Permanent magnet synchronous motor non-inductive control inductance online adjusting method

Abstract

The invention provides a permanent magnet synchronous motor non-inductive control inductance online adjustment method, and relates to the technical field of motor control, and the method comprises the steps: injecting a high-frequency sinusoidal signal into a permanent magnet synchronous motor, and extracting a high-frequency response amplitude; and according to the high-frequency response amplitude, inductance on-line adjustment is carried out on the permanent magnet synchronous motor. The method is rapid in adjustment and simple in calculation, can rapidly track the rotation speed and position changes of the motor rotor under different rotation speeds and loads, and effectively improves the control performance of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and is applied to online adjustment of inductance of a permanent magnet synchronous motor without sensor control based on high frequency injection correction, and specifically to an online adjustment method of inductance of a permanent magnet synchronous motor without sensor control. Background Art

[0002] Permanent magnet synchronous motor (PMSM) has the advantages of high power density, high efficiency, simple structure and wide speed range. It is increasingly valued in the fields of computer numerical control machine tools, elevator control and traction drive.

[0003] In practical applications, since the permanent magnet synchronous motor receives sinusoidal magnetic flux from the permanent magnets (PM) mounted on / in the rotor, it is necessary to obtain accurate rotor position and speed for normal control. Usually, the required information can be measured by position sensors. However, by using these additional position detection and signal processing devices, the cost is high and the mechanical robustness of the drive system is reduced. For this reason, sensorless control technology is now widely used. In sensorless control, changes in motor parameters such as stator resistance and stator inductance will bring deviations to the estimated back EMF, thereby reducing the accuracy of position estimation.

[0004] In the prior art, several existing methods for online inductance identification need to ignore position errors or establish a full-rank model or require a lot of convergence time, and there are problems such as complex calculations and cumbersome adjustment of design parameters.

[0005] In view of the problems in the prior art, the present invention provides an online adjustment method for the inductance of a permanent magnet synchronous motor without induction control. Summary of the invention

[0006] In view of the problems of the current prior art, the object of the present invention is to provide a method for online adjustment of the inductance of a permanent magnet synchronous motor with simple calculation and fast tracking.

[0007] The present invention provides a method for online adjustment of inductance of a permanent magnet synchronous motor without induction control, the method comprising the following steps:

[0008] Inject a high-frequency sinusoidal signal into the permanent magnet synchronous motor and extract the high-frequency response amplitude;

[0009] According to the high-frequency response amplitude, the inductance of the permanent magnet synchronous motor is adjusted online.

[0010] According to one embodiment of the present invention, the high frequency sinusoidal signal:

[0011] u′ d =U h cos(ωh t)

[0012] Where: u′ d is a high-frequency sinusoidal signal; U h is the voltage of the high-frequency sinusoidal signal; ω h is the angular frequency of the high-frequency sinusoidal signal; t is the time.

[0013] According to one embodiment of the present invention, the high frequency response amplitude is extracted by the following steps:

[0014] Inject the high-frequency sinusoidal signal into the d-axis of the permanent magnet synchronous motor, and use a second-order generalized integrator to obtain a high-frequency component of the back electromotive force observation value;

[0015] The sliding window is used to select the maximum high-frequency response amplitude of the high-frequency component of the back electromotive force observation value according to the period, and the maximum high-frequency response amplitude is used as the high-frequency response amplitude.

[0016] According to one embodiment of the present invention, the high frequency component of the back electromotive force observation value is:

[0017]

[0018] Where: is the high-frequency component of the back-electromotive force observation value; SOGI is a second-order generalized integrator; ω h ±ω e is the center frequency of the second-order generalized integrator; is the estimated value of the observed β-axis back EMF; is the amplitude of high-frequency component; t is time; is the phase of the fundamental wave.

[0019] According to one embodiment of the present invention, the maximum amplitude of the high frequency response is:

[0020]

[0021] Where: U t is the maximum amplitude of high frequency response; is the high-frequency component of the ti-th back-electromotive force observation value in the sliding window; n is the length of the sliding window.

