阅读说明：本技术 电机设备及抑制永磁同步电机稳态转速脉动的系统和方法 (Motor equipment and system and method for inhibiting steady-state rotating speed pulsation of permanent magnet synchronous motor ) 是由 王宇 沈文 王二峰 吴轩钦 于 2020-05-20 设计创作，主要内容包括：本申请公开了一种抑制永磁同步电机稳态转速脉动的系统,包括：永磁同步电机控制系统主体；信号调理模块,用于接收电流反馈信号并提取出位置跟踪误差信号ε(Δθ)；观测模块,用于根据接收的输入信号ε′(Δθ)输出位置反馈信号<Image he="84" wi="54" file="DDA0002500158670000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>以及转速反馈信号<Image he="74" wi="92" file="DDA0002500158670000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>以使永磁同步电机控制系统主体根据位置反馈信号<Image he="83" wi="54" file="DDA0002500158670000013.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>以及转速反馈信号<Image he="73" wi="64" file="DDA0002500158670000014.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>进行永磁同步电机的闭环反馈控制；脉动补偿模块,用于基于观测模块的输出信号,构建出针对第n次谐波的补偿信号ε<Sup>cn</Sup>(Δθ),以抵消位置跟踪误差信号ε(Δθ)中包含的第n次谐波,其中,ε′(Δθ)＝ε(Δθ)-ε<Sup>cn</Sup>(Δθ)。应用本申请的方案,可以对永磁同步电机稳态转速脉动进行有效的抑制。本申请还提供了一种电机设备及抑制永磁同步电机稳态转速脉动的方法,具有相应效果。(The application discloses system for restraining permanent magnet synchronous motor steady state rotational speed pulsation includes: a permanent magnet synchronous motor control system main body; the signal conditioning module is used for receiving the current feedback signal and extracting a position tracking error signal (delta theta); an observation module for outputting a position feedback signal based on the received input signal' (Δ θ) And a rotational speed feedback signal So that the main body of the permanent magnet synchronous motor control system feeds back signals according to the position And a rotational speed feedback signal Carrying out closed-loop feedback control on the permanent magnet synchronous motor; a ripple compensation module for constructing a compensation signal for the nth harmonic based on the output signal of the observation module cn (Δ θ) to cancel an nth harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) - cn (Δ θ). By applying the scheme of the application, the steady-state rotating speed pulsation of the permanent magnet synchronous motor can be effectively inhibited. The application also provides motor equipment and a method for inhibiting the steady-state rotating speed pulsation of the permanent magnet synchronous motor, and the motor equipment and the method have corresponding effects.)

1. A system for restraining the steady-state rotation speed pulsation of a permanent magnet synchronous motor is characterized by comprising

A permanent magnet synchronous motor control system main body;

a signal conditioning observer, and the signal conditioning observer comprises:

the signal conditioning module is used for receiving the current feedback signal and extracting a position tracking error signal (delta theta);

an observation module for outputting a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the PMSM control system main body feeds back signals according to the positionAnd the rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

a ripple compensation module for constructing a compensation signal for the nth harmonic based on the output signal of the observation module^cn(Δ θ) to cancel an nth order harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

2. The system for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to claim 1, wherein the ripple compensation module comprises:

a harmonic amplitude extraction unit for extracting a harmonic amplitude K of the nth harmonic from the output signal based on the output signal of the observation module_n；

An integral adjustment unit for adjusting the harmonic amplitude K_nAdjusting to obtain the output K of the integral adjusting unit_cps(ii) a So that K is output after adjustment_cpsIs equal to the position tracking error signal (Delta theta)) The harmonic amplitude of the nth harmonic in (a);

an output unit for connectingAs said compensation signal^cn(Δ θ) outputting; wherein the content of the first and second substances,an angular frequency of the input to the observation module isAnd a harmonic signal of the same angular frequency output by the observation module.

3. The system for suppressing the steady-state rotating speed pulsation of the PMSM according to claim 2, wherein the observation module is an observation module consisting of a PI (proportional integral) link and an integration link, and the input signal to the output position feedback signal of the observation moduleThe transfer function of (d) is expressed as:where s is a complex frequency domain operator, ω_nIs the bandwidth of the observation module; and is For a given speed signal.

4. The system for suppressing the steady-state rotating speed pulsation of the permanent magnet synchronous motor according to claim 2, wherein the harmonic amplitude extraction unit is specifically configured to:

the position feedback signal output by the observation moduleSubtracting the fundamental componentComparing the obtained difference withAfter multiplying, inputting the multiplied signals to a low-pass filtering link to extract the position feedback signalsHarmonic amplitude K of the nth harmonic comprised therein_nWherein, in the step (A),for a given speed signal.

