracting the fundamental wave back electromotive force and the harmonic wave back electromotive force output by the back electromotive force observation model through a frequency selection module.

5. The method of controlling an electric motor according to claim 4, wherein the frequency selection module comprises:

a plurality of back emf harmonic frequency selectors.

6. The method according to any one of claims 1 to 5, wherein the step of compensating the motor according to the fundamental back electromotive force and the harmonic back electromotive force specifically comprises:

determining a rotor position signal of the motor according to the fundamental wave back electromotive force;

obtaining a fundamental wave back electromotive force observation value and a harmonic wave back electromotive force observation value under a rectangular-to-orthogonal axis coordinate system according to the fundamental wave back electromotive force, the harmonic wave back electromotive force and the rotor position signal;

and performing feed-forward compensation on the motor according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

7. The method according to claim 6, wherein the step of performing feed-forward compensation on the motor based on the fundamental back electromotive force observed value and the harmonic back electromotive force observed value specifically comprises:

and compensating the voltage vector of the rectangular axis output by the current regulator according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

8. A control device of a motor, characterized by comprising:

a memory having a program or instructions stored thereon;

a processor configured to implement the method of controlling the electric machine of any one of claims 1 to 7 when executing the program or instructions.

9. The control device of the motor according to claim 8, further comprising:

and the frequency selector is connected with the processor.

10. A compressor, comprising:

a motor; and

a control apparatus for an electric motor according to claim 8 or 9.

11. A refrigeration apparatus, comprising:

the compressor of claim 10.

12. A readable storage medium on which a program or instructions are stored, characterized in that the program or instructions, when executed by a processor, implement a control method of an electric machine according to any one of claims 1 to 7.

Technical Field

The invention relates to the field of motors, in particular to a motor control method, a motor control device, a compressor, refrigeration equipment and a readable storage medium.

Background

In the related art, the basic working principle of the rotary single-rotor compressor is that an eccentric crankshaft drives a rolling piston to rotate, wherein when a cylinder is in compression work, the gas pressure in a compression cavity changes periodically, so that periodically changing torque pulsation is generated between the cylinder and the rotating crankshaft, which is the basic reason for generating torsional vibration of the compressor.

The torsional vibration of the compressor causes the working noise of the compressor to be larger, and influences the hearing.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art.

To this end, a first aspect of the invention proposes a method of controlling an electric machine.

A second aspect of the invention proposes a control device of an electric motor.

A third aspect of the present invention provides a compressor.

A fourth aspect of the present invention provides a refrigeration apparatus.

A fifth aspect of the invention proposes a readable storage medium.

In view of the above, according to a first aspect of the present invention, there is provided a control method of a motor, including: acquiring a current value and a voltage value of the motor; extracting fundamental wave back electromotive force and harmonic wave back electromotive force of the motor according to the current value and the voltage value; and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force.

The control method of the motor obtains the current value and the voltage value of the motor, and provides fundamental wave back electromotive force and harmonic wave back electromotive force of the motor according to the current value and the voltage value in a separation mode, so that the motor is compensated according to the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is the root cause of rotor vibration, the motor is compensated by the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is restrained, and the vibration and noise problems of a motor system are effectively improved.

In addition, according to the control method of the motor in the above technical solution provided by the present invention, the following additional technical features may be further provided:

in the above technical solution, further, the step of extracting a fundamental back electromotive force and a harmonic back electromotive force of the motor according to the current value and the voltage value specifically includes: and obtaining fundamental wave back electromotive force and harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value.

In the technical scheme, the step of extracting fundamental wave back electromotive force and harmonic back electromotive force of the motor according to the current value and the voltage value specifically comprises: based on the observation model, the fundamental wave back electromotive force and the harmonic wave back electromotive force of the motor are extracted according to the current value and the current voltage value of the motor, and then the fundamental wave back electromotive force and the harmonic wave back electromotive force can be extracted quickly by utilizing the observation model, so that the timeliness of compensating the motor is ensured.

In any of the above technical solutions, further, before the step of obtaining the current value and the voltage value of the motor, the method further includes: sampling a current value and a voltage value of the motor; and establishing a counter electromotive force observation model of the motor according to the sampled current value and the sampled voltage value.

In the technical scheme, the current value and the voltage value of the motor are sampled, namely, the continuous current value and the continuous voltage value are collected, specifically, the continuous current value forms a waveform, and the continuous voltage value also forms a waveform.

And then, considering the influence of the salient polarity of the motor, and establishing an observation model of the motor expanded back electromotive force by using the principle of effective magnetic flux as a reference. Because the current value and the voltage value are sampled based on the current motor, the accuracy of extracting the fundamental counter electromotive force and the harmonic counter electromotive force can be ensured on the basis of the observation model.

In any of the above technical solutions, further, the step of obtaining the fundamental back electromotive force and the harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value specifically includes: substituting the current value and the voltage value into a counter electromotive force observation model; and extracting fundamental wave back electromotive force and harmonic back electromotive force output by the back electromotive force observation model through a frequency selection module.

In the technical scheme, the current value and the current voltage value of the motor are input into the observation model, the frequency selector is utilized to select the frequency of fundamental wave back electromotive force and harmonic back electromotive force, and then required fundamental wave back electromotive force and harmonic back electromotive force of each order are extracted, so that corresponding fundamental wave back electromotive force and harmonic back electromotive force are extracted aiming at the current motor condition, the current motor requirement is met, and the frequency selector can be self-adaptive, and thus the fundamental wave back electromotive force and the harmonic back electromotive force required by the motor are quickly obtained.