[0022] According to one embodiment of the present invention, the inductance of the permanent magnet synchronous motor is adjusted online by the following steps:

[0023] Calculate the difference between the high-frequency response amplitude corresponding to the current cycle and the high-frequency response amplitude corresponding to the previous cycle, and record it as the high-frequency signal amplitude difference;

[0024] Based on the high-frequency signal amplitude difference, the inductance parameter value of the permanent magnet synchronous motor in this cycle is calculated through the inductance parameter value of the previous cycle to achieve online inductance adjustment.

[0025] According to one embodiment of the present invention, the high frequency signal amplitude difference is:

[0026] ΔU k =U k -U k-1

[0027] Where: ΔU k is the high frequency signal amplitude difference; U k is the high-frequency signal amplitude of this cycle, U k-1 is the high-frequency signal amplitude of the previous cycle.

[0028] According to one embodiment of the present invention, the inductance parameter value of the permanent magnet synchronous motor in this cycle is:

[0029] L k =L k-1 +α k sgn(▽f k )

[0030] Where: L k is the inductance parameter value of this cycle; L k-1 is the inductance parameter value of the previous cycle; α k is the adaptive step size; ▽f k is the gradient.

[0031] According to another aspect of the present invention, a storage medium is provided, which contains a series of instructions for executing the method steps as described in any one of the above.

[0032] According to another aspect of the present invention, there is also provided a permanent magnet synchronous motor sensorless control inductance online adjustment system, which executes the method as described in any one of the above items, and the system comprises:

[0033] An injection extraction module is used to inject a high-frequency sinusoidal signal into the permanent magnet synchronous motor and extract the high-frequency response amplitude;

[0034] An online adjustment module is used to perform online inductance adjustment on the permanent magnet synchronous motor according to the high-frequency response amplitude.

[0035] The present invention provides a method for online adjustment of inductance of a permanent magnet synchronous motor with inductive control. Compared with the prior art, the present invention has the following advantages: First, the present invention does not need to know the motor parameters and does not require additional circuits to adjust the inductance online. By constructing a SMO model, the inductance is adjusted through the relationship between the back electromotive force and the inductance parameters. Secondly, the present invention does not ignore the position error, but makes the motor position estimation more accurate by adjusting the inductance parameters. Finally, the present invention realizes online adjustment of the motor inductance by gradient descent with adaptive step size. The present invention has fast adjustment and simple calculation. It can quickly track the motor rotor speed and position changes at different speeds and loads, effectively improving the motor control performance.

[0036] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0038] Figure 1 A flowchart showing the steps of an online adjustment method for inductance of a permanent magnet synchronous motor with inductive control according to an embodiment of the present invention is shown;

[0039] Figure 2 A flowchart showing the steps of an online adjustment method for inductance of a permanent magnet synchronous motor with inductive control according to another embodiment of the present invention is shown;

[0040] Figure 3 A schematic diagram of an implementation principle according to an embodiment of the present invention is shown.

[0041] In the accompanying drawings, the same reference numerals are used for the same components. In addition, the accompanying drawings are not drawn according to the actual scale. DETAILED DESCRIPTION

[0042] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0043] Permanent magnet synchronous motor (PMSM) has the advantages of high power density, high efficiency, simple structure and wide speed range. It is increasingly valued in the fields of computer numerical control machine tools, elevator control and traction drive.

[0044] In practical applications, since the permanent magnet synchronous motor receives sinusoidal magnetic flux from the permanent magnets (PM) mounted on / in the rotor, it is necessary to obtain accurate rotor position and speed for normal control. Usually, the required information can be measured by position sensors. However, by using these additional position detection and signal processing devices, the cost is high and the mechanical robustness of the drive system is reduced. For this reason, sensorless control technology is now widely used. In sensorless control, changes in motor parameters such as stator resistance and stator inductance will bring deviations to the estimated back EMF, thereby reducing the accuracy of position estimation.

[0045] In the prior art, several existing methods for online inductance identification need to ignore position errors or establish a full-rank model or require a lot of convergence time, and there are problems such as complex calculations and cumbersome adjustment of design parameters.

[0046] In order to solve the defects of the above-mentioned prior art, the present invention proposes an online adjustment method for the inductance of a permanent magnet synchronous motor with inductive control based on high-frequency injection correction. The present invention can quickly track the changes in the motor rotor speed and position under different speeds and loads, obtain the PMSM inductance value, and effectively improve the rotor position estimation and motor control performance.