5. The system for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to any one of claims 1 to 4, further comprising:

a compensation trigger decision module for judging whether the permanent magnet synchronous motor is in a steady-state operation stage, if so, allowing the pulsation compensation module to output the compensation signal^cn(delta theta), if not, the compensation signal output by the pulsation compensation module is output^cn(Δ θ) was adjusted to 0.

6. The system for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to claim 5, wherein the compensation trigger decision module is specifically configured to:

when it is judged thatWhen the set-up duration is greater than or equal to a preset first time threshold, determining that the permanent magnet synchronous motor is in steady-state operationA line phase and allowing the ripple compensation module to output the compensation signal^cn(Δθ)；

When it is judged thatFail to stand or determineWhen the duration of the establishment is less than the first time threshold, determining that the permanent magnet synchronous motor is not in a steady-state operation stage, and outputting a compensation signal output by the pulse compensation module^cn(Δ θ) was adjusted to 0.

7. The system for suppressing steady-state rotational speed ripple of a PMSM according to claim 1, wherein the ripple compensation module constructs a compensation signal^cn(Δ θ) is the first compensation signal for the 1 st harmonic^c1(Δθ)；

Further comprising:

a second ripple compensation module for constructing a second compensation signal for the 2 nd harmonic based on the output signal of the observation module^c2(Δ θ) to cancel a 2 nd order harmonic contained in the position tracking error signal (Δ θ);

a third ripple compensation module for constructing a third compensation signal for the 6 th harmonic based on the output signal of the observation module^c6(Δ θ) to cancel a 6 th harmonic contained in the position tracking error signal (Δ θ);

wherein ([ Delta ] theta) -^c1(Δθ)-^c2(Δθ)-^c6(Δθ)。

8. A method for restraining the steady-state rotation speed pulsation of a permanent magnet synchronous motor is characterized by comprising

A permanent magnet synchronous motor control system main body;

a signal conditioning observer, and the signal conditioning observer comprises:

the signal conditioning module receives the current feedback signal and extracts a position tracking error signal (delta theta);

the observation module outputs a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the PMSM control system main body feeds back signals according to the positionAnd the rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

the pulsation compensation module constructs a compensation signal aiming at the nth harmonic wave based on the output signal of the observation module^cn(Δ θ) to cancel an nth order harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

9. The method for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to claim 8, further comprising:

the compensation triggering decision module judges whether the permanent magnet synchronous motor is in a steady-state operation stage, and if so, the pulsation compensation module is allowed to output the compensation signal^cn(delta theta), if not, the compensation signal output by the pulsation compensation module is output^cn(Δ θ) was adjusted to 0.

10. An electrical machine arrangement, characterized by comprising a system for suppressing steady state speed ripple of a permanent magnet synchronous machine according to any of claims 1 to 7.

Technical Field

The invention relates to the technical field of automatic control, in particular to a motor device and a system and a method for inhibiting steady-state rotating speed pulsation of a permanent magnet synchronous motor.

Background

The permanent magnet synchronous motor is widely applied to various industrial occasions due to the advantages of large torque density and high energy efficiency, and particularly, the motor is generally required to have the capacity of large torque output at low speed in the occasions of wire drawing machines, injection molding machines, hoisting and lifting and the like. To meet such a requirement, the motor must maintain a relatively precise orientation of the rotor field during operation. In consideration of system cost and reliability, a non-inductive vector observer is often selected to replace a position sensor with high cost in a practical scheme to acquire the rotor position information.

When the permanent magnet synchronous motor runs at a low speed, a non-inductive vector control algorithm based on high-frequency voltage injection is usually selected, and compared with a back electromotive force detection algorithm, the non-inductive vector control algorithm has a higher signal-to-noise ratio, can estimate the position of a rotor magnetic field more reliably, and achieves a better control effect on the rotating speed and the torque. For example, fig. 1 is a block diagram of a commonly-used non-inductive vector control structure of a permanent magnet synchronous motor based on high-frequency voltage injection.

In the high frequency injection algorithm, the input to the observer is a position tracking error signal extracted from the high frequency current response. During the operation of the motor, 1 st, 2 nd and 6 th harmonics are generated in an input signal of an observer respectively due to zero drift of current sampling, gain error and dead zone effect of an inverter, and after the harmonics are amplified by a closed-loop observer, a rotating speed observation error and a position observation error in the form of harmonics are generated and are superposed into feedback signals of rotating speed and position, so that low-frequency pulsation of rotating speed response is generated.