In any of the above technical solutions, further, the frequency selecting module includes: a plurality of back emf harmonic frequency selectors.

In the technical scheme, a plurality of counter electromotive force harmonic frequency selectors can be connected in parallel, so that self-adaptive frequency selection can be performed on fundamental counter electromotive force and harmonic counter electromotive force respectively, specifically, a proper frequency selector bandwidth is set, the proper frequency selector bandwidth ensures accurate extraction of frequency selection signals on one hand, and dynamic response of a system and other frequency signals are required to be filtered out on the other hand.

In any of the above technical solutions, further, the step of compensating the motor according to the fundamental back electromotive force and the harmonic back electromotive force specifically includes: determining a rotor position signal of the motor according to the fundamental wave back electromotive force; obtaining a fundamental wave back electromotive force observation value and a harmonic wave back electromotive force observation value under a rectangular-to-orthogonal axis coordinate system according to the fundamental wave back electromotive force, the harmonic wave back electromotive force and the rotor position signal; and performing feed-forward compensation on the motor according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

In this technical scheme, according to fundamental wave back electromotive force and harmonic back electromotive force, carry out the step of compensation to the motor, specifically include: the method comprises the steps of taking fundamental wave back electromotive force as a reference, combining a motor expansion back electromotive force calculation formula, extracting a position angle signal of a rotor by a phase-locked loop position angle extraction module, determining the position of the rotor, converting the fundamental wave back electromotive force and harmonic back electromotive force into a rectangular-to-orthogonal axis coordinate system by taking the rotor position signal as a calibration, obtaining a fundamental wave back electromotive force observation value and a harmonic back electromotive force observation value, and performing feedforward compensation on a motor according to the fundamental wave back electromotive force observation value and the harmonic back electromotive force observation value.

The feedforward compensation is insensitive to system parameter change, has strong system robustness and stability, has high response speed, can well inhibit torque harmonics, is simple to realize digitalization, is very convenient for engineering application, and can greatly improve the problems of vibration and noise of a motor system.

In any of the above technical solutions, further, the step of performing feed-forward compensation on the motor according to the fundamental back electromotive force observed value and the harmonic back electromotive force observed value specifically includes: and compensating the orthogonal axis voltage vector output by the current regulator according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

In the technical scheme, the fundamental wave counter electromotive force observation value and the harmonic counter electromotive force observation value are superposed on a voltage vector of a quadrature axis output by a current regulator of the driving motor, so that voltage is superposed, torque harmonic of the motor is restrained, and vibration and noise of the motor are reduced.

In any of the above technical solutions, further, the step of obtaining the current signal and the voltage signal of the motor specifically includes: and acquiring a current signal and a voltage signal of the motor through a microcontroller, and performing filtering processing to obtain a current value and the voltage value.

According to the technical scheme, when the current signal and the voltage signal of the motor are obtained, the current signal and the voltage signal are obtained by the microcontroller, and are filtered, so that accurate current values and accurate voltage values are obtained.

According to a second aspect of the present invention, there is provided a control device of a motor, comprising: a memory having a program or instructions stored thereon; a processor configured to implement the control method of the motor as set forth in any one of the above technical solutions when executing a program or an instruction.

The control device for the motor provided by the present invention includes a memory and a processor, and when the program or the instructions in the memory are executed by the processor, the control method for the motor according to any of the above technical solutions is performed.

In the above technical solution, further, the method further includes: and the frequency selector is connected with the processor.

In this technical solution, the control device for a motor further includes: the frequency selector is used for matching with the processor to execute the control method of the motor provided by any one of the above technical schemes.

According to a third aspect of the present invention, the present invention provides a compressor comprising: a motor; and a control device of the motor as set forth in any one of the above technical solutions.

The compressor provided by the present invention includes the control device of the motor according to any one of the above technical solutions, so that all the advantages of the control device of the motor according to any one of the above technical solutions are provided, and are not described herein.

According to a fourth aspect of the present invention, there is provided a refrigeration apparatus comprising: a compressor as set forth in any of the above solutions.

The refrigeration equipment provided by the invention comprises the compressor provided by any one of the above technical solutions, so that all the advantages of the compressor provided by any one of the above technical solutions are achieved, and the description is omitted.

According to a fifth aspect of the present invention, the present invention proposes a readable storage medium, on which a program or instructions are stored, which when executed by a processor implement the control method of the electric machine as set forth in any one of the above-mentioned technical solutions.