[0047] Figure 1 A flowchart of the steps of an online adjustment method for inductance of a permanent magnet synchronous motor with inductive control according to an embodiment of the present invention is shown.

[0048] like Figure 1 As shown, in step S11, a high-frequency sinusoidal signal is injected into the permanent magnet synchronous motor, and the high-frequency response amplitude is extracted.

[0049] In one embodiment, the high frequency sinusoidal signal:

[0050] u′ d =U h cos(ω h t)

[0051] Where: u′ d is a high-frequency sinusoidal signal; U h is the voltage of the high-frequency sinusoidal signal; ω h is the angular frequency of the high-frequency sinusoidal signal; t is the time.

[0052] In one embodiment, in step S11, the high-frequency response amplitude is extracted by the following steps: a high-frequency sinusoidal signal is injected into the d-axis of the permanent magnet synchronous motor, and a second-order generalized integrator is used to obtain the high-frequency component of the back-electromotive force observation value; through a sliding window, the high-frequency component of the back-electromotive force observation value is periodically selected to obtain the maximum high-frequency response amplitude as the high-frequency response amplitude.

[0053] Specifically, the high-frequency component of the back-EMF observation value is:

[0054]

[0055] Where: is the high-frequency component of the back-electromotive force observation value; SOGI is a second-order generalized integrator; ω h ±ω e is the center frequency of the second-order generalized integrator; is the estimated value of the observed β-axis back EMF; is the amplitude of high-frequency component; t is time; is the phase of the fundamental wave.

[0056] Specifically, the maximum amplitude of the high frequency response is:

[0057]

[0058] Where: U t is the maximum amplitude of the high frequency response; is the high-frequency component of the ti-th back-electromotive force observation value in the sliding window; n is the length of the sliding window.

[0059] like Figure 1 As shown, in step S12, the inductance of the permanent magnet synchronous motor is adjusted online according to the high-frequency response amplitude.

[0060] In one embodiment, in step S12, the inductance of the permanent magnet synchronous motor is adjusted online through the following steps: the difference between the high-frequency response amplitude corresponding to the current cycle and the high-frequency response amplitude corresponding to the previous cycle is calculated, and recorded as the high-frequency signal amplitude difference; based on the high-frequency signal amplitude difference, the inductance parameter value of the current cycle of the permanent magnet synchronous motor is calculated through the inductance parameter value of the previous cycle to achieve online inductance adjustment.

[0061] Specifically, the high frequency signal amplitude difference:

[0062] ΔU k =U k -U k-1

[0063] Where: ΔU k is the high frequency signal amplitude difference; U k is the high-frequency signal amplitude of this cycle, U k-1 is the high-frequency signal amplitude of the previous cycle.

[0064] Specifically, the inductance parameter value of the permanent magnet synchronous motor in this cycle is:

[0065] L k =L k-1 +α k sgn(▽f k )

[0066] Where: L k is the inductance parameter value of this cycle; L k-1 is the inductance parameter value of the previous cycle; α k is the adaptive step size; ▽f k is the gradient.

[0067] The present invention has fast adjustment and simple calculation, and can quickly track the speed and position changes of the motor rotor under different speeds and loads, thereby effectively improving the motor control performance.

[0068] Figure 2 A flowchart of the steps of an online adjustment method for inductance of a permanent magnet synchronous motor with inductive control according to another embodiment of the present invention is shown.

[0069] like Figure 2 As shown, in step S21, the effect of the change of the inductance and resistance parameters of the sliding mode observer model on the variables of the permanent magnet synchronous motor is analyzed to determine the influence relationship of the inductance parameters on the angle observation.

[0070] In one embodiment, the influence relationship of the inductance parameter on the angle observation is determined by the following steps: constructing a sliding mode observer model according to the voltage equation in the vector form of the permanent magnet synchronous motor; setting the permanent magnet synchronous motor to run on the sliding mode surface, and obtaining the geometric relationship between the electrical angle deviation and the inductance error according to the vector diagram of each variable of the permanent magnet synchronous motor; based on the geometric relationship, setting the resistance value of the permanent magnet synchronous motor equal to the resistance value of the sliding mode observer model, and analyzing the change of the inductance parameter value in the sliding mode observer model to obtain the influence relationship.