For the problem of the low-frequency ripple, some hardware methods can be used to effectively solve, for example, an operational amplifier and an analog-to-digital converter with high precision and low temperature drift are used to reduce the current sampling error, and the driving pulse is corrected according to the measured value of the three-phase output voltage to suppress the dead zone effect. In the other scheme, a method based on current harmonic detection is adopted to carry out online correction on a current sampling value or online compensation on command stator voltage, so that the method is only suitable for fundamental wave current control of non-high frequency voltage injection although the steady-state rotating speed pulsation of the motor can be suppressed and the parameter information of the motor is not required.

In summary, how to effectively suppress the steady-state rotation speed pulsation of the permanent magnet synchronous motor is a technical problem that needs to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide motor equipment and a system and a method for inhibiting steady-state rotating speed pulsation of a permanent magnet synchronous motor, so as to effectively inhibit the steady-state rotating speed pulsation of the permanent magnet synchronous motor.

In order to solve the technical problems, the invention provides the following technical scheme:

a system for suppressing the steady-state rotation speed pulsation of permanent-magnet synchronous motor includes

A permanent magnet synchronous motor control system main body;

a signal conditioning observer, and the signal conditioning observer comprises:

the signal conditioning module is used for receiving the current feedback signal and extracting a position tracking error signal (delta theta);

an observation module for outputting a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the PMSM control system main body feeds back signals according to the positionAnd the rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

a ripple compensation module for constructing a compensation signal for the nth harmonic based on the output signal of the observation module^cn(Δ θ) to cancel an nth order harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

Preferably, the ripple compensation module includes:

a harmonic amplitude extraction unit for extracting a harmonic amplitude K of the nth harmonic from the output signal based on the output signal of the observation module_n；

An integral adjustment unit for adjusting the harmonic amplitude K_nAdjusting to obtain the output K of the integral adjusting unit_cps(ii) a So that K is output after adjustment_cpsA harmonic amplitude equal to the nth harmonic in the position tracking error signal (Δ θ);

an output unit for connectingAs said compensation signal^cn(Δ θ) outputting; wherein the content of the first and second substances,an angular frequency of the input to the observation module isAnd a harmonic signal of the same angular frequency output by the observation module.

Preferably, the observation module is an observation module composed of a PI element and an integration element, and the input signal to the output position feedback signal of the observation moduleThe transfer function of (d) is expressed as:where s is a complex frequency domain operator, ω_nIs the bandwidth of the observation module; and is For a given speed signal.

Preferably, the harmonic amplitude extraction unit is specifically configured to:

the position feedback signal output by the observation moduleSubtracting the fundamental componentComparing the obtained difference withAfter multiplying, inputting the multiplied signals to a low-pass filtering link to extract the position feedback signalsHarmonic amplitude K of the nth harmonic comprised therein_nWherein, in the step (A),for a given speed signal.

Preferably, the method further comprises the following steps:

a compensation trigger decision module for judging whether the permanent magnet synchronous motor is in a steady-state operation stage, if so, allowing the pulsation compensation module to output the compensation signal^cn(delta theta), if not, the compensation signal output by the pulsation compensation module is output^cn(Δ θ) was adjusted to 0.

Preferably, the compensation trigger decision module is specifically configured to:

when it is judged thatWhen the condition is satisfied and the satisfied duration is greater than or equal to a preset first time threshold, determining that the permanent magnet synchronous motor is in a steady-state operation stage, and allowing the pulse compensation module to output the compensation signal^cn(Δθ)；

When it is judged thatFail to stand or determineWhen the duration of the establishment is less than the first time threshold, determining that the permanent magnet synchronous motor is not in a steady-state operation stage, and outputting a compensation signal output by the pulse compensation module^cn(Δ θ) was adjusted to 0.

Preferably, the compensation signal constructed by the ripple compensation module^cn(Δ θ) is the first compensation signal for the 1 st harmonic^c1(Δθ)；

Further comprising:

a second ripple compensation module for constructing a second compensation signal for the 2 nd harmonic based on the output signal of the observation module^c2(Δ θ) to cancel a 2 nd order harmonic contained in the position tracking error signal (Δ θ);

a third ripple compensation module for constructing a third compensation signal for the 6 th harmonic based on the output signal of the observation module^c6(Δ θ) to cancel a 6 th harmonic contained in the position tracking error signal (Δ θ);

wherein ([ Delta ] theta) -^c1(Δθ)-^c2(Δθ)-^c6(Δθ)。

A method for suppressing the steady-state rotation speed pulsation of permanent-magnet synchronous motor includes

A permanent magnet synchronous motor control system main body;

a signal conditioning observer, and the signal conditioning observer comprises:

the signal conditioning module receives the current feedback signal and extracts a position tracking error signal (delta theta);

the observation module outputs a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the PMSM control system main body feeds back signals according to the positionAnd the rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

the pulsation compensation module constructs a compensation signal aiming at the nth harmonic wave based on the output signal of the observation module^cn(Δ θ) to cancel an nth order harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

Preferably, the method further comprises the following steps:

the compensation triggering decision module judges whether the permanent magnet synchronous motor is in a steady-state operation stage or not, and if so, allows the pulsationThe compensation module outputs the compensation signal^cn(delta theta), if not, the compensation signal output by the pulsation compensation module is output^cn(Δ θ) was adjusted to 0.