The readable storage medium provided by the present invention stores a program or instructions for implementing the method for controlling a motor according to any one of the above-mentioned technical solutions when the readable storage medium is executed by a processor, so that all the advantages of the method for controlling a motor according to any one of the above-mentioned technical solutions are achieved, and are not described herein.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a flowchart illustrating a control method of a motor according to a first embodiment of the present invention;

fig. 2 is a flowchart illustrating a control method of a motor according to a second embodiment of the present invention;

fig. 3 is a flowchart illustrating a control method of a motor according to a third embodiment of the present invention;

fig. 4 is a flowchart illustrating a control method of a motor according to a fourth embodiment of the present invention;

fig. 5 is a flowchart showing a control method of a motor according to a fifth embodiment of the present invention;

fig. 6 is a flowchart showing a control method of a motor according to a sixth embodiment of the present invention;

fig. 7 is a flowchart illustrating a control method of a motor according to a seventh embodiment of the present invention;

fig. 8 is a flowchart showing a control method of a motor according to an eighth embodiment of the present invention;

fig. 9 is a functional block diagram of a frequency selector in the control method of the motor provided by the present invention;

fig. 10 shows an amplitude-frequency response curve of a frequency selector in the control method of the motor provided by the invention;

fig. 11 is a system block diagram of a rotor position signal extraction module in the control method of the motor according to the present invention;

fig. 12 is a graph showing a comparison of current waveforms of the motor in the related art and the control method of the motor according to the present invention;

fig. 13 is a graph showing a comparison between the control method of the motor according to the present invention and the OA value of the noise of the motor according to the related art.

Detailed Description

In order that the above objects, features and advantages of the present invention can be more clearly understood, a more particular description of the invention will be rendered by reference to the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A control method of a motor, a control apparatus of a motor, a compressor, a refrigeration apparatus, and a readable storage medium provided according to some embodiments of the present invention are described below with reference to fig. 1 to 13.

Example 1:

fig. 1 is a flowchart illustrating a control method of a motor according to a first embodiment of the present invention.

As shown in fig. 1, a control method of a motor according to a first embodiment of the present invention includes the following steps:

step 102: acquiring a current value and a voltage value of the motor;

step 104: extracting fundamental wave back electromotive force and harmonic wave back electromotive force of the motor according to the current value and the voltage value;

step 106: and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force.

According to the control method of the motor, the current value and the voltage value of the motor are obtained, the fundamental wave back electromotive force and the harmonic wave back electromotive force of the motor are proposed according to the current value and the voltage value in a separation mode, the motor is compensated according to the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is the root cause of rotor vibration, the motor is compensated through the fundamental wave back electromotive force and the harmonic wave back electromotive force, the torque harmonic wave of the motor is restrained, and the vibration and noise problems of a motor system are effectively improved.

Specifically, a current value and a voltage value of a current motor are obtained in real time by using an MCU (Micro Control Unit), specifically, a phase current value and a phase voltage value of the current motor are obtained by sampling in real time, and the obtained voltage value and current value are subjected to filtering preprocessing to filter out a high-frequency noise signal. Wherein the three-phase current values for the motor satisfy the relationship of adding and being equal to zero, so that the third phase current value can be calculated by obtaining any two-phase current value.

Example 2:

fig. 2 is a flowchart illustrating a control method of a motor according to a second embodiment of the present invention.

As shown in fig. 2, a control method of a motor according to a second embodiment of the present invention includes the following steps:

step 202: acquiring a current value and a voltage value of the motor;

step 204: obtaining fundamental wave back electromotive force and harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value;

step 206: and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force.

On the basis of embodiment 1, further, the step of extracting the fundamental back electromotive force and the harmonic back electromotive force of the motor according to the current value and the voltage value specifically includes: based on the observation model, the fundamental wave back electromotive force and the harmonic wave back electromotive force of the motor are extracted according to the current value and the current voltage value of the motor, and then the fundamental wave back electromotive force and the harmonic wave back electromotive force can be extracted quickly by utilizing the observation model, so that the timeliness of compensating the motor is ensured.

Example 3:

fig. 3 is a flowchart illustrating a control method of a motor according to a third embodiment of the present invention.

As shown in fig. 3, a flow of a control method for a motor according to a third embodiment of the present invention includes the following steps:

step 302: sampling a current value and a voltage value of the motor;

step 304: establishing a counter electromotive force observation model of the motor according to the current value and the voltage value obtained by sampling;

step 306: acquiring a current value and a voltage value of the motor;

step 308: obtaining fundamental wave back electromotive force and harmonic back electromotive force through a back electromotive force observation model according to the current value and the voltage value;

step 310: and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force.

On the basis of embodiment 2, further, the current value and the voltage value of the motor are sampled, that is, the current value and the voltage value are collected continuously, specifically, the current value forms a waveform continuously, and the voltage value forms a waveform continuously.

Specifically, a current value and a voltage value of a current motor are sampled in real time by using an MCU (Micro Control Unit), specifically, a phase current value and a phase voltage value of the current motor are sampled in real time, and the sampled voltage value and current value are subjected to filtering preprocessing to filter out a high-frequency noise signal. Wherein the three-phase current values for the motor satisfy the relationship of adding and being equal to zero, so that the third phase current value can be calculated by obtaining any two-phase current value.

The voltage and current equation under the stator reference coordinate system is mainly considered, so that the influence of quadrature-direct axis coupling and speed signal coupling can be avoided, and high dynamic response and high stability can be realized.

Meanwhile, considering the influence of the saliency of the motor, and by using the principle of effective magnetic flux for reference, an observation model of the expanded back electromotive force of the motor is established as follows:

wherein the content of the first and second substances,

andrepresenting the observed value of the amplitude of the fundamental current of the stator coordinate, omega representing the electronic rotating speed of the motor,andrepresenting stator coordinates nth harmonic current magnitude observations,

v_α＝v_α1cos(ωt+θ_α1)+v_α5cos(5ωt+θ_α5)+v_α7cos(7ωt+θ_α7)+…+v_αncos(nωt+θ_αn) (formula 4) of the reaction mixture,

v_β＝v_β1cos(ωt+θ_β1)+v_β5cos(5ωt+θ_β5)+v_β7cos(7ωt+θ_β7)+…+v_βncos(nωt+θ_βn) (formula 5) of the reaction mixture,

wherein v is_α1And v_β1Representing the fundamental voltage amplitude, v, of the stator coordinates_α1And v_β1Representing the stator coordinates nth harmonic voltage magnitude,

wherein the content of the first and second substances,

k represents a sliding mode control gain, z_αAnd z_βRepresenting the observed back emf signal.