[0071] Firstly, a sliding mode observer model is constructed according to the voltage equation of the permanent magnet synchronous motor in vector form.

[0072] Specifically, the voltage equation of a permanent magnet synchronous motor (such as a permanent magnet synchronous motor SPMSM) in vector form is:

[0073] U s =RI s +jω e LI s +E (1)

[0074] Where: U s ,I s are the stator voltage and stator current vectors respectively, E is the back electromotive force, ω e is the electrical angular velocity, ω e =dθ e / dt,θ e is the electrical angle, R and L are the resistance and inductance of the motor respectively, and the back electromotive force can be expressed as:

[0075]

[0076] Where: f is the flux linkage amplitude.

[0077] The constructed sliding mode observer model (SMO) is:

[0078]

[0079] Where: U s is the stator voltage vector value; is the observed value of the stator current vector; is the observed value of back EMF, is the observed value of electrical angular velocity, is the resistance value of the sliding mode observer model, is the inductance value of the sliding mode observer model.

[0080] When the vector control system operates stably on the sliding surface, In this case:

[0081]

[0082] Then, according to the vector diagram of each variable of the permanent magnet synchronous motor, the electrical angle deviation Δθ is obtained. e and inductance error The geometric relationship between the electrical angle deviation and the inductance error is:

[0083]

[0084] In the formula, Δθ e is the electrical angle deviation; ΔL is the inductance error; ψ f is the flux amplitude, I q is the q-axis current. It can be seen that there is a certain relationship between the rotor position and the inductance.

[0085] Finally, after obtaining the relationship between the two, let The inductance parameter value in the sliding mode observer model Analyze the impact of.

[0086] Specifically, when hour, The larger the Δθ e The larger the When When , the deviation generated is defined as According to the phasor relationship between the variables, it can be seen that when When , the voltage and current amplitudes increase, and the angle leads. It can be proved that in this case, equation (5) also holds.

[0087] like Figure 2As shown, in step S22, based on the influence relationship, a high-frequency sinusoidal signal is injected into the permanent magnet synchronous motor, and the high-frequency response amplitude is extracted. Specifically, in order to eliminate the influence of inductance on angle observation in the SMO model, based on the influence relationship determined in step S21, a high-frequency sinusoidal signal is injected into the d-axis of the permanent magnet synchronous motor, and then SOGI based on bilinear transformation and sliding window are used to extract the high-frequency response amplitude, which includes a signal ΔL of the difference between the SMO inductance value and the real inductance value.

[0088] Specifically, a high-frequency sinusoidal voltage is injected into the d-axis:

[0089] u′ d =U h cos(ω h t) (6)

[0090] Where: u′ d is a high-frequency sinusoidal signal; U h is the voltage of the high-frequency sinusoidal signal; ω h is the angular frequency of the high-frequency sinusoidal signal; t is the time.

[0091] Furthermore, U h The size should be chosen reasonably and should not affect the operation of the motor itself. h The choice of U should be high to reduce the torque fluctuation it produces. It should be noted that in practical applications, U h And ω h The value of can be determined according to the actual situation. h And ω h Limit the value.

[0092] After Park transform (called Park transform or Park transform):

[0093]

[0094] It can be seen that in the α-β coordinate system, the ω high-frequency injection voltage of the d-axis becomes ω h -ω e and ω h +ω e Voltages at two frequencies.

[0095] The dq axis current (i′) under high frequency injection d h , i′ q h ) The response is:

[0096]

[0097] Among them, L B =(L dh-L qh ) / 2,L A =(L dh +L qh ) / 2,L dh , L qh They represent the inductance components on the dq axis under high frequency injection. Ignoring the difference in inductance on the dq axis, let L B =0,L A =L, then:

[0098]

[0099] Similarly, the expression of the current under the action of high-frequency voltage in the α-β coordinate system is:

[0100]

[0101] It can be seen that the frequency of the current high-frequency response under α-β is also ω h -ω e and ω h +ω e The two frequencies have a phase lag of π / 2 compared to the high frequency voltage.