An electric machine apparatus comprising the system for suppressing steady-state rotation speed pulsation of a permanent magnet synchronous motor according to any one of the above.

By applying the technical scheme provided by the embodiment of the invention, the steady-state rotating speed pulsation of the permanent magnet synchronous motor is inhibited through signal compensation, so the implementation cost of the scheme is not increased, and the scheme can also be applied to the non-inductive vector control scheme of the permanent magnet synchronous motor based on high-frequency voltage injection. In the specific implementation of compensation, the ripple compensation module is arranged, and the output signal of the observation module contains harmonic information, so that a compensation signal for the nth harmonic can be constructed based on the output signal. That is, the ripple compensation module can construct a compensation signal for the nth harmonic based on the output signal of the observation module^cn(Δ θ) to cancel the nth harmonic contained in the position tracking error signal (Δ θ), and the compensated signal, i.e., the input signal of the observation module, can be represented as (Δ θ) — (Δ θ) -^cn(Δ θ). It can be seen that, because the input signal of the observation module is compensated according to the output signal of the observation module, the effective inhibition of the steady-state rotating speed pulsation of the permanent magnet synchronous motor is realized. In addition, the dynamic performance of observation can be improved, and the hardware cost cannot be greatly increased.

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 described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of a non-inductive vector control structure of a permanent magnet synchronous motor based on high-frequency voltage injection;

FIG. 2 is a schematic structural diagram of a system for suppressing steady-state rotational speed ripple of a PMSM according to the present invention;

fig. 3 is a schematic structural diagram of a system for suppressing steady-state rotational speed pulsation of a permanent magnet synchronous motor according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a ripple compensation module according to an embodiment of the present invention;

FIG. 5 is a graph comparing pre and post compensation effects in one embodiment of the present invention;

fig. 6 is a flowchart illustrating an implementation of a method for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to the present invention.

Detailed Description

The core of the invention is to provide a system for inhibiting the steady-state rotating speed pulsation of the permanent magnet synchronous motor, which can effectively inhibit the steady-state rotating speed pulsation of the permanent magnet synchronous motor.

In order that those skilled in the art will better understand the disclosure, the invention will be described in further detail with reference to the accompanying drawings and specific embodiments. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a system for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor according to the present invention, where the system for suppressing steady-state rotational speed ripple of a permanent magnet synchronous motor may include

A permanent magnet synchronous motor control system main body;

a signal conditioning observer, and the signal conditioning observer comprises:

a signal conditioning module 10, configured to receive the current feedback signal and extract a position tracking error signal (Δ θ);

an observation module 20 for outputting a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the main body of the permanent magnet synchronous motor control system feeds back signals according to the positionAnd a rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

a ripple compensation module 30 for constructing a compensation signal for the nth harmonic based on the output signal of the observation module 20^cn(Δ θ) to cancel an nth harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

The permanent magnet synchronous motor control system main body and the permanent magnet synchronous motor control system main body are not shown in fig. 2 and fig. 3 in the present application, which show the rest of the permanent magnet synchronous motor control system except for the signal conditioning observer, and the specific structure of the permanent magnet synchronous motor control system main body can refer to the existing relevant data, and the present application is not described again. For example, fig. 1 is a block diagram of a conventional high-frequency voltage injection-based non-inductive vector control structure of a permanent magnet synchronous motor, in which voltage pulse u_pulIs a high frequency quantity. However, it should be noted that, although the solution of the present application is particularly suitable for the non-inductive vector control based on the high-frequency voltage injection method, at the same time, the solution of the present application may also be applied to other non-inductive vector control based on the closed-loop observer, that is, the specific structure of the permanent magnet synchronous motor control system main body may be another type of structure than that shown in fig. 1.

The signal conditioning observer may be constituted by a signal conditioning module 10, an observation module 20 and a ripple compensation module 30.

The signal conditioning module 10 may receive the current feedback signal and extract the position tracking error signal (Δ θ), and the specific configuration of the signal conditioning module 10 may be set and adjusted according to the actual situation, which may refer to the existing related design.