Example 4:

fig. 4 shows a flowchart of a control method of a motor according to a fourth embodiment of the present invention.

As shown in fig. 4, a control method of a motor according to a fourth embodiment of the present invention includes the following steps:

step 402: sampling a current value and a voltage value of the motor;

step 404: establishing a counter electromotive force observation model of the motor according to the current value and the voltage value obtained by sampling;

step 406: acquiring a current value and a voltage value of the motor;

step 408: substituting the current value and the voltage value into a counter electromotive force observation model;

step 410: extracting fundamental wave back electromotive force and harmonic back electromotive force output by a back electromotive force observation model through a frequency selection module;

step 412: and compensating the motor according to the fundamental counter electromotive force and the harmonic counter electromotive force.

On the basis of embodiment 3, further, current value and voltage value of the motor are input to the observation model, frequency selection can be performed on fundamental wave back electromotive force and harmonic back electromotive force by using the frequency selector, and then required fundamental wave back electromotive force and harmonic back electromotive force of each order are extracted, so that corresponding fundamental wave back electromotive force and harmonic back electromotive force are extracted according to the current motor condition to meet the current motor requirement, and the frequency selector can perform self-adaptation, so that fundamental wave back electromotive force and harmonic back electromotive force required by the motor are rapidly obtained.

Specifically, according to the obtained phase current value and phase voltage value of the current motor, coordinate transformation is carried out to obtain a stator coordinate current value i of the current control period_αAnd i_βAnd a voltage value v_αAnd v_βDiscretizing the observation equation of the formula 1 to obtain,

is calculated to obtain z_α(k-1) and z_βThe time value of (k-1).

Wherein z is_αAnd z_βThe method comprises the motor back electromotive force observed value to be extracted, specifically comprises a fundamental wave back electromotive force observed value and an observed value of each subharmonic back electromotive force, and further comprises a noise signal and a sliding mode control switch signal, specifically as follows,

wherein the content of the first and second substances,andfundamental back emf magnitude observations representing stator coordinates,andobserved value of the amplitude of the back electromotive force of the nth harmonic wave representing the coordinates of the stator, N_αhAnd N_βhRepresenting other noise signals and sliding mode control switching signals.

Designing a counter electromotive force signal self-adaptive frequency selection group module, respectively carrying out self-adaptive frequency selection on fundamental wave counter electromotive force signals and harmonic counter electromotive force signals of the motor, and extracting the required fundamental wave counter electromotive force signals of the motorAndand harmonic back electromotive force signals of each orderAnd

further, the traditional low-pass filter takes zero frequency as the center frequency, the unit gain and the zero phase delay are ensured at the center frequency, if the center frequency is shifted to the fundamental frequency, the unit gain and the zero phase delay of the frequency point signal can be realized, the unit gain and the zero phase delay of the fundamental back electromotive force can be ensured, and the accurate self-adaptive extraction of the frequency point signal can be realized. Similar frequency selector module composed of multiple back electromotive force harmonic frequency selectors connected in parallel can realize self-adaptive frequency selection of fundamental wave back electromotive force signals and harmonic back electromotive force signals of the motor.

According to this design principle, the transfer function of the adaptive frequency selector is designed as follows:

wherein, ω is₀Representing the centre frequency, omega, after translation_cRepresenting the frequency selector cut-off frequency. Where omega is applied for self-adaptive frequency selection of fundamental back electromotive force signals and harmonic back electromotive force signals of motors₀Set to the adaptive frequency, i.e. the centre frequency is equal to the fundamental frequency and the corresponding harmonic frequency, ω_c＝k×ω₀And setting a proper frequency selector bandwidth, wherein the proper frequency selector bandwidth ensures accurate extraction of frequency selection signals on one hand, and gives consideration to the dynamic response of a system and the filtering of other frequency signals on the other hand.

According to the above design principle, the designed adaptive frequency selector bank module can realize the separation and extraction of fundamental wave back electromotive force and harmonic back electromotive force of the motor through the designed adaptive frequency selector bank module, such as the system function block diagram shown in fig. 9 and the system amplitude-frequency response curve shown in fig. 10.

Example 5:

fig. 5 is a flowchart illustrating a control method of a motor according to a fifth embodiment of the present invention.