[0102] The expression of formula (4) in the α-β coordinate system is:

[0103]

[0104] Among them, e α 、e β are the back electromotive force of α and β axes respectively, are the estimated values ​​of the αβ axis back electromotive force observed under the SMO model, and ΔR is the resistance error. Substituting (7) and (10) into (11), we get:

[0105]

[0106] It can be seen that the back electromotive force observation value has a frequency of ω e The back EMF sine wave, and ω h -ω e and ω h +ω e The high-frequency components of the two frequencies are related to the resistance and inductance parameters. Because the voltage injected by high frequency has a high frequency and a small amplitude, the influence of resistance on the observed value of back electromotive force is much smaller than that of inductance.

[0107] The frequency of the potential observation is ω h -ω e For example, the high frequency component amplitude The relationship between the inductance and the inductance is (after extracting the high-frequency component, in order to further extract the high-frequency response amplitude of the signal containing the inductance difference ΔL, the sliding

[0108] The window method is closer to the period [t-(n-1)*T s ,t] represents the maximum absolute value of ):

[0109]

[0110] It can be seen from this that when the inductance parameter value is equal to the true value, that is, ΔL = 0, the amplitude of the high-frequency component is the smallest. At this time, the value of the inductance parameter can be adjusted by adjusting the amplitude of the high-frequency component.

[0111] The high frequency components required here are through the center frequency ω h ±ω e SOGI EXTRACTION:

[0112]

[0113] Then, through the sliding window, the high-frequency components obtained by the above SOGI are selected according to the period to obtain the ones with the best high-frequency response.

[0114] Large value U t , based on the high-frequency component amplitude Adjust the inductance.

[0115] Specifically, in order to further extract the high-frequency response amplitude of the signal containing the inductance difference ΔL, the sliding

[0116] The window method is closer to the period [t-(n-1)*T s ,t] represents the maximum absolute value of

[0117]

[0118] in, is the length of the sliding window, T is the period of the high-frequency signal, T = 2π / (ω-ω e ), T s It is the program operation cycle.

[0119] like Figure 2 As shown, in step S23, the inductance of the permanent magnet synchronous motor is adjusted online according to the high-frequency response amplitude. Specifically, according to the extracted high-frequency response amplitude, the gradient descent method with an adaptive step size is used to adjust the inductance online to a correct value and keep it stable.

[0120] In step S23, according to formula (13), when the inductance parameter value of SMO is not equal to the true value,

[0121] That is, when ΔL≠0, the amplitude of the high-frequency component is not 0, and the larger ΔL is, The larger the value, the larger the value. Only when ΔL=0,

[0122] The minimum value is 0. Therefore, the present invention uses the idea of ​​gradient descent to update the SMO inductance parameter value in the opposite direction of the high-frequency signal to the inductance gradient, and finally converges to the true value.

[0123] Further, calculate the difference ΔU between the two measured high-frequency signal amplitudes k :

[0124] ΔU k =U k -U k-1 (16)

[0125] Among them, U k is the high-frequency signal amplitude measured this time, U k-1 is the high-frequency signal amplitude recorded last time.

[0126] Secondly, the gradient and adaptive step size are updated according to the high-frequency signal amplitude difference.

[0127] Update gradients:

[0128]

[0129] Among them, ▽f k is the gradient, ΔL k It is the difference between the previous two inductance parameter values ​​L.

[0130] Then, update the adaptive step size α k :

[0131]

[0132] Where l is the length of the adaptive step calculation window, θ is the maximum step size; ΔU k-i It is the difference between the amplitude of the high-frequency signal measured at the ki-th moment in the sliding window and the amplitude of the high-frequency signal recorded last time.

[0133] Finally, the inductance parameter value L is obtained k And output:

[0134] L k =L k-1 +α k sgn(▽f k ) (19)

[0135] Among them, L k-1 is the inductance parameter value of the previous cycle.

[0136] In this way, during the actual operation of the PMSM, the inductance obtained in step S23 will be fed back to the control system in real time for adjustment, so that the position estimation of the PMSM is more accurate.