For example, in one embodiment of FIG. 3, the current feedback signal received by signal conditioning module 10 is specifically current feedback signal i in the α - β coordinate system_α,βThe current feedback signal i under the dq coordinate system can be obtained through coordinate transformation_dm,qmIt is emphasized that in this embodiment of fig. 3, the current feedback signal i_dm,qmNot in the standard dq coordinate system but lags the d-axis by 45, i.e., by-pi/4 adjustment in the signal conditioning module 10 in fig. 3. Of course, in other embodiments, the d-axis may not be lagged, but a standard dq coordinate system may be selected, without affecting the implementation of the present invention, i.e., the solution of the present application may be selected from various existing designs of the signal conditioning module 10. After coordinate transformation, the high frequency content can be obtained by band-pass filteringFinally, the output quantity (Δ θ) of the signal conditioning module 10 can be obtained through signal demodulation, which represents the position tracking error signal.

The internal structure of the observation module 20 may also refer to the existing design, for example, a common structure is the scheme shown in fig. 3, the observation module 20 is the observation module 20 composed of a PI element and an integration element, and in the embodiment of fig. 3, the integration coefficient of the integration element is 1. Of course, in other specific cases, the internal structure of the observation module 20 may be adaptively adjusted according to actual needs.

In the conventional design, the output (Δ θ) of the signal conditioning module 10 is directly used as the input of the observation module 20, and in the solution of the present application, the (Δ θ) is compensated and then input to the observation module 20. That is, in the solution of the present application, the observation module 20 outputs the position feedback signal according to the received input signal' (Δ θ)And a rotational speed feedback signalSo that the main body of the permanent magnet synchronous motor control system feeds back signals according to the positionAnd a rotational speed feedback signalAnd carrying out closed-loop feedback control on the permanent magnet synchronous motor.

In the present application, it is considered that, since the observation module 20 has a definite transfer function, the harmonic in the input signal of the observation module 20 and the harmonic observation error wave included in the output signal of the observation module 20 have a definite amplitude relationship and phase relationship, and therefore, the present application considers that the harmonic information in the output signal of the observation module 20 is used to construct a corresponding compensation amount to compensate the input harmonic of the observation module 20.

Specifically, the ripple compensation module 30 is provided, and the ripple compensation module 30 may construct a compensation signal for the nth harmonic based on the output signal of the observation module 20^cn(Δ θ) to cancel an nth harmonic contained in the position tracking error signal (Δ θ), wherein (' (Δ θ) — (Δ θ) -^cn(Δθ)。

In general, the ripple compensation module 30 may be designed to be based on the position feedback signal output by the observation module 20Constructing a compensation signal for the nth harmonic^cn(Δ θ).

In one embodiment of the present invention, the ripple compensation module 30 may include:

a harmonic amplitude extraction unit for extracting the harmonic amplitude K of the nth harmonic from the output signal based on the output signal of the observation module 20_n；

Integral adjustment unit for adjusting harmonic amplitude K_nAdjusting to obtain the output K of the integral adjusting unit_cps(ii) a So that K is output after adjustment_cpsEqual to the position tracking error signal (Δ θ) harmonic amplitude of the nth harmonic;

an output unit for connectingAs compensation signals^cn(Δ θ) outputting; wherein the content of the first and second substances,the angular frequency input for the observation module 20 isAnd the harmonic signals of the same angular frequency output by the observation module 20.

The harmonic amplitude extraction unit needs to extract the harmonic amplitude K of the nth harmonic from the output signal based on the output signal of the observation module 20_nThe specific extraction manner of the harmonic amplitude extraction unit may be designed according to actual needs, for example, the specific implementation manner adopted in fig. 4 is a specific amplitude extraction manner, and specifically, in the implementation manner of fig. 4, the harmonic amplitude extraction unit is specifically configured to:

position feedback signal to be output by the observation module 20Subtracting the fundamental componentComparing the obtained difference withAfter multiplication, the signal is input to a low-pass filtering link to extract a position feedback signalHarmonic amplitude K of the nth harmonic comprised therein_nWherein, in the step (A),for a given speed signal.

Taking into account position feedback signalsOf the position feedback signalSubtracting the fundamental componentThen, the dc offset and the harmonic component of the nth harmonic can be obtained, and considering that only one harmonic component is usually obvious in the harmonic component of the nth harmonic, the formula can be expressed as follows:

it can be seen that in this equation, the DC offset K is listed₀And a harmonic component of the nth harmonic of the nth harmonicsn can be selected according to actual need, and this application can compensate for any one kind of harmonic in the n subharmonics as required promptly, of course, in practical application, n will select for a certain numerical value in 1, 2, 6 usually.

Will be provided withMultiplication, one can get:

it can be seen that the amplitude K of the nth harmonic component can be extracted through a low-pass filtering link_n. And it should be emphasized that, in order to avoid errors, the low-pass filtering section in the harmonic amplitude extraction unit should be selected to have a cut-off angular frequency far lower than that of the harmonic amplitude extraction unitThe low-pass filtering step of (1).