As shown in fig. 5, a control method for a motor according to a fifth embodiment of the present invention includes the following steps:

step 502: sampling a current value and a voltage value of the motor;

step 504: establishing a counter electromotive force observation model of the motor according to the current value and the voltage value obtained by sampling;

step 506: acquiring a current value and a voltage value of the motor;

step 508: substituting the current value and the voltage value into a counter electromotive force observation model;

step 510: extracting fundamental wave back electromotive force and harmonic back electromotive force output by a back electromotive force observation model through a frequency selection module;

step 512: determining a rotor position signal of the motor according to the fundamental wave back electromotive force;

step 514: obtaining a fundamental wave back electromotive force observation value and a harmonic wave back electromotive force observation value under a rectangular-to-orthogonal axis coordinate system according to the fundamental wave back electromotive force, the harmonic wave back electromotive force and the rotor position signal;

step 516: and performing feed-forward compensation on the motor according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

On the basis of embodiment 4, further, the step of compensating the motor according to the fundamental back electromotive force and the harmonic back electromotive force specifically includes: the method comprises the steps of taking fundamental wave back electromotive force as a reference, combining a motor expansion back electromotive force calculation formula, extracting a position angle signal of a rotor by a phase-locked loop position angle extraction module, determining the position of the rotor, converting the fundamental wave back electromotive force and harmonic back electromotive force into a rectangular-to-orthogonal axis coordinate system by taking the rotor position signal as a calibration, obtaining a fundamental wave back electromotive force observation value and a harmonic back electromotive force observation value, and performing feedforward compensation on a motor according to the fundamental wave back electromotive force observation value and the harmonic back electromotive force observation value.

The feedforward compensation is insensitive to system parameter change, has strong system robustness and stability, has high response speed, can well inhibit torque harmonics, is simple to realize digitalization, is very convenient for engineering application, and can greatly improve the problems of vibration and noise of a motor system.

In particular, based on the fundamental back electromotive force signalAndthe fundamental wave back electromotive force signal can be obtained by combining with the motor expansion back electromotive force calculation formula, as follows,

wherein E is_ebemf1Representing the fundamental extended back emf assignments,and the observation error representing the position angle of the rotor is obtained by the following steps that when the constructed counter electromotive force observation system enters a convergence state,approaching zero.

By extracting the back electromotive force signal of the motor fundamental waveAndthe motor rotor position signal can be obtained by performing trigonometric operation or a phase-locked loop module

According to the extracted motor fundamental wave back electromotive force signalAndand harmonic back electromotive force signals of each orderAnd

combining the extracted position signalsThe following coordinate transformation is carried out to obtain fundamental wave back electromotive force and harmonic wave back electromotive force observed values under an orthogonal synchronous coordinate system (namely dq synchronous coordinate system), and the calculation process is as follows:

the transformation matrix is:

then the observed values of the fundamental back electromotive force and the harmonic back electromotive force in the dq synchronous coordinate system are:

and obtaining a fundamental wave back electromotive force observation value and a harmonic wave back electromotive force observation value under the dq synchronous coordinate system, and suppressing and controlling the torque harmonic wave of the motor according to the fundamental wave back electromotive force observation value and the harmonic wave back electromotive force observation value.

Further, a normalized phase-locked loop module may be designed, the motor rotor position signal is solved according to the extracted fundamental wave back electromotive force, and a block diagram of the extraction module of the normalized phase-locked loop is shown in fig. 11.

Example 6:

fig. 6 shows a flowchart of a control method of a motor according to a sixth embodiment of the present invention.

As shown in fig. 6, a control method for a motor according to a sixth embodiment of the present invention includes the following steps:

step 602: sampling a current value and a voltage value of the motor;

step 604: establishing a counter electromotive force observation model of the motor according to the current value and the voltage value obtained by sampling;

step 606: acquiring a current value and a voltage value of the motor;

step 608: substituting the current value and the voltage value into a counter electromotive force observation model;

step 610: extracting fundamental wave back electromotive force and harmonic back electromotive force output by a back electromotive force observation model through a frequency selection module;

step 612: determining a rotor position signal of the motor according to the fundamental wave back electromotive force;

step 614: obtaining a fundamental wave back electromotive force observation value and a harmonic wave back electromotive force observation value under a rectangular-to-orthogonal axis coordinate system according to the fundamental wave back electromotive force, the harmonic wave back electromotive force and the rotor position signal;

step 616: and compensating the orthogonal axis voltage vector output by the current regulator according to the fundamental wave counter electromotive force observed value and the harmonic counter electromotive force observed value.

Specifically, fundamental back electromotive force and harmonic back electromotive force observed values in a dq synchronous coordinate system are obtained and compensated to a dq axis voltage vector output by a current regulator, and motor torque harmonic suppression and motor control are performed.

Is represented as follows:

specifically, as shown in fig. 12, after the control method of the motor provided by the invention is adopted, the current waveform of the motor is smooth, and the vibration and the noise of the rotor are further suppressed.

As shown in fig. 13, compared with the control method of the compressor in the related art, the control method of the compressor provided by the present invention has a dark color, which is the OA value of the noise generated after the control of the compressor by the control method of the compressor provided by the present invention, and obviously, the corresponding frequency is due to the noise of the compressor in the related art.

Specifically, at 250 hz, the present invention is 41.80 db, the correlation technique is 49.94 db, at 315 hz, the present invention is 34.22 db, the correlation technique is 33.71 db, at 400 hz, the present invention is 36.76 db, the correlation technique is 37.55 db, at 500 hz, the present invention is 39.32 db, the correlation technique is 40.60 db, at 630 hz, the present invention is 38.53 db, the correlation technique is 38.66 db, at 800 hz, the present invention is 38.86 db, the correlation technique is 40.60 db, at 1000 hz, the present invention is 38.13 db, the correlation technique is 38.80 db, at 1250 hz, the present invention is 40.84 db, the correlation technique is 39.94 db, at 4600 hz, the present invention is 38.34 db, and the correlation technique is 38.61 db. It can be seen that the noise reduction effect of the present invention is superior to that of the prior art in most frequencies.