[0137] In one embodiment, reference Figure 3 , the working principle of the original PMSM controller is explained. The outer loop is the speed loop, which uses the detected speed ω as feedback; the inner loop is the current loop, which uses current sampling to obtain the stator three-phase current i a 、i b and i c , and then through Clark transformation and Park transformation, the stator current i in the dq synchronous reference frame is obtained d and i q As feedback. Given speed ω * The given value of the q-axis stator current is obtained by subtracting the actual speed ω through the PI controller. The d-axis current given value The given value and the measured value of the two current components are subtracted and passed through the PI controller to obtain the stator voltage u in the dq synchronous reference system. d and u q , the two are transformed by Park inverse transformation to obtain the stator voltage u in the α-β coordinate system α and u β , which is input into SVPWM to obtain the three-phase duty cycle signal, and controls the on and off of the inverter switch tube, thereby realizing the control of PMSM.

[0138] The present invention discloses an online adjustment method for the inductance of a permanent magnet synchronous motor with inductive control based on high-frequency injection correction. The present invention does not need to know the motor parameters and does not require additional circuits to adjust the inductance online. By constructing a SMO model, the adjustment is performed through the relationship between the back electromotive force and the inductance parameters. Secondly, the present invention does not ignore the position error. Instead, by adjusting the inductance parameters, the motor position estimation is made more accurate. Finally, the present invention realizes the online adjustment of the motor inductance through the gradient descent of the adaptive step size. The adjustment is fast and the calculation is simple. It can quickly track the motor rotor speed and position changes at different speeds and loads, effectively improving the motor control performance.

[0139] The method for online adjustment of the inductance of the sensorless control of a permanent magnet synchronous motor provided by the present invention can also be used in conjunction with a computer-readable storage medium, on which a computer program is stored, and the computer program is executed to run the method for online adjustment of the inductance of the sensorless control of a permanent magnet synchronous motor. The computer program can run computer instructions, and the computer instructions include computer program code, which can be in source code form, object code form, executable file or some intermediate form, etc.

[0140] Computer-readable storage media may include: any entity or device that can carry computer program code, recording media, USB flash drives, mobile hard disks, magnetic disks, optical disks, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signals, telecommunication signals, and software distribution media, etc.

[0141] It should be noted that the content contained in computer-readable storage media can be appropriately increased or decreased based on the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, based on legislation and patent practices, computer-readable storage media do not include electrical carrier signals and telecommunications signals.

[0142] According to another aspect of the present invention, a permanent magnet synchronous motor sensorless control inductance online adjustment method system is also provided, which executes a permanent magnet synchronous motor sensorless control inductance online adjustment method, and the system includes: an injection extraction module and an online adjustment module.

[0143] In one embodiment, the injection extraction module is used to inject a high-frequency sinusoidal signal into the permanent magnet synchronous motor and extract the high-frequency response amplitude; the online adjustment module is used to perform online inductance adjustment on the permanent magnet synchronous motor according to the high-frequency response amplitude.

[0144] In summary, the present invention provides a method for online adjustment of inductance of a permanent magnet synchronous motor with non-inductive control. Compared with the prior art, the present invention has the following advantages: First, the present invention does not need to know the motor parameters and does not require additional circuits to adjust the inductance online. By constructing a SMO model, the inductance is adjusted through the relationship between the back electromotive force and the inductance parameters. Secondly, the present invention does not ignore the position error, but makes the motor position estimation more accurate by adjusting the inductance parameters. Finally, the present invention realizes online adjustment of the motor inductance by gradient descent with an adaptive step size. The present invention has fast adjustment and simple calculation. It can quickly track the motor rotor speed and position changes at different speeds and loads, effectively improving the motor control performance.

[0145] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should be extended to equivalent substitutions of these features understood by ordinary technicians in the relevant field. It should also be understood that the terms used herein are only used for the purpose of describing specific embodiments and are not meant to be limiting.

[0146] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0147] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0148] Certain terms are used throughout this application document to indicate specific system components. As those skilled in the art will recognize, different names can usually be used to indicate the same components, so this application document is not intended to distinguish those components that are only different in name but not in function. In this application document, the terms "comprise", "include" and "have" are used in an open form, and therefore should be interpreted as meaning "including but not limited to...". In addition, the terms "substantially", "substantially" or "approximately" that may be used in this article relate to the tolerances of the corresponding terms accepted by the industry. The term "coupling" as may be used in this article includes direct coupling and indirect coupling via other components, elements, circuits, or modules, wherein for indirect coupling, the components, elements, circuits, or modules between them do not change the information of the signal but can adjust its current level, voltage level, and / or power level. Inferred coupling (for example, one of the elements is coupled to another element by inference) includes direct and indirect coupling between two elements in the same way as "coupling".