It is further noted that, as described above,in this equation, only the DC offset K is listed₀And a harmonic component of the nth harmonic of the nth harmonicsIt is considered that only a certain harmonic component is usually significant, i.e.,the condition for this equation is the position feedback signal output by the observation module 20Contains only harmonics of a single frequency. However, even the position feedback signalWhen 2 or more harmonics of different frequencies are contained simultaneously, i.e., even ifThe right side of the expression needs to increase the sinusoidal quantity of other frequencies besides the sinusoidal quantity of n, 2n times, and the extracted direct current quantity can still be the amplitude quantity K of the nth harmonic component through the set low-pass filtering link_n。

That is, the feedback signal is independent of positionThe position feedback signal contains several harmonic waves with different frequenciesSubtracting the fundamental componentThen the obtained difference is compared withAfter the multiplied signals are input to a low-pass filtering link, position feedback signals can be extractedHarmonic amplitude K of the nth harmonic comprised therein_n. Of course, as described above, the low-pass filtering element should be chosen to have a cut-off frequency far below the cut-off frequencyThe low-pass filtering step of (1).

The harmonic amplitude extraction unit extracts the harmonic amplitude K of the nth harmonic_nHowever, it cannot be based directly on K_nThe compensation signal is constructed because the harmonic amplitude K_nIs the harmonic amplitude K in the output signal of the observation module 20_nCompensation signal of the present application^cn(Δ θ) is a compensation for the input to the observation module 20, and therefore, a conversion of the amplitude is also required.

When amplitude conversion is performed, this embodiment is implemented by an integral adjustment unit, which may specifically adjust the harmonic amplitude K_nAdjusting to obtain the output K of the integral adjusting unit_cps(ii) a So that K is output after adjustment_cpsA harmonic amplitude equal to the nth harmonic in the position tracking error signal (Δ θ); i.e. K of the output of the integral regulating unit_cpsAn amplitude quantity is indicated, which should be equal to the harmonic amplitude of the nth harmonic in the tracking error signal (Δ θ).

It will be appreciated that the integral adjustment unit may adjust K_nWhen the value is 0 as the regulation target, according to the regulation rule of closed loop regulation, when K is_nWhen the value is 0, the compensation loop reaches a steady state, and at this time, the content of the nth harmonic in the signal output by the observation module 20 is 0, so that the corresponding motor rotation speed pulsation is eliminated. The integral coefficient Kc of the integral adjustment unit may then be based on realThe requirements for the pulsation suppression rate in the actual application are set appropriately.

Output K of integral regulating unit_cpsBased on the position feedback signal output by the observation module 20The amplitude of the nth harmonic in the input signal of the observation module 20, and thus K, is determined from the harmonic information in (a)_cpsMultiplication byA compensation signal can be determined^cn(Δ θ). I.e. the output unit canAs compensation signals^cn(Δ θ) is output.

Wherein the content of the first and second substances,the angular frequency input for the observation module 20 isAnd the harmonic signals of the same angular frequency output by the observation module 20.

The specific values of (a) may be influenced by the structure of the observation module 20. For example, when the observation module 20 has the structure of fig. 3, the observation module 20 is an observation module 20 composed of a PI element and an integration element, and the input signal to the output position feedback signal of the observation module 20The transfer function of (a) is a typical type II transfer function, which can be expressed as:where s is a complex frequency domain operator，ω_nIs the bandwidth of the observation module 20; then For a given speed signal.

Further, in an embodiment of the present invention, considering that the system for suppressing the steady-state rotation speed ripple of the permanent magnet synchronous motor described above in the present application is generally effective in the steady-state operation stage of the motor, therefore, in order to avoid the influence on the dynamic performance of the observation module 20, in an embodiment, the compensation may be enabled only in the steady-state operation.

That is, in this embodiment, the method may further include:

a compensation trigger decision module 40 for determining whether the PMSM is in a steady-state operation stage, and if so, allowing the ripple compensation module 30 to output a compensation signal^cn(Δ θ), if not, the compensation signal output by the ripple compensation module 30^cn(Δ θ) was adjusted to 0.

For example, in the embodiments of fig. 3 and 4, a design with a compensation trigger decision module 40 is used.

The manner of determining whether the permanent magnet synchronous motor is in the steady-state operation stage specifically adopted by the compensation trigger decision module 40 may be selected according to actual needs, for example, in an embodiment of the present invention, the compensation trigger decision module 40 may specifically be configured to:

when it is judged thatWhen the time duration is greater than or equal to the preset first time duration threshold, it is determined that the permanent magnet synchronous motor is in the steady-state operation stage, and the pulse compensation module 30 is allowed to output the compensation signal^cn(Δθ)；

When it is judged thatMake upImmediately, or judgeWhen the duration of the establishment is less than the first time threshold, determining that the permanent magnet synchronous motor is not in a steady-state operation stage, and outputting a compensation signal output by the pulse compensation module 30^cn(Δ θ) was adjusted to 0.