Example 7:

fig. 7 is a flowchart illustrating a control method of a motor according to a seventh embodiment of the present invention.

As shown in fig. 7, a seventh embodiment of the present invention provides a method for controlling a motor, which includes the following steps:

step 702: acquiring a current signal and a voltage signal;

step 704: establishing a motor back electromotive force observation model;

step 706: observing the back electromotive force of the motor;

step 708: extracting fundamental wave back electromotive force and harmonic wave back electromotive force of the motor respectively;

step 710: solving a motor rotor position signal according to the extracted fundamental wave back electromotive force;

step 712: and carrying out suppression control on the motor torque harmonic according to the extracted fundamental wave counter electromotive force and harmonic counter electromotive force.

In this embodiment, step 702: a current signal and a voltage signal are acquired.

Specifically, the current value and the voltage value of the current motor are obtained in real time by using the MCU, specifically, the phase current value and the phase voltage value of the current motor are obtained through real-time sampling, and the obtained voltage value and current value are subjected to filtering pretreatment to filter high-frequency noise signals. Wherein the three-phase current values for the motor satisfy the relationship of adding and being equal to zero, so that the third phase current value can be calculated by obtaining any two-phase current value.

Step 704: and establishing a motor back electromotive force observation model.

Specifically, a motor back electromotive force observation model is established according to a voltage current equation of the motor and the current motor phase current value and the current phase voltage value obtained through sampling.

The voltage and current equation under the stator reference coordinate system is mainly considered, so that the influence of quadrature-direct axis coupling and speed signal coupling can be avoided, and high dynamic response and high stability can be realized.

Meanwhile, considering the influence of the saliency of the motor, and by using the principle of effective magnetic flux for reference, an observation model of the expanded back electromotive force of the motor is established as follows:

wherein the content of the first and second substances,

andrepresenting the observed value of the amplitude of the fundamental current of the stator coordinate, omega representing the electronic rotating speed of the motor,andrepresenting stator coordinates nth harmonic current magnitude observations,

v_α＝v_α1cos(ωt+θ_α1)+v_α5cos(5ωt+θ_α5)+v_α7cos(7ωt+θ_α7)+…+v_αncos(nωt+θ_αn) (the formula 21) is shown,

v_β＝v_β1cos(ωt+θ_β1)+v_β5cos(5ωt+θ_β5)+v_β7cos(7ωt+θ_β7)+…+v_βncos(nωt+θ_βn) (equation 22) of the above-mentioned formula,

wherein v is_α1And v_β1Representing the fundamental voltage amplitude, v, of the stator coordinates_α1And v_β1Representing the stator coordinates nth harmonic voltage magnitude,

k represents a sliding mode control gain, z_αAnd z_βRepresenting the observed back emf signal.

Step 706: and (5) observing the back electromotive force of the motor.

Specifically, according to the obtained phase current value and phase voltage value of the current motor, coordinate transformation is carried out to obtain a stator coordinate current value i of the current control period_αAnd i_βAnd a voltage value v_αAnd v_βDiscretizing the observation equation of the formula 1 to obtain,

is calculated to obtain z_α(k-1) and z_βThe time value of (k-1).

Wherein z is_αAnd z_βThe method comprises the motor back electromotive force observed value to be extracted, specifically comprises a fundamental wave back electromotive force observed value and an observed value of each subharmonic back electromotive force, and further comprises a noise signal and a sliding mode control switch signal, specifically as follows,

wherein the content of the first and second substances,andfundamental back emf magnitude observations representing stator coordinates,andobserved value of the amplitude of the back electromotive force of the nth harmonic wave representing the coordinates of the stator, N_αhAnd N_βhRepresenting other noise signals and sliding mode control switching signals.

Step 708: fundamental wave back electromotive force and harmonic wave back electromotive force of the motor are respectively extracted.

Specifically, a counter electromotive force signal self-adaptive frequency selection group module is designed to respectively carry out self-adaptive frequency selection on fundamental counter electromotive force signals and harmonic counter electromotive force signals of the motor, and required fundamental counter electromotive force signals of the motor are extractedAndand harmonic back electromotive force signals of each orderAnd

step 710: and solving a motor rotor position signal according to the extracted fundamental wave back electromotive force.

In particular, based on the fundamental back electromotive force signalAndthe fundamental wave back electromotive force signal can be obtained by combining with the motor expansion back electromotive force calculation formula, as follows,

wherein E is_ebemf1Representing the fundamental extended back emf assignments,and the observation error representing the position angle of the rotor is obtained by the following steps that when the constructed counter electromotive force observation system enters a convergence state,approaching zero.

By extracting the back electromotive force signal of the motor fundamental waveAndthe motor rotor position signal can be obtained by performing trigonometric operation or a phase-locked loop module

Step 712: and carrying out suppression control on the motor torque harmonic according to the extracted fundamental wave counter electromotive force and harmonic counter electromotive force.

Specifically, the back electromotive force signal of the motor fundamental wave is obtained according to the extractionAndand harmonic back electromotive force signals of each orderAnd

combining the extracted position signalsThe following coordinate transformation is carried out to obtain fundamental wave back electromotive force and harmonic wave back electromotive force observed values under an orthogonal synchronous coordinate system (namely dq synchronous coordinate system), and the calculation process is as follows:

the transformation matrix is:

then the observed values of the fundamental back electromotive force and the harmonic back electromotive force in the dq synchronous coordinate system are:

fundamental counter electromotive force and harmonic counter electromotive force observed values under a dq synchronous coordinate system are obtained and compensated to a dq axis voltage vector output by a current regulator, and motor torque harmonic suppression and motor control are performed.