[0149] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0150] The embodiments of the present invention are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0151] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A method for online adjustment of inductance of a permanent magnet synchronous motor without induction control, characterized in that: The method comprises the following steps: Inject a high-frequency sinusoidal signal into the permanent magnet synchronous motor and extract the high-frequency response amplitude; According to the high-frequency response amplitude, the inductance of the permanent magnet synchronous motor is adjusted online.

2. A method for online adjustment of inductance of a permanent magnet synchronous motor without inductance control as claimed in claim 1, characterized in that: The high frequency sinusoidal signal: u′ d =U h cos(ω h t) Where: u′ d is a high-frequency sinusoidal signal; U h is the voltage of the high-frequency sinusoidal signal; ω h is the angular frequency of the high-frequency sinusoidal signal; t is the time.

3. A method for online adjustment of inductance of a permanent magnet synchronous motor with inductive control as claimed in claim 1 or 2, characterized in that: The high frequency response amplitude is extracted by the following steps: Inject the high-frequency sinusoidal signal into the d-axis of the permanent magnet synchronous motor, and use a second-order generalized integrator to obtain a high-frequency component of the back electromotive force observation value; The sliding window is used to select the maximum high-frequency response amplitude of the high-frequency component of the back electromotive force observation value according to the period, and the maximum high-frequency response amplitude is used as the high-frequency response amplitude.

4. A method for online adjustment of inductance of a permanent magnet synchronous motor without inductance control as claimed in claim 3, characterized in that: The high frequency component of the back EMF observation value: Where: is the high-frequency component of the back-electromotive force observation value; SOGI is a second-order generalized integrator; ω h ±ω e is the center frequency of the second-order generalized integrator; is the estimated value of the observed β-axis back EMF; is the amplitude of the high-frequency component; t is the time; is the phase of the fundamental wave.

5. A method for online adjustment of inductance of a permanent magnet synchronous motor with inductive control as claimed in claim 3 or 4, characterized in that: The maximum amplitude of the high frequency response is: Where: U t is the maximum amplitude of high frequency response; is the high-frequency component of the ti-th back-electromotive force observation value in the sliding window; n is the length of the sliding window.

6. A method for online adjustment of inductance of a permanent magnet synchronous motor without inductance control according to any one of claims 1 to 5, characterized in that: Perform online inductance adjustment on the permanent magnet synchronous motor by following the steps below: Calculate the difference between the high-frequency response amplitude corresponding to the current cycle and the high-frequency response amplitude corresponding to the previous cycle, and record it as the high-frequency signal amplitude difference; Based on the high-frequency signal amplitude difference, the inductance parameter value of the permanent magnet synchronous motor in this cycle is calculated through the inductance parameter value of the previous cycle to achieve online inductance adjustment.

7. A method for online adjustment of inductance of a permanent magnet synchronous motor with inductive control as claimed in claim 6, characterized in that: The high frequency signal amplitude difference: ΔU k =U k -U k-1 Where: ΔU k is the high frequency signal amplitude difference; U k is the high-frequency signal amplitude of this cycle, U k-1 is the high-frequency signal amplitude of the previous cycle.

8. A method for online adjustment of inductance of a permanent magnet synchronous motor with inductive control as claimed in claim 6 or 7, characterized in that: The inductance parameter value of the permanent magnet synchronous motor in this cycle: Where: L k is the inductance parameter value of this cycle; L k-1 is the inductance parameter value of the previous cycle; α k is the adaptive step size; is the gradient.

9. A storage medium, characterized in that: It contains a series of instructions for executing the method steps as claimed in any one of claims 1 to 8.

10. A permanent magnet synchronous motor inductance online adjustment system without inductance control, characterized in that: The method according to any one of claims 1 to 8 is performed, wherein the system comprises: An injection extraction module is used to inject a high-frequency sinusoidal signal into the permanent magnet synchronous motor and extract the high-frequency response amplitude; An online adjustment module is used to perform online inductance adjustment on the permanent magnet synchronous motor according to the high-frequency response amplitude.

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