In fig. 3 and 4, when it is determined that the permanent magnet synchronous motor is in the steady-state operation stage, sw may be set to 1, and correspondingly, when it is determined that the permanent magnet synchronous motor is not in the steady-state operation stage, sw may be set to 0. The specific value of the first time threshold may also be set according to the actual situation, for example, may be set to 30 ms.

In addition, in the foregoing embodiments of the present application, the nth harmonic is taken as an example for explanation, that is, the foregoing embodiments describe compensation for a harmonic of a certain frequency, and n may be arbitrarily selected. In a few cases, there are cases where harmonics of two or more frequencies are present at the same time, for example, in actual operation of the motor, dead zone effects and current sampling errors may occur at the same time. For the case of two or more frequency harmonics, an alternative is to compensate the most significant harmonic, for example, in the operating range below 1Hz, the influence of the dead zone effect is significant, the rotation speed ripple is mainly embodied as 6-fold frequency ripple, and at this time, the number n of compensating harmonics may be set to 6. When the operating frequency is higher than 1Hz, the influence of the current sampling error is more obvious, the rotating speed pulsation is mainly reflected as one-time or two-time frequency pulsation, at the moment, the number n of compensating harmonic waves is set to be 1 or 2, and the number n can be specifically set according to the actual condition of a hardware platform.

Fig. 5 shows the comparison of the steady-state responses before and after compensation when the operating frequency of the motor is 0.5Hz, and it can be seen from the comparison result that the compensation scheme adopted by the invention can effectively suppress the rotation speed pulsation.

Further, 2 or more harmonics of different frequencies may be simultaneously compensated.

For example, in the present inventionIn one embodiment, the ripple compensation module 30 constructs a compensation signal^cn(Δ θ) is the first compensation signal for the 1 st harmonic^c1(Δθ)；

The method can also comprise the following steps:

a second ripple compensation module for constructing a second compensation signal for the 2 nd harmonic based on the output signal of the observation module 20^c2(Δ θ) to cancel out the 2 nd order harmonic contained in the position tracking error signal (Δ θ);

a third ripple compensation module for constructing a third compensation signal for the 6 th harmonic based on the output signal of the observation module 20^c6(Δ θ) to cancel out a 6 th harmonic contained in the position tracking error signal (Δ θ);

wherein ([ Delta ] theta) -^c1(Δθ)-^c2(Δθ)-^c6(Δθ)。

In this embodiment, 3 ripple compensation modules 30 are provided in parallel to compensate for the 1 st, 2 nd, and 6 th harmonics, respectively. It is to be understood that the specific structures of the second ripple compensation module 30 and the third ripple compensation module 30 in this embodiment may refer to the above description of the ripple compensation module 30, and a description thereof will not be repeated here. Because the 1 st harmonic, the 2 nd harmonic and the 6 th harmonic are compensated in the embodiment, the effect of inhibiting the steady-state rotating speed pulsation of the permanent magnet synchronous motor is further improved. The 1 st, 2 nd and 6 th harmonics are also the 3 highest in frequency of occurrence.

That is, when M kinds of harmonics need to be compensated, M parallel ripple compensation modules may be set, where M is a positive integer.

By applying the technical scheme provided by the embodiment of the invention, the steady-state rotating speed pulsation of the permanent magnet synchronous motor is inhibited through signal compensation, so the implementation cost of the scheme is not increased, and the scheme can also be applied to the non-inductive vector control scheme of the permanent magnet synchronous motor based on high-frequency voltage injection. In the present embodiment, the ripple compensation module 30 is provided to perform compensation, and the output signal of the observation module 20 contains harmonic information, so that the second target can be constructed based on the output signalCompensation signal of nth harmonic. That is, the ripple compensation module 30 may construct a compensation signal for the nth harmonic based on the output signal of the observation module 20^cn(Δ θ) to cancel the nth harmonic contained in the position tracking error signal (Δ θ), and the compensated signal, i.e., the input signal of the observation module 20, can be represented as (Δ θ) — (Δ θ) -^cn(Δ θ). It can be seen that, because the input signal of the observation module 20 is compensated according to the output signal of the observation module 20, the effective suppression of the steady-state rotating speed pulsation of the permanent magnet synchronous motor is realized. In addition, the dynamic performance of observation can be improved, and the hardware cost cannot be greatly increased.