Is represented as follows:

example 8:

fig. 8 is a flowchart illustrating a control method of a motor according to an eighth embodiment of the present invention.

As shown in fig. 8, a control method for a motor according to an eighth embodiment of the present invention includes the following steps:

step 802: acquiring a current signal and a voltage signal;

step 804: establishing a motor back electromotive force observation model;

step 806: observing the back electromotive force of the motor;

step 808: designing a counter electromotive force frequency selector module, and respectively extracting fundamental counter electromotive force and harmonic counter electromotive force of the motor;

step 810: designing a normalized locking collar module, and solving a motor rotor position signal according to the extracted fundamental wave back electromotive force;

step 812: carrying out suppression control on motor torque harmonics according to the extracted fundamental counter electromotive force and harmonic counter electromotive force;

step 814: self-adaptive motor torque harmonic suppression and motor variable frequency drive control.

In this embodiment, step 802: a current signal and a voltage signal are acquired.

Specifically, the current value and the voltage value of the current motor are obtained in real time by using the MCU, specifically, the phase current value and the phase voltage value of the current motor are obtained through real-time sampling, and the obtained voltage value and current value are subjected to filtering pretreatment to filter high-frequency noise signals. Wherein the three-phase current values for the motor satisfy the relationship of adding and being equal to zero, so that the third phase current value can be calculated by obtaining any two-phase current value.

Step 804: and establishing a motor back electromotive force observation model.

Specifically, a motor counter electromotive force observation model is established according to a voltage current equation of the motor and the current motor phase current value and the current phase voltage value obtained through sampling.

The voltage and current equation under the stator reference coordinate system is mainly considered, so that the influence of quadrature-direct axis coupling and speed signal coupling can be avoided, and high dynamic response and high stability can be realized.

Meanwhile, considering the influence of the saliency of the motor, and by using the principle of effective magnetic flux for reference, an observation model of the expanded back electromotive force of the motor is established as follows:

wherein the content of the first and second substances,

andrepresenting the observed value of the amplitude of the fundamental current of the stator coordinate, omega representing the electronic rotating speed of the motor,andrepresenting stator coordinates nth harmonic current magnitude observations,

v_α＝v_α1cos(ωt+θ_α1)+v_α5cos(5ωt+θ_α5)+v_α7cos(7ωt+θ_α7)+…+v_αncos(nωt+θ_αn) (equation 37) of the above-mentioned formula,

v_β＝v_β1cos(ωt+θ_β1)+v_β5cos(5ωt+θ_β5)+v_β7cos(7ωt+θ_β7)+…+v_βncos(nωt+θ_βn) (the formula 38),

wherein v is_α1And v_β1Representing the fundamental voltage amplitude, v, of the stator coordinates_α1And v_β1Representing the stator coordinates nth harmonic voltage magnitude,

k represents a sliding mode control gain, z_αAnd z_βRepresenting the observed back emf signal.

Step 806: and (5) observing the back electromotive force of the motor.

Specifically, according to the obtained phase current value and phase voltage value of the current motor, coordinate transformation is carried out to obtain a stator coordinate current value i of the current control period_αAnd i_βAnd a voltage value v_αAnd v_βDiscretizing the observation equation of the formula 1 to obtain,

is calculated to obtain z_α(k-1) and z_βThe time value of (k-1).

Wherein z is_αAnd z_βThe method comprises the motor back electromotive force observed value to be extracted, specifically comprises a fundamental wave back electromotive force observed value and an observed value of each subharmonic back electromotive force, and further comprises a noise signal and a sliding mode control switch signal, specifically as follows,

wherein the content of the first and second substances,andfundamental back emf magnitude observations representing stator coordinates,andobserved value of the amplitude of the back electromotive force of the nth harmonic wave representing the coordinates of the stator, N_αhAnd N_βhRepresenting other noise signals and sliding mode control switching signals.

Step 808: and designing a counter electromotive force frequency selector module to respectively extract fundamental counter electromotive force and harmonic counter electromotive force of the motor.

Specifically, a counter electromotive force signal self-adaptive frequency selection group module is designed to respectively carry out self-adaptive frequency selection on fundamental counter electromotive force signals and harmonic counter electromotive force signals of the motor, and required fundamental counter electromotive force signals of the motor are extractedAndand harmonic back electromotive force signals of each orderAnd

the design principle of the self-adaptive frequency selector bank module is as follows:

the traditional low-pass filter takes zero frequency as central frequency, unit gain and zero phase delay are ensured at the central frequency, if the central frequency is translated to fundamental frequency, the unit gain and the zero phase delay of the frequency point signal can be realized, the unit gain and the zero phase delay of fundamental back electromotive force can be ensured, and the accurate self-adaptive extraction of the frequency point signal can be realized. Similar frequency selector module composed of multiple back electromotive force harmonic frequency selectors connected in parallel can realize self-adaptive frequency selection of fundamental wave back electromotive force signals and harmonic back electromotive force signals of the motor.

According to this design principle, the transfer function of the adaptive frequency selector is designed as follows:

wherein, ω is₀Representing the centre frequency, omega, after translation_cRepresenting the frequency selector cut-off frequency. Where omega is applied for self-adaptive frequency selection of fundamental back electromotive force signals and harmonic back electromotive force signals of motors₀Set to the adaptive frequency, i.e. the centre frequency is equal to the fundamental frequency and the corresponding harmonic frequency, ω_c＝k×ω₀And setting a proper frequency selector bandwidth, wherein the proper frequency selector bandwidth ensures accurate extraction of frequency selection signals on one hand, and gives consideration to the dynamic response of a system and the filtering of other frequency signals on the other hand.

According to the above design principle, the designed adaptive frequency selector bank module can realize the separation and extraction of fundamental wave back electromotive force and harmonic back electromotive force of the motor through the designed adaptive frequency selector bank module, such as the system function block diagram shown in fig. 9 and the system amplitude-frequency response curve shown in fig. 10.

Step 810: and designing a normalized locking collar module, and solving a motor rotor position signal according to the extracted fundamental wave back electromotive force.

In particular, based on the fundamental back electromotive force signalAndthe fundamental wave back electromotive force signal can be obtained by combining with the motor expansion back electromotive force calculation formula, as follows,

wherein E is_ebemf1Representing the fundamental extended back emf assignments,and the observation error representing the position angle of the rotor is obtained by the following steps that when the constructed counter electromotive force observation system enters a convergence state,approaching zero.

A normalized phase-locked loop module can be designed, the motor rotor position signal is solved according to the extracted fundamental wave back electromotive force, and a block diagram of the extraction module of the normalized phase-locked loop is shown in fig. 11. By extracting the back electromotive force signal of the motor fundamental waveAndthe motor rotor position signal can be obtained by performing trigonometric operation or a phase-locked loop module

Step 812: and carrying out suppression control on the motor torque harmonic according to the extracted fundamental wave counter electromotive force and harmonic counter electromotive force.

Specifically, the back electromotive force signal of the motor fundamental wave is obtained according to the extractionAndand harmonic back electromotive force signals of each orderAnd

combining the extracted position signalsThe following coordinate transformation is carried out to obtain fundamental wave back electromotive force and harmonic wave back electromotive force observed values under an orthogonal synchronous coordinate system (namely dq synchronous coordinate system), and the calculation process is as follows:

the transformation matrix is:

then the observed values of the fundamental back electromotive force and the harmonic back electromotive force in the dq synchronous coordinate system are:

fundamental counter electromotive force and harmonic counter electromotive force observed values under a dq synchronous coordinate system are obtained and compensated to a dq axis voltage vector output by a current regulator, and motor torque harmonic suppression and motor control are performed.

Is represented as follows:

step 814: self-adaptive motor torque harmonic suppression and motor variable frequency drive control.

Specifically, according to the above designed adaptive motor torque harmonic suppression method, device and control system, the variable frequency drive control of the motor is performed, and it can be verified that the adaptive motor torque harmonic suppression method of the present invention can realize the compensation and effective suppression of the motor torque harmonic, and obviously improve the vibration and noise problems of the motor system through the comparison graph of the current waveform of the motor provided by the present invention in fig. 10 and the control method of the motor in the related art, and the comparison graph of the noise OA value of the motor provided by the present invention in fig. 11 and the control method of the motor in the related art.

Example 9:

according to a second aspect of the present invention, there is provided a control device of a motor, comprising: a memory having a program or instructions stored thereon; a processor configured to implement the control method of the motor as provided in any of the above embodiments when executing a program or instructions.

The control device for the motor provided by the present invention includes a memory and a processor, and when the program or the instructions in the memory are executed by the processor, the control method for the motor according to any of the above embodiments is implemented.

Example 10:

on the basis of embodiment 9, further, the method further comprises: and the frequency selector is connected with the processor.

In this embodiment, the control device of the motor further includes: the frequency selector is used for being matched with the processor to execute the control method of the motor provided by any one of the above embodiments.

Example 11:

according to a third aspect of the present invention, there is provided a compressor comprising: a motor; and a control device for a motor as provided in any of the above embodiments.

The compressor provided by the invention comprises the control device of the motor provided by any embodiment, so that all the beneficial effects of the control device of the motor provided by any embodiment are achieved, and the description is omitted.

Example 12:

according to a fourth aspect of the present invention, there is provided a refrigeration apparatus comprising: a compressor as in any one of the above embodiments.

The refrigeration equipment provided by the invention comprises the compressor provided by any embodiment, so that all the advantages of the compressor provided by any embodiment are achieved, and the description is omitted.

Example 13:

according to a fifth aspect of the present invention, there is provided a readable storage medium having stored thereon a program or instructions which, when executed by a processor, implement a method of controlling a motor as provided in any of the embodiments described above.

The readable storage medium provided by the present invention stores a program or instructions for implementing the method for controlling a motor according to any of the above embodiments when the readable storage medium is executed by a processor, so that all the advantages of the method for controlling a motor according to any of the above embodiments are achieved, and thus, the description thereof is omitted here.

In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; the term "plurality" means two or more unless expressly limited otherwise. The terms "mounted," "connected," "fixed," and the like are to be construed broadly, and for example, "connected" may be a fixed connection, a removable connection, or an integral connection; "coupled" may be direct or indirect through an intermediary. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "left", "right", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or unit must have a specific direction, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.