Corresponding to the above system embodiments, the embodiments of the present invention further provide a method for suppressing steady-state rotation speed pulsation of a permanent magnet synchronous motor, which can be referred to in correspondence with the above. Referring to fig. 6, the method for suppressing the steady-state rotation speed ripple of the permanent magnet synchronous motor may include:

step S101: the signal conditioning module receives the current feedback signal and extracts a position tracking error signal (delta theta);

step S102: the observation module outputs a position feedback signal based on the received input signal' (Δ θ)And a rotational speed feedback signalSo that the main body of the permanent magnet synchronous motor control system feeds back signals according to the positionAnd a rotational speed feedback signalCarrying out closed-loop feedback control on the permanent magnet synchronous motor;

step S103: the ripple compensation module constructs a compensation signal aiming at the nth harmonic wave based on the output signal of the observation module^cn(Δ θ) to cancel out the nth time included in the position tracking error signal (Δ θ)Harmonics;

wherein ([ Delta ] theta) -^cn(Δθ)。

In an embodiment of the present invention, step S103 specifically includes:

the method comprises the following steps: the harmonic amplitude extraction unit extracts the harmonic amplitude K of the nth harmonic in the output signal based on the output signal of the observation module_n；

Step two: integral regulating unit pair harmonic amplitude K_nAdjusting to obtain the output K of the integral adjusting unit_cps(ii) a So that K is output after adjustment_cpsA harmonic amplitude equal to the nth harmonic in the position tracking error signal (Δ θ);

step three: the output unit is toAs compensation signals^cn(Δ θ) outputting; wherein the content of the first and second substances,the angular frequency input to the observation module isAnd the harmonic signal of the same angular frequency output by the observation module.

In an embodiment of the present invention, the observation module is an observation module consisting of a PI element and an integration element, and the input signal to the output position feedback signal of the observation moduleThe transfer function of (d) is expressed as:where s is a complex frequency domain operator, ω_nIs the bandwidth of the observation module; and is For a given speed signal.

In an embodiment of the present invention, the first step specifically includes:

the harmonic amplitude extraction unit feeds back the position feedback signal output by the observation moduleSubtracting the fundamental componentComparing the obtained difference withAfter multiplication, the signal is input to a low-pass filtering link to extract a position feedback signalHarmonic amplitude K of the nth harmonic comprised therein_nWherein, in the step (A),for a given speed signal.

In one embodiment of the present invention, the method further comprises:

the compensation triggering decision module judges whether the permanent magnet synchronous motor is in a steady-state operation stage, and if so, the pulse compensation module is allowed to output a compensation signal^cn(Delta theta), if not, the compensation signal output by the ripple compensation module^cn(Δ θ) was adjusted to 0.

In an embodiment of the invention, the compensation triggering decision module judges whether the permanent magnet synchronous motor is in a steady-state operation stage, and if so, the pulse compensation module is allowed to output the compensation signal^cn(Delta theta), if not, the compensation signal output by the ripple compensation module^cnThe (Δ θ) is adjusted to 0, and specifically includes:

when it is judged thatWhen the condition is satisfied and the duration of the establishment is greater than or equal to a preset first time threshold, determining that the permanent magnet synchronous motor is in a steady-state operation stage, and allowing the pulse compensation module to output a compensation signal^cn(Δθ)；

When it is judged thatFail to stand or determineWhen the duration of the establishment is less than the first time threshold, determining that the permanent magnet synchronous motor is not in a steady-state operation stage, and outputting a compensation signal output by the pulse compensation module^cn(Δ θ) was adjusted to 0.

In an embodiment of the invention, the compensation signal is constructed by a ripple compensation module^cn(Δ θ) is the first compensation signal for the 1 st harmonic^c1(Δθ)；

Further comprising:

the second ripple compensation module constructs a second compensation signal for the 2 nd harmonic based on the output signal of the observation module^c2(Δ θ) to cancel out the 2 nd order harmonic contained in the position tracking error signal (Δ θ);

the third ripple compensation module constructs a third compensation signal aiming at the 6 th harmonic wave based on the output signal of the observation module^c6(Δ θ) to cancel out a 6 th harmonic contained in the position tracking error signal (Δ θ);

wherein ([ Delta ] theta) -^c1(Δθ)-^c2(Δθ)-^c6(Δθ)。

Corresponding to the above method and system embodiments, the present invention further provides an electric machine apparatus, which may include the system for suppressing the steady-state rotation speed pulsation of the permanent magnet synchronous motor in any of the above embodiments, and reference may be made to the above in correspondence with each other, and a description thereof will not be repeated here.

It is further noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The principle and the implementation of the present invention are explained in the present application by using specific examples, and the above description of the embodiments is only used to help understanding the technical solution and the core idea of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.